LEDMatrix/src/wifi_manager.py

"""
WiFi Manager for Raspberry Pi LED Matrix

Handles WiFi connection management, access point mode, and network scanning.
Only enables AP mode when there is no active WiFi connection.

Tested and optimized for:
- Raspberry Pi OS Trixie (Debian 13) with NetworkManager/Netplan
- Raspberry Pi OS Bookworm (Debian 12) with NetworkManager
- Raspberry Pi 3B+, 4, 5 with built-in WiFi

Sudoers Requirements:
    The following sudoers entries are required for passwordless operation.
    Add to /etc/sudoers.d/ledmatrix_wifi:

    ledpi ALL=(ALL) NOPASSWD: /usr/bin/nmcli
    ledpi ALL=(ALL) NOPASSWD: /usr/bin/systemctl start hostapd
    ledpi ALL=(ALL) NOPASSWD: /usr/bin/systemctl stop hostapd
    ledpi ALL=(ALL) NOPASSWD: /usr/bin/systemctl start dnsmasq
    ledpi ALL=(ALL) NOPASSWD: /usr/bin/systemctl stop dnsmasq
    ledpi ALL=(ALL) NOPASSWD: /usr/bin/systemctl restart NetworkManager
    ledpi ALL=(ALL) NOPASSWD: /usr/sbin/ip
    ledpi ALL=(ALL) NOPASSWD: /sbin/ip
    ledpi ALL=(ALL) NOPASSWD: /usr/sbin/rfkill
    ledpi ALL=(ALL) NOPASSWD: /usr/sbin/iptables
    ledpi ALL=(ALL) NOPASSWD: /usr/sbin/sysctl
    ledpi ALL=(ALL) NOPASSWD: /usr/bin/cp /tmp/hostapd.conf /etc/hostapd/hostapd.conf
    ledpi ALL=(ALL) NOPASSWD: /usr/bin/cp /tmp/dnsmasq.conf /etc/dnsmasq.d/ledmatrix-captive.conf
    ledpi ALL=(ALL) NOPASSWD: /usr/bin/rm -f /etc/dnsmasq.d/ledmatrix-captive.conf
"""

import subprocess
import json
import logging
import os
import time
import re
from pathlib import Path
from typing import Dict, List, Optional, Tuple
from dataclasses import dataclass, field

logger = logging.getLogger(__name__)

# Path for storing WiFi configuration (will be set dynamically)
# Default location, can be overridden
def get_wifi_config_path():
    """Get the WiFi configuration file path dynamically"""
    # Try to determine project root
    project_root = os.environ.get('LEDMATRIX_ROOT')
    if not project_root:
        # Try to find project root by looking for config directory
        current = Path(__file__).resolve().parent.parent
        if (current / 'config').exists():
            project_root = str(current)
        else:
            # Fallback to common location
            project_root = "/home/ledpi/LEDMatrix"
    
    return Path(project_root) / "config" / "wifi_config.json"

HOSTAPD_CONFIG_PATH = Path("/etc/hostapd/hostapd.conf")
DNSMASQ_CONFIG_PATH = Path("/etc/dnsmasq.d/ledmatrix-captive.conf")
# Drop-in config for NetworkManager's built-in dnsmasq (ipv4.method=shared).
# Writing address=/#/<ap_ip> here causes NM to resolve every hostname to the AP,
# triggering the OS captive-portal popup automatically on iOS/Android/Windows/macOS.
NM_DNSMASQ_SHARED_DIR = Path("/etc/NetworkManager/dnsmasq-shared.d")
NM_DNSMASQ_SHARED_CONF = NM_DNSMASQ_SHARED_DIR / "ledmatrix-captive.conf"
HOSTAPD_SERVICE = "hostapd"
DNSMASQ_SERVICE = "dnsmasq"

# Default AP settings
DEFAULT_AP_SSID = "LEDMatrix-Setup"
DEFAULT_AP_CHANNEL = 7

# LED status message file (for display_controller integration)
LED_STATUS_FILE = None  # Will be set dynamically

# NetworkManager connection file locations (Trixie uses /run, Bookworm uses /etc)
NM_CONNECTIONS_PATHS = [
    Path("/etc/NetworkManager/system-connections"),
    Path("/run/NetworkManager/system-connections"),  # Trixie with Netplan
]


@dataclass
class WiFiNetwork:
    """Represents a WiFi network"""
    ssid: str
    signal: int
    security: str  # 'open', 'wpa', 'wpa2', 'wpa3'
    frequency: float = 0.0
    bssid: str = ""


@dataclass
class WiFiStatus:
    """Current WiFi connection status"""
    connected: bool
    ssid: Optional[str] = None
    ip_address: Optional[str] = None
    signal: int = 0
    ap_mode_active: bool = False


class WiFiManager:
    """Manages WiFi connections and access point mode"""
    
    def __init__(self, config_path: Optional[Path] = None):
        """
        Initialize WiFi Manager
        
        Args:
            config_path: Path to WiFi configuration file (defaults to project config directory)
        """
        if config_path is None:
            self.config_path = get_wifi_config_path()
        else:
            self.config_path = config_path
        self.config_path.parent.mkdir(parents=True, exist_ok=True)
        self._load_config()
        
        # Set LED status file path (for display_controller integration)
        global LED_STATUS_FILE
        if LED_STATUS_FILE is None:
            project_root = self.config_path.parent.parent
            LED_STATUS_FILE = project_root / "config" / "wifi_status.json"
        
        # Check which tools are available
        self.has_nmcli = self._check_command("nmcli")
        self.has_iwlist = self._check_command("iwlist")
        self.has_hostapd = self._check_command("hostapd")
        self.has_dnsmasq = self._check_command("dnsmasq")

        # Discover WiFi interface (don't hardcode wlan0)
        self._wifi_interface = self._discover_wifi_interface()

        # Detect if we're running on Trixie (Netplan-based NetworkManager)
        self._is_trixie = self._detect_trixie()

        # Initialize disconnected check counter for grace period
        # This prevents AP mode from enabling on transient network hiccups
        self._disconnected_checks = 0
        self._disconnected_checks_required = 3  # Require 3 consecutive disconnected checks (90 seconds at 30s interval)

        # Timestamp set when AP mode is enabled; used for the idle-timeout check
        self._ap_enabled_at: Optional[float] = None
        # Which redirect backend was used (iptables/nftables/None); set per-instance
        self._redirect_backend: Optional[str] = None

        logger.info(f"WiFi Manager initialized - nmcli: {self.has_nmcli}, iwlist: {self.has_iwlist}, "
                   f"hostapd: {self.has_hostapd}, dnsmasq: {self.has_dnsmasq}, "
                   f"interface: {self._wifi_interface}, trixie: {self._is_trixie}")
    
    def _show_led_message(self, message: str, duration: int = 5):
        """
        Show a WiFi status message on the LED display.
        Writes to a JSON file that display_controller can read.
        
        Args:
            message: Text to display
            duration: How long to show message (seconds)
        """
        try:
            if LED_STATUS_FILE is None:
                return
            
            status = {
                'message': message,
                'timestamp': time.time(),
                'duration': duration
            }
            LED_STATUS_FILE.parent.mkdir(parents=True, exist_ok=True)
            with open(LED_STATUS_FILE, 'w') as f:
                json.dump(status, f)
            logger.info(f"LED message: {message}")
        except Exception as e:
            logger.debug(f"Could not write LED status message: {e}")
    
    def _clear_led_message(self):
        """Clear any WiFi status message from LED display."""
        try:
            if LED_STATUS_FILE and LED_STATUS_FILE.exists():
                LED_STATUS_FILE.unlink()
        except Exception as e:
            logger.debug(f"Could not clear LED status message: {e}")
    
    def _check_command(self, command: str) -> bool:
        """Check if a command is available"""
        try:
            # First try 'which' command
            result = subprocess.run(
                ["which", command],
                capture_output=True,
                timeout=2
            )
            if result.returncode == 0:
                return True
            
            # Check common sbin paths (not in standard user PATH)
            sbin_paths = [
                f"/usr/sbin/{command}",
                f"/sbin/{command}",
                f"/usr/local/sbin/{command}"
            ]
            for path in sbin_paths:
                if os.path.isfile(path) and os.access(path, os.X_OK):
                    return True
            
            return False
        except (subprocess.TimeoutExpired, subprocess.SubprocessError, OSError):
            return False

    def _find_command_path(self, command: str) -> Optional[str]:
        """
        Return the absolute path of a command, checking sbin locations that may not
        be on PATH in restricted service environments.  Returns None if not found.
        """
        try:
            result = subprocess.run(["which", command], capture_output=True,
                                    text=True, timeout=2)
            if result.returncode == 0 and result.stdout.strip():
                return result.stdout.strip()
        except (subprocess.TimeoutExpired, subprocess.SubprocessError, OSError):
            pass
        for path in [f"/usr/sbin/{command}", f"/sbin/{command}",
                     f"/usr/local/sbin/{command}"]:
            if os.path.isfile(path) and os.access(path, os.X_OK):
                return path
        return None

    def _discover_wifi_interface(self) -> str:
        """
        Discover the primary WiFi interface name dynamically.

        Returns the first WiFi interface found, or 'wlan0' as fallback.
        Supports various interface naming schemes:
        - Traditional: wlan0, wlan1
        - Predictable: wlp2s0, wlx<mac>
        - USB adapters: wlan1, wlx*
        """
        try:
            if self.has_nmcli:
                # Use nmcli to find WiFi devices (most reliable on NetworkManager systems)
                result = subprocess.run(
                    ["nmcli", "-t", "-f", "DEVICE,TYPE", "device", "status"],
                    capture_output=True,
                    text=True,
                    timeout=5
                )
                if result.returncode == 0:
                    for line in result.stdout.strip().split('\n'):
                        if ':' in line:
                            parts = line.split(':')
                            if len(parts) >= 2 and parts[1].strip() == 'wifi':
                                interface = parts[0].strip()
                                logger.debug(f"Discovered WiFi interface via nmcli: {interface}")
                                return interface

            # Fallback: Check /sys/class/net for wireless interfaces
            net_path = Path("/sys/class/net")
            if net_path.exists():
                for iface in net_path.iterdir():
                    wireless_path = iface / "wireless"
                    if wireless_path.exists():
                        interface = iface.name
                        logger.debug(f"Discovered WiFi interface via /sys: {interface}")
                        return interface

            # Last resort: Check common interface names
            for iface in ["wlan0", "wlan1", "wlp2s0", "wlp3s0"]:
                iface_path = Path(f"/sys/class/net/{iface}")
                if iface_path.exists():
                    logger.debug(f"Found WiFi interface by name probe: {iface}")
                    return iface

        except (subprocess.TimeoutExpired, subprocess.SubprocessError, OSError) as e:
            logger.warning(f"Error discovering WiFi interface: {e}")

        logger.warning("Could not discover WiFi interface, defaulting to wlan0")
        return "wlan0"

    def _detect_trixie(self) -> bool:
        """
        Detect if running on Raspberry Pi OS Trixie (Debian 13).

        Trixie uses Netplan with NetworkManager, which changes behavior:
        - Connection files are stored in /run/NetworkManager/system-connections
        - nmcli hotspot requires different handling
        - PMF (Protected Management Frames) may need to be disabled
        """
        try:
            # Check for Netplan (primary indicator of Trixie)
            netplan_path = Path("/etc/netplan")
            if netplan_path.exists() and any(netplan_path.glob("*.yaml")):
                logger.debug("Detected Trixie: Netplan configuration found")
                return True

            # Check Debian version
            os_release = Path("/etc/os-release")
            if os_release.exists():
                content = os_release.read_text()
                if 'VERSION_CODENAME=trixie' in content or 'VERSION_ID="13"' in content:
                    logger.debug("Detected Trixie: os-release indicates Debian 13")
                    return True

            # Check if NM connections are in /run (Trixie behavior)
            # NM_CONNECTIONS_PATHS[0] = /etc/..., NM_CONNECTIONS_PATHS[1] = /run/...
            etc_nm_path = NM_CONNECTIONS_PATHS[0]  # Bookworm location
            run_nm_path = NM_CONNECTIONS_PATHS[1]  # Trixie location
            if run_nm_path.exists() and any(run_nm_path.glob("*.nmconnection")):
                if not etc_nm_path.exists() or not any(etc_nm_path.glob("*.nmconnection")):
                    logger.debug("Detected Trixie: NM connections in /run only")
                    return True

        except (OSError, PermissionError) as e:
            logger.debug(f"Could not detect Trixie: {e}")

        return False

    def _load_config(self):
        """Load WiFi configuration from file"""
        if self.config_path.exists():
            try:
                with open(self.config_path, 'r') as f:
                    self.config = json.load(f)
                logger.info(f"Loaded WiFi config from {self.config_path}")
            except Exception as e:
                logger.warning(f"Failed to load WiFi config: {e}")
                self.config = {}
        else:
            self.config = {
                "ap_ssid": DEFAULT_AP_SSID,
                "ap_channel": DEFAULT_AP_CHANNEL,
                "auto_enable_ap_mode": True,  # Default: auto-enable when no network (safe due to grace period)
                "saved_networks": []
            }
            self._save_config()
        
        # Ensure auto_enable_ap_mode exists in config (for existing configs)
        if "auto_enable_ap_mode" not in self.config:
            self.config["auto_enable_ap_mode"] = True  # Default: auto-enable when no network (safe due to grace period)
            self._save_config()
    
    def _save_config(self):
        """Save WiFi configuration to file"""
        try:
            with open(self.config_path, 'w') as f:
                json.dump(self.config, f, indent=2)
            logger.info(f"Saved WiFi config to {self.config_path}")
        except Exception as e:
            logger.error(f"Failed to save WiFi config: {e}")
    
    def get_wifi_status(self) -> WiFiStatus:
        """
        Get current WiFi connection status
        
        Returns:
            WiFiStatus object with connection information
        """
        try:
            if self.has_nmcli:
                return self._get_status_nmcli()
            else:
                return self._get_status_iwconfig()
        except Exception as e:
            logger.error(f"Error getting WiFi status: {e}")
            return WiFiStatus(connected=False)
    
    def _get_status_nmcli(self) -> WiFiStatus:
        """Get WiFi status using nmcli"""
        try:
            # Check if connected - use device status first (more reliable)
            result = subprocess.run(
                ["nmcli", "-t", "-f", "DEVICE,TYPE,STATE", "device", "status"],
                capture_output=True,
                text=True,
                timeout=5
            )
            
            if result.returncode != 0:
                logger.warning("nmcli device status failed, assuming disconnected")
                return WiFiStatus(connected=False)
            
            wifi_connected = False
            ssid = None
            ip_address = None
            signal = 0
            wlan_device = None
            
            # Find WiFi device and check its state
            for line in result.stdout.strip().split('\n'):
                if not line:
                    continue
                parts = line.split(':')
                if len(parts) >= 3:
                    device = parts[0].strip()
                    dev_type = parts[1].strip().lower()
                    state = parts[2].strip().lower()
                    
                    # Check if it's a WiFi device
                    if dev_type == "wifi" or device.startswith("wlan"):
                        wlan_device = device
                        if state == "connected":
                            wifi_connected = True
                            break
                        elif state in ["disconnected", "unavailable", "unmanaged"]:
                            # Explicitly disconnected
                            wifi_connected = False
                            break
            
            # Get actual SSID and signal strength from WiFi device if connected
            # Use device show to get the real SSID and signal, not the connection name
            if wifi_connected and wlan_device:
                # Get both SSID and signal in one query for efficiency
                result = subprocess.run(
                    ["nmcli", "-t", "-f", "802-11-wireless.ssid,WIFI.SIGNAL", "device", "show", wlan_device],
                    capture_output=True,
                    text=True,
                    timeout=5
                )
                if result.returncode == 0:
                    for line in result.stdout.strip().split('\n'):
                        if '802-11-wireless.ssid:' in line:
                            ssid = line.split(':', 1)[1].strip()
                            if ssid:
                                continue
                        elif 'WIFI.SIGNAL:' in line:
                            try:
                                signal = int(line.split(':', 1)[1].strip())
                            except (ValueError, IndexError):
                                pass
                
                # Fallback: Get SSID from active WiFi connection list if not found
                if not ssid:
                    result = subprocess.run(
                        ["nmcli", "-t", "-f", "active,ssid", "device", "wifi"],
                        capture_output=True,
                        text=True,
                        timeout=5
                    )
                    if result.returncode == 0:
                        for line in result.stdout.strip().split('\n'):
                            parts = line.split(':')
                            if len(parts) >= 2 and parts[0].strip() == "yes":
                                ssid = parts[1].strip()
                                if ssid:
                                    break
                
                # Fallback: Get signal strength if not already retrieved
                if signal == 0 and wlan_device:
                    result = subprocess.run(
                        ["nmcli", "-t", "-f", "WIFI.SIGNAL", "device", "show", wlan_device],
                        capture_output=True,
                        text=True,
                        timeout=5
                    )
                    if result.returncode == 0:
                        for line in result.stdout.strip().split('\n'):
                            if 'WIFI.SIGNAL:' in line:
                                try:
                                    signal = int(line.split(':', 1)[1].strip())
                                    break
                                except (ValueError, IndexError):
                                    pass
            
            # Get IP address if connected
            if wifi_connected and wlan_device:
                result = subprocess.run(
                    ["nmcli", "-t", "-f", "IP4.ADDRESS", "device", "show", wlan_device],
                    capture_output=True,
                    text=True,
                    timeout=5
                )
                if result.returncode == 0:
                    for line in result.stdout.strip().split('\n'):
                        if '/' in line:
                            ip_address = line.split('/')[0].strip()
                            break
                
                # Final fallback: Get signal strength by matching SSID in WiFi list
                # (Only if we still don't have signal from device properties)
                if signal == 0 and ssid:
                    result = subprocess.run(
                        ["nmcli", "-t", "-f", "SSID,SIGNAL", "device", "wifi"],
                        capture_output=True,
                        text=True,
                        timeout=5
                    )
                    if result.returncode == 0:
                        for line in result.stdout.strip().split('\n'):
                            parts = line.split(':')
                            if len(parts) >= 2:
                                line_ssid = parts[0].strip()
                                if line_ssid == ssid:
                                    try:
                                        signal = int(parts[1].strip())
                                        break
                                    except (ValueError, IndexError):
                                        pass
            
            # Check if AP mode is active
            ap_active = self._is_ap_mode_active()
            
            return WiFiStatus(
                connected=wifi_connected,
                ssid=ssid,
                ip_address=ip_address,
                signal=signal,
                ap_mode_active=ap_active
            )
        except Exception as e:
            logger.error(f"Error getting status with nmcli: {e}")
            return WiFiStatus(connected=False)
    
    def _get_status_iwconfig(self) -> WiFiStatus:
        """Get WiFi status using iwconfig (fallback)"""
        try:
            result = subprocess.run(
                ["iwconfig", self._wifi_interface],
                capture_output=True,
                text=True,
                timeout=5
            )
            
            if result.returncode != 0:
                return WiFiStatus(connected=False)
            
            output = result.stdout
            connected = "ESSID:" in output and "not-associated" not in output
            
            ssid = None
            if connected:
                match = re.search(r'ESSID:"([^"]+)"', output)
                if match:
                    ssid = match.group(1)
            
            # Get IP address
            ip_address = None
            if connected:
                result = subprocess.run(
                    ["hostname", "-I"],
                    capture_output=True,
                    text=True,
                    timeout=5
                )
                if result.returncode == 0:
                    ips = result.stdout.strip().split()
                    for ip in ips:
                        if not ip.startswith('192.168.4.1'):  # Exclude AP IP
                            ip_address = ip
                            break
            
            ap_active = self._is_ap_mode_active()
            
            return WiFiStatus(
                connected=connected,
                ssid=ssid,
                ip_address=ip_address,
                ap_mode_active=ap_active
            )
        except Exception as e:
            logger.error(f"Error getting status with iwconfig: {e}")
            return WiFiStatus(connected=False)
    
    def _is_ethernet_connected(self) -> bool:
        """
        Check if Ethernet connection is active
        
        Returns:
            True if Ethernet is connected and has an IP address
        """
        try:
            # Check for Ethernet interfaces (eth0, enp*, etc.)
            # First try nmcli if available
            if self.has_nmcli:
                result = subprocess.run(
                    ["nmcli", "-t", "-f", "DEVICE,TYPE,STATE", "device", "status"],
                    capture_output=True,
                    text=True,
                    timeout=5
                )
                if result.returncode == 0:
                    for line in result.stdout.strip().split('\n'):
                        parts = line.split(':')
                        if len(parts) >= 3:
                            device = parts[0].strip()
                            dev_type = parts[1].strip().lower()
                            state = parts[2].strip().lower()
                            
                            # Check if it's an Ethernet interface and connected
                            if dev_type == "ethernet" and state == "connected":
                                # Verify it has an IP address
                                ip_result = subprocess.run(
                                    ["nmcli", "-t", "-f", "IP4.ADDRESS", "device", "show", device],
                                    capture_output=True,
                                    text=True,
                                    timeout=5
                                )
                                if ip_result.returncode == 0 and ip_result.stdout.strip():
                                    return True
            
            # Fallback: Check using ip command
            result = subprocess.run(
                ["ip", "addr", "show"],
                capture_output=True,
                text=True,
                timeout=5
            )
            if result.returncode == 0:
                # Look for Ethernet interfaces (eth0, enp*, etc.)
                lines = result.stdout.split('\n')
                in_ethernet = False
                for line in lines:
                    # Check if line starts interface name (e.g., "2: eth0:")
                    if re.match(r'^\d+:\s+(eth\d+|enp\d+s\d+|enx[0-9a-f]+):', line):
                        in_ethernet = True
                    elif in_ethernet and 'inet ' in line and not '127.0.0.1' in line:
                        # Found an IP address on Ethernet interface
                        return True
                    elif re.match(r'^\d+:', line) and in_ethernet:
                        # Moved to next interface
                        in_ethernet = False
            
            return False
        except Exception as e:
            logger.debug(f"Error checking Ethernet connection: {e}")
            return False
    
    def _has_connectivity_safety(self) -> bool:
        """
        Check if there's a safe fallback connectivity option available.
        
        Returns True if either:
        - Ethernet is connected, OR
        - WiFi radio is enabled (even if not connected to a network)
        
        This helps prevent lockout scenarios where we might disable WiFi
        without having Ethernet as backup.
        
        Returns:
            True if there's a safe connectivity option available
        """
        try:
            # Check if Ethernet is connected (safest fallback)
            if self._is_ethernet_connected():
                return True
            
            # Check if WiFi radio is enabled (at least WiFi is available)
            result = subprocess.run(
                ["nmcli", "radio", "wifi"],
                capture_output=True,
                text=True,
                timeout=5
            )
            if result.returncode == 0:
                status = result.stdout.strip().lower()
                if status == "enabled":
                    return True
            
            return False
        except Exception as e:
            logger.debug(f"Error checking connectivity safety: {e}")
            # If we can't determine, assume unsafe to be conservative
            return False
    
    def _is_ap_mode_active(self) -> bool:
        """Check if access point mode is currently active"""
        try:
            # Check if hostapd is running (captive portal mode)
            result = subprocess.run(
                ["systemctl", "is-active", HOSTAPD_SERVICE],
                capture_output=True,
                text=True,
                timeout=2
            )
            if result.stdout.strip() == "active":
                return True

            # Check if nmcli hotspot is active (fallback mode)
            hotspot_status = self._get_ap_status_nmcli()
            if hotspot_status.get('active'):
                return True

            return False
        except (subprocess.TimeoutExpired, subprocess.SubprocessError, OSError):
            return False

    # ---------------------------------------------------------------------------
    # Helpers
    # ---------------------------------------------------------------------------

    _IP_FORWARD_SAVE_PATH = Path("/tmp/ledmatrix_ip_forward_saved")

    def _validate_ap_config(self) -> Tuple[str, int]:
        """Return a sanitized (ssid, channel) pair from config, falling back to defaults."""
        ssid = str(self.config.get("ap_ssid", DEFAULT_AP_SSID))
        if not ssid or len(ssid) > 32 or not re.match(r'^[\x20-\x7E]+$', ssid):
            logger.warning(f"AP SSID '{ssid}' is invalid, falling back to default")
            ssid = DEFAULT_AP_SSID
        try:
            channel = int(self.config.get("ap_channel", DEFAULT_AP_CHANNEL))
            if channel < 1 or channel > 14:
                raise ValueError
        except (TypeError, ValueError):
            logger.warning("AP channel out of range, falling back to default")
            channel = DEFAULT_AP_CHANNEL
        return ssid, channel

    def _setup_iptables_redirect(self) -> bool:
        """
        Add port 80 → 5000 redirect rules for the captive portal.

        Tries iptables first, falls back to nftables (used by Debian Trixie).
        When neither tool is available, logs a warning and returns True — the AP
        still works and DNS spoofing still triggers the OS popup; users just land
        on port 5000 directly rather than being redirected from port 80.

        Only returns False when a tool was found but the rule addition itself failed.
        """
        try:
            iptables = self._find_command_path("iptables")
            nft = self._find_command_path("nft")

            if not iptables and not nft:
                logger.warning(
                    "Neither iptables nor nft found; captive portal port-80 redirect unavailable. "
                    "DNS spoofing will still trigger the OS popup but HTTP on port 80 won't reach Flask."
                )
                self._redirect_backend = None
                return True  # AP works; redirect is best-effort

            if iptables:
                return self._setup_iptables_redirect_iptables(iptables)
            else:
                return self._setup_iptables_redirect_nftables(nft)

        except Exception as e:
            logger.warning(f"Could not set up port redirect: {e}")
            try:
                self._teardown_iptables_redirect()
            except Exception as cleanup_e:
                logger.warning(f"Cleanup after redirect exception also failed: {cleanup_e}")
            return False

    def _setup_iptables_redirect_iptables(self, iptables: str) -> bool:
        """Set up port 80→5000 redirect using iptables."""
        # Save ip_forward state before enabling
        try:
            current_fwd = Path("/proc/sys/net/ipv4/ip_forward").read_text().strip()
        except OSError:
            current_fwd = None
        if current_fwd is not None:
            try:
                self._IP_FORWARD_SAVE_PATH.write_text(current_fwd)
            except OSError:
                current_fwd = None
                logger.warning("Could not write ip_forward save file; state will not be restored")

        if current_fwd != "1":
            sysctl = self._find_command_path("sysctl")
            sysctl_bin = sysctl if sysctl else "sysctl"
            r = subprocess.run(["sudo", sysctl_bin, "-w", "net.ipv4.ip_forward=1"],
                               capture_output=True, text=True, timeout=5)
            if r.returncode != 0:
                logger.error(f"Failed to enable ip_forward: {r.stderr.strip()}")
                self._teardown_iptables_redirect()
                return False

        if subprocess.run(
            ["sudo", iptables, "-t", "nat", "-C", "PREROUTING",
             "-i", self._wifi_interface, "-p", "tcp", "--dport", "80",
             "-j", "REDIRECT", "--to-port", "5000"],
            capture_output=True, timeout=5
        ).returncode != 0:
            r = subprocess.run(
                ["sudo", iptables, "-t", "nat", "-A", "PREROUTING",
                 "-i", self._wifi_interface, "-p", "tcp", "--dport", "80",
                 "-j", "REDIRECT", "--to-port", "5000"],
                capture_output=True, text=True, timeout=5
            )
            if r.returncode != 0:
                logger.error(f"Failed to add PREROUTING rule: {r.stderr.strip()}")
                self._teardown_iptables_redirect()
                return False

        if subprocess.run(
            ["sudo", iptables, "-C", "INPUT",
             "-i", self._wifi_interface, "-p", "tcp", "--dport", "5000", "-j", "ACCEPT"],
            capture_output=True, timeout=5
        ).returncode != 0:
            r = subprocess.run(
                ["sudo", iptables, "-A", "INPUT",
                 "-i", self._wifi_interface, "-p", "tcp", "--dport", "5000", "-j", "ACCEPT"],
                capture_output=True, text=True, timeout=5
            )
            if r.returncode != 0:
                logger.error(f"Failed to add INPUT rule: {r.stderr.strip()}")
                self._teardown_iptables_redirect()
                return False

        self._redirect_backend = "iptables"
        logger.info("iptables: port 80→5000 redirect rules added")
        return True

    def _setup_iptables_redirect_nftables(self, nft: str) -> bool:
        """Set up port 80→5000 redirect using nftables (Debian Trixie / modern systems)."""
        # NM's ipv4.method=shared already enables ip_forward; no sysctl needed.
        cmds = [
            ["sudo", nft, "add", "table", "ip", "ledmatrix"],
            ["sudo", nft, "add", "chain", "ip", "ledmatrix", "prerouting",
             "{", "type", "nat", "hook", "prerouting", "priority", "-100", ";", "}"],
            ["sudo", nft, "add", "rule", "ip", "ledmatrix", "prerouting",
             "iif", self._wifi_interface, "tcp", "dport", "80", "redirect", "to", ":5000"],
        ]
        for cmd in cmds:
            r = subprocess.run(cmd, capture_output=True, text=True, timeout=5)
            if r.returncode != 0:
                # Table/chain may already exist — only fail on rule add
                if "add rule" in " ".join(cmd):
                    logger.error(f"Failed to add nftables redirect rule: {r.stderr.strip()}")
                    self._teardown_iptables_redirect()
                    return False
                logger.debug(f"nft cmd non-zero (may already exist): {r.stderr.strip()}")

        self._redirect_backend = "nftables"
        logger.info("nftables: port 80→5000 redirect rule added")
        return True

    def _teardown_iptables_redirect(self) -> None:
        """Remove the port 80→5000 redirect rules and restore ip_forward if saved."""
        try:
            backend = self._redirect_backend
            self._redirect_backend = None

            if backend == "iptables":
                iptables = self._find_command_path("iptables")
                if iptables:
                    subprocess.run(
                        ["sudo", iptables, "-t", "nat", "-D", "PREROUTING",
                         "-i", self._wifi_interface, "-p", "tcp", "--dport", "80",
                         "-j", "REDIRECT", "--to-port", "5000"],
                        capture_output=True, timeout=5
                    )
                    subprocess.run(
                        ["sudo", iptables, "-D", "INPUT",
                         "-i", self._wifi_interface, "-p", "tcp", "--dport", "5000",
                         "-j", "ACCEPT"],
                        capture_output=True, timeout=5
                    )
                # Restore ip_forward only when we saved it
                if self._IP_FORWARD_SAVE_PATH.exists():
                    try:
                        saved = self._IP_FORWARD_SAVE_PATH.read_text().strip()
                        self._IP_FORWARD_SAVE_PATH.unlink(missing_ok=True)
                        sysctl = self._find_command_path("sysctl")
                        sysctl_bin = sysctl if sysctl else "sysctl"
                        subprocess.run(["sudo", sysctl_bin, "-w", f"net.ipv4.ip_forward={saved}"],
                                       capture_output=True, timeout=5)
                        logger.info(f"ip_forward restored to {saved}")
                    except OSError as e:
                        logger.warning(f"Could not restore ip_forward: {e}")
                else:
                    logger.debug("ip_forward not modified by setup; leaving unchanged")

            elif backend == "nftables":
                nft = self._find_command_path("nft")
                if nft:
                    subprocess.run(
                        ["sudo", nft, "delete", "table", "ip", "ledmatrix"],
                        capture_output=True, timeout=5
                    )
                    logger.info("nftables ledmatrix table removed")

            else:
                # No redirect was set up (neither tool available); nothing to tear down
                self._IP_FORWARD_SAVE_PATH.unlink(missing_ok=True)

        except Exception as e:
            logger.warning(f"Could not tear down port redirect: {e}")

    def _write_nm_dnsmasq_captive_conf(self, ap_ip: str = "192.168.4.1") -> None:
        """
        Write the NM dnsmasq-shared.d drop-in that makes NM's built-in dnsmasq
        resolve every hostname to the AP IP.  This triggers the OS captive-portal
        popup automatically on iOS / Android / Windows / macOS as soon as the
        device connects — no manual navigation required.

        NetworkManager reads /etc/NetworkManager/dnsmasq-shared.d/*.conf when it
        starts the dnsmasq instance for ipv4.method=shared connections.
        """
        try:
            content = f"# LEDMatrix captive portal: resolve all hostnames to AP\naddress=/#/{ap_ip}\n"
            with open("/tmp/ledmatrix-nm-dnsmasq.conf", "w") as f:
                f.write(content)
            subprocess.run(
                ["sudo", "mkdir", "-p", str(NM_DNSMASQ_SHARED_DIR)],
                capture_output=True, timeout=5
            )
            subprocess.run(
                ["sudo", "cp", "/tmp/ledmatrix-nm-dnsmasq.conf", str(NM_DNSMASQ_SHARED_CONF)],
                capture_output=True, timeout=5
            )
            logger.info(f"Wrote NM dnsmasq captive-portal config: {NM_DNSMASQ_SHARED_CONF}")
        except Exception as e:
            logger.warning(f"Could not write NM dnsmasq captive config: {e}")

    def _remove_nm_dnsmasq_captive_conf(self) -> None:
        """Remove the NM dnsmasq-shared.d drop-in written by _write_nm_dnsmasq_captive_conf."""
        try:
            subprocess.run(
                ["sudo", "rm", "-f", str(NM_DNSMASQ_SHARED_CONF)],
                capture_output=True, timeout=5
            )
            logger.info("Removed NM dnsmasq captive-portal config")
        except Exception as e:
            logger.warning(f"Could not remove NM dnsmasq captive config: {e}")

    def _check_internet_connectivity(self, timeout: int = 5) -> bool:
        """
        Test actual internet reachability — not just nmcli association state.

        A device can be 'connected' in nmcli (associated with an AP) while the
        router has no WAN link.  This check catches that case so the daemon can
        auto-enable AP mode even when nmcli reports a connection.

        Returns True if at least one reachability method succeeds.
        """
        try:
            r = subprocess.run(
                ["ping", "-c", "1", "-W", str(timeout), "8.8.8.8"],
                capture_output=True, timeout=timeout + 1
            )
            if r.returncode == 0:
                logger.debug("Internet connectivity confirmed via ping 8.8.8.8")
                return True
        except (subprocess.SubprocessError, OSError):
            pass
        try:
            import urllib.request as _ureq
            _ureq.urlopen("http://connectivity-check.ubuntu.com/", timeout=timeout)
            logger.debug("Internet connectivity confirmed via HTTP check")
            return True
        except OSError:
            pass
        logger.debug("Internet connectivity check failed (both ping and HTTP)")
        return False

    def check_internet_connectivity(self, timeout: int = 5) -> bool:
        """Public wrapper around _check_internet_connectivity for use by the daemon."""
        return self._check_internet_connectivity(timeout=timeout)

    def _has_ap_clients(self) -> bool:
        """
        Return True if at least one client is associated with the AP.
        Uses 'iw dev <iface> station dump' which works for both hostapd and
        nmcli AP modes.
        """
        try:
            result = subprocess.run(
                ["iw", "dev", self._wifi_interface, "station", "dump"],
                capture_output=True, text=True, timeout=5
            )
            return bool(result.stdout.strip())
        except Exception:
            return False

    def scan_networks(self, allow_cached: bool = True) -> Tuple[List[WiFiNetwork], bool]:
        """
        Scan for available WiFi networks.

        When AP mode is active, returns cached scan results instead of
        disabling AP (which would disconnect the user). Cached results
        come from either nmcli's internal cache or a pre-scan file saved
        before AP mode was enabled.

        Returns:
            Tuple of (list of WiFiNetwork objects, was_cached bool)
        """
        try:
            ap_active = self._is_ap_mode_active()

            if ap_active:
                # Don't disable AP — user would lose their connection.
                # Try nmcli cached results first (no rescan trigger).
                logger.info("AP mode active — returning cached scan results")
                networks = self._scan_nmcli_cached()
                if not networks and allow_cached:
                    networks = self._load_cached_scan()
                return networks, True

            # Normal scan (not in AP mode)
            if self.has_nmcli:
                networks = self._scan_nmcli()
            elif self.has_iwlist:
                networks = self._scan_iwlist()
            else:
                logger.error("No WiFi scanning tools available")
                networks = []

            # Save results for later use in AP mode
            if networks:
                self._save_cached_scan(networks)

            return networks, False

        except Exception as e:
            logger.error(f"Error scanning networks: {e}")
            return [], False

    def _scan_nmcli_cached(self) -> List[WiFiNetwork]:
        """Return nmcli's cached WiFi list without triggering a rescan."""
        networks = []
        try:
            result = subprocess.run(
                ["nmcli", "-t", "-f", "SSID,SIGNAL,SECURITY,FREQ", "device", "wifi", "list"],
                capture_output=True, text=True, timeout=5
            )
            if result.returncode != 0:
                return []

            seen_ssids = set()
            for line in result.stdout.strip().split('\n'):
                if not line or ':' not in line:
                    continue
                parts = line.split(':')
                if len(parts) >= 3:
                    ssid = parts[0].strip()
                    if not ssid or ssid in seen_ssids:
                        continue
                    seen_ssids.add(ssid)
                    try:
                        signal = int(parts[1].strip())
                        security = parts[2].strip() if len(parts) > 2 else "open"
                        frequency_str = parts[3].strip() if len(parts) > 3 else "0"
                        frequency_str = frequency_str.replace(" MHz", "").replace("MHz", "").strip()
                        frequency = float(frequency_str) if frequency_str else 0.0
                        if "WPA3" in security:
                            sec_type = "wpa3"
                        elif "WPA2" in security:
                            sec_type = "wpa2"
                        elif "WPA" in security:
                            sec_type = "wpa"
                        else:
                            sec_type = "open"
                        networks.append(WiFiNetwork(ssid=ssid, signal=signal, security=sec_type, frequency=frequency))
                    except (ValueError, IndexError):
                        continue
            networks.sort(key=lambda x: x.signal, reverse=True)
        except Exception as e:
            logger.debug(f"nmcli cached list failed: {e}")
        return networks

    def _save_cached_scan(self, networks: List[WiFiNetwork]) -> None:
        """Save scan results to a cache file for use during AP mode."""
        try:
            cache_path = get_wifi_config_path().parent / "cached_networks.json"
            data = [{"ssid": n.ssid, "signal": n.signal, "security": n.security, "frequency": n.frequency} for n in networks]
            with open(cache_path, 'w') as f:
                json.dump({"timestamp": time.time(), "networks": data}, f)
        except Exception as e:
            logger.debug(f"Failed to save cached scan: {e}")

    def _load_cached_scan(self) -> List[WiFiNetwork]:
        """Load pre-cached scan results (saved before AP mode was enabled)."""
        try:
            cache_path = get_wifi_config_path().parent / "cached_networks.json"
            if not cache_path.exists():
                return []
            with open(cache_path) as f:
                data = json.load(f)
            # Accept cache up to 10 minutes old
            if time.time() - data.get("timestamp", 0) > 600:
                return []
            return [WiFiNetwork(ssid=n["ssid"], signal=n["signal"], security=n["security"], frequency=n.get("frequency", 0.0))
                    for n in data.get("networks", [])]
        except Exception as e:
            logger.debug(f"Failed to load cached scan: {e}")
            return []

    def _scan_nmcli(self) -> List[WiFiNetwork]:
        """Scan networks using nmcli"""
        networks = []
        try:
            # Trigger scan
            subprocess.run(
                ["nmcli", "device", "wifi", "rescan"],
                capture_output=True,
                timeout=10
            )
            time.sleep(2)  # Wait for scan to complete
            
            # Get scan results
            result = subprocess.run(
                ["nmcli", "-t", "-f", "SSID,SIGNAL,SECURITY,FREQ", "device", "wifi", "list"],
                capture_output=True,
                text=True,
                timeout=10
            )
            
            if result.returncode != 0:
                return []
            
            seen_ssids = set()
            for line in result.stdout.strip().split('\n'):
                if not line or ':' not in line:
                    continue
                
                parts = line.split(':')
                if len(parts) >= 3:
                    ssid = parts[0].strip()
                    if not ssid or ssid in seen_ssids:
                        continue
                    
                    seen_ssids.add(ssid)
                    
                    try:
                        signal = int(parts[1].strip())
                        security = parts[2].strip() if len(parts) > 2 else "open"
                        
                        # Parse frequency - strip " MHz" if present
                        frequency_str = parts[3].strip() if len(parts) > 3 else "0"
                        frequency_str = frequency_str.replace(" MHz", "").replace("MHz", "").strip()
                        frequency = float(frequency_str) if frequency_str else 0.0
                        
                        # Normalize security type
                        if "WPA3" in security:
                            sec_type = "wpa3"
                        elif "WPA2" in security:
                            sec_type = "wpa2"
                        elif "WPA" in security:
                            sec_type = "wpa"
                        else:
                            sec_type = "open"
                        
                        networks.append(WiFiNetwork(
                            ssid=ssid,
                            signal=signal,
                            security=sec_type,
                            frequency=frequency
                        ))
                    except (ValueError, IndexError) as e:
                        logger.debug(f"Skipping network line due to parsing error: {line[:50]}... Error: {e}")
                        continue
            
            # Sort by signal strength
            networks.sort(key=lambda x: x.signal, reverse=True)
            return networks
        except Exception as e:
            logger.error(f"Error scanning with nmcli: {e}")
            return []
    
    def _scan_iwlist(self) -> List[WiFiNetwork]:
        """Scan networks using iwlist (fallback)"""
        networks = []
        try:
            result = subprocess.run(
                ["iwlist", self._wifi_interface, "scan"],
                capture_output=True,
                text=True,
                timeout=30
            )
            
            if result.returncode != 0:
                return []
            
            output = result.stdout
            seen_ssids = set()
            current_ssid = None
            current_signal = 0
            current_security = "open"
            
            for line in output.split('\n'):
                line = line.strip()
                
                # Extract SSID
                if 'ESSID:' in line:
                    match = re.search(r'ESSID:"([^"]+)"', line)
                    if match:
                        if current_ssid and current_ssid not in seen_ssids:
                            networks.append(WiFiNetwork(
                                ssid=current_ssid,
                                signal=current_signal,
                                security=current_security
                            ))
                            seen_ssids.add(current_ssid)
                        current_ssid = match.group(1)
                        current_signal = 0
                        current_security = "open"
                
                # Extract signal strength
                elif 'Signal level=' in line:
                    match = re.search(r'Signal level=(-?\d+)', line)
                    if match:
                        # Convert to percentage (approximate)
                        dbm = int(match.group(1))
                        current_signal = max(0, min(100, (dbm + 100) * 2))
                
                # Extract security
                elif 'Encryption key:' in line:
                    if 'on' in line.lower():
                        current_security = "wpa"  # Default, will check for WPA2/WPA3
                elif 'WPA2' in line:
                    current_security = "wpa2"
                elif 'WPA3' in line:
                    current_security = "wpa3"
            
            # Add last network
            if current_ssid and current_ssid not in seen_ssids:
                networks.append(WiFiNetwork(
                    ssid=current_ssid,
                    signal=current_signal,
                    security=current_security
                ))
            
            # Sort by signal strength
            networks.sort(key=lambda x: x.signal, reverse=True)
            return networks
        except Exception as e:
            logger.error(f"Error scanning with iwlist: {e}")
            return []
    
    def connect_to_network(self, ssid: str, password: str) -> Tuple[bool, str]:
        """
        Connect to a WiFi network with failsafe to restore original connection on failure.
        
        Args:
            ssid: Network SSID
            password: Network password (empty for open networks)
            
        Returns:
            Tuple of (success, message)
        """
        # Save current connection info for failsafe restoration
        original_connection = None
        original_ssid = None
        try:
            status = self.get_wifi_status()
            if status.connected and status.ssid:
                original_ssid = status.ssid
                # Get the active connection name/UUID for WiFi interface
                result = subprocess.run(
                    ["nmcli", "-t", "-f", "GENERAL.CONNECTION", "device", "show", self._wifi_interface],
                    capture_output=True,
                    text=True,
                    timeout=5
                )
                if result.returncode == 0:
                    for line in result.stdout.strip().split('\n'):
                        if 'GENERAL.CONNECTION:' in line:
                            connection_name = line.split(':', 1)[1].strip()
                            if connection_name and connection_name != '--':
                                original_connection = connection_name
                                break
                
                # Fallback: try to find connection by SSID
                if not original_connection:
                    result = subprocess.run(
                        ["nmcli", "-t", "-f", "NAME", "connection", "show"],
                        capture_output=True,
                        text=True,
                        timeout=5
                    )
                    if result.returncode == 0:
                        for line in result.stdout.strip().split('\n'):
                            if original_ssid.lower() in line.lower():
                                original_connection = line.strip()
                                break
                
                logger.info(f"Saving original connection for failsafe: {original_ssid} ({original_connection})")
        except Exception as e:
            logger.debug(f"Could not save original connection info: {e}")
        
        try:
            # Check if already connected to the target network
            if original_ssid and original_ssid == ssid:
                logger.info(f"Already connected to {ssid}, verifying connection...")
                status = self.get_wifi_status()
                if status.connected and status.ssid == ssid:
                    logger.info(f"Already connected to {ssid} with IP {status.ip_address}")
                    return True, f"Already connected to {ssid}"
                else:
                    logger.warning(f"Status shows not connected to {ssid}, attempting reconnection...")
            
            # First, disable AP mode if active
            # This is critical - if AP mode is active, we must disable it before connecting
            if self._is_ap_mode_active():
                logger.info("AP mode is active, disabling before connecting to WiFi network...")
                disable_success, disable_msg = self.disable_ap_mode()
                if not disable_success:
                    error_msg = f"Failed to disable AP mode: {disable_msg}. Cannot connect to WiFi while AP mode is active."
                    logger.error(error_msg)
                    return False, error_msg
                
                # Wait for NetworkManager to restart and stabilize (if it was restarted)
                # NetworkManager restart can take 3-5 seconds, so wait a bit longer
                logger.info("Waiting for NetworkManager to stabilize after AP mode disable...")
                time.sleep(5)
                
                # Verify AP mode is actually disabled
                max_verify_attempts = 5
                for attempt in range(max_verify_attempts):
                    if not self._is_ap_mode_active():
                        logger.info("AP mode successfully disabled, proceeding with connection")
                        break
                    if attempt < max_verify_attempts - 1:
                        logger.debug(f"AP mode still active, waiting... (attempt {attempt + 1}/{max_verify_attempts})")
                        time.sleep(2)
                    else:
                        error_msg = "AP mode disable reported success but AP mode is still active. Cannot connect to WiFi."
                        logger.error(error_msg)
                        return False, error_msg
            
            # If we're currently connected to a different network, disconnect first
            # This ensures a clean switch between networks
            if original_ssid and original_ssid != ssid:
                logger.info(f"Switching networks: disconnecting from {original_ssid} before connecting to {ssid}")
                self._show_led_message(f"Switching networks...", duration=3)
                # Skip AP mode check since we're about to connect to a new network
                disconnect_success, disconnect_msg = self.disconnect_from_network(skip_ap_check=True)
                if disconnect_success:
                    logger.info(f"Disconnected from {original_ssid}: {disconnect_msg}")
                    # Wait for device to be ready for new connection
                    # Check device state before proceeding
                    max_wait = 5
                    wait_count = 0
                    while wait_count < max_wait:
                        time.sleep(1)
                        result = subprocess.run(
                            ["nmcli", "-t", "-f", "STATE", "device", "status", self._wifi_interface],
                            capture_output=True,
                            text=True,
                            timeout=5
                        )
                        if result.returncode == 0:
                            state = result.stdout.strip().split(':')[-1] if ':' in result.stdout else result.stdout.strip()
                            # Device is ready if it's disconnected or unavailable (not connecting/connected)
                            if state in ["disconnected", "unavailable", "unmanaged"]:
                                logger.info(f"Device ready for new connection (state: {state})")
                                break
                        wait_count += 1
                    
                    if wait_count >= max_wait:
                        logger.warning("Device may not be ready, but proceeding with connection attempt")
                else:
                    logger.warning(f"Failed to disconnect from {original_ssid}: {disconnect_msg}")
                    # Continue anyway - NetworkManager might handle it, but wait a bit
                    time.sleep(2)
            
            # Ensure WiFi radio is enabled before attempting connection (safety measure)
            if not self._ensure_wifi_radio_enabled():
                logger.warning("WiFi radio enable check failed, but continuing with connection attempt")
            
            if self.has_nmcli:
                success, message = self._connect_nmcli(ssid, password)
                
                # If connection failed, try to restore original connection
                if not success and original_connection and original_ssid:
                    logger.warning(f"Connection to {ssid} failed, attempting to restore original connection: {original_ssid}")
                    self._show_led_message(f"Restoring {original_ssid}...", duration=5)
                    
                    restore_success = self._restore_original_connection(original_connection, original_ssid)
                    if restore_success:
                        logger.info(f"Successfully restored original connection: {original_ssid}")
                        self._show_led_message("Restored!", duration=3)
                        return False, f"Failed to connect to {ssid}, restored {original_ssid}"
                    else:
                        logger.error(f"Failed to restore original connection: {original_ssid}")
                        # Trigger AP mode as last resort
                        self._show_led_message("Enabling AP mode...", duration=5)
                        ap_success, ap_msg = self.enable_ap_mode()
                        if ap_success:
                            logger.info("AP mode enabled as failsafe")
                            return False, f"Connection failed and restoration failed. AP mode enabled."
                        else:
                            logger.error(f"Failed to enable AP mode: {ap_msg}")
                            return False, f"Connection failed, restoration failed, and AP mode failed: {ap_msg}"
                
                # If connection failed and no original connection to restore, enable AP mode
                elif not success:
                    logger.warning(f"Connection to {ssid} failed and no original connection to restore")
                    self._show_led_message("Enabling AP mode...", duration=5)
                    ap_success, ap_msg = self.enable_ap_mode()
                    if ap_success:
                        logger.info("AP mode enabled as failsafe")
                        return False, f"Connection failed. AP mode enabled."
                    else:
                        return False, f"Connection failed and AP mode failed: {ap_msg}"
                
                return success, message
            else:
                return self._connect_wpa_supplicant(ssid, password)
        except Exception as e:
            logger.error(f"Error connecting to network: {e}")
            # Try to restore original connection on exception
            if original_connection and original_ssid:
                try:
                    logger.warning(f"Exception during connection, attempting to restore: {original_ssid}")
                    self._restore_original_connection(original_connection, original_ssid)
                except Exception as restore_error:
                    logger.error(f"Failed to restore after exception: {restore_error}")
                    # Last resort: enable AP mode
                    try:
                        self.enable_ap_mode()
                    except Exception:
                        pass
            return False, str(e)
    
    def _restore_original_connection(self, connection_name: str, ssid: str) -> bool:
        """
        Restore a previously active WiFi connection.
        
        Args:
            connection_name: NetworkManager connection name or UUID
            ssid: SSID for verification
            
        Returns:
            True if restoration successful, False otherwise
        """
        try:
            logger.info(f"Attempting to restore connection: {connection_name} ({ssid})")
            
            # Try to activate the connection
            result = subprocess.run(
                ["nmcli", "connection", "up", connection_name],
                capture_output=True,
                text=True,
                timeout=30
            )
            
            if result.returncode == 0:
                # Wait for connection to stabilize
                time.sleep(3)
                
                # Verify connection
                status = self.get_wifi_status()
                if status.connected:
                    # Double-check SSID matches (if we can get it)
                    if status.ssid:
                        if status.ssid == ssid:
                            logger.info(f"Successfully restored connection to {ssid}")
                            return True
                        else:
                            logger.warning(f"Restored connection but SSID mismatch: expected {ssid}, got {status.ssid}")
                            # Still consider it success if we're connected
                            return True
                    else:
                        # Connected but can't verify SSID - assume success
                        logger.info("Restored connection (SSID verification unavailable)")
                        return True
                else:
                    logger.warning("Connection activation succeeded but not connected")
                    return False
            else:
                error_msg = result.stderr.strip() or result.stdout.strip()
                logger.error(f"Failed to restore connection {connection_name}: {error_msg}")
                return False
        except Exception as e:
            logger.error(f"Error restoring connection: {e}")
            return False
    
    def _connect_nmcli(self, ssid: str, password: str) -> Tuple[bool, str]:
        """Connect using nmcli"""
        try:
            # Show LED message
            self._show_led_message(f"Connecting to {ssid}...", duration=10)
            
            # First, check if connection already exists and try to activate it
            # NetworkManager connection names might not match SSID exactly, so search by SSID
            check_result = subprocess.run(
                ["nmcli", "-t", "-f", "NAME,802-11-wireless.ssid", "connection", "show"],
                capture_output=True,
                text=True,
                timeout=5
            )
            
            existing_conn_name = None
            if check_result.returncode == 0:
                for line in check_result.stdout.strip().split('\n'):
                    if ':' in line:
                        parts = line.split(':')
                        if len(parts) >= 2:
                            conn_name = parts[0].strip()
                            conn_ssid = parts[1].strip() if len(parts) > 1 else ""
                            if conn_ssid == ssid:
                                existing_conn_name = conn_name
                                break
            
            # Also try direct lookup by SSID (in case connection name matches SSID)
            if not existing_conn_name:
                direct_check = subprocess.run(
                    ["nmcli", "connection", "show", ssid],
                    capture_output=True,
                    text=True,
                    timeout=5
                )
                if direct_check.returncode == 0:
                    existing_conn_name = ssid
            
            if existing_conn_name:
                # Connection exists, try to activate it first (faster and more reliable)
                logger.info(f"Found existing connection for {ssid}, activating...")
                
                # Ensure device is ready before activating
                # Wait for device to be in disconnected/unavailable state
                max_wait = 3
                for wait_attempt in range(max_wait):
                    device_result = subprocess.run(
                        ["nmcli", "-t", "-f", "STATE", "device", "status", self._wifi_interface],
                        capture_output=True,
                        text=True,
                        timeout=5
                    )
                    if device_result.returncode == 0:
                        state = device_result.stdout.strip().split(':')[-1] if ':' in device_result.stdout else device_result.stdout.strip()
                        if state in ["disconnected", "unavailable", "unmanaged"]:
                            break
                    if wait_attempt < max_wait - 1:
                        time.sleep(1)
                
                result = subprocess.run(
                    ["nmcli", "connection", "up", existing_conn_name],
                    capture_output=True,
                    text=True,
                    timeout=30
                )
                
                if result.returncode == 0:
                    # Wait longer for connection to stabilize and verify multiple times
                    max_verification_attempts = 5
                    verification_delay = 2
                    connected = False
                    
                    for attempt in range(max_verification_attempts):
                        time.sleep(verification_delay)
                        status = self.get_wifi_status()
                        if status.connected and status.ssid == ssid:
                            connected = True
                            break
                    
                    if connected:
                        # Save network to config
                        self._save_network(ssid, password)
                        
                        ip = status.ip_address or "Unknown"
                        self._show_led_message(f"Connected! {ip}", duration=5)
                        logger.info(f"Successfully connected to {ssid} with IP {ip}")
                        return True, f"Connected to {ssid}"
                    else:
                        logger.warning(f"Connection activation succeeded but verification failed for {ssid}")
                        self._show_led_message("Verification failed", duration=5)
                        return False, "Connection activated but verification failed"
            
            # No existing connection or activation failed, create new connection
            logger.info(f"Creating new connection for {ssid}...")
            self._save_network(ssid, password)
            
            # Connect using nmcli
            if password:
                cmd = ["nmcli", "device", "wifi", "connect", ssid, "password", password]
            else:
                cmd = ["nmcli", "device", "wifi", "connect", ssid]
            
            result = subprocess.run(
                cmd,
                capture_output=True,
                text=True,
                timeout=30
            )
            
            if result.returncode == 0:
                # Wait longer for connection to stabilize and verify multiple times
                max_verification_attempts = 5
                verification_delay = 2
                connected = False
                
                for attempt in range(max_verification_attempts):
                    time.sleep(verification_delay)
                    status = self.get_wifi_status()
                    if status.connected:
                        # Verify we're connected to the correct SSID
                        if status.ssid == ssid:
                            connected = True
                            break
                        elif status.ssid:
                            # Connected to different network - this is a failure
                            logger.warning(f"Connected to wrong network: {status.ssid} instead of {ssid}")
                            break
                
                if connected:
                    ip = status.ip_address or "Unknown"
                    self._show_led_message(f"Connected! {ip}", duration=5)
                    logger.info(f"Successfully connected to {ssid} with IP {ip}")
                    return True, f"Connected to {ssid}"
                else:
                    self._show_led_message("Connection failed", duration=5)
                    return False, "Connection command succeeded but verification failed"
            else:
                error_msg = result.stderr.strip() or result.stdout.strip()
                logger.error(f"Failed to connect to {ssid}: {error_msg}")
                self._show_led_message("Connection failed", duration=5)
                if self._is_wrong_password_error(error_msg):
                    return False, f"wrong_password: {error_msg}"
                return False, error_msg
        except Exception as e:
            logger.error(f"Error connecting with nmcli: {e}")
            self._show_led_message("Connection error", duration=5)
            return False, str(e)

    @staticmethod
    def _is_wrong_password_error(error_msg: str) -> bool:
        """Return True when nmcli's error output indicates an authentication failure."""
        indicators = [
            "secrets were required",
            "no secret agent",
            "802-11-wireless-security.psk",
            "authentication rejected",
            "association rejected",
        ]
        lower = error_msg.lower()
        return any(ind in lower for ind in indicators)

    def _connect_wpa_supplicant(self, ssid: str, password: str) -> Tuple[bool, str]:
        """Connect using wpa_supplicant (fallback)"""
        try:
            self._save_network(ssid, password)
            
            # This would require modifying /etc/wpa_supplicant/wpa_supplicant.conf
            # For now, return not implemented
            return False, "wpa_supplicant connection not yet implemented. Please use NetworkManager (nmcli)."
        except Exception as e:
            logger.error(f"Error connecting with wpa_supplicant: {e}")
            return False, str(e)
    
    def disconnect_from_network(self, skip_ap_check: bool = False) -> Tuple[bool, str]:
        """
        Disconnect from the current WiFi network
        
        Args:
            skip_ap_check: If True, skip auto-enabling AP mode after disconnect
                          (useful when switching networks)
        
        Returns:
            Tuple of (success, message)
        """
        try:
            # Check if WiFi is connected
            status = self.get_wifi_status()
            if not status.connected:
                return True, "Not connected to any WiFi network"
            
            # Disconnect using nmcli
            if self.has_nmcli:
                # Try to disconnect the specific connection first (more reliable)
                if status.ssid:
                    # Find the connection name for this SSID
                    conn_result = subprocess.run(
                        ["nmcli", "-t", "-f", "NAME,802-11-wireless.ssid", "connection", "show"],
                        capture_output=True,
                        text=True,
                        timeout=5
                    )
                    if conn_result.returncode == 0:
                        for line in conn_result.stdout.strip().split('\n'):
                            if ':' in line:
                                parts = line.split(':')
                                if len(parts) >= 2:
                                    conn_name = parts[0].strip()
                                    conn_ssid = parts[1].strip() if len(parts) > 1 else ""
                                    if conn_ssid == status.ssid:
                                        # Disconnect this specific connection
                                        subprocess.run(
                                            ["nmcli", "connection", "down", conn_name],
                                            capture_output=True,
                                            timeout=10
                                        )
                                        logger.info(f"Disconnected connection {conn_name} for {status.ssid}")
                                        break
                
                # Also disconnect the device to ensure clean state
                result = subprocess.run(
                    ["nmcli", "device", "disconnect", self._wifi_interface],
                    capture_output=True,
                    text=True,
                    timeout=10
                )
                
                if result.returncode == 0:
                    logger.info("Successfully disconnected from WiFi network")
                    # Wait longer for the disconnect to fully complete
                    time.sleep(2)
                    
                    # Check if AP mode should be auto-enabled
                    # Skip if we're switching networks (skip_ap_check=True)
                    if not skip_ap_check:
                        auto_enable = self.config.get("auto_enable_ap_mode", True)
                        if auto_enable:
                            # Give it a moment, then check if we should enable AP mode
                            time.sleep(1)
                            self.check_and_manage_ap_mode()
                    else:
                        logger.debug("Skipping AP mode check (network switch in progress)")
                    
                    return True, "Disconnected from WiFi network"
                else:
                    error_msg = result.stderr.strip() or result.stdout.strip()
                    logger.error(f"Failed to disconnect from WiFi: {error_msg}")
                    return False, f"Failed to disconnect: {error_msg}"
            else:
                return False, "nmcli is required to disconnect from WiFi"
        except Exception as e:
            logger.error(f"Error disconnecting from WiFi: {e}")
            return False, str(e)
    
    def _save_network(self, ssid: str, password: str):
        """Save network credentials to config"""
        # Remove existing entry for this SSID
        self.config["saved_networks"] = [
            n for n in self.config["saved_networks"]
            if n.get("ssid") != ssid
        ]
        
        # Add new entry
        self.config["saved_networks"].append({
            "ssid": ssid,
            "password": password,
            "saved_at": time.time()
        })
        
        self._save_config()
    
    def _ensure_wifi_radio_enabled(self, max_retries: int = 3) -> bool:
        """
        Ensure WiFi radio is enabled (not soft-blocked) with retry logic and verification.
        
        Args:
            max_retries: Maximum number of retry attempts to enable WiFi radio
            
        Returns:
            True if WiFi is enabled or was successfully enabled, False otherwise
        """
        for attempt in range(max_retries):
            try:
                # Check if WiFi radio is enabled
                result = subprocess.run(
                    ["nmcli", "radio", "wifi"],
                    capture_output=True,
                    text=True,
                    timeout=5
                )
                
                if result.returncode == 0:
                    status = result.stdout.strip().lower()
                    if status == "enabled":
                        # Verify with rfkill as well
                        rfkill_result = subprocess.run(
                            ["rfkill", "list", "wifi"],
                            capture_output=True,
                            text=True,
                            timeout=5
                        )
                        if "Soft blocked: yes" not in rfkill_result.stdout:
                            logger.debug(f"WiFi radio confirmed enabled (attempt {attempt + 1})")
                            return True
                        # If soft-blocked, continue to unblock logic below
                    
                    if status == "disabled" or attempt > 0:
                        # Try to enable WiFi radio
                        if attempt == 0:
                            logger.info("WiFi radio is disabled, attempting to enable...")
                        else:
                            logger.info(f"WiFi radio still disabled, retry {attempt + 1}/{max_retries}...")
                        
                        enable_result = subprocess.run(
                            ["sudo", "nmcli", "radio", "wifi", "on"],
                            capture_output=True,
                            text=True,
                            timeout=10
                        )
                        if enable_result.returncode == 0:
                            # Also unblock via rfkill in case it's soft-blocked
                            subprocess.run(
                                ["sudo", "rfkill", "unblock", "wifi"],
                                capture_output=True,
                                timeout=5
                            )
                            # Wait longer for it to actually enable
                            time.sleep(2)
                            
                            # Verify it's actually enabled now
                            verify_result = subprocess.run(
                                ["nmcli", "radio", "wifi"],
                                capture_output=True,
                                text=True,
                                timeout=5
                            )
                            if verify_result.returncode == 0 and verify_result.stdout.strip().lower() == "enabled":
                                logger.info("WiFi radio enabled and verified successfully")
                                return True
                            elif attempt < max_retries - 1:
                                logger.warning(f"WiFi radio enable command succeeded but not verified, will retry...")
                                time.sleep(1)
                                continue
                        else:
                            logger.warning(f"Failed to enable WiFi radio: {enable_result.stderr}")
                            if attempt < max_retries - 1:
                                time.sleep(1)
                                continue
                            return False
                
                # Fallback: try rfkill
                rfkill_result = subprocess.run(
                    ["rfkill", "list", "wifi"],
                    capture_output=True,
                    text=True,
                    timeout=5
                )
                if "Soft blocked: yes" in rfkill_result.stdout:
                    logger.info("WiFi is soft-blocked, unblocking via rfkill...")
                    subprocess.run(
                        ["sudo", "rfkill", "unblock", "wifi"],
                        capture_output=True,
                        timeout=5
                    )
                    time.sleep(2)
                    # Verify unblock worked
                    verify_rfkill = subprocess.run(
                        ["rfkill", "list", "wifi"],
                        capture_output=True,
                        text=True,
                        timeout=5
                    )
                    if "Soft blocked: yes" not in verify_rfkill.stdout:
                        logger.info("WiFi unblocked via rfkill and verified")
                        return True
                    elif attempt < max_retries - 1:
                        time.sleep(1)
                        continue
                
                # If we get here and haven't returned, assume enabled if we can't determine
                if attempt == 0:
                    logger.debug("Could not determine WiFi radio status, assuming enabled")
                    return True
                else:
                    time.sleep(1)
                    continue
                    
            except Exception as e:
                logger.warning(f"Could not check/enable WiFi radio (attempt {attempt + 1}): {e}")
                if attempt < max_retries - 1:
                    time.sleep(1)
                    continue
                # On last attempt, assume enabled to avoid blocking operations
                return True
        
        logger.warning(f"Failed to enable WiFi radio after {max_retries} attempts")
        return False
    
    def enable_ap_mode(self) -> Tuple[bool, str]:
        """
        Enable access point mode
        
        Only enables AP mode if:
        - WiFi is NOT connected AND
        - Ethernet is NOT connected
        
        Tries hostapd/dnsmasq first (captive portal), falls back to nmcli hotspot if that fails.
        
        Returns:
            Tuple of (success, message)
        """
        try:
            # Check if already in AP mode
            if self._is_ap_mode_active():
                return True, "AP mode already active"
            
            # Ensure WiFi radio is enabled
            if not self._ensure_wifi_radio_enabled():
                return False, "WiFi radio is disabled and could not be enabled"
            
            # Check if WiFi is connected
            status = self.get_wifi_status()
            if status.connected:
                return False, "Cannot enable AP mode while WiFi is connected"
            
            # Check if Ethernet is connected
            if self._is_ethernet_connected():
                return False, "Cannot enable AP mode while Ethernet is connected"
            
            # Try hostapd/dnsmasq first (captive portal mode)
            if self.has_hostapd and self.has_dnsmasq:
                result = self._enable_ap_mode_hostapd()
                if result[0]:
                    self._ap_enabled_at = time.time()
                    return result

            # Fallback to nmcli hotspot (simpler, no captive portal)
            if self.has_nmcli:
                logger.info("hostapd/dnsmasq failed or unavailable, trying nmcli hotspot fallback...")
                self._show_led_message("Setup Mode", duration=5)
                result = self._enable_ap_mode_nmcli_hotspot()
                if result[0]:
                    self._ap_enabled_at = time.time()
                return result

            return False, "No WiFi tools available (nmcli, hostapd, or dnsmasq required)"
        except Exception as e:
            logger.error(f"Error in enable_ap_mode: {e}")
            return False, str(e)
    
    def _enable_ap_mode_hostapd(self) -> Tuple[bool, str]:
        """Enable AP mode using hostapd and dnsmasq (captive portal)"""
        try:
            
            # Create hostapd config
            self._create_hostapd_config()
            
            # Create dnsmasq config
            self._create_dnsmasq_config()
            
            # Set up WiFi interface for AP mode
            try:
                # Disconnect from any existing WiFi network
                subprocess.run(
                    ["sudo", "nmcli", "device", "disconnect", self._wifi_interface],
                    capture_output=True,
                    timeout=10
                )

                # Set static IP for AP mode
                subprocess.run(
                    ["sudo", "ip", "addr", "flush", "dev", self._wifi_interface],
                    capture_output=True,
                    timeout=10
                )
                subprocess.run(
                    ["sudo", "ip", "addr", "add", "192.168.4.1/24", "dev", self._wifi_interface],
                    capture_output=True,
                    timeout=10
                )
                subprocess.run(
                    ["sudo", "ip", "link", "set", self._wifi_interface, "up"],
                    capture_output=True,
                    timeout=10
                )
                logger.info(f"Configured {self._wifi_interface} with IP 192.168.4.1 for AP mode")
            except (subprocess.TimeoutExpired, subprocess.SubprocessError, OSError) as e:
                logger.warning(f"Error setting up {self._wifi_interface} IP: {e}")
            
            # Start services
            try:
                # Start hostapd first (it sets up the AP)
                result = subprocess.run(
                    ["sudo", "systemctl", "start", HOSTAPD_SERVICE],
                    capture_output=True,
                    text=True,
                    timeout=15
                )
                if result.returncode != 0:
                    return False, f"Failed to start hostapd: {result.stderr}"
                
                # Give hostapd time to initialize
                time.sleep(1)
                
                # Start dnsmasq
                result = subprocess.run(
                    ["sudo", "systemctl", "start", DNSMASQ_SERVICE],
                    capture_output=True,
                    text=True,
                    timeout=10
                )
                if result.returncode != 0:
                    # Stop hostapd if dnsmasq failed
                    subprocess.run(["sudo", "systemctl", "stop", HOSTAPD_SERVICE], timeout=5)
                    return False, f"Failed to start dnsmasq: {result.stderr}"
                
                # Set up iptables port forwarding (port 80 → 5000) and save ip_forward state
                if not self._setup_iptables_redirect():
                    logger.error("Captive-portal redirect setup failed; stopping AP services")
                    subprocess.run(["sudo", "systemctl", "stop", HOSTAPD_SERVICE],
                                   capture_output=True, timeout=10)
                    subprocess.run(["sudo", "systemctl", "stop", DNSMASQ_SERVICE],
                                   capture_output=True, timeout=10)
                    return False, "AP started but captive-portal redirect setup failed"

                logger.info("AP mode enabled successfully")
                # Use the validated SSID so the displayed name matches what hostapd broadcast
                ap_ssid, _ = self._validate_ap_config()
                self._show_led_message(
                    f"WiFi Setup\n{ap_ssid}\nNo password\n192.168.4.1:5000", duration=10
                )
                return True, "AP mode enabled"
            except Exception as e:
                logger.error(f"Error starting AP services: {e}")
                return False, str(e)
        except Exception as e:
            logger.error(f"Error enabling AP mode: {e}")
            return False, str(e)
    
    def _enable_ap_mode_nmcli_hotspot(self) -> Tuple[bool, str]:
        """
        Enable AP mode using nmcli as an open (passwordless) access point.

        Uses 'nmcli connection add type wifi 802-11-wireless.mode ap' instead of
        'nmcli device wifi hotspot' because the hotspot subcommand always creates a
        WPA2-protected network on Bookworm/Trixie and silently ignores attempts to
        strip security after creation.

        Tested for both Bookworm and Trixie (Netplan-based NetworkManager).
        """
        try:
            # Stop any existing connection
            self.disconnect_from_network()
            time.sleep(1)

            ap_ssid, ap_channel = self._validate_ap_config()

            # Delete only the specific application-managed AP profiles by name.
            # Never delete by SSID — that would destroy a user's saved home network.
            for conn_name in ["Hotspot", "LEDMatrix-Setup-AP", "TickerSetup-AP"]:
                subprocess.run(["nmcli", "connection", "down", conn_name],
                                capture_output=True, timeout=5)
                subprocess.run(["nmcli", "connection", "delete", conn_name],
                                capture_output=True, timeout=10)

            time.sleep(1)

            # Create an open AP connection profile from scratch.
            # Using 'connection add' instead of 'device wifi hotspot' because the
            # hotspot subcommand always attaches a WPA2 PSK on Bookworm/Trixie and
            # ignores post-creation security modifications.
            logger.info(f"Creating open AP with nmcli connection add: {ap_ssid} on "
                        f"{self._wifi_interface} (no password)")
            cmd = [
                "nmcli", "connection", "add",
                "type", "wifi",
                "con-name", "LEDMatrix-Setup-AP",
                "ifname", self._wifi_interface,
                "ssid", ap_ssid,
                "802-11-wireless.mode", "ap",
                "802-11-wireless.band", "bg",   # 2.4 GHz for maximum compatibility
                "802-11-wireless.channel", str(ap_channel),
                "ipv4.method", "shared",
                "ipv4.addresses", "192.168.4.1/24",
                # No 802-11-wireless-security section → open network
            ]

            # PMF (Protected Management Frames) is only meaningful for WPA2/WPA3.
            # An open AP has no security section, so adding 802-11-wireless-security.pmf
            # would cause NM to require key-mgmt too, breaking the connection add on
            # Trixie NM 1.52+. Leave PMF untouched — open APs have no frame protection.

            result = subprocess.run(cmd, capture_output=True, text=True, timeout=30)

            if result.returncode != 0:
                error_msg = result.stderr.strip() or result.stdout.strip()
                logger.error(f"Failed to create AP connection profile: {error_msg}")
                self._show_led_message("AP mode failed", duration=5)
                return False, f"Failed to create AP profile: {error_msg}"

            # Write the NM dnsmasq-shared.d captive-portal config BEFORE bringing up
            # the connection so NM's dnsmasq picks it up at start time.
            # This causes every hostname DNS query from a connected device to resolve
            # to 192.168.4.1, automatically triggering the OS captive-portal popup.
            self._write_nm_dnsmasq_captive_conf()

            logger.info("AP connection profile created, bringing it up...")
            up_result = subprocess.run(
                ["nmcli", "connection", "up", "LEDMatrix-Setup-AP"],
                capture_output=True, text=True, timeout=20
            )
            if up_result.returncode != 0:
                error_msg = up_result.stderr.strip() or up_result.stdout.strip()
                logger.error(f"Failed to bring up AP connection: {error_msg}")
                self._remove_nm_dnsmasq_captive_conf()
                subprocess.run(["nmcli", "connection", "delete", "LEDMatrix-Setup-AP"],
                               capture_output=True, timeout=10)
                self._show_led_message("AP mode failed", duration=5)
                return False, f"Failed to start AP: {error_msg}"

            time.sleep(2)

            # NM's ipv4.method=shared manages ip_forward automatically, so we only
            # need to add the iptables port-redirect rules for the captive portal.
            if not self._setup_iptables_redirect():
                logger.error("Captive-portal redirect setup failed; rolling back AP profile")
                self._remove_nm_dnsmasq_captive_conf()
                subprocess.run(["nmcli", "connection", "down", "LEDMatrix-Setup-AP"],
                               capture_output=True, timeout=10)
                subprocess.run(["nmcli", "connection", "delete", "LEDMatrix-Setup-AP"],
                               capture_output=True, timeout=10)
                self._clear_led_message()
                return False, "AP started but captive-portal redirect setup failed"

            # Verify the AP is actually running
            status = self._get_ap_status_nmcli()
            if status.get('active'):
                ip = status.get('ip', '192.168.4.1')
                logger.info(f"AP mode confirmed active at {ip} (open network, no password)")
                self._show_led_message(f"WiFi Setup\n{ap_ssid}\nNo password\n{ip}:5000", duration=10)
                return True, f"AP mode enabled (open network) - Access at {ip}:5000"
            else:
                logger.error("AP mode started but not verified by status check — rolling back")
                self._teardown_iptables_redirect()
                self._remove_nm_dnsmasq_captive_conf()
                subprocess.run(["nmcli", "connection", "down", "LEDMatrix-Setup-AP"],
                               capture_output=True, timeout=10)
                subprocess.run(["nmcli", "connection", "delete", "LEDMatrix-Setup-AP"],
                               capture_output=True, timeout=10)
                self._clear_led_message()
                return False, "AP mode started but verification failed"

        except Exception as e:
            logger.error(f"Error starting AP mode with nmcli: {e}")
            self._remove_nm_dnsmasq_captive_conf()
            self._show_led_message("Setup mode error", duration=5)
            return False, str(e)
    
    def _get_ap_status_nmcli(self) -> Dict:
        """
        Get AP status using nmcli (for hotspot mode).

        Returns:
            Dict with AP status info including active state, SSID, IP, and interface
        """
        try:
            # Check if hotspot connection is active
            result = subprocess.run(
                ["nmcli", "-t", "-f", "NAME,TYPE,DEVICE", "connection", "show", "--active"],
                capture_output=True,
                text=True,
                timeout=5
            )

            for line in result.stdout.strip().split('\n'):
                parts = line.split(':')
                if len(parts) < 2:
                    continue
                conn_name = parts[0].strip()
                conn_type = parts[1].strip().lower()
                # Match our known AP profile name OR the legacy nmcli hotspot type
                if conn_name == "LEDMatrix-Setup-AP" or 'hotspot' in conn_type:
                    # Get actual IP address (may be 192.168.4.1 or 10.42.0.1 depending on config)
                    ip = '192.168.4.1'
                    interface = parts[2] if len(parts) > 2 else self._wifi_interface
                    try:
                        ip_result = subprocess.run(
                            ["nmcli", "-t", "-f", "IP4.ADDRESS", "device", "show", interface],
                            capture_output=True,
                            text=True,
                            timeout=5
                        )
                        if ip_result.returncode == 0:
                            for ip_line in ip_result.stdout.strip().split('\n'):
                                if '/' in ip_line:
                                    ip = ip_line.split('/')[0].split(':')[-1].strip()
                                    break
                    except (subprocess.TimeoutExpired, subprocess.SubprocessError):
                        pass

                    return {
                        'active': True,
                        'ssid': self.config.get("ap_ssid", DEFAULT_AP_SSID),
                        'ip': ip,
                        'interface': interface
                    }

            return {'active': False}

        except (subprocess.TimeoutExpired, subprocess.SubprocessError, OSError) as e:
            logger.error(f"Error getting AP status with nmcli: {e}")
            return {'active': False}
    
    def disable_ap_mode(self) -> Tuple[bool, str]:
        """
        Disable access point mode
        
        Returns:
            Tuple of (success, message)
        """
        try:
            if not self._is_ap_mode_active():
                return True, "AP mode not active"
            
            # Check which AP mode is active and disable accordingly
            # First check if hostapd is running (captive portal mode)
            hostapd_active = False
            try:
                result = subprocess.run(
                    ["systemctl", "is-active", HOSTAPD_SERVICE],
                    capture_output=True,
                    text=True,
                    timeout=2
                )
                hostapd_active = result.stdout.strip() == "active"
            except (subprocess.TimeoutExpired, subprocess.SubprocessError, OSError):
                pass
            
            # Stop services
            try:
                if hostapd_active:
                    # Disable hostapd/dnsmasq mode (captive portal)
                    subprocess.run(
                        ["sudo", "systemctl", "stop", HOSTAPD_SERVICE],
                        capture_output=True,
                        timeout=10
                    )
                    subprocess.run(
                        ["sudo", "systemctl", "stop", DNSMASQ_SERVICE],
                        capture_output=True,
                        timeout=10
                    )
                else:
                    # Disable nmcli hotspot mode (fallback)
                    for conn_name in ["LEDMatrix-Setup-AP", "Hotspot", "TickerSetup-AP"]:
                        subprocess.run(
                            ["nmcli", "connection", "down", conn_name],
                            capture_output=True,
                            timeout=10
                        )
                        subprocess.run(
                            ["nmcli", "connection", "delete", conn_name],
                            capture_output=True,
                            timeout=10
                        )
                
                # Remove the drop-in captive portal config (only for hostapd mode)
                if hostapd_active and DNSMASQ_CONFIG_PATH.exists():
                    try:
                        subprocess.run(
                            ["sudo", "rm", "-f", str(DNSMASQ_CONFIG_PATH)],
                            capture_output=True, timeout=5
                        )
                        logger.info(f"Removed captive portal dnsmasq config: {DNSMASQ_CONFIG_PATH}")
                    except Exception as e:
                        logger.warning(f"Could not remove dnsmasq drop-in config: {e}")
                
                # Remove iptables redirect rules and restore ip_forward state (hostapd mode only)
                if hostapd_active:
                    self._teardown_iptables_redirect()

                    # Clean up WiFi interface IP configuration
                    subprocess.run(
                        ["sudo", "ip", "addr", "del", "192.168.4.1/24", "dev", self._wifi_interface],
                        capture_output=True,
                        timeout=10
                    )
                    
                    # Only restart NetworkManager if hostapd was active (needed for hostapd/dnsmasq cleanup)
                    # Before restarting, ensure we have connectivity safety (Ethernet or WiFi enabled)
                    connectivity_safe = self._has_connectivity_safety()
                    
                    if not connectivity_safe:
                        # Ensure WiFi radio is enabled before restart to maintain connectivity option
                        logger.warning("No connectivity safety detected (no Ethernet, WiFi may be disabled), ensuring WiFi radio enabled before restart")
                        self._ensure_wifi_radio_enabled()
                    
                    logger.info("Restarting NetworkManager to restore normal WiFi operation after hostapd cleanup")
                    subprocess.run(
                        ["sudo", "systemctl", "restart", "NetworkManager"],
                        capture_output=True,
                        timeout=15
                    )
                    # Give NetworkManager time to restart
                    time.sleep(2)
                    
                    # Explicitly ensure WiFi radio is enabled after restart (with retries for safety)
                    wifi_enabled = self._ensure_wifi_radio_enabled(max_retries=5)
                    if not wifi_enabled:
                        logger.warning("WiFi radio may be disabled after NetworkManager restart - this could cause lockout if Ethernet not connected")
                        # Try one more time with rfkill as last resort
                        try:
                            subprocess.run(
                                ["sudo", "rfkill", "unblock", "wifi"],
                                capture_output=True,
                                timeout=5
                            )
                            time.sleep(1)
                            logger.info("Attempted final WiFi radio unblock via rfkill")
                        except Exception as e:
                            logger.error(f"Final WiFi radio unblock attempt failed: {e}")
                else:
                    # nmcli AP mode — NM's ipv4.method=shared manages ip_forward automatically,
                    # so we only need to remove the iptables redirect rules we added.
                    logger.info("Skipping NetworkManager restart (nmcli AP mode, restart not needed)")
                    self._teardown_iptables_redirect()
                    self._remove_nm_dnsmasq_captive_conf()
                    # Ensure WiFi radio is enabled after nmcli operations
                    wifi_enabled = self._ensure_wifi_radio_enabled(max_retries=3)
                    if not wifi_enabled:
                        logger.warning("WiFi radio may be disabled after nmcli AP cleanup")

                self._ap_enabled_at = None
                logger.info("AP mode disabled successfully")
                return True, "AP mode disabled"
            except Exception as e:
                logger.error(f"Error stopping AP services: {e}")
                return False, str(e)
        except Exception as e:
            logger.error(f"Error disabling AP mode: {e}")
            return False, str(e)
    
    def _create_hostapd_config(self):
        """Create hostapd configuration file"""
        try:
            config_dir = HOSTAPD_CONFIG_PATH.parent
            config_dir.mkdir(parents=True, exist_ok=True)

            # Use validated values — strips invalid chars and ensures channel is an int.
            # Also strip newlines from SSID to prevent config-file injection.
            ap_ssid, ap_channel = self._validate_ap_config()
            ap_ssid = ap_ssid.replace('\n', '').replace('\r', '')

            # Open network configuration (no password) for easy setup access
            config_content = f"""interface={self._wifi_interface}
driver=nl80211
ssid={ap_ssid}
hw_mode=g
channel={ap_channel}
wmm_enabled=0
macaddr_acl=0
auth_algs=1
ignore_broadcast_ssid=0
# Open network - no WPA/WPA2 encryption
"""

            # Write config (requires sudo)
            with open("/tmp/hostapd.conf", 'w') as f:
                f.write(config_content)

            # Copy to final location with sudo
            subprocess.run(
                ["sudo", "cp", "/tmp/hostapd.conf", str(HOSTAPD_CONFIG_PATH)],
                timeout=10
            )

            logger.info(f"Created hostapd config at {HOSTAPD_CONFIG_PATH} for {self._wifi_interface}")
        except (OSError, subprocess.TimeoutExpired, subprocess.SubprocessError) as e:
            logger.error(f"Error creating hostapd config: {e}")
            raise

    def _check_dnsmasq_conflict(self) -> Tuple[bool, str]:
        """
        Check if dnsmasq is already in use for other purposes (e.g., Pi-hole).

        Returns:
            Tuple of (conflict_detected, description)
        """
        try:
            # Check if dnsmasq service is active
            result = subprocess.run(
                ["systemctl", "is-active", "dnsmasq"],
                capture_output=True,
                text=True,
                timeout=5
            )
            if result.stdout.strip() == "active":
                # Check if it's configured for something other than our AP
                if DNSMASQ_CONFIG_PATH.exists():
                    try:
                        content = DNSMASQ_CONFIG_PATH.read_text()
                        # Check for Pi-hole or other common dnsmasq uses
                        if 'pihole' in content.lower() or 'pi-hole' in content.lower():
                            return True, "Pi-hole detected - dnsmasq is in use"
                        if 'server=' in content and self._wifi_interface not in content:
                            return True, "dnsmasq appears to be configured for DNS forwarding"
                    except (OSError, PermissionError):
                        pass

            return False, ""
        except (subprocess.TimeoutExpired, subprocess.SubprocessError):
            return False, ""

    def _create_dnsmasq_config(self):
        """
        Create dnsmasq drop-in configuration for captive portal DNS redirection.

        Writes to /etc/dnsmasq.d/ledmatrix-captive.conf so we don't overwrite
        the main /etc/dnsmasq.conf (preserves Pi-hole, etc.).
        """
        try:
            # Using a drop-in file in /etc/dnsmasq.d/ to avoid overwriting the
            # main /etc/dnsmasq.conf (which may belong to Pi-hole or other services).
            config_content = f"""interface={self._wifi_interface}
dhcp-range=192.168.4.2,192.168.4.20,255.255.255.0,24h

# Captive portal: Redirect all DNS queries to Pi
address=/#/192.168.4.1

# Captive portal detection endpoints
address=/captive.apple.com/192.168.4.1
address=/connectivitycheck.gstatic.com/192.168.4.1
address=/www.msftconnecttest.com/192.168.4.1
address=/detectportal.firefox.com/192.168.4.1
"""

            # Write config (requires sudo)
            with open("/tmp/dnsmasq.conf", 'w') as f:
                f.write(config_content)

            # Copy to final location with sudo
            subprocess.run(
                ["sudo", "cp", "/tmp/dnsmasq.conf", str(DNSMASQ_CONFIG_PATH)],
                timeout=10
            )

            logger.info(f"Created dnsmasq config at {DNSMASQ_CONFIG_PATH} for {self._wifi_interface}")
        except (OSError, subprocess.TimeoutExpired, subprocess.SubprocessError) as e:
            logger.error(f"Error creating dnsmasq config: {e}")
            raise
    
    def check_and_manage_ap_mode(self) -> bool:
        """
        Check WiFi and Ethernet connection status and enable/disable AP mode accordingly.
        Only auto-enables AP mode if:
        - auto_enable_ap_mode is enabled in config AND
        - WiFi is NOT connected AND
        - Ethernet is NOT connected AND
        - Multiple consecutive disconnected checks (grace period to avoid false positives)
        
        Always auto-disables AP mode when WiFi or Ethernet connects.
        
        This should be called periodically by a background service.
        
        Returns:
            True if AP mode state changed, False otherwise
        """
        try:
            # Get status with retry for more reliable detection
            status = self._get_wifi_status_with_retry()
            ethernet_connected = self._is_ethernet_connected()
            ap_active = self._is_ap_mode_active()
            auto_enable = self.config.get("auto_enable_ap_mode", True)  # Default: True (safe due to grace period)
            
            # Log current state for debugging
            logger.debug(f"WiFi status: connected={status.connected}, SSID={status.ssid}, "
                        f"Ethernet={ethernet_connected}, AP_active={ap_active}, "
                        f"auto_enable={auto_enable}, disconnected_checks={self._disconnected_checks}")
            
            # Determine if we should have AP mode active.
            # AP-enable uses only the nmcli association state (fast, no network calls).
            # This keeps the same reliable behaviour as before: momentary packet loss
            # while on working WiFi does NOT trigger AP mode.  The internet-reachability
            # check is performed separately in the daemon watchdog for NM recovery.
            is_disconnected = not status.connected and not ethernet_connected

            if is_disconnected:
                # Increment disconnected check counter
                self._disconnected_checks += 1
                logger.debug(f"Network disconnected (check {self._disconnected_checks}/{self._disconnected_checks_required})")
            else:
                # Reset counter if we're associated
                if self._disconnected_checks > 0:
                    logger.debug("Network connected, resetting disconnected check counter")
                self._disconnected_checks = 0
            
            # Only enable AP if we've had enough consecutive disconnected checks
            should_have_ap = (auto_enable and 
                            is_disconnected and 
                            self._disconnected_checks >= self._disconnected_checks_required)
            
            if should_have_ap and not ap_active:
                # Pre-cache a WiFi scan so the captive portal can show networks
                try:
                    logger.info("Running pre-AP WiFi scan for captive portal cache...")
                    networks, _cached = self.scan_networks(allow_cached=False)
                    if networks:
                        self._save_cached_scan(networks)
                        logger.info(f"Cached {len(networks)} networks for captive portal")
                except Exception as scan_err:
                    logger.debug(f"Pre-AP scan failed (non-critical): {scan_err}")

                logger.info(f"Enabling AP mode after {self._disconnected_checks} consecutive disconnected checks")
                success, message = self.enable_ap_mode()
                if success:
                    logger.info("Auto-enabled AP mode (no WiFi or Ethernet connection after grace period)")
                    self._disconnected_checks = 0  # Reset counter after enabling
                    return True
                else:
                    logger.warning(f"Failed to enable AP mode: {message}")
            elif not should_have_ap and ap_active:
                # Should not have AP but do - disable AP mode
                # Always disable if WiFi or Ethernet connects, regardless of auto_enable setting
                if status.connected or ethernet_connected:
                    success, message = self.disable_ap_mode()
                    if success:
                        if status.connected:
                            logger.info("Auto-disabled AP mode (WiFi connected)")
                        elif ethernet_connected:
                            logger.info("Auto-disabled AP mode (Ethernet connected)")
                        self._disconnected_checks = 0  # Reset counter
                        return True
                    else:
                        logger.warning(f"Failed to auto-disable AP mode: {message}")
                elif not auto_enable:
                    # AP is active but auto_enable is disabled - this means it was manually enabled
                    # Don't disable it automatically, let it stay active
                    logger.debug("AP mode is active (manually enabled), keeping active")

            # Idle-timeout check: disable AP if no client has connected within the window.
            # Only applies when AP is active and we haven't just decided to enable/disable it.
            if ap_active and self._ap_enabled_at is not None:
                try:
                    idle_timeout_min = max(1, min(1440, int(self.config.get("ap_idle_timeout_minutes", 15))))
                except (TypeError, ValueError):
                    idle_timeout_min = 15
                elapsed = time.time() - self._ap_enabled_at
                if elapsed > idle_timeout_min * 60 and not self._has_ap_clients():
                    logger.info(
                        f"AP idle timeout ({idle_timeout_min} min, no clients) — disabling AP"
                    )
                    success, message = self.disable_ap_mode()
                    if success:
                        return True
                    else:
                        logger.warning(f"Failed to disable AP on idle timeout: {message}")
            
            return False
        except Exception as e:
            logger.error(f"Error checking AP mode: {e}", exc_info=True)
            return False
    
    def _get_wifi_status_with_retry(self, max_retries=2) -> WiFiStatus:
        """
        Get WiFi status with retry logic to avoid false negatives.
        
        Args:
            max_retries: Number of retry attempts if first check fails
            
        Returns:
            WiFiStatus object
        """
        for attempt in range(max_retries + 1):
            status = self.get_wifi_status()
            # If we get a connected status, trust it immediately
            if status.connected:
                return status
            
            # If disconnected, wait a bit and retry (in case of transient issues)
            if attempt < max_retries:
                time.sleep(1)
                logger.debug(f"WiFi status check attempt {attempt + 1}/{max_retries + 1}: disconnected, retrying...")
        
        # Return the last status (disconnected)
        return status