import { useState, useEffect } from 'react';
import { api } from '../utils/api.js';
import { useToast } from '../contexts/ToastContext.jsx';

// ── Helpers ───────────────────────────────────────────────────────────────────

const APP_TYPES = {
  'JAMA-Chat':  { label: 'JAMA-Chat',  desc: 'Chat only. No Branding, Group Manager or Schedule Manager.' },
  'JAMA-Brand': { label: 'JAMA-Brand', desc: 'Chat and Branding.' },
  'JAMA-Team':  { label: 'JAMA-Team',  desc: 'Chat, Branding, Group Manager and Schedule Manager.' },
};

// ── Team Management Tab ───────────────────────────────────────────────────────
function TeamManagementTab() {
  const toast = useToast();
  const [userGroups, setUserGroups] = useState([]);
  const [toolManagers, setToolManagers] = useState([]);
  const [saving, setSaving] = useState(false);

  useEffect(() => {
    api.getUserGroups().then(({ groups }) => setUserGroups(groups || [])).catch(() => {});
    api.getSettings().then(({ settings }) => {
      // Read from unified key, fall back to legacy key
      setToolManagers(JSON.parse(settings.team_tool_managers || settings.team_group_managers || '[]'));
    }).catch(() => {});
  }, []);

  const toggle = (id) => {
    setToolManagers(prev => prev.includes(id) ? prev.filter(x => x !== id) : [...prev, id]);
  };

  const handleSave = async () => {
    setSaving(true);
    try {
      await api.updateTeamSettings({ toolManagers });
      toast('Team settings saved', 'success');
      window.dispatchEvent(new Event('jama:settings-changed'));
    } catch (e) { toast(e.message, 'error'); }
    finally { setSaving(false); }
  };

  return (
    <div>
      <div className="settings-section-label">Tool Managers</div>
      <p style={{ fontSize: 12, color: 'var(--text-tertiary)', marginBottom: 12 }}>
        Members of selected groups can access Group Manager, Schedule Manager, and User Manager. Admin users always have access to all three tools.
      </p>
      {userGroups.length === 0 ? (
        <p style={{ fontSize: 13, color: 'var(--text-tertiary)', marginBottom: 16 }}>No user groups created yet. Create groups in the Group Manager first.</p>
      ) : (
        <div style={{ border: '1px solid var(--border)', borderRadius: 'var(--radius)', overflow: 'hidden', marginBottom: 16 }}>
          {userGroups.map(g => (
            <label key={g.id} style={{ display: 'flex', alignItems: 'center', gap: 10, padding: '9px 14px', borderBottom: '1px solid var(--border)', cursor: 'pointer' }}>
              <input type="checkbox" checked={toolManagers.includes(g.id)} onChange={() => toggle(g.id)}
                style={{ accentColor: 'var(--primary)', width: 15, height: 15 }} />
              <div style={{ width: 24, height: 24, borderRadius: 5, background: 'var(--primary)', display: 'flex', alignItems: 'center', justifyContent: 'center', color: 'white', fontSize: 9, fontWeight: 700, flexShrink: 0 }}>UG</div>
              <span style={{ flex: 1, fontSize: 14 }}>{g.name}</span>
              <span style={{ fontSize: 12, color: 'var(--text-tertiary)' }}>{g.member_count} member{g.member_count !== 1 ? 's' : ''}</span>
            </label>
          ))}
        </div>
      )}
      {toolManagers.length === 0 && (
        <p style={{ fontSize: 12, color: 'var(--text-tertiary)', marginBottom: 16 }}>No groups selected — tools are admin-only.</p>
      )}
      <button className="btn btn-primary" onClick={handleSave} disabled={saving}>
        {saving ? 'Saving…' : 'Save'}
      </button>
    </div>
  );
}

// ── Registration Tab ──────────────────────────────────────────────────────────
function RegistrationTab({ onFeaturesChanged }) {
  const toast = useToast();
  const [settings, setSettings] = useState({});
  const [regCode, setRegCode] = useState('');
  const [regLoading, setRegLoading] = useState(false);
  const [copied, setCopied] = useState(false);

  useEffect(() => {
    api.getSettings().then(({ settings }) => setSettings(settings)).catch(() => {});
  }, []);

  const appType = settings.app_type || 'JAMA-Chat';
  const activeCode = settings.registration_code || '';
  const adminEmail = settings.admin_email || '—';

  // Placeholder serial number derived from hostname
  const serialNumber = btoa(window.location.hostname).replace(/[^A-Z0-9]/gi, '').toUpperCase().slice(0, 16).padEnd(16, '0');

  const handleCopySerial = async () => {
    await navigator.clipboard.writeText(serialNumber).catch(() => {});
    setCopied(true);
    setTimeout(() => setCopied(false), 2000);
  };

  const handleRegister = async () => {
    if (!regCode.trim()) return toast('Enter a registration code', 'error');
    setRegLoading(true);
    try {
      const { features: f } = await api.registerCode(regCode.trim());
      setRegCode('');
      const fresh = await api.getSettings();
      setSettings(fresh.settings);
      toast('Registration applied successfully.', 'success');
      window.dispatchEvent(new Event('jama:settings-changed'));
      onFeaturesChanged && onFeaturesChanged(f);
    } catch (e) { toast(e.message || 'Invalid registration code', 'error'); }
    finally { setRegLoading(false); }
  };

  const handleClear = async () => {
    try {
      const { features: f } = await api.registerCode('');
      const fresh = await api.getSettings();
      setSettings(fresh.settings);
      toast('Registration cleared.', 'success');
      window.dispatchEvent(new Event('jama:settings-changed'));
      onFeaturesChanged && onFeaturesChanged(f);
    } catch (e) { toast(e.message, 'error'); }
  };

  const typeInfo = APP_TYPES[appType] || APP_TYPES['JAMA-Chat'];
  const siteUrl = window.location.origin;

  return (
    <div>
      {/* Info box */}
      <div style={{ background: 'var(--surface-variant)', border: '1px solid var(--border)', borderRadius: 'var(--radius)', padding: '14px 16px', marginBottom: 24 }}>
        <p style={{ fontSize: 13, fontWeight: 600, marginBottom: 6 }}>
          Registration {activeCode ? 'is' : 'required:'}
        </p>
        <p style={{ fontSize: 13, color: 'var(--text-secondary)', lineHeight: 1.6 }}>
          JAMA {activeCode ? 'is' : 'will be'} registered to:<br />
          <strong>Type:</strong> {typeInfo.label}<br />
          <strong>URL:</strong> {siteUrl}
        </p>
      </div>

      {/* Type */}
      <div style={{ marginBottom: 16 }}>
        <div className="settings-section-label">Application Type</div>
        <div style={{ display: 'flex', alignItems: 'center', gap: 10, marginTop: 6 }}>
          <div style={{ padding: '7px 14px', borderRadius: 'var(--radius)', border: '1px solid var(--border)', background: 'var(--surface-variant)', fontSize: 14, fontWeight: 600, color: 'var(--primary)' }}>
            {typeInfo.label}
          </div>
          <span style={{ fontSize: 12, color: 'var(--text-tertiary)' }}>{typeInfo.desc}</span>
        </div>
      </div>

      {/* Serial Number */}
      <div style={{ marginBottom: 16 }}>
        <div className="settings-section-label">Serial Number</div>
        <div style={{ display: 'flex', alignItems: 'center', gap: 8, marginTop: 6 }}>
          <input className="input flex-1" value={serialNumber} readOnly style={{ fontFamily: 'monospace', letterSpacing: 1 }} />
          <button className="btn btn-secondary btn-sm" onClick={handleCopySerial} style={{ flexShrink: 0 }}>
            {copied ? '✓ Copied' : (
              <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2"><rect x="9" y="9" width="13" height="13" rx="2" ry="2"/><path d="M5 15H4a2 2 0 0 1-2-2V4a2 2 0 0 1 2-2h9a2 2 0 0 1 2 2v1"/></svg>
            )}
          </button>
        </div>
      </div>

      {/* Registration Code */}
      <div style={{ marginBottom: 20 }}>
        <div className="settings-section-label">Registration Code</div>
        <div style={{ display: 'flex', gap: 8, marginTop: 6 }}>
          <input className="input flex-1" placeholder="Enter registration code" value={regCode}
            onChange={e => setRegCode(e.target.value)} onKeyDown={e => e.key === 'Enter' && handleRegister()} />
          <button className="btn btn-primary btn-sm" onClick={handleRegister} disabled={regLoading}>
            {regLoading ? '…' : 'Register'}
          </button>
        </div>
      </div>

      {activeCode && (
        <div style={{ display: 'flex', alignItems: 'center', gap: 10 }}>
          <span style={{ fontSize: 13, color: 'var(--success)', display: 'flex', alignItems: 'center', gap: 5 }}>
            <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2.5"><polyline points="20 6 9 17 4 12"/></svg>
            Registered — {typeInfo.label}
          </span>
          <button className="btn btn-secondary btn-sm" onClick={handleClear}>Clear</button>
        </div>
      )}

      <p style={{ fontSize: 12, color: 'var(--text-tertiary)', marginTop: 16, lineHeight: 1.5 }}>
        Registration codes unlock application features. Contact your JAMA provider for a code.<br />
        <strong>JAMA-Brand</strong> — unlocks Branding.&nbsp;
        <strong>JAMA-Team</strong> — unlocks Branding, Group Manager and Schedule Manager.
      </p>
    </div>
  );
}

// ── Web Push Tab ──────────────────────────────────────────────────────────────
function WebPushTab() {
  const toast = useToast();
  const [vapidPublic, setVapidPublic] = useState('');
  const [loading, setLoading] = useState(true);
  const [generating, setGenerating] = useState(false);
  const [showRegenWarning, setShowRegenWarning] = useState(false);

  useEffect(() => {
    api.getSettings().then(({ settings }) => {
      setVapidPublic(settings.vapid_public || '');
      setLoading(false);
    }).catch(() => setLoading(false));
  }, []);

  const doGenerate = async () => {
    setGenerating(true);
    setShowRegenWarning(false);
    try {
      const { publicKey } = await api.generateVapidKeys();
      setVapidPublic(publicKey);
      toast('VAPID keys generated. Push notifications are now active.', 'success');
    } catch (e) {
      toast(e.message || 'Failed to generate keys', 'error');
    } finally { setGenerating(false); }
  };

  if (loading) return <p style={{ fontSize: 13, color: 'var(--text-secondary)' }}>Loading…</p>;

  return (
    <div>
      <div className="settings-section-label" style={{ marginBottom: 12 }}>Web Push Notifications (VAPID)</div>

      {vapidPublic ? (
        <div style={{ marginBottom: 16 }}>
          <div style={{ background: 'var(--surface-variant)', border: '1px solid var(--border)', borderRadius: 'var(--radius)', padding: '10px 12px', marginBottom: 10 }}>
            <div style={{ fontSize: 11, color: 'var(--text-tertiary)', marginBottom: 4, textTransform: 'uppercase', letterSpacing: '0.5px' }}>Public Key</div>
            <code style={{ fontSize: 11, color: 'var(--text-primary)', wordBreak: 'break-all', lineHeight: 1.5, display: 'block' }}>{vapidPublic}</code>
          </div>
          <span style={{ fontSize: 13, color: 'var(--success)', display: 'flex', alignItems: 'center', gap: 5 }}>
            <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2.5"><polyline points="20 6 9 17 4 12"/></svg>
            Push notifications active
          </span>
        </div>
      ) : (
        <p style={{ fontSize: 13, color: 'var(--text-secondary)', marginBottom: 12 }}>
          No VAPID keys found. Generate keys to enable Web Push notifications.
        </p>
      )}

      {showRegenWarning && (
        <div style={{ background: '#fce8e6', border: '1px solid #f5c6c2', borderRadius: 'var(--radius)', padding: '14px 16px', marginBottom: 16 }}>
          <p style={{ fontSize: 13, fontWeight: 600, color: 'var(--error)', marginBottom: 8 }}>⚠️ Regenerate VAPID keys?</p>
          <p style={{ fontSize: 13, color: '#5c2c28', marginBottom: 12, lineHeight: 1.5 }}>
            Generating new keys will <strong>invalidate all existing push subscriptions</strong>. Users will need to re-enable notifications.
          </p>
          <div style={{ display: 'flex', gap: 8 }}>
            <button className="btn btn-sm" style={{ background: 'var(--error)', color: 'white' }} onClick={doGenerate} disabled={generating}>{generating ? 'Generating…' : 'Yes, regenerate keys'}</button>
            <button className="btn btn-secondary btn-sm" onClick={() => setShowRegenWarning(false)}>Cancel</button>
          </div>
        </div>
      )}
      {!showRegenWarning && (
        <button className="btn btn-primary btn-sm" onClick={() => vapidPublic ? setShowRegenWarning(true) : doGenerate()} disabled={generating}>
          {generating ? 'Generating…' : vapidPublic ? 'Regenerate Keys' : 'Generate Keys'}
        </button>
      )}
      <p style={{ fontSize: 12, color: 'var(--text-tertiary)', marginTop: 12, lineHeight: 1.5 }}>
        Requires HTTPS. On iOS, the app must be installed to the home screen first.
      </p>
    </div>
  );
}

// ── Main modal ────────────────────────────────────────────────────────────────
export default function SettingsModal({ onClose, onFeaturesChanged }) {
  const [tab, setTab] = useState('registration');
  const [appType, setAppType] = useState('JAMA-Chat');

  useEffect(() => {
    api.getSettings().then(({ settings }) => {
      setAppType(settings.app_type || 'JAMA-Chat');
    }).catch(() => {});
    const handler = () => api.getSettings().then(({ settings }) => setAppType(settings.app_type || 'JAMA-Chat')).catch(() => {});
    window.addEventListener('jama:settings-changed', handler);
    return () => window.removeEventListener('jama:settings-changed', handler);
  }, []);

  const isTeam = appType === 'JAMA-Team';

  const tabs = [
    isTeam && { id: 'team', label: 'Team Management' },
    { id: 'registration', label: 'Registration' },
    { id: 'webpush', label: 'Web Push' },
  ].filter(Boolean);

  return (
    <div className="modal-overlay" onClick={e => e.target === e.currentTarget && onClose()}>
      <div className="modal" style={{ maxWidth: 520 }}>
        <div className="flex items-center justify-between" style={{ marginBottom: 20 }}>
          <h2 className="modal-title" style={{ margin: 0 }}>Settings</h2>
          <button className="btn-icon" onClick={onClose}>
            <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2"><line x1="18" y1="6" x2="6" y2="18"/><line x1="6" y1="6" x2="18" y2="18"/></svg>
          </button>
        </div>

        {/* Tab buttons */}
        <div className="flex gap-2" style={{ marginBottom: 24 }}>
          {tabs.map(t => (
            <button key={t.id} className={`btn btn-sm ${tab === t.id ? 'btn-primary' : 'btn-secondary'}`} onClick={() => setTab(t.id)}>
              {t.label}
            </button>
          ))}
        </div>

        {tab === 'team'         && <TeamManagementTab />}
        {tab === 'registration' && <RegistrationTab onFeaturesChanged={onFeaturesChanged} />}
        {tab === 'webpush'      && <WebPushTab />}
      </div>
    </div>
  );
}