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LEDMatrix/web_interface/blueprints/api_v3/fonts.py
T
ChuckandClaude Opus 5.5 f3894916a9 feat(web): show which plugins use each font; warn before deleting one (#619)
* feat(web): show which plugins use each font, warn before deleting one

The Fonts tab lists font files from the web process's own scan, and the
plugins that register fonts run in the display process, so the tab had no
way to say whether a font was in use before deleting it.

The display service now publishes {catalog key: [plugin ids]} to the
shared cache (font_usage_snapshot, src/font_usage.py), built from the
loaded plugins' FontManager.register_manager_font() registrations. A
daemon thread checks every 10 s and writes only when the usage changed
(plus a daily refresh so cache cleanup cannot expire it); it never raises.
Families, aliases (press_start, four_by_six, ...) and paths are resolved
through FontManager's catalog to the file stem the Fonts tab keys rows by;
fonts outside assets/fonts are left out. Unloading a plugin drops its
registrations (new FontManager.forget_manager_fonts).

GET /api/v3/fonts/catalog merges used_by into each row per request (the
5-minute scan cache is copied, never edited): a list of plugin ids, or
null when the display service has not reported. The tab shows a Used by
column ("unknown" / "-" / ids, rendered as text) and deleting an in-use
font names the plugins in the confirmation, from a fresh read. The server
still refuses only system fonts. Catalog fetches bypass the browser's
5-second API cache, which otherwise served the pre-delete list.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix: call forget_manager_fonts through a hasattr check pylint can follow

getattr(..., None) then callable() is fine at runtime, but pylint's E1102
("not callable") can't see through it, and Codacy fails the check on it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
2026-09-23 16:50:42 -04:00

491 lines
21 KiB
Python

"""Font catalogue, upload, preview and deletion.
Routes decorate the shared `api_v3` Blueprint from ._common, so their
endpoint names are unchanged by living here.
"""
from web_interface.blueprints.api_v3 import (
PROJECT_ROOT, Path, Response, SYSTEM_FONTS, api_v3, describe_exception,
jsonify, logger, os, re, request, validate_file_upload,
)
def _catalog_response(catalog):
"""The catalog response, with each font's ``used_by`` merged in now.
Usage comes from the display service (src/font_usage.py) and changes
independently of the files, so it is read per request and never stored
in the 5-minute ``fonts_catalog`` cache: entries are copied, not edited.
``used_by`` is a list of plugin ids, empty when no loaded plugin
registered the font, and None when the display service has not reported.
"""
from src.font_usage import read_font_usage
from web_interface.blueprints.api_v3.display import _cache_manager
try:
usage = read_font_usage(_cache_manager())
except Exception:
logger.debug("[FontCatalog] Could not read font usage", exc_info=True)
usage = None
used_by = {}
if usage is not None:
# The snapshot keys fonts by file stem, as the catalog does; match
# case-insensitively too, since FontManager lower-cases families.
by_lower = {key.lower(): key for key in catalog}
for key, plugin_ids in usage['fonts'].items():
row = key if key in catalog else by_lower.get(key.lower())
if row is not None:
used_by.setdefault(row, set()).update(plugin_ids)
merged = {
key: dict(info, used_by=(sorted(used_by.get(key, ())) if usage is not None else None))
for key, info in catalog.items()
}
return jsonify({'status': 'success', 'data': {
'catalog': merged,
'font_usage': {
'available': usage is not None,
'generated_at': usage['generated_at'] if usage is not None else None,
},
}})
@api_v3.route('/fonts/catalog', methods=['GET'])
def get_fonts_catalog():
"""Get fonts catalog"""
try:
# Check cache first (5 minute TTL)
try:
from web_interface.cache import get_cached, set_cached
cached_result = get_cached('fonts_catalog', ttl_seconds=300)
if cached_result is not None:
return _catalog_response(cached_result)
except ImportError:
# Cache not available, continue without caching
get_cached = None
set_cached = None
# Try to import freetype, but continue without it if unavailable
try:
import freetype
freetype_available = True
except ImportError:
freetype_available = False
# Scan assets/fonts directory for actual font files
fonts_dir = PROJECT_ROOT / "assets" / "fonts"
catalog = {}
if fonts_dir.exists() and fonts_dir.is_dir():
for filename in os.listdir(fonts_dir):
if filename.endswith(('.ttf', '.otf', '.bdf')):
filepath = fonts_dir / filename
# Generate family name from filename (without extension)
family_name = os.path.splitext(filename)[0]
# Try to get font metadata using freetype (for TTF/OTF)
metadata = {}
if filename.endswith(('.ttf', '.otf')) and freetype_available:
try:
face = freetype.Face(str(filepath))
if face.valid:
# Get font family name from font file
family_name_from_font = face.family_name.decode('utf-8') if face.family_name else family_name
metadata = {
'family': family_name_from_font,
'style': face.style_name.decode('utf-8') if face.style_name else 'Regular',
'num_glyphs': face.num_glyphs,
'units_per_em': face.units_per_EM
}
# Use font's family name if available
if family_name_from_font:
family_name = family_name_from_font
except Exception:
# If freetype fails, use filename-based name
pass
# Store relative path from project root
relative_path = str(filepath.relative_to(PROJECT_ROOT))
font_type = 'ttf' if filename.endswith('.ttf') else 'otf' if filename.endswith('.otf') else 'bdf'
# Generate human-readable display name from family_name
display_name = family_name.replace('-', ' ').replace('_', ' ')
# Add space before capital letters for camelCase names
display_name = re.sub(r'([a-z])([A-Z])', r'\1 \2', display_name)
# Add space before numbers that follow letters
display_name = re.sub(r'([a-zA-Z])(\d)', r'\1 \2', display_name)
# Clean up multiple spaces
display_name = ' '.join(display_name.split())
# Use filename (without extension) as unique key to avoid collisions
# when multiple files share the same family_name from font metadata
catalog_key = os.path.splitext(filename)[0]
# Check if this is a system font (cannot be deleted)
is_system = catalog_key.lower() in SYSTEM_FONTS
# BDF files are fixed-size bitmap strikes: FreeType
# accepts only the pixel size baked into the file. The
# UI needs to know that before offering a size control,
# or it offers a number that cannot take effect.
native_size = None
if font_type == 'bdf':
try:
from src.element_style import _read_bdf_native_size
native_size = _read_bdf_native_size(str(filepath))
except Exception as e:
logger.debug("Could not read native size for BDF font %s: %s",
filepath, e)
native_size = None
catalog[catalog_key] = {
'filename': filename,
'family_name': family_name,
'display_name': display_name,
'path': relative_path,
'type': font_type,
'is_system': is_system,
'scalable': font_type != 'bdf',
'native_size': native_size,
'metadata': metadata if metadata else None
}
# Cache the result (5 minute TTL) if available
if set_cached:
try:
set_cached('fonts_catalog', catalog, ttl_seconds=300)
except Exception:
logger.error("[FontCatalog] Failed to cache fonts_catalog", exc_info=True)
return _catalog_response(catalog)
except Exception as e:
logger.error("%s failed", request.path, exc_info=True)
return jsonify({'status': 'error',
'message': 'An error occurred; see logs for details',
'details': describe_exception(e)}), 500
@api_v3.route('/fonts/tokens', methods=['GET'])
def get_font_tokens():
"""Get font size tokens"""
try:
# This would integrate with the actual font system
# For now, return sample tokens
tokens = {
'xs': 6,
'sm': 8,
'md': 10,
'lg': 12,
'xl': 14,
'xxl': 16
}
return jsonify({'status': 'success', 'data': {'tokens': tokens}})
except Exception as e:
logger.error('Unhandled exception', exc_info=True)
return jsonify({'status': 'error', 'message': 'An error occurred; see logs for details', 'details': describe_exception(e)}), 500
@api_v3.route('/fonts/upload', methods=['POST'])
def upload_font():
"""Upload font file"""
try:
if 'font_file' not in request.files:
return jsonify({'status': 'error', 'message': 'No font file provided'}), 400
font_file = request.files['font_file']
if font_file.filename == '':
return jsonify({'status': 'error', 'message': 'No file selected'}), 400
# Validate filename. validate_file_upload takes max_size_mb but only
# checks the filename/extension with it -- it never looks at the
# actual upload size, so the size limit below is enforced separately
# before the file is saved (same pattern as the .star upload above).
MAX_FONT_SIZE_MB = 10
is_valid, error_msg = validate_file_upload(
font_file.filename,
max_size_mb=MAX_FONT_SIZE_MB,
allowed_extensions=['.ttf', '.otf', '.bdf']
)
if not is_valid:
return jsonify({'status': 'error', 'message': error_msg}), 400
# Check file size (stated limit is MAX_FONT_SIZE_MB)
font_file.seek(0, 2) # Seek to end
file_size = font_file.tell()
font_file.seek(0) # Reset to beginning
max_font_size_bytes = MAX_FONT_SIZE_MB * 1024 * 1024
if file_size > max_font_size_bytes:
return jsonify({
'status': 'error',
'message': f'File too large (max {MAX_FONT_SIZE_MB}MB, got {file_size / 1024 / 1024:.1f}MB)'
}), 400
font_family = request.form.get('font_family', '')
if not font_family:
return jsonify({'status': 'error', 'message': 'Font file and family name required'}), 400
# Validate font family name
if not font_family.replace('_', '').replace('-', '').isalnum():
return jsonify({'status': 'error', 'message': 'Font family name must contain only letters, numbers, underscores, and hyphens'}), 400
# Save the font file to assets/fonts directory
fonts_dir = PROJECT_ROOT / "assets" / "fonts"
fonts_dir.mkdir(parents=True, exist_ok=True)
# Create filename from family name
original_ext = os.path.splitext(font_file.filename)[1].lower()
safe_filename = f"{font_family}{original_ext}"
filepath = fonts_dir / safe_filename
# Check if file already exists
if filepath.exists():
return jsonify({'status': 'error', 'message': f'Font with name {font_family} already exists'}), 400
# Save the file
font_file.save(str(filepath))
# Clear font catalog cache
try:
from web_interface.cache import delete_cached
delete_cached('fonts_catalog')
except ImportError as e:
logger.warning("[FontUpload] Cache module not available: %s", e)
except Exception:
logger.error("[FontUpload] Failed to clear fonts_catalog cache", exc_info=True)
return jsonify({
'status': 'success',
'message': f'Font {font_family} uploaded successfully',
'font_family': font_family,
'filename': safe_filename,
'path': f'assets/fonts/{safe_filename}'
})
except Exception as e:
logger.error('Unhandled exception', exc_info=True)
return jsonify({'status': 'error', 'message': 'An error occurred; see logs for details', 'details': describe_exception(e)}), 500
@api_v3.route('/fonts/preview', methods=['GET'])
def get_font_preview() -> tuple[Response, int] | Response:
"""Generate a preview image of text rendered with a specific font"""
try:
from PIL import Image, ImageDraw, ImageFont
import io
import base64
# Limits to prevent DoS via large image generation on constrained devices
MAX_TEXT_CHARS = 100
MAX_TEXT_LINES = 3
MAX_DIM = 1024 # Max width or height in pixels
MAX_PIXELS = 500000 # Max total pixels (e.g., ~700x700)
font_filename = request.args.get('font', '')
text = request.args.get('text', 'Sample Text 123')
bg_color = request.args.get('bg', '000000')
fg_color = request.args.get('fg', 'ffffff')
# Validate text length and line count early
if len(text) > MAX_TEXT_CHARS:
return jsonify({'status': 'error', 'message': f'Text exceeds maximum length of {MAX_TEXT_CHARS} characters'}), 400
if text.count('\n') >= MAX_TEXT_LINES:
return jsonify({'status': 'error', 'message': f'Text exceeds maximum of {MAX_TEXT_LINES} lines'}), 400
# Safe integer parsing for size
try:
size = int(request.args.get('size', 12))
except (ValueError, TypeError, OverflowError):
return jsonify({'status': 'error', 'message': 'Invalid font size'}), 400
if not font_filename:
return jsonify({'status': 'error', 'message': 'Font filename required'}), 400
# Validate size
if size < 4 or size > 72:
return jsonify({'status': 'error', 'message': 'Font size must be between 4 and 72'}), 400
# Security: Validate font_filename to prevent path traversal
# Only allow alphanumeric, hyphen, underscore, and dot (for extension)
safe_name = Path(font_filename).name # Strip any directory components
if safe_name != font_filename or '..' in font_filename:
return jsonify({'status': 'error', 'message': 'Invalid font filename'}), 400
# Validate extension
allowed_extensions = ['.ttf', '.otf', '.bdf']
has_valid_ext = any(safe_name.lower().endswith(ext) for ext in allowed_extensions)
name_without_ext = safe_name.rsplit('.', 1)[0] if '.' in safe_name else safe_name
# Find the font file
fonts_dir = PROJECT_ROOT / "assets" / "fonts"
if not fonts_dir.exists():
return jsonify({'status': 'error', 'message': 'Fonts directory not found'}), 404
font_path = fonts_dir / safe_name
if not font_path.exists() and not has_valid_ext:
# Try finding by family name (without extension)
for ext in allowed_extensions:
potential_path = fonts_dir / f"{name_without_ext}{ext}"
if potential_path.exists():
font_path = potential_path
break
# Final security check: ensure path is within fonts_dir
try:
font_path.resolve().relative_to(fonts_dir.resolve())
except ValueError:
return jsonify({'status': 'error', 'message': 'Invalid font path'}), 400
if not font_path.exists():
return jsonify({'status': 'error', 'message': f'Font file not found: {font_filename}'}), 404
# Parse colors
try:
bg_rgb = tuple(int(bg_color[i:i+2], 16) for i in (0, 2, 4))
fg_rgb = tuple(int(fg_color[i:i+2], 16) for i in (0, 2, 4))
except (ValueError, IndexError):
bg_rgb = (0, 0, 0)
fg_rgb = (255, 255, 255)
# Load font
font = None
if str(font_path).endswith('.bdf'):
# BDF fonts require complex per-glyph rendering via freetype
# Return explicit error rather than showing misleading preview with default font
return jsonify({
'status': 'error',
'message': 'BDF font preview not supported. BDF fonts will render correctly on the LED matrix.'
}), 400
else:
# TTF/OTF fonts
try:
font = ImageFont.truetype(str(font_path), size)
except (IOError, OSError) as e:
# IOError/OSError raised for invalid/corrupt font files
logger.warning("[FontPreview] Failed to load font %s: %s", font_path, e)
font = ImageFont.load_default()
# Calculate text size
temp_img = Image.new('RGB', (1, 1))
temp_draw = ImageDraw.Draw(temp_img)
bbox = temp_draw.textbbox((0, 0), text, font=font)
text_width = bbox[2] - bbox[0]
text_height = bbox[3] - bbox[1]
# Create image with padding
padding = 10
img_width = max(text_width + padding * 2, 100)
img_height = max(text_height + padding * 2, 30)
# Validate resulting image size to prevent memory/CPU spikes
if img_width > MAX_DIM or img_height > MAX_DIM:
return jsonify({'status': 'error', 'message': 'Requested image too large'}), 400
if img_width * img_height > MAX_PIXELS:
return jsonify({'status': 'error', 'message': 'Requested image too large'}), 400
img = Image.new('RGB', (img_width, img_height), bg_rgb)
draw = ImageDraw.Draw(img)
# Center text
x = (img_width - text_width) // 2
y = (img_height - text_height) // 2
draw.text((x, y), text, font=font, fill=fg_rgb)
# Convert to base64
buffer = io.BytesIO()
img.save(buffer, format='PNG')
buffer.seek(0)
img_base64 = base64.b64encode(buffer.getvalue()).decode('utf-8')
return jsonify({
'status': 'success',
'data': {
'image': f'data:image/png;base64,{img_base64}',
'width': img_width,
'height': img_height
}
})
except Exception as e:
logger.error('Unhandled exception', exc_info=True)
return jsonify({'status': 'error', 'message': 'An error occurred; see logs for details', 'details': describe_exception(e)}), 500
@api_v3.route('/fonts/<font_family>', methods=['DELETE'])
def delete_font(font_family: str) -> tuple[Response, int] | Response:
"""Delete a user-uploaded font file"""
try:
# Security: Validate font_family to prevent path traversal
# Reject if it contains path separators or ..
if '..' in font_family or '/' in font_family or '\\' in font_family:
return jsonify({'status': 'error', 'message': 'Invalid font family name'}), 400
# Only allow safe characters: alphanumeric, hyphen, underscore, dot
if not re.match(r'^[a-zA-Z0-9_\-\.]+$', font_family):
return jsonify({'status': 'error', 'message': 'Invalid font family name'}), 400
# Check if this is a system font (uses module-level SYSTEM_FONTS frozenset)
if font_family.lower() in SYSTEM_FONTS:
return jsonify({'status': 'error', 'message': 'Cannot delete system fonts'}), 403
# Find and delete the font file
fonts_dir = PROJECT_ROOT / "assets" / "fonts"
# Ensure fonts directory exists
if not fonts_dir.exists() or not fonts_dir.is_dir():
return jsonify({'status': 'error', 'message': 'Fonts directory not found'}), 404
deleted = False
deleted_filename = None
# Only try valid font extensions (no empty string to avoid matching directories)
for ext in ['.ttf', '.otf', '.bdf']:
potential_path = fonts_dir / f"{font_family}{ext}"
# Security: Verify path is within fonts_dir
try:
potential_path.resolve().relative_to(fonts_dir.resolve())
except ValueError:
continue # Path escapes fonts_dir, skip
if potential_path.exists() and potential_path.is_file():
potential_path.unlink()
deleted = True
deleted_filename = f"{font_family}{ext}"
break
if not deleted:
# Try case-insensitive match within fonts directory
font_family_lower = font_family.lower()
for filename in os.listdir(fonts_dir):
# Only consider files with valid font extensions
if not any(filename.lower().endswith(ext) for ext in ['.ttf', '.otf', '.bdf']):
continue
name_without_ext = os.path.splitext(filename)[0]
if name_without_ext.lower() == font_family_lower:
filepath = fonts_dir / filename
# Security: Verify path is within fonts_dir
try:
filepath.resolve().relative_to(fonts_dir.resolve())
except ValueError:
continue # Path escapes fonts_dir, skip
if filepath.is_file():
filepath.unlink()
deleted = True
deleted_filename = filename
break
if not deleted:
return jsonify({'status': 'error', 'message': f'Font not found: {font_family}'}), 404
# Clear font catalog cache
try:
from web_interface.cache import delete_cached
delete_cached('fonts_catalog')
except ImportError as e:
logger.warning("[FontDelete] Cache module not available: %s", e)
except Exception:
logger.error("[FontDelete] Failed to clear fonts_catalog cache", exc_info=True)
return jsonify({
'status': 'success',
'message': f'Font {deleted_filename} deleted successfully'
})
except Exception as e:
logger.error('Unhandled exception', exc_info=True)
return jsonify({'status': 'error', 'message': 'An error occurred; see logs for details', 'details': describe_exception(e)}), 500