Add default branding assets when missing

backend/app/routers/branding.py

@@ -4,7 +4,7 @@ from typing import Any, Dict
 
 from fastapi import APIRouter, HTTPException, UploadFile, File
 from fastapi.responses import FileResponse
-from PIL import Image
+from PIL import Image, ImageDraw, ImageFont
 
 router = APIRouter(prefix="/branding", tags=["branding"])
 
@@ -23,8 +23,52 @@ def _resize_image(image: Image.Image, max_size: int = 300) -> Image.Image:
     return image
 
 
+def _load_font(size: int) -> ImageFont.ImageFont:
+    candidates = [
+        "/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf",
+        "/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf",
+    ]
+    for path in candidates:
+        if os.path.exists(path):
+            try:
+                return ImageFont.truetype(path, size)
+            except OSError:
+                continue
+    return ImageFont.load_default()
+
+
+def _ensure_default_branding() -> None:
+    if os.path.exists(_LOGO_PATH) and os.path.exists(_FAVICON_PATH):
+        return
+    _ensure_branding_dir()
+    if not os.path.exists(_LOGO_PATH):
+        image = Image.new("RGBA", (300, 300), (12, 18, 28, 255))
+        draw = ImageDraw.Draw(image)
+        font = _load_font(160)
+        text = "M"
+        box = draw.textbbox((0, 0), text, font=font)
+        text_w = box[2] - box[0]
+        text_h = box[3] - box[1]
+        draw.text(
+            ((300 - text_w) / 2, (300 - text_h) / 2 - 6),
+            text,
+            font=font,
+            fill=(255, 255, 255, 255),
+        )
+        image.save(_LOGO_PATH, format="PNG")
+    if not os.path.exists(_FAVICON_PATH):
+        favicon = Image.open(_LOGO_PATH).copy()
+        favicon.thumbnail((64, 64))
+        try:
+            favicon.save(_FAVICON_PATH, format="ICO", sizes=[(32, 32), (64, 64)])
+        except OSError:
+            favicon.save(_FAVICON_PATH, format="ICO")
+
+
 @router.get("/logo.png")
 async def branding_logo() -> FileResponse:
+    if not os.path.exists(_LOGO_PATH):
+        _ensure_default_branding()
     if not os.path.exists(_LOGO_PATH):
         raise HTTPException(status_code=404, detail="Logo not found")
     headers = {"Cache-Control": "public, max-age=300"}
@@ -33,6 +77,8 @@ async def branding_logo() -> FileResponse:
 
 @router.get("/favicon.ico")
 async def branding_favicon() -> FileResponse:
+    if not os.path.exists(_FAVICON_PATH):
+        _ensure_default_branding()
     if not os.path.exists(_FAVICON_PATH):
         raise HTTPException(status_code=404, detail="Favicon not found")
     headers = {"Cache-Control": "public, max-age=300"}