feat: complete grounded digital avatar chat experience

digital-avatar-app/backend/routers/avatars.py

@@ -1,4 +1,7 @@
-from fastapi import APIRouter, Depends, Body, Header
+import os
+import uuid
+
+from fastapi import APIRouter, Depends, Body, Header, UploadFile, File, HTTPException
 from sqlalchemy.orm import Session
 
 from database import get_db
@@ -6,6 +9,9 @@ from models import Avatar, KnowledgeDoc, KnowledgeChunk, QAPair, Authorization,
 from responses import ok, fail
 
 router = APIRouter(tags=["分身"])
+UPLOAD_DIR = os.path.join(os.path.dirname(os.path.abspath(__file__)), "uploads")
+ALLOWED_AVATAR_EXTENSIONS = {".jpg", ".jpeg", ".png", ".webp", ".gif"}
+MAX_AVATAR_BYTES = 5 * 1024 * 1024
 
 
 def _resolve_user(authorization: str | None, db: Session):
@@ -16,6 +22,40 @@ def _resolve_user(authorization: str | None, db: Session):
     return db.query(User).filter(User.app_token == token).first()
 
 
+def _require_owned_avatar(db: Session, avatar_id: str, authorization: str | None):
+    avatar = db.query(Avatar).filter(Avatar.id == avatar_id).first()
+    if not avatar:
+        raise HTTPException(status_code=404, detail="分身不存在")
+    user = _resolve_user(authorization, db)
+    if not user:
+        raise HTTPException(status_code=401, detail="未登录")
+    if avatar.owner_id and avatar.owner_id != user.huihui_user_id:
+        raise HTTPException(status_code=403, detail="无权访问该分身")
+    return avatar
+
+
+@router.post("/avatar/{avatar_id}/photo")
+async def upload_avatar_photo(
+    avatar_id: str,
+    file: UploadFile = File(...),
+    authorization: str = Header(None),
+    db: Session = Depends(get_db),
+):
+    _require_owned_avatar(db, avatar_id, authorization)
+    extension = os.path.splitext(file.filename or "")[1].lower()
+    if extension not in ALLOWED_AVATAR_EXTENSIONS or not (file.content_type or "").startswith("image/"):
+        return fail("仅支持 JPG、PNG、WebP 或 GIF 图片", code=400)
+    content = await file.read()
+    if len(content) > MAX_AVATAR_BYTES:
+        return fail("头像图片不能超过 5MB", code=400)
+    avatar_dir = os.path.join(UPLOAD_DIR, avatar_id)
+    os.makedirs(avatar_dir, exist_ok=True)
+    stored_name = f"avatar-{uuid.uuid4().hex}{extension}"
+    with open(os.path.join(avatar_dir, stored_name), "wb") as stream:
+        stream.write(content)
+    return ok({"photoUrl": f"/api/files/{avatar_id}/{stored_name}"})
+
+
 @router.get("/avatar")
 def list_avatars(page: int = 1, limit: int = 20, authorization: str = Header(None), db: Session = Depends(get_db)):
     # 仅返回当前登录用户自己的分身；未登录返回空，避免看到种子/他人数据