Files
2026-06-16 04:38:23 +00:00

253 lines
9.0 KiB
Python

import asyncio
import json
from fastapi import APIRouter, Depends, HTTPException, Request
from fastapi.responses import StreamingResponse
from sqlalchemy.orm import Session
from app.api.chat_schemas import GenerationStatusOut, MessagesPageOut
from app.api.schemas import (
MessageCreate,
SessionCreate,
SessionDetailOut,
SessionOut,
)
from app.auth.deps import get_current_user
from app.chat.generation import (
GenerationBusyError,
get_active_handle,
is_generation_active,
start_generation,
subscribe_generation,
)
from app.chat.service import ChatService
from app.config import get_settings
from app.db.base import get_db
from app.db.models import User
from app.vision import VisionService, format_user_messages, vision_debug_payloads
from app.vision.analyze import VisionUnavailableError
from app.vision.preprocess import prepare_image
from app.vision.storage import format_upload_images_markdown, save_upload
router = APIRouter()
ALLOWED_IMAGE_TYPES = {"image/jpeg", "image/png", "image/webp", "image/gif"}
@router.post("/sessions", response_model=SessionOut)
def create_session(payload: SessionCreate, db: Session = Depends(get_db), user: User = Depends(get_current_user)) -> SessionOut:
service = ChatService(db, user.id)
return service.create_session(title=payload.title)
@router.get("/sessions", response_model=list[SessionOut])
def list_sessions(db: Session = Depends(get_db), user: User = Depends(get_current_user)) -> list[SessionOut]:
service = ChatService(db, user.id)
return service.list_sessions()
@router.get("/sessions/{session_id}", response_model=SessionDetailOut)
def get_session(session_id: int, db: Session = Depends(get_db), user: User = Depends(get_current_user)) -> SessionDetailOut:
service = ChatService(db, user.id)
session = service.get_session(session_id)
if not session:
raise HTTPException(status_code=404, detail="Session not found")
return session
@router.get("/sessions/{session_id}/messages", response_model=MessagesPageOut)
def list_messages(
session_id: int,
limit: int = 30,
before_id: int | None = None,
after_id: int | None = None,
db: Session = Depends(get_db), user: User = Depends(get_current_user),
) -> MessagesPageOut:
service = ChatService(db, user.id)
if not service.get_session(session_id):
raise HTTPException(status_code=404, detail="Session not found")
messages, has_more = service.list_messages(
session_id,
limit=min(max(limit, 1), 100),
before_id=before_id,
after_id=after_id,
)
return MessagesPageOut(messages=messages, has_more=has_more)
@router.get("/sessions/{session_id}/generation", response_model=GenerationStatusOut)
def generation_status(session_id: int, db: Session = Depends(get_db), user: User = Depends(get_current_user)) -> GenerationStatusOut:
service = ChatService(db, user.id)
if not service.get_session(session_id):
raise HTTPException(status_code=404, detail="Session not found")
return GenerationStatusOut(active=is_generation_active(session_id))
@router.get("/sessions/{session_id}/generation/stream")
async def generation_stream(session_id: int, db: Session = Depends(get_db), user: User = Depends(get_current_user)) -> StreamingResponse:
service = ChatService(db, user.id)
if not service.get_session(session_id):
raise HTTPException(status_code=404, detail="Session not found")
handle = get_active_handle(session_id)
if not handle:
raise HTTPException(status_code=404, detail="No active generation")
async def event_stream():
async for chunk in subscribe_generation(handle):
yield chunk
return StreamingResponse(
event_stream(),
media_type="text/event-stream",
headers={
"Cache-Control": "no-cache",
"Connection": "keep-alive",
"X-Accel-Buffering": "no",
},
)
@router.delete("/sessions/{session_id}")
def delete_session(session_id: int, db: Session = Depends(get_db), user: User = Depends(get_current_user)) -> dict[str, bool]:
service = ChatService(db, user.id)
if not service.delete_session(session_id):
raise HTTPException(status_code=404, detail="Session not found")
return {"ok": True}
def _collect_form_uploads(form) -> list:
uploads: list = []
seen_ids: set[int] = set()
def _append(item) -> None:
if item is None or not hasattr(item, "read"):
return
item_id = id(item)
if item_id in seen_ids:
return
seen_ids.add(item_id)
uploads.append(item)
if hasattr(form, "getlist"):
for item in form.getlist("images"):
_append(item)
single = form.get("image")
_append(single)
return uploads
async def _analyze_upload(raw: bytes, *, caption: str, user_id: int):
prepared = prepare_image(raw)
filename = save_upload(prepared, user_id=user_id)
result = await VisionService().analyze_prepared(prepared, user_hint=caption)
return result, filename
async def _parse_message_request(
request: Request,
*,
user_id: int,
) -> tuple[str, dict | None]:
content_type = (request.headers.get("content-type") or "").lower()
if "multipart/form-data" not in content_type:
try:
body = await request.json()
except json.JSONDecodeError as exc:
raise HTTPException(status_code=400, detail="Invalid JSON body") from exc
payload = MessageCreate.model_validate(body)
return payload.content, None
form = await request.form()
caption = str(form.get("content") or "").strip()
uploads = _collect_form_uploads(form)
if not uploads:
raise HTTPException(status_code=400, detail="Field 'images' or 'image' is required for multipart upload")
max_images = max(1, int(get_settings().vision_max_images))
if len(uploads) > max_images:
raise HTTPException(
status_code=400,
detail=f"Too many images (max {max_images})",
)
raw_images: list[bytes] = []
for upload in uploads:
raw = await upload.read()
if not raw:
raise HTTPException(status_code=400, detail="Empty image file")
mime = getattr(upload, "content_type", None) or "application/octet-stream"
if mime not in ALLOWED_IMAGE_TYPES:
raise HTTPException(status_code=400, detail=f"Unsupported image type: {mime}")
raw_images.append(raw)
try:
analyzed = await asyncio.gather(
*(_analyze_upload(raw, caption=caption, user_id=user_id) for raw in raw_images)
)
except VisionUnavailableError as exc:
raise HTTPException(status_code=502, detail=str(exc)) from exc
results = [item[0] for item in analyzed]
filenames = [item[1] for item in analyzed]
debug = vision_debug_payloads(results)
vision_text = format_user_messages(caption, results)
images_md = format_upload_images_markdown(user_id, filenames)
user_text = f"{images_md}\n\n{vision_text}" if images_md else vision_text
if not user_text.strip():
raise HTTPException(status_code=400, detail="Could not build message from image")
return user_text, debug
@router.post("/sessions/{session_id}/messages")
async def send_message(
session_id: int,
request: Request,
db: Session = Depends(get_db),
user: User = Depends(get_current_user),
) -> StreamingResponse:
service = ChatService(db, user.id)
if not service.get_session(session_id):
raise HTTPException(status_code=404, detail="Session not found")
if is_generation_active(session_id):
raise HTTPException(status_code=409, detail="Generation already in progress")
user_text, vision_debug = await _parse_message_request(request, user_id=user.id)
service.save_user_message(session_id, user_text)
try:
handle = await start_generation(session_id, user.id, user_text)
except GenerationBusyError:
raise HTTPException(status_code=409, detail="Generation already in progress") from None
async def event_stream():
try:
if vision_debug:
yield ChatService._sse("vision", vision_debug)
async for chunk in subscribe_generation(handle):
yield chunk
except asyncio.CancelledError:
raise
return StreamingResponse(
event_stream(),
media_type="text/event-stream",
headers={
"Cache-Control": "no-cache",
"Connection": "keep-alive",
"X-Accel-Buffering": "no",
},
)
@router.get("/sessions/{session_id}/context-preview")
def context_preview(
session_id: int,
query: str | None = None,
db: Session = Depends(get_db), user: User = Depends(get_current_user),
) -> dict:
service = ChatService(db, user.id)
return service.context_preview(session_id, query=query)