Add video generation API with job tracking and model loading

app/main.py

@@ -1,19 +1,24 @@
 from __future__ import annotations
 
 import logging
+import re
 from contextlib import asynccontextmanager
 from typing import AsyncGenerator
 
 from fastapi import FastAPI, File, Form, HTTPException, UploadFile
+from pydantic import ValidationError
 from fastapi.responses import FileResponse, JSONResponse
 
 from app.config import settings
-from app.models import JobSubmitResponse, JobStatusResponse
+from app.models import GenerateForm, JobSubmitResponse, JobStatusResponse
 from app.service import get_service
 
 logging.basicConfig(level=logging.INFO, format="%(asctime)s [%(levelname)s] %(message)s")
 logger = logging.getLogger(__name__)
 
+JOB_ID_RE = re.compile(r"[a-f0-9]{12}")
+MAX_IMAGE_SIZE = 10 * 1024 * 1024  # 10 MB
+
 
 @asynccontextmanager
 async def lifespan(app: FastAPI) -> AsyncGenerator:
@@ -44,7 +49,7 @@ async def health() -> JSONResponse:
 
 @app.post("/generate", status_code=201)
 async def generate(
-    image: UploadFile = File(..., description="Input image (PNG, JPG, etc.)"),
+    image: UploadFile = File(...),
     prompt: str | None = Form(None),
     width: int = Form(768),
     height: int = Form(512),
@@ -54,10 +59,25 @@ async def generate(
 ) -> JobSubmitResponse:
     from PIL import Image
 
-    img_bytes = await image.read()
-    pil_image = Image.open(img_bytes).convert("RGB")
+    if image.content_length and image.content_length > MAX_IMAGE_SIZE:
+        raise HTTPException(status_code=400, detail="Image file must be under 10MB")
 
-    validate_frame_count(num_frames)
+    try:
+        GenerateForm(
+            prompt=prompt,
+            width=width,
+            height=height,
+            num_frames=num_frames,
+            fps=fps,
+            seed=seed,
+        )
+    except ValidationError as e:
+        raise HTTPException(status_code=422, detail=str(e))
+
+    img_bytes = await image.read()
+    if len(img_bytes) > MAX_IMAGE_SIZE:
+        raise HTTPException(status_code=400, detail="Image file must be under 10MB")
+    pil_image = Image.open(img_bytes).convert("RGB")
 
     svc = await get_service()
     job = await svc.submit_job(pil_image, {
@@ -71,8 +91,18 @@ async def generate(
     return JobSubmitResponse(job_id=job.id)
 
 
+def _resolve_job_id(job_id: str) -> str:
+    if not JOB_ID_RE.fullmatch(job_id):
+        raise HTTPException(
+            status_code=400,
+            detail="Invalid job_id format. Expected 12 lowercase hex characters.",
+        )
+    return job_id
+
+
 @app.get("/jobs/{job_id}")
 async def get_job(job_id: str) -> JobStatusResponse:
+    _resolve_job_id(job_id)
     svc = await get_service()
     job = await svc.get_job(job_id)
     if job is None:
@@ -90,12 +120,13 @@ async def get_job(job_id: str) -> JobStatusResponse:
 
 @app.get("/jobs/{job_id}/download")
 async def download_video(job_id: str) -> FileResponse:
+    _resolve_job_id(job_id)
     svc = await get_service()
     job = await svc.get_job(job_id)
     if job is None:
         raise HTTPException(status_code=404, detail="Job not found")
     if job.status != "completed":
-        raise HTTPException(status_code=404, detail="Video not ready")
+        raise HTTPException(status_code=503, detail="Video not ready")
 
     video_path = await svc.get_video_path(job_id)
     if video_path is None:
@@ -105,6 +136,7 @@ async def download_video(job_id: str) -> FileResponse:
 
 @app.delete("/jobs/{job_id}")
 async def delete_job(job_id: str) -> dict:
+    _resolve_job_id(job_id)
     svc = await get_service()
     job = await svc.get_job(job_id)
     if job is None:
@@ -115,16 +147,6 @@ async def delete_job(job_id: str) -> dict:
     return {"deleted": job_id}
 
 
-def validate_frame_count(num_frames: int) -> None:
-    valid = {8 * n + 1 for n in range(1, 129)}
-    if num_frames not in valid:
-        candidates = sorted(f for f in valid if abs(f - num_frames) <= 8)
-        raise HTTPException(
-            status_code=400,
-            detail=f"num_frames must be 8n+1. Got {num_frames}. Closest valid: {candidates[:4]}",
-        )
-
-
 @app.exception_handler(HTTPException)
 async def http_exception_handler(_, exc: HTTPException) -> JSONResponse:
     return JSONResponse(