from fastapi import FastAPI, UploadFile, File
from fastapi.responses import FileResponse, JSONResponse
import os, subprocess, logging

app = FastAPI()

JOBS_DIR = "/tmp/jobs"
os.makedirs(JOBS_DIR, exist_ok=True)

logging.basicConfig(level=logging.INFO)

job_status = {
    "status": "idle",
    "error": None,
}


def run_ffmpeg(base_file, overlay_file, output_file):
    cmd = [
        "ffmpeg", "-y", "-i", base_file, "-i", overlay_file,
        "-filter_complex", "[0:v][1:v]overlay=10:10:format=auto",
        "-c:a", "copy", output_file
    ]
    logging.info(f"Running FFmpeg: {' '.join(cmd)}")
    result = subprocess.run(cmd, capture_output=True, text=True)
    logging.info(f"FFmpeg stdout: {result.stdout}")
    logging.info(f"FFmpeg stderr: {result.stderr}")
    return result.returncode == 0


@app.post("/generate-video/")
async def generate_video(video: UploadFile = File(...), overlay: UploadFile = File(...)):
    base_file = os.path.join(JOBS_DIR, "current_base.mp4")
    overlay_file = os.path.join(JOBS_DIR, "current_overlay.mp4")
    output_file = os.path.join(JOBS_DIR, "current_output.mp4")

    # Clear old files
    for f in [base_file, overlay_file, output_file]:
        if os.path.exists(f):
            os.remove(f)

    with open(base_file, "wb") as f:
        f.write(await video.read())
    with open(overlay_file, "wb") as f:
        f.write(await overlay.read())

    job_status["status"] = "processing"
    job_status["error"] = None

    try:
        success = run_ffmpeg(base_file, overlay_file, output_file)
        if success and os.path.exists(output_file):
            job_status["status"] = "completed"
        else:
            job_status["status"] = "failed"
            job_status["error"] = "FFmpeg failed or output missing."
    except Exception as e:
        job_status["status"] = "failed"
        job_status["error"] = str(e)

    return {"status": job_status["status"]}


@app.get("/status/")
async def check_status():
    return JSONResponse(job_status)


@app.get("/download/")
async def download_video():
    output_file = os.path.join(JOBS_DIR, "current_output.mp4")
    if job_status["status"] != "completed" or not os.path.exists(output_file):
        return JSONResponse({"error": "No completed video to download."}, status_code=404)
    return FileResponse(output_file, media_type="video/mp4", filename="output.mp4")