from fastapi import FastAPI, UploadFile, File, HTTPException
from fastapi.responses import FileResponse
import subprocess
import shutil
import os

app = FastAPI(
    title="Wav2Lip API",
    version="1.0"
)

os.makedirs("sample_data", exist_ok=True)
os.makedirs("results", exist_ok=True)


def merge_audio_video(video_path, audio_path, output_path):

    if os.path.exists(output_path):
        os.remove(output_path)

    subprocess.run(
        [
            "ffmpeg",
            "-y",
            "-i", video_path,
            "-i", audio_path,
            "-c:v", "copy",
            "-c:a", "aac",
            "-map", "0:v:0",
            "-map", "1:a:0",
            output_path
        ],
        check=True
    )

    return output_path


@app.get("/")
def root():
    return {
        "message": "Wav2Lip API is running",
        "docs": "/docs"
    }


@app.post("/generate-video")
async def generate_video(
    image: UploadFile = File(...),
    audio: UploadFile = File(...)
):

    image_path = "sample_data/input_image.png"
    audio_path = "sample_data/input_audio.mp3"

    with open(image_path, "wb") as f:
        shutil.copyfileobj(image.file, f)

    with open(audio_path, "wb") as f:
        shutil.copyfileobj(audio.file, f)

    process = subprocess.run(
        [
            "python",
            "inference.py",
            "--checkpoint_path",
            "checkpoints/wav2lip_gan.pth",
            "--face",
            image_path,
            "--audio",
            audio_path
        ],
        capture_output=True,
        text=True
    )

    # دمج stdout و stderr
    output = (process.stdout or "") + "\n" + (process.stderr or "")

    if process.returncode != 0:

        # خطأ عدم اكتشاف وجه
        if "Face not detected!" in output or "No face detected" in output:
            raise HTTPException(
                status_code=400,
                detail="No face detected in the uploaded image. Please upload a clear front-facing image."
            )

        # خطأ الملف الصوتي
        if "Mel contains nan" in output:
            raise HTTPException(
                status_code=400,
                detail="The uploaded audio is invalid or unsupported."
            )

        # أي خطأ آخر
        raise HTTPException(
            status_code=500,
            detail=output
        )

    wav2lip_video = "results/result_voice.mp4"

    if not os.path.exists(wav2lip_video):
        raise HTTPException(
            status_code=500,
            detail="Wav2Lip output video not found."
        )

    final_video = "results/final_output.mp4"

    merge_audio_video(
        wav2lip_video,
        audio_path,
        final_video
    )

    return FileResponse(
        final_video,
        media_type="video/mp4",
        filename="final_output.mp4"
    )