# main.py
import shutil
import tempfile
import requests
from fastapi import FastAPI, Query, HTTPException
from fastapi.responses import FileResponse
import os
from urllib.parse import urlparse

app = FastAPI(title="Telegram-Friendly Video Proxy")

@app.get("/download")
def download_video(url: str = Query(..., description="Public video URL")):
    """
    Downloads a video from a streaming/HTML-wrapped URL and serves it
    as a raw file Telegram can accept.
    """
    # Validate URL
    parsed = urlparse(url)
    if not parsed.scheme.startswith("http"):
        raise HTTPException(status_code=400, detail="Invalid URL")

    # Extract file extension for naming
    _, ext = os.path.splitext(parsed.path)
    if ext.lower() not in [".mp4", ".mkv", ".webm", ".mov", ".avi"]:
        ext = ".mp4"  # default fallback

    # Temp file to download
    tmp_file = tempfile.mktemp(suffix=ext)

    try:
        # Download the video
        with requests.get(url, stream=True, timeout=60) as r:
            r.raise_for_status()
            with open(tmp_file, "wb") as f:
                shutil.copyfileobj(r.raw, f)

        # Serve with Content-Disposition so Telegram sees it as a file
        return FileResponse(
            tmp_file,
            media_type="application/octet-stream",
            filename=f"video{ext}",
            headers={"Content-Disposition": f'attachment; filename="video{ext}"'}
        )

    except Exception as e:
        # Clean up in case of failure
        if os.path.exists(tmp_file):
            os.remove(tmp_file)
        raise HTTPException(status_code=500, detail=f"Failed to download file: {repr(e)}")