from fastapi import FastAPI, HTTPException
from fastapi.staticfiles import StaticFiles
from pydantic import BaseModel, HttpUrl
from typing import List
import os
import subprocess
import uuid
import requests
import re
from urllib.parse import urlparse
import shutil

# Create FastAPI app
app = FastAPI()

# Create and mount staticfiles directory
os.makedirs("staticfiles", exist_ok=True)
app.mount("/static", StaticFiles(directory="staticfiles"), name="static")

# Define input model for the request
class SlideshowRequest(BaseModel):
    image_urls: List[HttpUrl]
    audio_url: HttpUrl
    duration: int

def extract_google_drive_id(url):
    """Extract file ID from a Google Drive URL"""
    pattern = r'(?:/file/d/|id=|/open\?id=)([^/&]+)'
    match = re.search(pattern, str(url))
    return match.group(1) if match else None

def download_file(url, local_path):
    """Download a file from URL to local path"""
    try:
        # Handle Google Drive URLs
        if "drive.google.com" in str(url):
            file_id = extract_google_drive_id(url)
            if file_id:
                url = f"https://drive.google.com/uc?export=download&id={file_id}"
        
        response = requests.get(str(url), stream=True)
        response.raise_for_status()
        
        with open(local_path, 'wb') as f:
            for chunk in response.iter_content(chunk_size=8192):
                f.write(chunk)
        return True
    except Exception as e:
        print(f"Error downloading {url}: {str(e)}")
        return False

def create_slideshow(image_paths, audio_path, output_path, duration):
    """Generate slideshow from images and audio using ffmpeg"""
    # Create temporary file list for ffmpeg concat
    concat_file = "temp_concat.txt"
    
    with open(concat_file, "w") as f:
        for img in image_paths:
            f.write(f"file '{img}'\n")
            f.write(f"duration {duration}\n")
        
        # Add the last image again without duration (required by ffmpeg)
        if image_paths:
            f.write(f"file '{image_paths[-1]}'\n")
    
    # Run ffmpeg command to create slideshow with audio
    cmd = [
        "ffmpeg",
        "-f", "concat",
        "-safe", "0",
        "-i", concat_file,
        "-i", audio_path,
        "-c:v", "libx264",
        "-pix_fmt", "yuv420p",
        "-c:a", "aac",
        "-shortest",
        "-y",
        output_path
    ]
    
    try:
        subprocess.run(cmd, check=True, capture_output=True)
        os.remove(concat_file)
        return True
    except subprocess.CalledProcessError as e:
        print(f"FFmpeg error: {e.stderr.decode()}")
        if os.path.exists(concat_file):
            os.remove(concat_file)
        return False

@app.post("/make_slideshow")
async def make_slideshow(request: SlideshowRequest):
    """
    Create a slideshow from images and audio with specified duration per image.
    Returns the URL of the generated video.
    """
    # Create unique directory for this request
    request_id = str(uuid.uuid4())
    request_dir = os.path.join("staticfiles", request_id)
    os.makedirs(request_dir, exist_ok=True)
    
    try:
        # Download images
        image_paths = []
        for i, url in enumerate(request.image_urls):
            image_path = os.path.join(request_dir, f"image_{i:03d}.png")
            if download_file(url, image_path):
                image_paths.append(image_path)
            else:
                raise HTTPException(status_code=400, detail=f"Failed to download image: {url}")
        
        # Download audio
        audio_path = os.path.join(request_dir, "audio.mp3")
        if not download_file(request.audio_url, audio_path):
            raise HTTPException(status_code=400, detail=f"Failed to download audio: {request.audio_url}")
        
        # Output video path
        output_path = os.path.join(request_dir, "slideshow.mp4")
        
        # Generate slideshow
        if not create_slideshow(image_paths, audio_path, output_path, request.duration):
            raise HTTPException(status_code=500, detail="Failed to create slideshow")
        
        # Return URL to the video
        base_url = "/static"
        video_url = f"{base_url}/{request_id}/slideshow.mp4"
        return {"url": video_url}
    
    except Exception as e:
        # Clean up on error
        if os.path.exists(request_dir):
            shutil.rmtree(request_dir)
        raise HTTPException(status_code=500, detail=f"Error: {str(e)}")

if __name__ == "__main__":
    import uvicorn
    uvicorn.run(app, host="0.0.0.0", port=7860)