import os
import tempfile
import ffmpeg
import yt_dlp
from pathlib import Path
from typing import Optional, List

# Global list to track temp files for cleanup
_temp_files: List[str] = []

def cleanup_temp_files():
    """Clean up temporary files created during processing"""
    global _temp_files
    for temp_file in _temp_files:
        try:
            if os.path.exists(temp_file):
                os.unlink(temp_file)
        except Exception:
            pass
    _temp_files.clear()

def download_from_url(url: str) -> Optional[str]:
    """
    Download media from URL using yt-dlp
    
    Args:
        url: URL to download from
    
    Returns:
        Path to downloaded file or None if failed
    """
    try:
        # Create temp directory
        temp_dir = tempfile.mkdtemp()
        
        # Configure yt-dlp options
        ydl_opts = {
            'format': 'best[ext=mp4]/best',
            'outtmpl': os.path.join(temp_dir, '%(id)s.%(ext)s'),
            'quiet': True,
            'no_warnings': True,
            'extract_flat': False,
        }
        
        with yt_dlp.YoutubeDL(ydl_opts) as ydl:
            # Extract info and download
            info = ydl.extract_info(url, download=True)
            if not info:
                return None
            
            # Find downloaded file
            video_id = info.get('id', '')
            ext = info.get('ext', 'mp4')
            downloaded_file = os.path.join(temp_dir, f"{video_id}.{ext}")
            
            if os.path.exists(downloaded_file):
                _temp_files.append(downloaded_file)
                return downloaded_file
            
        return None
        
    except Exception as e:
        print(f"Download error: {e}")
        return None

def convert_media_file(input_path: str, output_format: str) -> Optional[str]:
    """
    Convert media file to target format using ffmpeg
    
    Args:
        input_path: Path to input file
        output_format: Target format (e.g., 'mp4', 'mp3')
    
    Returns:
        Path to converted file or None if failed
    """
    try:
        # Create output path
        temp_dir = tempfile.mkdtemp()
        base_name = Path(input_path).stem
        output_path = os.path.join(temp_dir, f"{base_name}.{output_format}")
        
        # Determine if we need audio-only conversion
        audio_formats = ["mp3", "wav", "aac", "flac", "ogg", "m4a", "wma", "opus", "aiff"]
        is_audio_only = output_format in audio_formats
        
        # Build ffmpeg command based on output format
        if is_audio_only:
            # Extract audio only
            stream = ffmpeg.input(input_path)
            audio = stream.audio
            stream = ffmpeg.output(audio, output_path, **{'q:a': 0, 'map_a': 0})
        else:
            # Full video conversion
            if output_format == "gif":
                # Special handling for GIF
                stream = ffmpeg.input(input_path)
                stream = ffmpeg.output(
                    stream, 
                    output_path, 
                    vf="fps=10,scale=320:-1:flags=lanczos", 
                    **{'loop': 0}
                )
            else:
                # Standard video conversion
                stream = ffmpeg.input(input_path)
                stream = ffmpeg.output(stream, output_path, **{'c:v': 'libx264', 'crf': 23})
        
        # Run conversion
        ffmpeg.run(stream, overwrite_output=True, quiet=True)
        
        if os.path.exists(output_path):
            _temp_files.append(output_path)
            return output_path
        
        return None
        
    except ffmpeg.Error as e:
        print(f"FFmpeg error: {e}")
        return None
    except Exception as e:
        print(f"Conversion error: {e}")
        return None

def get_media_info(file_path: str) -> dict:
    """
    Get media file information using ffmpeg
    
    Args:
        file_path: Path to media file
    
    Returns:
        Dictionary with media info
    """
    try:
        probe = ffmpeg.probe(file_path)
        video_streams = [stream for stream in probe['streams'] if stream['codec_type'] == 'video']
        audio_streams = [stream for stream in probe['streams'] if stream['codec_type'] == 'audio']
        
        info = {
            'duration': float(probe['format'].get('duration', 0)),
            'size': int(probe['format'].get('size', 0)),
            'bitrate': int(probe['format'].get('bit_rate', 0)),
            'has_video': len(video_streams) > 0,
            'has_audio': len(audio_streams) > 0,
        }
        
        if video_streams:
            info['video_codec'] = video_streams[0].get('codec_name')
            info['width'] = video_streams[0].get('width')
            info['height'] = video_streams[0].get('height')
            info['fps'] = eval(video_streams[0].get('r_frame_rate', '0'))
        
        if audio_streams:
            info['audio_codec'] = audio_streams[0].get('codec_name')
            info['sample_rate'] = audio_streams[0].get('sample_rate')
            info['channels'] = audio_streams[0].get('channels')
        
        return info
        
    except Exception as e:
        print(f"Error getting media info: {e}")
        return {}