import gradio as gr
import yt_dlp
import os
import tempfile
import shutil
from pathlib import Path
import re

class YouTubeDownloader:
    def __init__(self):
        self.download_dir = tempfile.mkdtemp()
        
    def is_valid_youtube_url(self, url):
        """Validate if the URL is a valid YouTube URL"""
        youtube_regex = re.compile(
            r'(https?://)?(www\.)?(youtube|youtu|youtube-nocookie)\.(com|be)/'
            r'(watch\?v=|embed/|v/|.+\?v=)?([^&=%\?]{11})'
        )
        return youtube_regex.match(url) is not None
    
    def get_video_info(self, url, progress=gr.Progress()):
        """Get detailed video information without downloading"""
        if not url or not url.strip():
            return None, "❌ Please enter a YouTube URL"
        
        if not self.is_valid_youtube_url(url):
            return None, "❌ Invalid YouTube URL. Please enter a valid YouTube video URL"
        
        try:
            progress(0.2, desc="Fetching video information...")
            
            # Configure yt-dlp options for info extraction
            ydl_opts = {
                'noplaylist': True,
                'extract_flat': False,
            }
            
            with yt_dlp.YoutubeDL(ydl_opts) as ydl:
                try:
                    info = ydl.extract_info(url, download=False)
                    
                    # Extract detailed information
                    video_info = {
                        'title': info.get('title', 'Unknown'),
                        'description': info.get('description', 'No description available'),
                        'duration': info.get('duration', 0),
                        'view_count': info.get('view_count', 0),
                        'like_count': info.get('like_count', 0),
                        'comment_count': info.get('comment_count', 0),
                        'upload_date': info.get('upload_date', ''),
                        'uploader': info.get('uploader', 'Unknown'),
                        'channel': info.get('channel', 'Unknown'),
                        'channel_followers': info.get('channel_follower_count', 0),
                        'tags': info.get('tags', []),
                        'categories': info.get('categories', []),
                        'thumbnail': info.get('thumbnail', ''),
                        'webpage_url': info.get('webpage_url', url)
                    }
                    
                    progress(1.0, desc="Information retrieved!")
                    
                    return video_info, "✅ Video information retrieved successfully"
                    
                except yt_dlp.DownloadError as e:
                    error_msg = str(e)
                    if "Video unavailable" in error_msg:
                        return None, "❌ Video is unavailable or private"
                    elif "age-restricted" in error_msg.lower():
                        return None, "❌ Video is age-restricted"
                    else:
                        return None, f"❌ Failed to get video info: {error_msg}"
                        
        except Exception as e:
            return None, f"❌ An unexpected error occurred: {str(e)}"

    def download_video(self, url, progress=gr.Progress()):
        """Download YouTube video using yt-dlp"""
        if not url or not url.strip():
            return None, "❌ Please enter a YouTube URL"
        
        if not self.is_valid_youtube_url(url):
            return None, "❌ Invalid YouTube URL. Please enter a valid YouTube video URL"
        
        try:
            progress(0.1, desc="Initializing download...")
            
            # Configure yt-dlp options
            ydl_opts = {
                'format': 'best[ext=mp4]/best',  # Prefer mp4 format
                'outtmpl': os.path.join(self.download_dir, '%(title)s.%(ext)s'),
                'noplaylist': True,  # Download only single video, not playlist
            }
            
            progress(0.3, desc="Fetching video information...")
            
            with yt_dlp.YoutubeDL(ydl_opts) as ydl:
                # Get video info first
                try:
                    info = ydl.extract_info(url, download=False)
                    video_title = info.get('title', 'Unknown')
                    duration = info.get('duration', 0)
                    
                    progress(0.5, desc=f"Downloading: {video_title[:50]}...")
                    
                    # Download the video
                    ydl.download([url])
                    
                    progress(0.9, desc="Finalizing download...")
                    
                    # Find the downloaded file
                    downloaded_files = list(Path(self.download_dir).glob('*'))
                    if downloaded_files:
                        downloaded_file = downloaded_files[0]
                        file_size = downloaded_file.stat().st_size / (1024 * 1024)  # Size in MB
                        
                        progress(1.0, desc="Download completed!")
                        
                        success_message = f"✅ Successfully downloaded: {video_title}\n"
                        success_message += f"📁 File size: {file_size:.1f} MB\n"
                        success_message += f"⏱️ Duration: {duration//60}:{duration%60:02d}" if duration else ""
                        
                        return str(downloaded_file), success_message
                    else:
                        return None, "❌ Download completed but file not found"
                        
                except yt_dlp.DownloadError as e:
                    error_msg = str(e)
                    if "Video unavailable" in error_msg:
                        return None, "❌ Video is unavailable or private"
                    elif "age-restricted" in error_msg.lower():
                        return None, "❌ Video is age-restricted and cannot be downloaded"
                    elif "copyright" in error_msg.lower():
                        return None, "❌ Video cannot be downloaded due to copyright restrictions"
                    else:
                        return None, f"❌ Download failed: {error_msg}"
                        
        except Exception as e:
            return None, f"❌ An unexpected error occurred: {str(e)}"
    
    def format_video_info(self, video_info):
        """Format video information for display"""
        if not video_info:
            return "No video information available"
        
        # Format duration
        duration = video_info.get('duration', 0)
        if duration:
            minutes = duration // 60
            seconds = duration % 60
            duration_str = f"{minutes}:{seconds:02d}"
        else:
            duration_str = "Unknown"
        
        # Format upload date
        upload_date = video_info.get('upload_date', '')
        if upload_date and len(upload_date) == 8:
            formatted_date = f"{upload_date[6:8]}/{upload_date[4:6]}/{upload_date[:4]}"
        else:
            formatted_date = "Unknown"
        
        # Format numbers with commas
        def format_number(num):
            if isinstance(num, (int, float)) and num > 0:
                return f"{int(num):,}"
            return "0"
        
        # Get video details
        title = video_info.get('title', 'Unknown')
        channel = video_info.get('channel', 'Unknown')
        uploader = video_info.get('uploader', 'Unknown')
        views = format_number(video_info.get('view_count', 0))
        likes = format_number(video_info.get('like_count', 0))
        comments = format_number(video_info.get('comment_count', 0))
        subscribers = format_number(video_info.get('channel_followers', 0))
        description = video_info.get('description', 'No description available')
        tags = video_info.get('tags', [])
        
        # Create detailed analysis
        info_text = f"""VIDEO ANALYSIS RESULTS
========================

BASIC INFORMATION:
- Title: {title}
- Channel: {channel}
- Uploader: {uploader}
- Duration: {duration_str}
- Upload Date: {formatted_date}

ENGAGEMENT STATISTICS:
- Total Views: {views}
- Total Likes: {likes}
- Total Comments: {comments}
- Channel Subscribers: {subscribers}

CONTENT TAGS:
{', '.join(tags[:15]) if tags else 'No tags available'}

VIDEO DESCRIPTION:
{description[:1000]}{'...(truncated)' if len(description) > 1000 else ''}

ANALYSIS SUMMARY:
- Video has {views} views with {likes} likes
- Engagement rate based on likes to views ratio
- Video duration is {duration_str}
- Posted on {formatted_date}
- Contains {len(tags)} tags for discoverability"""
        
        return info_text
    
    def cleanup(self):
        """Clean up temporary files"""
        try:
            shutil.rmtree(self.download_dir, ignore_errors=True)
        except:
            pass

# Initialize downloader
downloader = YouTubeDownloader()

# Create Gradio interface
def create_interface():
    with gr.Blocks(
        title="YouTube Video Downloader & Analyzer",
        theme="soft",
        css="""
        .container {
            max-width: 900px;
            margin: 0 auto;
        }
        .header {
            text-align: center;
            margin-bottom: 2rem;
        }
        .instructions {
            background-color: #f8f9fa;
            padding: 1rem;
            border-radius: 8px;
            margin-bottom: 1rem;
        }
        """
    ) as demo:
        
        gr.HTML("""
        <div class="header">
            <h1>YouTube Video Downloader & Analyzer</h1>
            <p>Download YouTube videos and get detailed analysis results</p>
        </div>
        """)
        
        gr.HTML("""
        <div class="instructions">
            <h3>How to use:</h3>
            <ul>
                <li>1. Enter a YouTube video URL</li>
                <li>2. Click "Download Video" to download the video file</li>
                <li>3. After download, click "Show Analysis Results" to see detailed video information</li>
                <li>4. View comprehensive statistics including views, likes, comments, description, and more</li>
            </ul>
            <p><strong>Note:</strong> This tool respects YouTube's terms of service. Only download videos you have permission to download.</p>
        </div>
        """)
        
        # State to store video info
        video_info_state = gr.State(value=None)
        
        url_input = gr.Textbox(
            label="YouTube URL",
            placeholder="https://www.youtube.com/watch?v=...",
            lines=1,
            max_lines=1
        )
        
        download_btn = gr.Button(
            "Download Video",
            variant="primary",
            size="lg"
        )
        
        status_output = gr.Textbox(
            label="Download Status",
            lines=3,
            max_lines=5,
            interactive=False
        )
        
        file_output = gr.File(
            label="Downloaded Video",
            visible=False
        )
        
        analysis_btn = gr.Button(
            "Show Analysis Results",
            variant="secondary",
            size="lg",
            visible=False
        )
        
        analysis_output = gr.Textbox(
            label="Video Analysis Results",
            lines=20,
            max_lines=25,
            interactive=False,
            visible=False
        )
        
        # Event handlers
        def handle_download(url):
            if not url or not url.strip():
                return "Please enter a YouTube URL", gr.File(visible=False), gr.Button(visible=False), None
            
            # First get video info and store it
            video_info, info_message = downloader.get_video_info(url)
            
            # Then download the video
            file_path, download_message = downloader.download_video(url)
            
            if file_path and video_info:
                success_message = f"{download_message}\n\nVideo downloaded successfully! Click 'Show Analysis Results' to see detailed information."
                return (
                    success_message,
                    gr.File(value=file_path, visible=True),
                    gr.Button(visible=True),
                    video_info
                )
            elif file_path:
                return (
                    f"{download_message}\n\nVideo downloaded but analysis data unavailable.",
                    gr.File(value=file_path, visible=True),
                    gr.Button(visible=False),
                    None
                )
            else:
                return (
                    download_message,
                    gr.File(visible=False),
                    gr.Button(visible=False),
                    None
                )
        
        def show_analysis(video_info):
            if video_info:
                formatted_info = downloader.format_video_info(video_info)
                return formatted_info, gr.Textbox(visible=True)
            else:
                return "No analysis data available.", gr.Textbox(visible=True)
        
        # Button click events
        download_btn.click(
            fn=handle_download,
            inputs=[url_input],
            outputs=[status_output, file_output, analysis_btn, video_info_state],
            show_progress="full"
        )
        
        analysis_btn.click(
            fn=show_analysis,
            inputs=[video_info_state],
            outputs=[analysis_output, analysis_output]
        )
        
        # Allow Enter key to trigger download
        url_input.submit(
            fn=handle_download,
            inputs=[url_input],
            outputs=[status_output, file_output, analysis_btn, video_info_state],
            show_progress="full"
        )
        
        gr.HTML("""
        <div style="margin-top: 2rem; text-align: center; color: #666;">
            <p><strong>Legal Notice:</strong> Please ensure you have the right to download the content. 
            Respect copyright laws and YouTube's terms of service.</p>
        </div>
        """)
    
    return demo

# Create and launch the app
if __name__ == "__main__":
    demo = create_interface()
    
    # Clean up on exit
    import atexit
    atexit.register(downloader.cleanup)
    
    # Launch the app
    demo.launch(
        server_name="0.0.0.0",
        server_port=5000,
        share=False,
        show_error=True
    )