import gradio as gr
from yt_dlp import YoutubeDL
import tempfile
import os
import subprocess

def download_snippet(url, duration_sec):
    """Download and trim audio snippet"""
    # Create temp directory
    temp_dir = tempfile.mkdtemp()
    
    try:
        # First, download the full track (or best we can get)
        ydl_opts = {
            'format': 'bestaudio/best',
            'outtmpl': os.path.join(temp_dir, 'full_audio.%(ext)s'),
            'quiet': True,
            'no_warnings': True,
            'noplaylist': True,
        }
        
        with YoutubeDL(ydl_opts) as ydl:
            # Get info for filename
            info = ydl.extract_info(url, download=False)
            title = info.get('title', 'soundcloud_track')
            safe_title = "".join(c for c in title if c.isalnum() or c in (' ', '-', '_')).rstrip()
            
            # Download
            ydl.download([url])
        
        # Find the downloaded file
        downloaded_files = [f for f in os.listdir(temp_dir) if f.startswith('full_audio')]
        if not downloaded_files:
            raise Exception("No file was downloaded")
        
        input_file = os.path.join(temp_dir, downloaded_files[0])
        
        # Check if file exists and has content
        if not os.path.exists(input_file) or os.path.getsize(input_file) == 0:
            raise Exception("Downloaded file is empty")
        
        # Create output filename
        output_file = os.path.join(temp_dir, f"{safe_title}_{duration_sec}s.mp3")
        
        # Use ffmpeg to trim (this is the key fix!)
        cmd = [
            'ffmpeg',
            '-i', input_file,          # Input file
            '-t', str(duration_sec),   # Duration to keep
            '-acodec', 'libmp3lame',   # MP3 codec
            '-q:a', '2',               # Good quality
            '-y',                      # Overwrite output
            output_file
        ]
        
        # Run ffmpeg
        result = subprocess.run(cmd, capture_output=True, text=True)
        
        if result.returncode != 0:
            raise Exception(f"FFmpeg error: {result.stderr}")
        
        # Check if output was created
        if not os.path.exists(output_file) or os.path.getsize(output_file) == 0:
            raise Exception("Trimmed file is empty")
        
        return output_file, f"{safe_title}_{duration_sec}s.mp3"
        
    except Exception as e:
        # Clean up on error
        if os.path.exists(temp_dir):
            import shutil
            shutil.rmtree(temp_dir, ignore_errors=True)
        raise e

# Simple Gradio interface
with gr.Blocks(title="SoundCloud Snippet", theme=gr.themes.Soft()) as demo:
    gr.Markdown("""
    # 🎵 SoundCloud Snippet Downloader
    Download the first N seconds of any public SoundCloud track
    """)
    
    with gr.Row():
        url = gr.Textbox(
            label="SoundCloud URL",
            placeholder="https://soundcloud.com/artist/track-name",
            value="https://soundcloud.com/emma-eline-pihlstr-m/have-yourself-a-merry-little-christmas",
            lines=2
        )
    
    with gr.Row():
        duration = gr.Slider(
            minimum=5,
            maximum=400,
            value=30,
            step=5,
            label="Duration (seconds)"
        )
    
    with gr.Row():
        download_btn = gr.Button("Download Snippet", variant="primary")
    
    with gr.Row():
        audio_player = gr.Audio(label="Preview", type="filepath")
        download_file = gr.DownloadButton("Save MP3", visible=False)
    
    # Store file path
    file_path = gr.State()
    
    def process_download(url, duration):
        if not url or 'soundcloud.com' not in url.lower():
            raise gr.Error("Please enter a valid SoundCloud URL")
        
        try:
            filepath, filename = download_snippet(url, duration)
            return {
                audio_player: filepath,
                download_file: gr.DownloadButton(visible=True),
                file_path: filepath
            }
        except Exception as e:
            raise gr.Error(f"Download failed: {str(e)}")
    
    download_btn.click(
        process_download,
        inputs=[url, duration],
        outputs=[audio_player, download_file, file_path]
    )
    
    download_file.click(
        lambda x: x if x and os.path.exists(x) else None,
        inputs=[file_path],
        outputs=None
    )

if __name__ == "__main__":
    demo.launch()