from flask import Flask, render_template, send_from_directory, jsonify, request
import os
import mutagen
from mutagen.flac import FLAC
from mutagen.mp3 import MP3
from mutagen.wave import WAVE
from functools import lru_cache
import base64
from pathlib import Path

app = Flask(__name__)

# Configure music folder using Path for better path handling
app.config['MUSIC_FOLDER'] = Path(__file__).parent / 'music'

# Global cache for metadata
METADATA_CACHE = {}
STRUCTURE_CACHE = None
CACHE_VERSION = 1  # Increment this when changing cache logic

@lru_cache(maxsize=100)
def get_audio_metadata(file_path):
    """Cache metadata for frequently accessed files"""
    try:
        # Check if metadata is in cache
        if file_path in METADATA_CACHE:
            return METADATA_CACHE[file_path]

        metadata = None
        if file_path.endswith('.flac'):
            audio = FLAC(file_path)
            metadata = {
                'title': str(audio.get('title', [Path(file_path).name])[0]),
                'artist': str(audio.get('artist', ['Unknown'])[0]),
                'album': str(audio.get('album', ['Unknown'])[0]),
                'duration': int(audio.info.length),
                'sample_rate': audio.info.sample_rate,
                'channels': audio.info.channels,
                'artwork': None,
                'lyrics': str(audio.get('lyrics', [''])[0]),
                'synchronized_lyrics': get_synchronized_lyrics(audio)
            }
            
            if audio.pictures:
                try:
                    artwork_data = audio.pictures[0].data
                    metadata['artwork'] = f"data:image/jpeg;base64,{base64.b64encode(artwork_data).decode('utf-8')}"
                except Exception:
                    pass
            
        elif file_path.endswith('.mp3'):
            audio = MP3(file_path)
            metadata = {
                'title': audio.tags.get('TIT2', [Path(file_path).name])[0] if hasattr(audio, 'tags') else Path(file_path).name,
                'artist': audio.tags.get('TPE1', ['Unknown'])[0] if hasattr(audio, 'tags') else 'Unknown',
                'album': audio.tags.get('TALB', ['Unknown'])[0] if hasattr(audio, 'tags') else 'Unknown',
                'duration': int(audio.info.length),
                'sample_rate': audio.info.sample_rate,
                'channels': audio.info.channels,
                'artwork': None,
                'lyrics': get_mp3_lyrics(audio),
                'synchronized_lyrics': get_mp3_synchronized_lyrics(audio)
            }
            
            if hasattr(audio, 'tags'):
                try:
                    apic_keys = [k for k in audio.tags.keys() if k.startswith('APIC:')]
                    if apic_keys:
                        artwork_data = audio.tags[apic_keys[0]].data
                        metadata['artwork'] = f"data:image/jpeg;base64,{base64.b64encode(artwork_data).decode('utf-8')}"
                except Exception:
                    pass
            
        elif file_path.endswith('.wav'):
            audio = WAVE(file_path)
            metadata = {
                'title': Path(file_path).name,
                'artist': 'Unknown',
                'album': 'Unknown',
                'duration': int(audio.info.length),
                'sample_rate': audio.info.sample_rate,
                'channels': audio.info.channels,
                'artwork': None,
                'lyrics': '',
                'synchronized_lyrics': []
            }

        if metadata:
            METADATA_CACHE[file_path] = metadata
            return metadata
        return None

    except Exception as e:
        print(f"Error reading metadata for {file_path}: {str(e)}")
        return {
            'title': Path(file_path).name,
            'artist': 'Unknown',
            'album': 'Unknown',
            'duration': 0,
            'sample_rate': 0,
            'channels': 0,
            'artwork': None
        }

def get_folder_structure(path):
    """Get folder structure with caching"""
    global STRUCTURE_CACHE
    
    try:
        if STRUCTURE_CACHE is not None:
            return STRUCTURE_CACHE

        if not Path(path).exists():
            return []
            
        structure = []
        for item in Path(path).iterdir():
            if item.is_file() and item.suffix.lower() in ('.mp3', '.wav', '.flac'):
                metadata = get_audio_metadata(str(item))
                if metadata:
                    structure.append({
                        'type': 'file',
                        'name': item.name,
                        'path': str(item.relative_to(app.config['MUSIC_FOLDER'])),
                        'metadata': metadata
                    })
            elif item.is_dir():
                structure.append({
                    'type': 'folder',
                    'name': item.name,
                    'path': str(item.relative_to(app.config['MUSIC_FOLDER'])),
                    'contents': get_folder_structure(item)
                })
        
        STRUCTURE_CACHE = structure
        return structure
    except Exception as e:
        print(f"Error scanning directory {path}: {str(e)}")
        return []

@app.route('/api/music-structure')
def get_music_structure():
    """Get music structure with caching"""
    music_dir = app.config['MUSIC_FOLDER']
    
    if not music_dir.exists():
        music_dir.mkdir(parents=True, exist_ok=True)
        return jsonify([])
    
    if not any(music_dir.iterdir()):
        return jsonify([])
    
    structure = get_folder_structure(music_dir)
    return jsonify(structure)

# Add cache invalidation endpoint for development
@app.route('/api/clear-cache', methods=['POST'])
def clear_cache():
    """Clear all caches - use in development only"""
    global STRUCTURE_CACHE, METADATA_CACHE
    STRUCTURE_CACHE = None
    METADATA_CACHE.clear()
    get_audio_metadata.cache_clear()
    return jsonify({"message": "Cache cleared"})

@app.route('/music/<path:filename>')
def serve_music(filename):
    return send_from_directory('music', filename)

@app.route('/')
def index():
    return render_template('index.html')

@app.route('/static/default-cover.png')
def default_cover():
    return send_from_directory('static', 'default-cover.png')

@app.route('/api/playlists', methods=['GET', 'POST', 'DELETE'])
def manage_playlists():
    global playlists
    if request.method == 'GET':
        return jsonify(playlists)
    
    if request.method == 'POST':
        data = request.get_json()
        playlist_name = data.get('name')
        songs = data.get('songs', [])
        
        if playlist_name:
            playlists[playlist_name] = songs
            return jsonify({'message': f'Playlist {playlist_name} created/updated'})
        
        return jsonify({'error': 'No playlist name provided'}), 400
    
    if request.method == 'DELETE':
        playlist_name = request.args.get('name')
        if playlist_name in playlists:
            del playlists[playlist_name]
            return jsonify({'message': f'Playlist {playlist_name} deleted'})
        
        return jsonify({'error': 'Playlist not found'}), 404

@app.route('/api/playlists/<name>/add', methods=['POST'])
def add_to_playlist(name):
    data = request.get_json()
    songs = data.get('songs', [])
    
    if name not in playlists:
        playlists[name] = []
    
    playlists[name].extend(songs)
    return jsonify(playlists[name])

@app.route('/api/playlists/<name>/remove', methods=['POST'])
def remove_from_playlist(name):
    if name not in playlists:
        return jsonify({'error': 'Playlist not found'}), 404
        
    data = request.get_json()
    indices = data.get('indices', [])
    
    # Remove songs in reverse order to avoid index shifting
    for index in sorted(indices, reverse=True):
        if 0 <= index < len(playlists[name]):
            playlists[name].pop(index)
    
    return jsonify(playlists[name])

def get_synchronized_lyrics(audio):
    """Extract synchronized lyrics from FLAC metadata"""
    try:
        if 'LYRICS' in audio.tags:
            # Try to parse synchronized lyrics in LRC format
            lyrics = audio.tags['LYRICS'][0]
            return parse_lrc_format(lyrics)
    except Exception as e:
        print(f"Error parsing synchronized lyrics: {str(e)}")
    return []

def get_mp3_lyrics(audio):
    """Extract plain lyrics from MP3 metadata"""
    try:
        if hasattr(audio, 'tags'):
            # Try different common lyrics tag formats
            for tag in ['USLT::', 'LYRICS', 'LYRICS:']:
                if tag in audio.tags:
                    return str(audio.tags[tag])
    except Exception as e:
        print(f"Error extracting MP3 lyrics: {str(e)}")
    return ''

def get_mp3_synchronized_lyrics(audio):
    """Extract synchronized lyrics from MP3 metadata"""
    try:
        if hasattr(audio, 'tags'):
            # Look for SYLT (Synchronized Lyrics) frames
            sylt_frames = [f for f in audio.tags if f.startswith('SYLT:')]
            if sylt_frames:
                sylt = audio.tags[sylt_frames[0]]
                return parse_sylt_format(sylt)
    except Exception as e:
        print(f"Error extracting MP3 synchronized lyrics: {str(e)}")
    return []

def parse_lrc_format(lrc_text):
    """Parse LRC format synchronized lyrics"""
    lyrics = []
    for line in lrc_text.split('\n'):
        if line.strip():
            try:
                # LRC format: [mm:ss.xx]lyrics text
                time_str = line[1:line.find(']')]
                text = line[line.find(']')+1:].strip()
                
                # Convert time to seconds
                if '.' in time_str:
                    mm_ss, ms = time_str.split('.')
                else:
                    mm_ss, ms = time_str, '0'
                minutes, seconds = map(int, mm_ss.split(':'))
                timestamp = minutes * 60 + seconds + float(f'0.{ms}')
                
                lyrics.append({'time': timestamp, 'text': text})
            except:
                continue
    return sorted(lyrics, key=lambda x: x['time'])

def parse_sylt_format(sylt):
    """Parse SYLT format synchronized lyrics"""
    lyrics = []
    for time, text in sylt.text:
        lyrics.append({
            'time': time / 1000.0,  # Convert milliseconds to seconds
            'text': text
        })
    return sorted(lyrics, key=lambda x: x['time'])

if __name__ == '__main__':
    # Create music directory if it doesn't exist
    if not os.path.exists(app.config['MUSIC_FOLDER']):
        os.makedirs(app.config['MUSIC_FOLDER'])
    
    # Use environment variables for host and port
    port = int(os.environ.get('PORT', 7860))
    app.run(host='0.0.0.0', port=port)