"""
Ultimate Reaper Project Generator
- Precise tempo map with fluctuations
- Chord change markers throughout track
- Region-based song structure
- Lyric file integration for better structure detection
- Color-coded markers and regions
"""

from pathlib import Path
import numpy as np
import re

try:
    import librosa
    LIBROSA_AVAILABLE = True
except ImportError:
    LIBROSA_AVAILABLE = False


# Color scheme for Reaper (BGR format as integers)
COLORS = {
    # Regions
    'intro': 8421504,      # Gray
    'verse': 16744703,     # Light blue
    'pre-chorus': 16777011, # Light yellow
    'chorus': 8454143,     # Green
    'bridge': 16744576,    # Orange
    'solo': 16711935,      # Purple
    'outro': 8421504,      # Gray
    'fill': 12632256,      # Light gray
    
    # Chords - by function
    'tonic': 8454143,      # Green (I, i)
    'subdominant': 16776960, # Yellow (IV, iv)
    'dominant': 33488896,  # Red (V, V7)
    'default': 16777215,   # White
}


def create_reaper_project(song_name, stems_dir, tempo, key, structure=None, 
                         chords=None, lyrics_file=None, audio_file=None):
    """
    Generate ultimate Reaper project with full integration
    
    Args:
        song_name: Name of the song
        stems_dir: Directory containing stem files
        tempo: Average tempo in BPM
        key: Musical key
        structure: Detected song structure
        chords: List of (timestamp, chord_name) tuples
        lyrics_file: Optional path to lyric file with structure tags
        audio_file: Original audio file for beat detection
    
    Returns:
        RPP file content as string
    """
    
    stems_dir = Path(stems_dir)
    stem_files = sorted(stems_dir.glob('*.mp3'))
    
    if not stem_files:
        return create_empty_project(song_name, tempo)
    
    # Parse lyric file if provided
    lyric_structure = None
    if lyrics_file and Path(lyrics_file).exists():
        print("   Parsing lyric file for structure...")
        lyric_structure = parse_lyric_file(lyrics_file)
    
    # Merge detected structure with lyric structure
    if lyric_structure:
        structure = merge_structures(structure, lyric_structure)
    
    # Detect precise beats and tempo map
    print("   Detecting precise beat grid and tempo map...")
    audio_to_analyze = audio_file if audio_file else stem_files[0]
    beats, downbeats, tempo_map = detect_precise_beats(audio_to_analyze)
    
    # Start building RPP
    rpp_lines = []
    
    # === HEADER ===
    rpp_lines.append('<REAPER_PROJECT 0.1 "6.0/linux-x86_64" 1234567890')
    rpp_lines.append('  RIPPLE 0')
    rpp_lines.append('  GROUPOVERRIDE 0 0 0')
    rpp_lines.append('  AUTOXFADE 1')
    
    # === TEMPO MAP ===
    if tempo_map and len(tempo_map) > 1:
        # Variable tempo - use multiple TEMPO markers (Reaper 6.x format)
        print(f"   Creating tempo map with {len(tempo_map)} changes...")
        
        # First tempo at project start
        rpp_lines.append(f'  TEMPO {tempo_map[0]["bpm"]:.6f} 4 4')
        
        # Add tempo changes as additional TEMPO lines with time position
        # Format: TEMPO bpm timesig beat_position
        for i, tm in enumerate(tempo_map[1:], 1):
            # Calculate beat position from time
            beat_pos = tm["time"] * tempo_map[0]["bpm"] / 60.0
            rpp_lines.append(f'  TEMPO {tm["bpm"]:.6f} 4 4 {beat_pos:.6f}')
    else:
        # Constant tempo
        rpp_lines.append(f'  TEMPO {tempo:.6f} 4 4')
    
    rpp_lines.append('  PLAYRATE 1 0 0.25 4')
    rpp_lines.append('  CURSOR 0')
    rpp_lines.append('  ZOOM 100 0 0')
    rpp_lines.append('  VZOOMEX 1 0')
    rpp_lines.append('  USE_REC_CFG 0')
    rpp_lines.append('  RECMODE 1')
    rpp_lines.append('  SMPTESYNC 0 30 100 40 1000 300 0 0 1 0 0')
    rpp_lines.append('  LOOP 0')
    rpp_lines.append('  LOOPGRAN 0 4')
    rpp_lines.append('  RECORD_PATH "" ""')
    rpp_lines.append('')
    
    # === DOWNBEAT MARKERS (BAR LINES) ===
    if downbeats is not None and len(downbeats) > 0:
        print(f"   Creating {len(downbeats)} bar markers...")
        for i, beat_time in enumerate(downbeats):
            bar_number = i + 1
            adjusted_time = beat_time + 8.0  # Offset by pre-roll
            rpp_lines.append(f'  MARKER {bar_number} {adjusted_time:.6f} "Bar {bar_number}" 0 0')
    
    # === CHORD MARKERS ===
    marker_id = len(downbeats) + 1 if downbeats is not None else 1
    
    if chords and len(chords) > 0:
        print(f"   Creating {len(chords)} chord change markers...")
        for time, chord in chords:
            color = get_chord_color(chord, key)
            adjusted_time = time + 8.0  # Offset by pre-roll
            rpp_lines.append(f'  MARKER {marker_id} {adjusted_time:.6f} "{chord}" 0 {color}')
            marker_id += 1
    
    rpp_lines.append('')
    
    # === REGIONS (SONG STRUCTURE) ===
    
    # Add count-in region at start
    print("   Creating count-in region (8 seconds)...")
    rpp_lines.append(f'  MARKER {marker_id} 0.0 "Count-In" 1 {COLORS["intro"]} {{}} 0')
    marker_id += 1
    rpp_lines.append(f'  MARKER {marker_id} 8.0 "" 1 {COLORS["intro"]} {{}} 0')
    marker_id += 1
    
    if structure and len(structure) > 0:
        print(f"   Creating {len(structure)} structural regions...")
        region_id = 1
        for section in structure:
            section_name = section['name']
            start = section['start'] + 8.0  # Offset by pre-roll
            end = section['end'] + 8.0
            color = get_section_color(section_name)
            
            # Regions use different format: MARKER with region flag
            rpp_lines.append(
                f'  MARKER {marker_id} {start:.6f} "{section_name}" 1 {color} {{}} {region_id}'
            )
            marker_id += 1
            
            # Region end
            rpp_lines.append(
                f'  MARKER {marker_id} {end:.6f} "" 1 {color} {{}} {region_id}'
            )
            marker_id += 1
            region_id += 1
    
    rpp_lines.append('')
    
    # === TRACKS ===
    track_number = 1
    
    for stem_file in stem_files:
        stem_name = stem_file.stem.replace('_', ' ').title()
        color = get_track_color(stem_name)
        
        rpp_lines.append('  <TRACK')
        rpp_lines.append(f'    NAME "{stem_name}"')
        rpp_lines.append(f'    PEAKCOL {color}')
        rpp_lines.append('    BEAT -1')
        rpp_lines.append('    AUTOMODE 0')
        rpp_lines.append('    VOLPAN 1 0 -1 -1 1')
        rpp_lines.append('    MUTESOLO 0 0 0')
        rpp_lines.append('    IPHASE 0')
        rpp_lines.append('    PLAYOFFS 0 1')
        rpp_lines.append('    ISBUS 0 0')
        rpp_lines.append('    BUSCOMP 0 0 0 0 0')
        rpp_lines.append('    SHOWINMIX 1 0.6667 0.5 1 0.5 0 0 0')
        rpp_lines.append('    FREEMODE 0')
        rpp_lines.append('    SEL 0')
        rpp_lines.append('    REC 0 0 1 0 0 0 0')
        rpp_lines.append('    VU 2')
        rpp_lines.append('    TRACKHEIGHT 0 0 0 0 0 0')
        rpp_lines.append('    INQ 0 0 0 0.5 100 0 0 100')
        rpp_lines.append('    NCHAN 2')
        rpp_lines.append('    FX 1')
        rpp_lines.append('    TRACKID')
        rpp_lines.append('    PERF 0')
        rpp_lines.append('    MIDIOUT -1')
        rpp_lines.append('    MAINSEND 1 0')
        
        # Item (audio)
        rpp_lines.append('    <ITEM')
        rpp_lines.append('      POSITION 8.0')  # 8-second pre-roll
        rpp_lines.append('      SNAPOFFS 0')
        rpp_lines.append('      LENGTH 0')
        rpp_lines.append('      LOOP 0')
        rpp_lines.append('      ALLTAKES 0')
        rpp_lines.append('      FADEIN 1 0.01 0 1 0 0 0')
        rpp_lines.append('      FADEOUT 1 0.01 0 1 0 0 0')
        rpp_lines.append('      MUTE 0 0')
        rpp_lines.append('      SEL 1')
        rpp_lines.append('      IGUID')
        rpp_lines.append(f'      IID {track_number}')
        rpp_lines.append(f'      NAME "{stem_name}"')
        rpp_lines.append('      VOLPAN 1 0 1 -1')
        rpp_lines.append('      SOFFS 0 0')
        rpp_lines.append('      PLAYRATE 1 1 0 -1 0 0.0025')
        rpp_lines.append('      CHANMODE 0')
        rpp_lines.append('      GUID')
        rpp_lines.append('      RESOURCECH 0')
        rpp_lines.append('      <SOURCE WAVE')
        rpp_lines.append(f'        FILE "{stem_file.absolute()}"')
        rpp_lines.append('      >')
        rpp_lines.append('    >')
        rpp_lines.append('  >')
        rpp_lines.append('')
        
        track_number += 1
    
    # Footer
    rpp_lines.append('>')
    
    return '\n'.join(rpp_lines)


def parse_lyric_file(lyrics_path):
    """
    Parse lyric file with structure tags
    
    Expected format:
        [Intro]
        
        [Verse 1]
        Lyrics here...
        
        [Chorus]
        Lyrics here...
    
    Returns:
        List of {'name': str, 'lyrics': str} dicts
    """
    
    with open(lyrics_path, 'r', encoding='utf-8') as f:
        content = f.read()
    
    # Pattern: [Section Name]
    sections = []
    current_section = None
    current_lyrics = []
    
    for line in content.split('\n'):
        # Check for section tag
        match = re.match(r'\[(.*?)\]', line.strip())
        if match:
            # Save previous section
            if current_section:
                sections.append({
                    'name': current_section,
                    'lyrics': '\n'.join(current_lyrics).strip()
                })
            
            # Start new section
            current_section = match.group(1)
            current_lyrics = []
        else:
            # Add to current section
            if current_section:
                current_lyrics.append(line)
    
    # Save last section
    if current_section:
        sections.append({
            'name': current_section,
            'lyrics': '\n'.join(current_lyrics).strip()
        })
    
    return sections


def merge_structures(detected_structure, lyric_structure):
    """
    Merge detected structure with lyric file structure
    Lyric file takes precedence for naming
    """
    
    if not detected_structure:
        return lyric_structure
    
    if not lyric_structure:
        return detected_structure
    
    # Use detected timestamps but lyric names
    merged = []
    
    for i, detected in enumerate(detected_structure):
        if i < len(lyric_structure):
            # Use lyric name but detected times
            merged.append({
                'name': lyric_structure[i]['name'],
                'start': detected['start'],
                'end': detected['end'],
                'lyrics': lyric_structure[i].get('lyrics', '')
            })
        else:
            merged.append(detected)
    
    return merged


def detect_precise_beats(audio_file):
    """
    Detect beats, downbeats, and tempo map with high precision
    
    Returns:
        (beats, downbeats, tempo_map)
    """
    
    if not LIBROSA_AVAILABLE:
        return None, None, None
    
    try:
        # Load audio
        y, sr = librosa.load(str(audio_file), sr=22050)
        duration = len(y) / sr
        
        # Detect all beats
        tempo, beat_frames = librosa.beat.beat_track(y=y, sr=sr, units='frames')
        beat_times = librosa.frames_to_time(beat_frames, sr=sr)
        
        # Estimate downbeats (every 4 beats assuming 4/4)
        downbeat_times = beat_times[::4]
        
        # Create detailed tempo map (every 2 seconds)
        tempo_map = []
        window_size = 2.0  # seconds
        
        for start_time in np.arange(0, duration, window_size):
            end_time = min(start_time + window_size, duration)
            start_sample = int(start_time * sr)
            end_sample = int(end_time * sr)
            
            if end_sample > start_sample:
                segment = y[start_sample:end_sample]
                try:
                    segment_tempo, _ = librosa.beat.beat_track(y=segment, sr=sr)
                    tempo_map.append({
                        'time': float(start_time),
                        'bpm': float(segment_tempo)
                    })
                except:
                    # Use global tempo if segment fails
                    tempo_map.append({
                        'time': float(start_time),
                        'bpm': float(tempo)
                    })
        
        # Smooth tempo map to reduce noise
        tempo_map = smooth_tempo_map(tempo_map)
        
        # Check if tempo is stable enough to treat as constant
        tempos = [tm['bpm'] for tm in tempo_map]
        tempo_std = np.std(tempos)
        
        if tempo_std < 3:  # Less than 3 BPM variation
            tempo_map = [tempo_map[0]]  # Use constant tempo
        
        return beat_times, downbeat_times, tempo_map
        
    except Exception as e:
        print(f"   [WARN]  Beat detection failed: {e}")
        return None, None, None


def smooth_tempo_map(tempo_map, window=3):
    """Smooth tempo map with moving average"""
    
    if len(tempo_map) <= window:
        return tempo_map
    
    smoothed = []
    for i, tm in enumerate(tempo_map):
        start = max(0, i - window // 2)
        end = min(len(tempo_map), i + window // 2 + 1)
        
        avg_tempo = np.mean([tempo_map[j]['bpm'] for j in range(start, end)])
        
        smoothed.append({
            'time': tm['time'],
            'bpm': float(avg_tempo)
        })
    
    return smoothed


def get_chord_color(chord, key):
    """Get color for chord based on function in key"""
    
    # Simplified: just use default white for now
    # Could be enhanced to detect I, IV, V based on key
    return COLORS['default']


def get_section_color(section_name):
    """Get color for section type"""
    
    name_lower = section_name.lower()
    
    for section_type, color in COLORS.items():
        if section_type in name_lower:
            return color
    
    return COLORS['intro']  # Default


def get_track_color(track_name):
    """Get color for track based on instrument"""
    
    name_lower = track_name.lower()
    
    if 'vocal' in name_lower or 'voice' in name_lower:
        return 16576  # Blue
    elif 'drum' in name_lower:
        return 33488896  # Red
    elif 'bass' in name_lower:
        return 25387775  # Purple
    elif 'guitar' in name_lower:
        return 8454143  # Green
    elif 'piano' in name_lower or 'key' in name_lower:
        return 16776960  # Yellow
    else:
        return 8421504  # Gray


def create_empty_project(song_name, tempo):
    """Create minimal project if no stems found"""
    
    return f"""<REAPER_PROJECT 0.1 "6.0/linux-x86_64" 1234567890
  TEMPO {tempo} 4 4
>
"""


if __name__ == "__main__":
    print("Reaper Ultimate Integration Module")
    print("Features:")
    print("  • Precise tempo map with fluctuation detection")
    print("  • Chord change markers throughout track")
    print("  • Region-based song structure")
    print("  • Lyric file integration")
    print("  • Color-coded everything")