migrate_add_language.py

#!/usr/bin/env python3
"""
Migration: Add language detection and instrumental flag to the search index.
Runs langdetect on parakeet_transcription to determine language.
Marks tracks as instrumental if has_lyrics=0 AND transcription is short/empty.
"""
import sqlite3
import sys
import time
from datetime import timedelta
from langdetect import detect, LangDetectException

DB_PATH = "/home/deployer/laion/music/laion-tunes-final/search_index/metadata.db"
BATCH_SIZE = 5000

def migrate():
    conn = sqlite3.connect(DB_PATH)
    conn.execute("PRAGMA journal_mode=WAL")
    conn.execute("PRAGMA synchronous=NORMAL")

    # Add columns if not exist
    cols = [row[1] for row in conn.execute("PRAGMA table_info(tracks)")]
    if "language" not in cols:
        conn.execute("ALTER TABLE tracks ADD COLUMN language TEXT DEFAULT ''")
        print("Added 'language' column")
    if "is_instrumental" not in cols:
        conn.execute("ALTER TABLE tracks ADD COLUMN is_instrumental INTEGER DEFAULT 0")
        print("Added 'is_instrumental' column")
    conn.commit()

    # Create index for language
    conn.execute("CREATE INDEX IF NOT EXISTS idx_language ON tracks(language)")
    conn.execute("CREATE INDEX IF NOT EXISTS idx_instrumental ON tracks(is_instrumental)")
    conn.commit()

    # Step 1: Mark instrumental tracks
    # Instrumental = has_lyrics=0 AND (transcription is NULL or short)
    print("Marking instrumental tracks...")
    conn.execute("""
        UPDATE tracks SET is_instrumental = 1
        WHERE has_lyrics = 0
        AND (parakeet_transcription IS NULL OR LENGTH(parakeet_transcription) < 10)
    """)
    # Also mark tracks where lyrics exist but are very short (likely "[Instrumental]" tags)
    conn.execute("""
        UPDATE tracks SET is_instrumental = 1
        WHERE has_lyrics = 1
        AND (parakeet_transcription IS NULL OR LENGTH(parakeet_transcription) < 10)
        AND is_instrumental = 0
    """)
    conn.commit()
    instr_count = conn.execute("SELECT COUNT(*) FROM tracks WHERE is_instrumental=1").fetchone()[0]
    print(f"  Instrumental: {instr_count:,}")

    # Step 2: Detect language from transcriptions
    total = conn.execute(
        "SELECT COUNT(*) FROM tracks WHERE has_transcription=1 AND (language IS NULL OR language='')"
    ).fetchone()[0]
    print(f"Detecting language for {total:,} transcriptions...")

    t0 = time.time()
    processed = 0
    offset = 0

    while True:
        rows = conn.execute(
            "SELECT row_id, parakeet_transcription FROM tracks "
            "WHERE has_transcription=1 AND (language IS NULL OR language='') "
            "LIMIT ? OFFSET ?",
            (BATCH_SIZE, offset)
        ).fetchall()
        if not rows:
            break

        updates = []
        for row_id, text in rows:
            if not text or len(text.strip()) < 10:
                updates.append(("unknown", row_id))
                continue
            try:
                # Use first 300 chars for speed
                lang = detect(text[:300])
                updates.append((lang, row_id))
            except LangDetectException:
                updates.append(("unknown", row_id))

        conn.executemany("UPDATE tracks SET language=? WHERE row_id=?", updates)
        conn.commit()
        processed += len(rows)
        offset += BATCH_SIZE

        elapsed = time.time() - t0
        rate = processed / elapsed if elapsed > 0 else 0
        remaining = (total - processed) / rate if rate > 0 else 0
        print(f"  {processed:,}/{total:,} ({processed*100//total}%) "
              f"{rate:.0f}/s ETA: {timedelta(seconds=int(remaining))}")

    # Step 3: For tracks without transcription, try langdetect on tags or title
    # (less reliable but better than nothing)
    no_lang = conn.execute(
        "SELECT COUNT(*) FROM tracks WHERE (language IS NULL OR language='') AND has_transcription=0"
    ).fetchone()[0]
    print(f"\nTracks without language (no transcription): {no_lang:,}")
    print("Setting these to 'unknown'...")
    conn.execute("UPDATE tracks SET language='unknown' WHERE language IS NULL OR language=''")
    conn.commit()

    # Print language distribution
    print("\nLanguage distribution:")
    for row in conn.execute(
        "SELECT language, COUNT(*) as cnt FROM tracks GROUP BY language ORDER BY cnt DESC LIMIT 20"
    ):
        print(f"  {row[0]:>10}: {row[1]:>8,}")

    print(f"\nDone in {timedelta(seconds=int(time.time() - t0))}")
    conn.close()

if __name__ == "__main__":
    migrate()