# migrate_to_files.py - One-time: base64 in DB → files on disk (v4.2 → v4.3)

import sqlite3
import base64

from config import DATABASE
from db import init_db
from media_storage import save_audio, save_image, save_thumbnail


def migrate():
    # নিশ্চিত করি নতুন কলামগুলো (audio_path, image_path, thumbnail_path) তৈরি আছে
    print("🔧 Ensuring schema is up to date...")
    init_db()

    conn = sqlite3.connect(DATABASE)
    conn.row_factory = sqlite3.Row
    cur = conn.cursor()

    # --- Audio ---
    cur.execute('''
        SELECT mb.id as block_id, mb.audio_data, mb.audio_format, c.project_id
        FROM markdown_blocks mb JOIN chapters c ON mb.chapter_id = c.id
        WHERE mb.audio_data IS NOT NULL AND mb.audio_data != ''
              AND (mb.audio_path IS NULL OR mb.audio_path = '')
    ''')
    rows = cur.fetchall()
    print(f"🔊 Migrating {len(rows)} audio blocks...")
    done = 0
    for r in rows:
        try:
            rel = save_audio(r['project_id'], r['block_id'], r['audio_data'], r['audio_format'] or 'mp3')
            if rel:
                cur.execute("UPDATE markdown_blocks SET audio_path=?, audio_data='' WHERE id=?",
                            (rel, r['block_id']))
                done += 1
        except Exception as e:
            print(f"  ⚠️ Audio block {r['block_id']} failed: {e}")
    conn.commit()
    print(f"   ✅ {done} audio files written")

    # --- Images ---
    cur.execute('''
        SELECT bi.id as image_id, bi.image_data, bi.image_format, c.project_id
        FROM block_images bi
        JOIN markdown_blocks mb ON bi.block_id = mb.id
        JOIN chapters c ON mb.chapter_id = c.id
        WHERE bi.image_data IS NOT NULL AND bi.image_data != ''
              AND (bi.image_path IS NULL OR bi.image_path = '')
    ''')
    rows = cur.fetchall()
    print(f"🖼️  Migrating {len(rows)} images...")
    done = 0
    for r in rows:
        try:
            rel = save_image(r['project_id'], r['image_id'], r['image_data'], r['image_format'] or 'png')
            if rel:
                cur.execute("UPDATE block_images SET image_path=?, image_data='' WHERE id=?",
                            (rel, r['image_id']))
                done += 1
        except Exception as e:
            print(f"  ⚠️ Image {r['image_id']} failed: {e}")
    conn.commit()
    print(f"   ✅ {done} image files written")

    # --- Thumbnails ---
    cur.execute('''
        SELECT id, thumbnail_data, thumbnail_format FROM projects
        WHERE thumbnail_data IS NOT NULL AND thumbnail_data != ''
              AND (thumbnail_path IS NULL OR thumbnail_path = '')
    ''')
    rows = cur.fetchall()
    print(f"📕 Migrating {len(rows)} thumbnails...")
    done = 0
    for r in rows:
        try:
            raw = base64.b64decode(r['thumbnail_data'])
            rel = save_thumbnail(r['id'], raw, r['thumbnail_format'] or 'png')
            if rel:
                cur.execute("UPDATE projects SET thumbnail_path=?, thumbnail_data=NULL WHERE id=?",
                            (rel, r['id']))
                done += 1
        except Exception as e:
            print(f"  ⚠️ Thumbnail {r['id']} failed: {e}")
    conn.commit()
    print(f"   ✅ {done} thumbnails written")

    print("🧹 Running VACUUM (this may take a while on a large DB)...")
    conn.execute('VACUUM')
    conn.commit()
    conn.close()
    print("✅ Migration complete! Database should now be much smaller.")


if __name__ == '__main__':
    migrate()