"""
Миграция данных из SQLite в PostgreSQL.
Запуск: python migrate_db.py
Требует настроенного PostgreSQL (см. database.py)
"""
import sys
from pathlib import Path
sys.path.insert(0, str(Path(__file__).parent))

from sqlalchemy import create_engine, text
from sqlalchemy.orm import sessionmaker
from database import DATABASE_URL, ASYNC_DATABASE_URL, Base, User, InventoryItem, CaseOpening, Contract
from database import Achievement, UserAchievement, ActivityFeed, UserRPU, UpgradeRPU, Upgrade, PromoCode, TransactionLog

# Sync SQLite source
SOURCE_URL = DATABASE_URL
# Sync PostgreSQL target (derive from async URL)
TARGET_URL = ASYNC_DATABASE_URL.replace("+asyncpg", "").replace("+aiosqlite", "")

if "sqlite" in SOURCE_URL:
    print(f"Source: {SOURCE_URL}")
    print(f"Target: {TARGET_URL}")
    print("---")
else:
    print("Source already PostgreSQL — nothing to migrate.")
    sys.exit(0)

source_engine = create_engine(SOURCE_URL)
target_engine = create_engine(TARGET_URL, pool_pre_ping=True)

SourceSession = sessionmaker(bind=source_engine)
TargetSession = sessionmaker(bind=target_engine)

def migrate_table(model, target_session):
    """Copies all rows from source model to target model"""
    source_session = SourceSession()
    try:
        rows = source_session.query(model).all()
        if not rows:
            return 0
        count = 0
        for row in rows:
            # Detach from source session
            source_session.expunge(row)
            target_session.merge(row)
            count += 1
        target_session.commit()
        return count
    except Exception as e:
        target_session.rollback()
        print(f"  ERROR: {e}")
        return 0
    finally:
        source_session.close()

def main():
    print("Creating target tables...")
    Base.metadata.create_all(bind=target_engine)
    
    target_session = TargetSession()
    models = [
        (User, "users"),
        (UserRPU, "user_rpu"),
        (UpgradeRPU, "upgrade_rpu"),
        (InventoryItem, "inventory_items"),
        (CaseOpening, "case_openings"),
        (Contract, "contracts"),
        (Achievement, "achievements"),
        (UserAchievement, "user_achievements"),
        (ActivityFeed, "activity_feed"),
        (Upgrade, "upgrades"),
        (PromoCode, "promo_codes"),
        (TransactionLog, "transaction_log"),
    ]
    
    for model, name in models:
        print(f"Migrating {name}... ", end="", flush=True)
        count = migrate_table(model, target_session)
        print(f"{count} rows")
    
    target_session.close()
    print("\nMigration complete! Set ASYNC_DATABASE_URL to the PostgreSQL URL to use it.")

if __name__ == "__main__":
    main()