import sys, os
sys.path.insert(0, os.path.join(os.path.dirname(os.path.abspath(__file__)), '..'))

from app import create_app
from sqlalchemy import text
import sqlite3

SQLITE_PATH = os.path.join(os.path.dirname(os.path.abspath(__file__)), '..', 'data', 'aufmass.db')

# Tables in FK-safe order (parents first)
TABLE_ORDER = [
    'companies',
    'users',
    'licenses',
    'contracts',
    'modules',
    'aufmass_typen',
    'projekte',
    'custom_modules',
    'company_modules',
    'license_modules',
    'aufmass',
    'lv_positionen',
    'positionen',
    'project_access',
    'custom_module_assignments',
    'user_module_permissions',
    'view_profiles',
]

def main():
    print("=" * 60)
    print("SQLite -> PostgreSQL Migration v2")
    print("=" * 60)

    if not os.path.exists(SQLITE_PATH):
        print(f"SQLite DB nicht gefunden: {SQLITE_PATH}")
        return

    # Read all SQLite data
    print("\n1. Lese SQLite-Daten...")
    conn = sqlite3.connect(SQLITE_PATH)
    conn.row_factory = sqlite3.Row
    c = conn.cursor()
    sqlite_data = {}
    for table_name in TABLE_ORDER:
        c.execute(f'SELECT * FROM "{table_name}"')
        rows = [dict(r) for r in c.fetchall()]
        sqlite_data[table_name] = rows
        print(f"  {table_name}: {len(rows)} Zeilen")
    conn.close()

    # Create Flask app -> creates PG tables + seed defaults
    print("\n2. Starte Flask-App mit PostgreSQL...")
    app = create_app()

    with app.app_context():
        from app import db

        # Delete all existing data in reverse FK order
        print("   Entferne vorhandene Daten...")
        with db.engine.connect() as c:
            for table_name in reversed(TABLE_ORDER):
                c.execute(text(f'DELETE FROM "{table_name}"'))
            c.commit()

        # Import in FK-safe order
        print("\n3. Importiere Daten in FK-Reihenfolge...")
        meta = __import__('sqlalchemy', fromlist=['MetaData']).MetaData()
        meta.reflect(bind=db.engine)

        total_ok = 0
        total_fail = 0

        for table_name in TABLE_ORDER:
            rows = sqlite_data.get(table_name, [])
            if not rows:
                print(f"  -- {table_name}: keine Daten")
                continue

            table = __import__('sqlalchemy', fromlist=['Table']).Table(table_name, meta, autoload_with=db.engine)
            pg_cols = {c.name for c in table.columns}

            ok = 0
            fail = 0
            with db.engine.connect() as pg_conn:
                for row in rows:
                    filtered = {k: v for k, v in row.items() if k in pg_cols}
                    try:
                        pg_conn.execute(table.insert().values(**filtered))
                        ok += 1
                    except Exception as e:
                        fail += 1
                        if fail <= 2:
                            print(f"     Fehler {table_name} ID={row.get('id','?')}: {e}")
                pg_conn.commit()

            total_ok += ok
            total_fail += fail
            status = "+" if ok else " "
            print(f"  {status} {table_name}: {ok}/{len(rows)} OK" + (f" ({fail} Fehler)" if fail else ""))

        print(f"\nErgebnis: {total_ok} Zeilen importiert" + (f", {total_fail} Fehler" if total_fail else ""))

    print("\nFertig! Starte Flask-App neu -> _seed_defaults() ergaenzt Seed-Daten via Upsert.")
    print("PostgreSQL ist bereit fuer AufmassWeb.")

if __name__ == '__main__':
    main()