import os
from dotenv import load_dotenv
from sqlalchemy import create_engine, text
from alembic import command
from alembic.config import Config

# Cargamos variables de entorno
load_dotenv()

# Construimos la URL de conexión
DATABASE_URL = os.getenv("DATABASE_URL")
if not DATABASE_URL:
    DATABASE_URL = (
        f"postgresql://{os.getenv('DB_USER')}:{os.getenv('DB_PASSWORD')}"
        f"@{os.getenv('DB_HOST')}:{os.getenv('DB_PORT')}/{os.getenv('DB_NAME')}"
    )

# Configuración de Alembic
alembic_cfg = Config("alembic.ini")

# Limpiar alembic_version huérfana si existe
engine = create_engine(DATABASE_URL)

with engine.connect() as conn:
    result = conn.execute(
        text(
            "SELECT EXISTS ("
            "SELECT 1 FROM information_schema.tables "
            "WHERE table_name='alembic_version'"
            ")"
        )
    )
    exists = result.scalar()

    if exists:
        print("⚠️ Tabla alembic_version existente detectada. Eliminando...")
        conn.execute(text("DROP TABLE alembic_version"))
        conn.commit()

# Crear migración automáticamente
print("🛠️ Generando migración...")
command.revision(alembic_cfg, message="crear tablas", autogenerate=True)

# Aplicar migración
print("⬆️ Aplicando migración (upgrade head)...")
command.upgrade(alembic_cfg, "head")

print("✅ Migración completada correctamente")