"""Alembic environment — uses sync psycopg2 driver for migrations."""

from __future__ import annotations

import os
from logging.config import fileConfig

from alembic import context
from sqlalchemy import create_engine

# this is the Alembic Config object
config = context.config

# Interpret the config file for Python logging.
if config.config_file_name is not None:
    fileConfig(config.config_file_name)

# Read DATABASE_URL from environment (preferred) or alembic.ini
database_url = os.environ.get("DATABASE_URL") or config.get_main_option("sqlalchemy.url")
if not database_url:
    raise RuntimeError(
        "mals/alembic: DATABASE_URL is required. "
        "Set it as an environment variable or in alembic.ini."
    )

# Convert asyncpg URL to psycopg2 (sync) for Alembic
sync_url = (
    database_url.replace("postgresql+asyncpg://", "postgresql://")
    .replace("asyncpg://", "postgresql://")
)

target_metadata = None


def run_migrations_offline() -> None:
    """Run migrations in 'offline' mode (generate SQL only)."""
    context.configure(
        url=sync_url,
        target_metadata=target_metadata,
        literal_binds=True,
        dialect_opts={"paramstyle": "named"},
    )
    with context.begin_transaction():
        context.run_migrations()


def run_migrations_online() -> None:
    """Run migrations against a live database."""
    connectable = create_engine(sync_url)
    with connectable.connect() as connection:
        context.configure(connection=connection, target_metadata=target_metadata)
        with context.begin_transaction():
            context.run_migrations()


if context.is_offline_mode():
    run_migrations_offline()
else:
    run_migrations_online()