from importlib import import_module
from alembic import context
from alchemical.alembic.env import run_migrations

# Load Alembic configuration
config = context.config

try:
    # Import the Alchemical database instance as specified in alembic.ini
    import_mod, db_name = config.get_main_option('alchemical_db', '').split(':')
    db = getattr(import_module(import_mod), db_name)
    print(f"Successfully loaded Alchemical database instance: {db}")

    # Use the metadata associated with the Alchemical instance
    metadata = db.Model.metadata
    print(f"Metadata tables detected: {metadata.tables.keys()}")  # Debug output
except (ModuleNotFoundError, AttributeError) as e:
    raise ValueError(
        'Could not import the Alchemical database instance or access metadata. '
        'Ensure that the alchemical_db setting in alembic.ini is correct and '
        'that the Alchemical instance is correctly configured.'
    ) from e

# Run migrations with metadata
run_migrations(db, {
    'render_as_batch': True,
    'compare_type': True,
})