from __future__ import with_statement
import sys
import os
from logging.config import fileConfig
from sqlalchemy import engine_from_config
from sqlalchemy import pool
from alembic import context

# ensure backend is importable
ROOT = os.path.abspath(os.path.join(os.path.dirname(__file__), '..'))
if ROOT not in sys.path:
    sys.path.insert(0, ROOT)

# this is the Alembic Config object, which provides
# access to the values within the .ini file in use.
config = context.config

# Interpret the config file for Python logging.
fileConfig(config.config_file_name)

# Import your metadata object here
from db.database import Base

target_metadata = Base.metadata

# Get DB URL from environment or ini
db_url = os.getenv('DATABASE_URL')
if not db_url:
    # fallback to default sqlite path
    db_file = os.path.join(os.path.dirname(__file__), '..', 'data', 'secureshield.db')
    db_url = f'sqlite+aiosqlite:///{db_file}'

config.set_main_option('sqlalchemy.url', db_url)


def run_migrations_offline():
    """Run migrations in 'offline' mode."""
    url = config.get_main_option("sqlalchemy.url")
    context.configure(
        url=url,
        target_metadata=target_metadata,
        literal_binds=True,
        dialect_opts={"paramstyle": "named"},
    )

    with context.begin_transaction():
        context.run_migrations()


def run_migrations_online():
    """Run migrations in 'online' mode."""
    connectable = engine_from_config(
        config.get_section(config.config_ini_section),
        prefix='sqlalchemy.',
        poolclass=pool.NullPool,
    )

    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()