from __future__ import with_statement, print_function

import os

from alembic import context
from sqlalchemy import create_engine, pool
from logging.config import fileConfig

# 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.
# This line sets up loggers basically.
fileConfig(config.config_file_name)


if 'PAGURE_CONFIG' not in os.environ \
        and os.path.exists('/etc/pagure/pagure.cfg'):
    print('Using configuration file `/etc/pagure/pagure.cfg`')
    os.environ['PAGURE_CONFIG'] = '/etc/pagure/pagure.cfg'


try:
    import pagure
    import pagure.lib.model
except ImportError:
    import sys
    sys.path.insert(0, '.')
    import pagure
    import pagure.lib.model


# add your model's MetaData object here
# for 'autogenerate' support
target_metadata = pagure.lib.model.BASE.metadata

# other values from the config, defined by the needs of env.py,
# can be acquired:
# my_important_option = config.get_main_option("my_important_option")
# ... etc.

DBURL = config.get_main_option("sqlalchemy.url")
if not DBURL:
    DBURL = pagure.config.config['DB_URL']


def run_migrations_offline():
    """Run migrations in 'offline' mode.

    This configures the context with just a URL
    and not an Engine, though an Engine is acceptable
    here as well.  By skipping the Engine creation
    we don't even need a DBAPI to be available.

    Calls to context.execute() here emit the given string to the
    script output.

    """

    context.configure(url=DBURL, target_metadata=target_metadata)

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


def run_migrations_online():
    """Run migrations in 'online' mode.

    In this scenario we need to create an Engine
    and associate a connection with the context.

    """
    connectable = create_engine(DBURL, 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()