# Copyright 2018 TrilioData Inc.
# All Rights Reserved.
from alembic import context
from logging.config import fileConfig

from dmapi.storage import impl_sqlalchemy
from dmapi.storage.sqlalchemy import models


# 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)

# add your model's MetaData object here
# for 'autogenerate' support
# from myapp import mymodel
# target_metadata = mymodel.Base.metadata
target_metadata = models.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.


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.

    """
    conf = config.conf
    context.configure(url=conf.database.connection,
                      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.

    """
    conf = config.conf
    conn = impl_sqlalchemy.Connection(conf, conf.database.connection)
    connectable = conn._engine_facade.get_engine()

    with connectable.connect() as connection:
        context.configure(
            connection=connection,
            target_metadata=target_metadata
        )

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


if not hasattr(config, "conf"):
    from dmapi import service
    config.conf = service.prepare_service([])

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