# -*- coding: utf-8 -*-

# This program is free software: you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation, either version 3 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# Alembic migration environment (configuration).

import logging

from logging.config import fileConfig

from alembic import context

from sqlalchemy import engine_from_config, pool

from kallithea.model import db

# The alembic.config.Config object, which wraps the current .ini file.

config = context.config

# Default to use the main Kallithea database string in [app:main].

# For advanced uses, this can be overridden by specifying an explicit

# [alembic] sqlalchemy.url.

database_url = (

    config.get_main_option('sqlalchemy.url') or

    config.get_section_option('app:main', 'sqlalchemy.url')

)

# Configure default logging for Alembic. (This can be overriden by the

# config file, but usually isn't.)

logging.getLogger('alembic').setLevel(logging.INFO)

# Setup Python loggers based on the config file provided to the alembic

# command. If we're being invoked via the Alembic API (presumably for

# stamping during "kallithea-cli db-create"), config_file_name is not available,

# and loggers are assumed to already have been configured.

if config.config_file_name:

    fileConfig(config.config_file_name,

        {'__file__': config.config_file_name, 'here': os.path.dirname(config.config_file_name)},

        disable_existing_loggers=False)

def include_in_autogeneration(object, name, type, reflected, compare_to):

    """Filter changes subject to autogeneration of migrations. """

    # Don't include changes to sqlite_sequence.

    if type == 'table' and name == 'sqlite_sequence':

        return False

    return True

def run_migrations_offline():

    """Run migrations in 'offline' (--sql) mode.

    This produces an SQL script instead of directly applying the changes.

    Some migrations may not run in offline mode.

    """

    context.configure(

        url=database_url,

        literal_binds=True,

    )

    with context.begin_transaction():

        context.run_migrations()

def run_migrations_online():

    """Run migrations in 'online' mode.

    Connects to the database and directly applies the necessary

    migrations.

    """

    cfg = config.get_section(config.config_ini_section)

    cfg['sqlalchemy.url'] = database_url

    connectable = engine_from_config(

        cfg,

        prefix='sqlalchemy.',

        poolclass=pool.NullPool)

    with connectable.connect() as connection:

        context.configure(

            connection=connection,

            # Support autogeneration of migration scripts based on "diff" between

            # current database schema and kallithea.model.db schema.

            target_metadata=db.Base.metadata,

            include_object=include_in_autogeneration,

            render_as_batch=True, # batch mode is needed for SQLite support

        )

        with context.begin_transaction():

            context.run_migrations()

if context.is_offline_mode():

    run_migrations_offline()

else:

    run_migrations_online()