# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from alembic import context
from sqlalchemy import create_engine, pool, text

from warehouse import db


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.
    """
    url = context.config.get_main_option("sqlalchemy.url")
    context.configure(url=url, compare_server_default=True)

    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 = context.config.attributes.get("connection", None)

    if connectable is None:
        options = context.config.get_section(context.config.config_ini_section)
        url = options.pop("url")
        connectable = create_engine(url, poolclass=pool.NullPool)

        with connectable.connect() as connection:
            connection.execute(text("SET statement_timeout = 5000"))
            connection.execute(text("SET lock_timeout = 4000"))

            context.configure(
                connection=connection,
                target_metadata=db.metadata,
                compare_server_default=True,
                transaction_per_migration=True,
            )
            with context.begin_transaction():
                context.run_migrations()
    else:
        context.configure(
            connection=connectable,
            target_metadata=db.metadata,
            compare_server_default=True,
            transaction_per_migration=True,
        )
        context.execute(text("SET statement_timeout = 5000"))
        context.execute(text("SET lock_timeout = 4000"))

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


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