"""Add granularity to watching repos

Revision ID: d4d2c5aa8a0

Revises: 4255158a6913

Create Date: 2017-04-28 14:39:09.746953

"""

# revision identifiers, used by Alembic.

revision = 'd4d2c5aa8a0'

down_revision = '4255158a6913'

from alembic import op

import sqlalchemy as sa

# A helper table that is a hybrid with both states. This is used for data

# migrations later on.

watcher_helper = sa.Table(

    'watchers',

    sa.MetaData(),

    sa.Column('id', sa.Integer, primary_key=True),

    sa.Column('watch_issues', sa.Boolean),

    sa.Column('watch_commits', sa.Boolean),

    sa.Column('watch', sa.Boolean),

)

def upgrade():

    op.add_column('watchers', sa.Column('watch_commits', sa.Boolean(),

                                        nullable=True))

    op.add_column('watchers', sa.Column('watch_issues', sa.Boolean(),

                                        nullable=True))

    # This section is to update the `watch_issues` and `watch_commits` columns

    # with the value of `watch`

    connection = op.get_bind()

    for watcher in connection.execute(watcher_helper.select()):

        connection.execute(

            watcher_helper.update().where(

                watcher_helper.c.id == watcher.id

            ).values(

                watch_issues=watcher.watch,

                watch_commits=False

            )

        )

    with op.batch_alter_table('watchers') as b:

        # Set nullable to False now that we've set values

        b.alter_column('watch_issues', nullable=False)

        b.alter_column('watch_commits', nullable=False)

        # Remove the watch column

        b.drop_column('watch')

def downgrade():

    op.add_column('watchers', sa.Column('watch', sa.BOOLEAN(), nullable=True))

    # This section is to update the `watch` column with the value of

    # `watch_issues`

    connection = op.get_bind()

    for watcher in connection.execute(watcher_helper.select()):

        connection.execute(

            watcher_helper.update().where(

                watcher_helper.c.id == watcher.id

            ).values(

                watch=watcher.watch_issues

            )

        )

    with op.batch_alter_table('watchers') as b:

        # Set nullable to False now that we've set values

        b.alter_column('watch', nullable=False)

        # Drop the added columns

        b.drop_column('watch_issues')

        b.drop_column('watch_commits')