"""empty message

Revision ID: b25f088d40c2
Revises: fcd9cebaa79c
Create Date: 2019-06-11 12:31:41.697842

"""
from alembic import op


# revision identifiers, used by Alembic.
revision = "b25f088d40c2"
down_revision = "fcd9cebaa79c"
branch_labels = None
depends_on = None


def upgrade():
    # Remove all task ids in messages for tasks that don't exists anynmore
    query = """
            UPDATE messages SET task_id = NULL
            WHERE task_id NOT IN (SELECT id FROM tasks WHERE project_id = messages.project_id);
            """
    op.execute(query)

    op.create_foreign_key(
        "messages_tasks",
        "messages",
        "tasks",
        ["task_id", "project_id"],
        ["id", "project_id"],
    )


def downgrade():
    op.drop_constraint("messages_tasks", "messages", type_="foreignkey")