"""evotor webhook token flow: add evotor_user_id, make user_id nullable

Revision ID: f6a7b8c9d0e1
Revises: e5f6a7b8c9d0
Branch Labels: None
Depends On: None

"""
from alembic import op
import sqlalchemy as sa

revision = 'f6a7b8c9d0e1'
down_revision = 'e5f6a7b8c9d0'
branch_labels = None
depends_on = None


def upgrade() -> None:
    conn = op.get_bind()

    # Check existing columns
    columns = [row[0] for row in conn.execute(sa.text(
        "SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS "
        "WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'evotor_connections'"
    ))]

    if 'evotor_user_id' not in columns:
        op.add_column('evotor_connections',
            sa.Column('evotor_user_id', sa.String(255), nullable=True))

    # Check existing indexes
    indexes = [row[2] for row in conn.execute(sa.text(
        "SHOW INDEX FROM evotor_connections"
    ))]

    if 'uq_evotor_connections_evotor_user_id' not in indexes:
        op.create_unique_constraint('uq_evotor_connections_evotor_user_id',
            'evotor_connections', ['evotor_user_id'])

    if 'ix_evotor_connections_evotor_user_id' not in indexes:
        op.create_index('ix_evotor_connections_evotor_user_id',
            'evotor_connections', ['evotor_user_id'])

    op.alter_column('evotor_connections', 'user_id',
        existing_type=sa.Integer(), nullable=True)


def downgrade() -> None:
    op.alter_column('evotor_connections', 'user_id',
        existing_type=sa.Integer(), nullable=False)
    op.drop_index('ix_evotor_connections_evotor_user_id', 'evotor_connections')
    op.drop_constraint('uq_evotor_connections_evotor_user_id', 'evotor_connections')
    op.drop_column('evotor_connections', 'evotor_user_id')