"""Expand AQMM references from VARCHAR(120) to TEXT.

Revision ID: 20260919_aqmm_ref_text
Revises: 20260919_task_inheritance
"""
from alembic import op
import sqlalchemy as sa

revision = "20260919_aqmm_ref_text"
down_revision = "20260919_task_inheritance"
branch_labels = None
depends_on = None

_TABLES = (
    "service_default_task_templates",
    "firm_service_task_templates",
    "client_service_task_instances",
)


def upgrade() -> None:
    bind = op.get_bind()
    inspector = sa.inspect(bind)
    existing_tables = set(inspector.get_table_names())

    for table_name in _TABLES:
        if table_name not in existing_tables:
            continue
        columns = {col["name"]: col for col in inspector.get_columns(table_name)}
        if "aqmm_reference" not in columns:
            continue
        with op.batch_alter_table(table_name) as batch:
            batch.alter_column(
                "aqmm_reference",
                existing_type=sa.String(length=120),
                type_=sa.Text(),
                existing_nullable=True,
            )


def downgrade() -> None:
    bind = op.get_bind()
    inspector = sa.inspect(bind)
    existing_tables = set(inspector.get_table_names())

    for table_name in reversed(_TABLES):
        if table_name not in existing_tables:
            continue
        columns = {col["name"]: col for col in inspector.get_columns(table_name)}
        if "aqmm_reference" not in columns:
            continue
        with op.batch_alter_table(table_name) as batch:
            batch.alter_column(
                "aqmm_reference",
                existing_type=sa.Text(),
                type_=sa.String(length=120),
                existing_nullable=True,
            )