"""add ai pmo simulation field

Revision ID: add_ai_pmo_simulation_field
Revises: add_ai_pmo_kernel_tables
Create Date: 2026-03-09
"""

from __future__ import annotations

from alembic import op
import sqlalchemy as sa


revision = "add_ai_pmo_simulation_field"
down_revision = "add_ai_pmo_kernel_tables"
branch_labels = None
depends_on = None


def _table_exists(bind, table_name: str) -> bool:
    return sa.inspect(bind).has_table(table_name)


def _column_exists(bind, table_name: str, column_name: str) -> bool:
    inspector = sa.inspect(bind)
    if not inspector.has_table(table_name):
        return False
    return any(col.get("name") == column_name for col in inspector.get_columns(table_name))


def upgrade() -> None:
    bind = op.get_bind()
    if _table_exists(bind, "decision_records") and not _column_exists(bind, "decision_records", "simulation_result"):
        op.add_column("decision_records", sa.Column("simulation_result", sa.JSON(), nullable=True))


def downgrade() -> None:
    bind = op.get_bind()
    if _table_exists(bind, "decision_records") and _column_exists(bind, "decision_records", "simulation_result"):
        op.drop_column("decision_records", "simulation_result")