"""fk delete rules

Revision ID: 7884505b16b3
Revises: 7f567c8bafdb
Create Date: 2026-06-10 13:50:39.153585

"""
from typing import Sequence, Union

from alembic import op
import sqlalchemy as sa
import sqlmodel


# revision identifiers, used by Alembic.
revision: str = '7884505b16b3'
down_revision: Union[str, Sequence[str], None] = '7f567c8bafdb'
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    """Add delete rules to the three FKs (review ARCH-09/BE-11).

    Transactions and recurring items outlive their category (SET NULL);
    water readings die with their receipt (CASCADE). Constraint names match
    both pre-Alembic databases and fresh baseline builds (Postgres default
    naming).
    """
    op.drop_constraint("transaction_category_id_fkey", "transaction", type_="foreignkey")
    op.create_foreign_key(
        "transaction_category_id_fkey", "transaction", "category",
        ["category_id"], ["id"], ondelete="SET NULL",
    )
    op.drop_constraint("recurringitem_category_id_fkey", "recurringitem", type_="foreignkey")
    op.create_foreign_key(
        "recurringitem_category_id_fkey", "recurringitem", "category",
        ["category_id"], ["id"], ondelete="SET NULL",
    )
    op.drop_constraint("watermeterreading_receipt_id_fkey", "watermeterreading", type_="foreignkey")
    op.create_foreign_key(
        "watermeterreading_receipt_id_fkey", "watermeterreading", "municipalreceipt",
        ["receipt_id"], ["id"], ondelete="CASCADE",
    )

def downgrade() -> None:
    op.drop_constraint("watermeterreading_receipt_id_fkey", "watermeterreading", type_="foreignkey")
    op.create_foreign_key(
        "watermeterreading_receipt_id_fkey", "watermeterreading", "municipalreceipt",
        ["receipt_id"], ["id"],
    )
    op.drop_constraint("recurringitem_category_id_fkey", "recurringitem", type_="foreignkey")
    op.create_foreign_key(
        "recurringitem_category_id_fkey", "recurringitem", "category",
        ["category_id"], ["id"],
    )
    op.drop_constraint("transaction_category_id_fkey", "transaction", type_="foreignkey")
    op.create_foreign_key(
        "transaction_category_id_fkey", "transaction", "category",
        ["category_id"], ["id"],
    )