"""Add user_id FK to todos table.

Revision ID: 027
Revises: 026
Create Date: 2026-02-26
"""
from alembic import op
import sqlalchemy as sa

revision = "027"
down_revision = "026"
branch_labels = None
depends_on = None


def upgrade() -> None:
    op.add_column("todos", sa.Column("user_id", sa.Integer(), nullable=True))
    op.execute(
        "UPDATE todos SET user_id = ("
        "  SELECT id FROM users WHERE role = 'admin' ORDER BY id LIMIT 1"
        ")"
    )
    op.create_foreign_key(
        "fk_todos_user_id", "todos", "users",
        ["user_id"], ["id"], ondelete="CASCADE"
    )
    op.alter_column("todos", "user_id", nullable=False)
    op.create_index("ix_todos_user_id", "todos", ["user_id"])
    op.create_index("ix_todos_user_completed", "todos", ["user_id", "completed"])
    op.create_index("ix_todos_user_due_date", "todos", ["user_id", "due_date"])


def downgrade() -> None:
    op.drop_index("ix_todos_user_due_date", table_name="todos")
    op.drop_index("ix_todos_user_completed", table_name="todos")
    op.drop_index("ix_todos_user_id", table_name="todos")
    op.drop_constraint("fk_todos_user_id", "todos", type_="foreignkey")
    op.drop_column("todos", "user_id")