"""add threads.pinned

Denormalized "pinned" state for a thread (SPEC extension for the UI pin action):
true when any message in the thread carries the \\Flagged flag.

Revision ID: 0004
Revises: 0003
Create Date: 2026-07-17
"""

from __future__ import annotations

from collections.abc import Sequence

from alembic import op

revision: str = "0004"
down_revision: str | None = "0003"
branch_labels: str | Sequence[str] | None = None
depends_on: str | Sequence[str] | None = None


def upgrade() -> None:
    op.execute("ALTER TABLE threads ADD COLUMN pinned boolean NOT NULL DEFAULT false")


def downgrade() -> None:
    op.execute("ALTER TABLE threads DROP COLUMN IF EXISTS pinned")