"""Attendance: HR-maintained roster overlay (include / exclude).

Adds ``attendance_roster_overrides`` so HR can patch the Feishu-derived
intern roster without losing the auto-pull: ``include`` rows drag a person
into the report even when they are not in the Feishu 通讯录 department
(the 许晴 case — onboarded in Helix but never added to the Feishu group),
``exclude`` rows keep a Feishu member out. Effective roster =
(Feishu members ∪ includes) − excludes.

``id`` / ``person_id`` / ``created_by`` use ``id_type_for('identity_persons')``
so the column type matches ``identity_persons.id`` (TiDB is strict about
CHAR↔VARCHAR); no DB FK is declared, matching the sibling attendance_cycles
/ attendance_reports convention (person identity is resolved at the
serializer layer). One override per person (UNIQUE person_id).

Revision ID: 380
Revises: 379
"""
from __future__ import annotations

import sqlalchemy as sa

from alembic import op

from app.core.migration_helpers import id_type_for, table_kw_for

revision = "380"
down_revision = "379"
branch_labels = None
depends_on = None

TABLE = "attendance_roster_overrides"


def _table_exists(bind, name: str) -> bool:
    return bool(bind.execute(
        sa.text(
            "SELECT 1 FROM information_schema.tables "
            "WHERE table_schema = DATABASE() AND table_name = :t LIMIT 1"
        ),
        {"t": name},
    ).scalar())


def upgrade() -> None:
    bind = op.get_bind()
    if _table_exists(bind, TABLE):
        return
    pid = id_type_for("identity_persons")
    op.create_table(
        TABLE,
        sa.Column("id", pid, nullable=False),
        sa.Column("person_id", pid, nullable=False),
        sa.Column("mode", sa.String(16), nullable=False),
        sa.Column("note", sa.Text(), nullable=True),
        sa.Column("created_by", pid, nullable=True),
        sa.Column(
            "created_at", sa.DateTime(timezone=True),
            nullable=False, server_default=sa.func.now(),
        ),
        sa.Column(
            "updated_at", sa.DateTime(timezone=True),
            nullable=False, server_default=sa.func.now(),
        ),
        sa.PrimaryKeyConstraint("id"),
        sa.UniqueConstraint("person_id", name="uq_attendance_roster_overrides_person"),
        **table_kw_for("identity_persons"),
    )


def downgrade() -> None:
    bind = op.get_bind()
    if _table_exists(bind, TABLE):
        op.drop_table(TABLE)