"""回归：时间列统一走 ``UTCDateTime`` —— 读出来必须带时区，写进去必须存 UTC。

背景：库里存的是 naive UTC，读出来也是裸时间，于是每一处比较/输出都要自己记得
补时区。项目里因此散了三份 ``_as_utc`` 和一堆 ``replace(tzinfo=UTC)``，还踩过一次

    TypeError: can't compare offset-naive and offset-aware datetimes

（P1a 的 CK 巡检排下一轮时间时炸的）。现在把边界收在 ``UTCDateTime``：
写时 aware→UTC 裸值、naive 视为 UTC；读时一律补 UTC 时区。

这组测试盯三件事：读出来是 aware、能和 ``datetime.now(UTC)`` 直接比、写进去
落的是 UTC 而不是本地时间。
"""

from datetime import UTC, datetime, timedelta, timezone

from sqlalchemy import text

from tests.support.db import get_test_engine, make_test_session
from web.backend.database import Base, UTCDateTime
from web.backend.models import Account, AutomationRun, LoginTask, User


class TestUtcDateTime:
    def setup_method(self):
        self.engine = get_test_engine()
        self.session = make_test_session(self.engine)

    def teardown_method(self):
        self.session.close()

    def _row(self, started_at):
        self.session.add(
            AutomationRun(job_key="k", started_at=started_at, status="success")
        )
        self.session.commit()
        return self.session.query(AutomationRun).one()

    def test_read_back_is_timezone_aware(self):
        row = self._row(datetime(2026, 10, 2, 12, 0, tzinfo=UTC))
        assert row.started_at.tzinfo is not None
        assert row.started_at.utcoffset() == timedelta(0)

    def test_read_back_value_can_compare_with_now(self):
        """这条就是当初炸掉的写法：库里的时间直接和 datetime.now(UTC) 比。"""
        row = self._row(datetime.now(UTC) - timedelta(minutes=1))
        assert row.started_at < datetime.now(UTC)  # 不再 TypeError

    def test_write_converts_local_aware_to_utc(self):
        """带 +08:00 的时间要按 UTC 落库，不能把本地壁钟直接存进去。"""
        local = datetime(2026, 10, 2, 20, 0, tzinfo=timezone(timedelta(hours=8)))
        row = self._row(local)
        assert row.started_at == datetime(2026, 10, 2, 12, 0, tzinfo=UTC)
        raw = self.session.execute(
            text("SELECT started_at FROM automation_runs")
        ).scalar()
        assert str(raw).startswith("2026-10-02 12:00")

    def test_naive_write_is_treated_as_utc(self):
        """库里读出来的裸值再写回去（常见于搬迁/复制）不能被当成本地时间再减 8 小时。"""
        naive_utc = datetime(2026, 10, 2, 12, 0)  # noqa: DTZ001 刻意构造裸 UTC
        row = self._row(naive_utc)
        assert row.started_at == datetime(2026, 10, 2, 12, 0, tzinfo=UTC)

    def test_none_stays_none(self):
        assert UTCDateTime().process_bind_param(None, None) is None
        assert UTCDateTime().process_result_value(None, None) is None

    def test_all_model_datetime_columns_use_utc_type(self):
        """新增时间列若忘了用 UTCDateTime，这里直接失败。"""
        offenders = []
        for table in Base.metadata.sorted_tables:
            for column in table.columns:
                if isinstance(column.type, UTCDateTime):
                    continue
                if str(column.type).upper().startswith("DATETIME"):
                    offenders.append(f"{table.name}.{column.name}")
        assert not offenders, f"这些时间列没用 UTCDateTime: {offenders}"

    def test_login_task_attempt_at_round_trips_as_utc(self):
        """真实模型抽查：写 aware、读 aware、能直接比较。"""
        user = User(username="u", password_hash="p", role="admin")
        account = Account(username="a", password="p", email="e", email_password="ep")
        self.session.add_all([user, account])
        self.session.commit()
        task = LoginTask(
            batch_id="b",
            account_id=account.id,
            created_by=user.id,
            attempt_at=datetime(2026, 10, 2, 12, 0, tzinfo=UTC),
        )
        self.session.add(task)
        self.session.commit()
        self.session.refresh(task)
        assert task.attempt_at == datetime(2026, 10, 2, 12, 0, tzinfo=UTC)
        # 模型侧保证 aware，所以业务代码可以直接比较
        assert task.attempt_at < datetime.now(UTC)