"""회기 읽기 모델의 시간 직렬화 계약 테스트."""

from __future__ import annotations

import unittest
from datetime import datetime, timezone

from .session_projection import iso
from .session_read_model import session_calendar_date
from .services.session_metrics import iso_datetime


class SessionReadModelIsoTest(unittest.TestCase):
    def test_none_remains_none(self) -> None:
        self.assertIsNone(iso(None))

    def test_epoch_is_serialized_as_utc_with_offset(self) -> None:
        self.assertEqual(iso(0), "1970-01-01T00:00:00+00:00")

    def test_timestamp_round_trips_without_local_timezone_drift(self) -> None:
        timestamp = 1_800_000_120.0

        rendered = iso(timestamp)

        self.assertIsNotNone(rendered)
        assert rendered is not None
        parsed = datetime.fromisoformat(rendered)
        self.assertEqual(parsed.tzinfo, timezone.utc)
        self.assertEqual(parsed.timestamp(), timestamp)

    def test_serialized_timestamp_has_explicit_utc_suffix(self) -> None:
        rendered = iso(1_800_000_120.0)

        self.assertIsNotNone(rendered)
        assert rendered is not None
        self.assertTrue(rendered.endswith("+00:00"))

    def test_dashboard_metrics_use_the_same_utc_contract(self) -> None:
        timestamp = 1_800_000_120.0

        self.assertEqual(iso_datetime(timestamp), iso(timestamp))

    def test_review_calendar_date_uses_korea_standard_time(self) -> None:
        utc_late_afternoon = datetime(2026, 8, 8, 15, 30, tzinfo=timezone.utc)

        self.assertEqual(session_calendar_date(utc_late_afternoon.timestamp()), "2026-08-09")


if __name__ == "__main__":
    unittest.main()