"""Deye systémový čas 62–64: dekódování, toleranční verify, politika driftu."""

from __future__ import annotations

import unittest
from datetime import datetime, timedelta, timezone

from services.control_exporter import (
    DEYE_CLOCK_DRIFT_OK_SEC,
    DEYE_CLOCK_RESYNC_INTERVAL_HOURS,
    DEYE_CLOCK_VERIFY_MAX_DELTA_SEC,
    InverterConfig,
    PRAGUE_TZ,
    _deye_clock_registers_verify_match,
    _deye_registers_to_prague_datetime,
    _deye_should_skip_time_sync_after_read,
    _deye_system_time_register_rows,
)


def _inv(
    *,
    sync_at: datetime | None = None,
) -> InverterConfig:
    return InverterConfig(
        id=1,
        code="deye-main",
        host="127.0.0.1",
        port=502,
        unit_id=1,
        max_export_power_w=13_500,
        max_import_power_w=13_500,
        no_export=False,
        max_battery_charge_w=10_000,
        max_battery_discharge_w=10_000,
        min_soc_percent=12,
        reserve_soc_percent=20,
        max_soc_percent=95,
        usable_capacity_wh=64_000,
        max_charge_a=100,
        max_discharge_a=100,
        deye_last_system_time_sync_at=sync_at,
    )


class DeyeClockDecodeTests(unittest.TestCase):
    def test_roundtrip_encode_decode(self) -> None:
        now_cet, rows = _deye_system_time_register_rows()
        r62 = next(v for a, _, v in rows if a == 62)
        r63 = next(v for a, _, v in rows if a == 63)
        r64 = next(v for a, _, v in rows if a == 64)
        dt = _deye_registers_to_prague_datetime(r62, r63, r64)
        self.assertIsNotNone(dt)
        assert dt is not None
        self.assertEqual(dt.tzinfo, PRAGUE_TZ)
        self.assertEqual(dt.year, now_cet.year)
        self.assertEqual(dt.month, now_cet.month)
        self.assertEqual(dt.day, now_cet.day)
        self.assertEqual(dt.hour, now_cet.hour)
        self.assertEqual(dt.minute, now_cet.minute)
        self.assertEqual(dt.second, 0)

    def test_verify_same_triplet(self) -> None:
        # 2006-10-03 15:45:00 Praha (platné měsíc/den/hod/min/sec)
        r62, r63, r64 = 0x060A, 0x030F, 0x2D00
        self.assertTrue(_deye_clock_registers_verify_match(r62, r63, r64, r62, r63, r64))

    def test_verify_seconds_within_tolerance(self) -> None:
        w62 = (2026 - 2000) << 8 | 4
        w63 = 3 << 8 | 14
        w64 = 30 << 8 | 10
        a64 = 30 << 8 | 50
        self.assertTrue(_deye_clock_registers_verify_match(w62, w63, w64, w62, w63, a64))
        self.assertLessEqual(40, DEYE_CLOCK_VERIFY_MAX_DELTA_SEC)

    def test_verify_fails_when_minute_differs_beyond_tolerance(self) -> None:
        w62 = (2026 - 2000) << 8 | 4
        w63 = 3 << 8 | 14
        w64 = 30 << 8 | 0
        a64 = 33 << 8 | 0
        self.assertFalse(_deye_clock_registers_verify_match(w62, w63, w64, w62, w63, a64))


class DeyeSkipTimeSyncPolicyTests(unittest.TestCase):
    def test_no_skip_when_never_written_even_if_drift_ok(self) -> None:
        wall = datetime.now(PRAGUE_TZ)
        r62 = ((wall.year - 2000) << 8) | wall.month
        r63 = (wall.day << 8) | wall.hour
        r64 = (wall.minute << 8) | wall.second
        self.assertFalse(
            _deye_should_skip_time_sync_after_read(_inv(sync_at=None), r62, r63, r64)
        )

    def test_no_skip_when_drift_large(self) -> None:
        wall = datetime.now(PRAGUE_TZ)
        wrong_min = (wall.minute - 3) % 60
        r62 = ((wall.year - 2000) << 8) | wall.month
        r63 = (wall.day << 8) | wall.hour
        r64 = (wrong_min << 8) | wall.second
        self.assertFalse(_deye_should_skip_time_sync_after_read(_inv(sync_at=None), r62, r63, r64))

    def test_no_skip_after_24h_even_if_drift_small(self) -> None:
        wall = datetime.now(PRAGUE_TZ)
        r62 = ((wall.year - 2000) << 8) | wall.month
        r63 = (wall.day << 8) | wall.hour
        r64 = (wall.minute << 8) | wall.second
        old = datetime.now(timezone.utc) - timedelta(hours=DEYE_CLOCK_RESYNC_INTERVAL_HOURS) - timedelta(minutes=1)
        self.assertFalse(
            _deye_should_skip_time_sync_after_read(_inv(sync_at=old), r62, r63, r64)
        )

    def test_skip_within_24h_and_small_drift(self) -> None:
        wall = datetime.now(PRAGUE_TZ)
        r62 = ((wall.year - 2000) << 8) | wall.month
        r63 = (wall.day << 8) | wall.hour
        r64 = (wall.minute << 8) | min(59, wall.second + 5)
        recent = datetime.now(timezone.utc) - timedelta(hours=1)
        self.assertTrue(
            _deye_should_skip_time_sync_after_read(_inv(sync_at=recent), r62, r63, r64)
        )
        self.assertGreater(DEYE_CLOCK_DRIFT_OK_SEC, 5)


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