from datetime import UTC, datetime
from unittest.mock import Mock

import pytest

from production_analytics.power_meter.config import load_power_meter_config
from production_analytics.power_meter.gateway import PowerMeterGateway
from production_analytics.power_meter.repository import counter_delta


def test_b2_config_has_only_verified_signals() -> None:
    config = load_power_meter_config("config/power-meters.example.yaml", "B2")
    assert config.machine_uuid == "0d7955e9-5cde-4e14-9af7-5b041dc796f0"
    assert config.signals.energy_total == "0f5c0853-1aa7-4fa3-b267-ea2669024e46"
    assert config.signals.power_outages is None


def test_counter_reset_starts_new_epoch() -> None:
    assert counter_delta(None, 7) == 0
    assert counter_delta(100, 105) == 5
    assert counter_delta(100, 4) == 4


def test_gateway_keeps_optional_phases_and_handles_pagination() -> None:
    config = load_meter()
    client = Mock()
    client.post_json.side_effect = [
        Mock(body={"data": {"columns": ["time", "e", "p", "f", "l1"],
                            "records": [["2026-09-01T00:00:00Z", 10, 4, 50, 2]]},
                   "metadata": {"next_cursor": "next"}}),
        Mock(body={"data": {"columns": ["time", "e", "p", "f", "l1"],
                            "records": [["2026-09-01T00:01:00Z", 11, 5, 49.9, 3]]},
                   "metadata": {"next_cursor": None}}),
    ]
    readings = PowerMeterGateway(client).read(config, datetime(2026, 9, 1, tzinfo=UTC),
                                              datetime(2026, 9, 2, tzinfo=UTC))
    assert [item.energy_total_kwh for item in readings] == [10, 11]
    assert readings[0].phase_active_power_kw == (("L1", 2.0),)
    assert client.post_json.call_args_list[1].args[1]["cursor"] == "next"


def load_meter():
    from production_analytics.power_meter.config import PowerMeterConfig, PowerMeterSignals
    return PowerMeterConfig("B2", "machine", PowerMeterSignals("e", "p", "f", phase_active_power=(("L1", "l1"),)))