import json
from pathlib import Path
from typing import Any, Callable
from unittest.mock import Mock, patch

import pandas as pd
import pytest
from loguru import logger

from akkudoktoreos.core.cache import CacheFileStore
from akkudoktoreos.core.coreabc import get_ems
from akkudoktoreos.prediction.weatheropenmeteo import WeatherOpenMeteo
from akkudoktoreos.utils.datetimeutil import to_datetime

DIR_TESTDATA = Path(__file__).absolute().parent.joinpath("testdata")

FILE_TESTDATA_WEATHEROPENMETEO_1_JSON = DIR_TESTDATA.joinpath("weatherforecast_openmeteo_1.json")
FILE_TESTDATA_WEATHEROPENMETEO_2_JSON = DIR_TESTDATA.joinpath("weatherforecast_openmeteo_2.json")


@pytest.fixture
def provider(monkeypatch):
    """Fixture to create a WeatherProvider instance."""
    monkeypatch.setenv("EOS_WEATHER__WEATHER_PROVIDER", "OpenMeteo")
    monkeypatch.setenv("EOS_GENERAL__LATITUDE", "50.0")
    monkeypatch.setenv("EOS_GENERAL__LONGITUDE", "10.0")
    return WeatherOpenMeteo()


@pytest.fixture
def sample_openmeteo_1_json():
    """Fixture that returns sample forecast data report from Open-Meteo."""
    with FILE_TESTDATA_WEATHEROPENMETEO_1_JSON.open("r", encoding="utf-8", newline=None) as f_res:
        input_data = json.load(f_res)
    return input_data


@pytest.fixture
def sample_openmeteo_2_json():
    """Fixture that returns sample processed forecast data from Open-Meteo."""
    with FILE_TESTDATA_WEATHEROPENMETEO_2_JSON.open("r", encoding="utf-8", newline=None) as f_res:
        input_data = json.load(f_res)
    return input_data


@pytest.fixture
def cache_store():
    """A pytest fixture that creates a new CacheFileStore instance for testing."""
    return CacheFileStore()


# ------------------------------------------------
# General forecast
# ------------------------------------------------


def test_singleton_instance(provider):
    """Test that WeatherForecast behaves as a singleton."""
    another_instance = WeatherOpenMeteo()
    assert provider is another_instance


def test_invalid_provider(provider, monkeypatch):
    """Test requesting an unsupported provider."""
    monkeypatch.setenv("EOS_WEATHER__WEATHER_PROVIDER", "<invalid>")
    provider.config.reset_settings()
    assert not provider.enabled()


def test_invalid_coordinates(provider, monkeypatch):
    """Test invalid coordinates raise ValueError."""
    monkeypatch.setenv("EOS_GENERAL__LATITUDE", "1000")
    monkeypatch.setenv("EOS_GENERAL__LONGITUDE", "1000")
    with pytest.raises(
        ValueError,  # match="Latitude '1000' and/ or longitude `1000` out of valid range."
    ):
        provider.config.reset_settings()


# ------------------------------------------------
# Irradiance calculation
# ------------------------------------------------


def test_irridiance_estimate_from_cloud_cover(provider):
    """Test cloud cover to irradiance estimation (fallback method)."""
    cloud_cover_data = pd.Series(
        data=[20, 50, 80], index=pd.date_range("2023-10-22", periods=3, freq="h")
    )

    ghi, dni, dhi = provider.estimate_irradiance_from_cloud_cover(50.0, 10.0, cloud_cover_data)

    # This is just the fallback method - Open-Meteo normally provides direct values
    assert len(ghi) == 3
    assert len(dni) == 3
    assert len(dhi) == 3
    # Values should be floats (actual values depend on the algorithm)
    assert all(isinstance(x, float) for x in ghi)
    assert all(isinstance(x, float) for x in dni)
    assert all(isinstance(x, float) for x in dhi)


# ------------------------------------------------
# Open-Meteo
# ------------------------------------------------


@patch("requests.get")
def test_request_forecast(mock_get, provider, sample_openmeteo_1_json):
    """Test requesting forecast from Open-Meteo."""
    # Mock response object
    mock_response = Mock()
    mock_response.status_code = 200
    mock_response.json.return_value = sample_openmeteo_1_json
    mock_response.content = json.dumps(sample_openmeteo_1_json)
    mock_get.return_value = mock_response

    # Test function
    openmeteo_data = provider._request_forecast()

    # Verify API was called with correct parameters
    mock_get.assert_called_once()
    call_args = mock_get.call_args
    assert call_args[0][0] == "https://api.open-meteo.com/v1/forecast"
    assert "latitude" in call_args[1]["params"]
    assert "longitude" in call_args[1]["params"]
    assert "hourly" in call_args[1]["params"]

    # Verify returned data structure
    assert isinstance(openmeteo_data, dict)
    assert "hourly" in openmeteo_data
    assert "time" in openmeteo_data["hourly"]
    assert "temperature_2m" in openmeteo_data["hourly"]
    assert "shortwave_radiation" in openmeteo_data["hourly"]  # GHI
    assert "direct_radiation" in openmeteo_data["hourly"]     # DNI
    assert "diffuse_radiation" in openmeteo_data["hourly"]    # DHI


@pytest.mark.asyncio
@pytest.mark.parametrize("host_timezone", ["UTC", "Europe/Berlin"])
@patch("requests.get")
async def test_update_data(
    mock_get: Mock,
    provider: WeatherOpenMeteo,
    sample_openmeteo_1_json: dict[str, Any],
    cache_store: CacheFileStore,
    set_other_timezone: Callable[[str], str],
    host_timezone: str,
) -> None:
    """Map each forecast hour in the provider timezone, regardless of the host timezone."""
    set_other_timezone(host_timezone)
    # Mock response object
    mock_response = Mock()
    mock_response.status_code = 200
    mock_response.json.return_value = sample_openmeteo_1_json
    mock_response.content = json.dumps(sample_openmeteo_1_json)
    mock_get.return_value = mock_response

    cache_store.clear(clear_all=True)

    # Call the method
    ems_eos = get_ems()
    start_datetime = to_datetime("2026-03-02 09:00:00+01:00", in_timezone="Europe/Berlin")
    ems_eos.set_start_datetime(start_datetime)
    await provider.update_data(force_enable=True, force_update=True)

    # Assert: Verify the result is as expected
    mock_get.assert_called_once()
    assert len(provider) > 0

    # Open-Meteo returns local wall times without offsets or seconds. Build the
    # expected instants independently of to_datetime, including midnight boundaries.
    hourly = sample_openmeteo_1_json["hourly"]
    expected_datetimes = pd.DatetimeIndex(hourly["time"], tz="Europe/Berlin").to_pydatetime()
    for source_key, record_key in (
        ("shortwave_radiation", "weather_ghi"),
        ("direct_radiation", "weather_dni"),
        ("diffuse_radiation", "weather_dhi"),
    ):
        datetimes, values = await provider.key_to_lists(record_key)
        assert list(datetimes) == list(expected_datetimes)
        assert values == hourly[source_key]


# ------------------------------------------------
# Test specific Open-Meteo features
# ------------------------------------------------


def test_openmeteo_radiation_mapping(provider):
    """Test that radiation values are correctly mapped from Open-Meteo keys."""
    # Verify mapping contains the radiation fields
    from akkudoktoreos.prediction.weatheropenmeteo import WeatherDataOpenMeteoMapping

    radiation_keys = [item[0] for item in WeatherDataOpenMeteoMapping
                     if item[0] in ['shortwave_radiation', 'direct_radiation', 'diffuse_radiation']]

    assert 'shortwave_radiation' in radiation_keys
    assert 'direct_radiation' in radiation_keys
    assert 'diffuse_radiation' in radiation_keys

    # Verify they map to correct descriptions
    for key, desc, _ in WeatherDataOpenMeteoMapping:
        if key == 'shortwave_radiation':
            assert desc == "Global Horizontal Irradiance (W/m2)"
        elif key == 'direct_radiation':
            assert desc == "Direct Normal Irradiance (W/m2)"
        elif key == 'diffuse_radiation':
            assert desc == "Diffuse Horizontal Irradiance (W/m2)"


def test_openmeteo_unit_conversions(provider):
    """Test that unit conversions are correctly applied."""
    from akkudoktoreos.prediction.weatheropenmeteo import WeatherDataOpenMeteoMapping

    # Check wind speed conversion (m/s to km/h)
    wind_speed_mapping = next(item for item in WeatherDataOpenMeteoMapping
                             if item[0] == 'wind_speed_10m')
    assert wind_speed_mapping[2] == 3.6  # Conversion factor

    # Check pressure conversion (Pa to hPa)
    pressure_mapping = next(item for item in WeatherDataOpenMeteoMapping
                           if item[0] == 'pressure_msl')
    assert pressure_mapping[2] == 0.01  # Conversion factor


@pytest.mark.parametrize(
    "start_offset_days, expected_keys, forbidden_keys",
    [
        # Future → forecast mode
        (1, ["forecast_days"], ["start_date", "end_date", "models"]),
        # Today (edge case, should still be forecast)
        (0, ["forecast_days"], ["start_date", "end_date", "models"]),
        # Past → historical mode
        (-2, ["start_date", "end_date", "models"], ["forecast_days"]),
    ],
)
@patch("requests.get")
def test_openmeteo_request_mode_selection(
    mock_get,
    provider,
    sample_openmeteo_1_json,
    start_offset_days,
    expected_keys,
    forbidden_keys,
):
    """Test that Open-Meteo request switches correctly between forecast and historical modes."""

    # Mock response
    mock_response = Mock()
    mock_response.status_code = 200
    mock_response.json.return_value = sample_openmeteo_1_json
    mock_response.content = str(sample_openmeteo_1_json)
    mock_get.return_value = mock_response

    # Fixed current time to avoid timing issues
    fixed_now = to_datetime("2026-03-26 12:00:00+01:00", in_timezone="Europe/Berlin")

    # Patch to_datetime to return fixed_now when called without a datetime argument
    with patch("akkudoktoreos.prediction.weatheropenmeteo.to_datetime") as mock_to_datetime:
        def to_datetime_side_effect(dt=None, in_timezone=None):
            if dt is None:
                return fixed_now
            # Otherwise fall back to the real function
            from akkudoktoreos.utils.datetimeutil import to_datetime as real_to_datetime
            return real_to_datetime(dt, in_timezone=in_timezone)

        mock_to_datetime.side_effect = to_datetime_side_effect

        # Set deterministic start time based on fixed_now
        start = fixed_now + pd.Timedelta(days=start_offset_days)

        ems_eos = get_ems()
        ems_eos.set_start_datetime(start)

        # Execute
        provider._request_forecast()

    # Inspect request params
    params = mock_get.call_args[1]["params"]

    # Assertions
    for key in expected_keys:
        assert key in params, f"Expected '{key}' in params but got {params}"

    for key in forbidden_keys:
        assert key not in params, f"Did not expect '{key}' in params but got {params}"

    if "forecast_days" in params:
        assert params["forecast_days"] >= 1
        assert params["forecast_days"] <= 16


# ------------------------------------------------
# Development Open-Meteo
# ------------------------------------------------


@pytest.mark.asyncio
async def test_openmeteo_development_forecast_data(provider, config_eos, is_system_test):
    """Fetch data from real Open-Meteo server for development purposes."""
    if not is_system_test:
        return

    # Us actual date for forecast (not historic data)
    now = to_datetime(in_timezone="Europe/Berlin")
    start_date = now.replace(hour=0, minute=0, second=0, microsecond=0)
    end_date = start_date + pd.Timedelta(days=3)  # 3 Tage Vorhersage

    ems_eos = get_ems()
    ems_eos.set_start_datetime(start_date)

    config_eos.general.latitude = 50.0
    config_eos.general.longitude = 10.0

    # Fetch raw data from Open-Meteo
    try:
        openmeteo_data = provider._request_forecast()

        # Save raw API response
        with FILE_TESTDATA_WEATHEROPENMETEO_1_JSON.open("w", encoding="utf-8", newline="\n") as f_out:
            json.dump(openmeteo_data, f_out, indent=4)

        # Update and process data
        await provider.update_data(force_enable=True, force_update=True)

        # Save processed data
        with FILE_TESTDATA_WEATHEROPENMETEO_2_JSON.open("w", encoding="utf-8", newline="\n") as f_out:
            f_out.write(provider.model_dump_json(indent=4))

        # Verify radiation values
        if len(provider) > 0:
            records = list(provider.records)

            # Check fo radiation values available
            has_ghi = any(hasattr(r, 'ghi') and r.ghi is not None for r in records)
            has_dni = any(hasattr(r, 'dni') and r.dni is not None for r in records)
            has_dhi = any(hasattr(r, 'dhi') and r.dhi is not None for r in records)

            logger.info(f"Open-Meteo data verification: GHI={has_ghi}, DNI={has_dni}, DHI={has_dhi}")

            # Optional: Check for positive values (at day time)
            daytime_values = [getattr(r, 'ghi', 0) for r in records[:24]
                            if hasattr(r, 'ghi') and r.ghi is not None and r.ghi > 10]
            if daytime_values:
                logger.info(f"Found {len(daytime_values)} positive GHI values")

    except Exception as e:
        logger.error(f"Error fetching Open-Meteo data: {e}")
        # Debug-Ausgabe
        logger.error(f"Request would have been: https://api.open-meteo.com/v1/forecast?latitude=50.0&longitude=10.0&hourly=temperature_2m,relative_humidity_2m,shortwave_radiation&timezone=Europe/Berlin&forecast_days=3")
        raise