using Evergreen.Health.Application.Health.Integrations.HomeAssistant;
using Evergreen.Health.Application.Health.Policies;
using Evergreen.Health.Application.Health.Scenes;
using Microsoft.Extensions.Options;
using System.Globalization;

namespace Evergreen.Health.Application.Health.Devices.Environment;

public sealed class IndoorEnvironmentReader
{
    private readonly HomeAssistantEntityOptions _entities;
    private readonly TimeProvider _time;
    public IndoorEnvironmentReader(IOptions<HomeAssistantOptions> options, TimeProvider time)
        => (_entities, _time) = (options.Value.Entities, time);

    public IndoorTemperatureSample Read(IReadOnlyDictionary<string, HomeAssistantState> states) =>
        ReadState(string.IsNullOrWhiteSpace(_entities.Temperature) ? null : states.GetValueOrDefault(_entities.Temperature));

    public IndoorTemperatureSample Read(IReadOnlyList<HomeAssistantState> states) =>
        ReadState(states.LastOrDefault(state =>
            string.Equals(state.EntityId, _entities.Temperature, StringComparison.OrdinalIgnoreCase)));

    private IndoorTemperatureSample ReadState(HomeAssistantState? state)
    {
        if (state is null || !DeviceActionRunner.IsAvailable(state))
            return new(null, null, false, "室内温度实体未配置或不可用") { Issue = IndoorTemperatureIssue.Unavailable };
        var observedAt = state.LastReported ?? state.LastUpdated;
        var now = _time.GetUtcNow();
        if (observedAt is null || now - observedAt > TimeSpan.FromMinutes(30) || observedAt > now.AddMinutes(1))
            return new(null, observedAt, false, "室内温度数据缺少有效时间或已过期") { Issue = IndoorTemperatureIssue.Stale };
        if (!double.TryParse(state.State, NumberStyles.Float, CultureInfo.InvariantCulture, out var celsius) ||
            !double.IsFinite(celsius))
            return new(null, observedAt, false, "室内温度数据无效") { Issue = IndoorTemperatureIssue.Invalid };
        var unit = state.GetStringAttribute("unit_of_measurement");
        if (unit is "°F" or "F") celsius = (celsius - 32) * 5 / 9;
        else if (!string.IsNullOrWhiteSpace(unit) && unit is not ("°C" or "C" or "℃"))
            return new(null, observedAt, false, "室内温度单位未识别") { Issue = IndoorTemperatureIssue.Invalid };
        if (celsius is < -20 or > 60)
            return new(null, observedAt, false, "室内温度超出有效范围") { Issue = IndoorTemperatureIssue.Invalid };
        return new(celsius, observedAt, true, "室内温度数据有效");
    }
}