using Evergreen.Health.Application.Health.Devices.Contracts;
using Evergreen.Health.Application.Health.Devices.Environment;
using Evergreen.Health.Application.Health.Integrations.HomeAssistant;
using Evergreen.Health.Application.Health.Policies;
using Evergreen.Health.Application.Health.Scenes;
using Evergreen.Health.Application.Health.Sleep;
using Microsoft.Extensions.Options;

namespace Evergreen.Health.Application.Health.Devices.Climate;

public sealed class BedPresenceClimateHeatAction(ClimateModule climate, IndoorEnvironmentReader environment,
    DeviceActionRunner runner, IOptions<HomeAssistantOptions> options) : IBedPresenceAction
{
    private const int TargetTemperature = 22;

    public string Key => "climate-heat-start";
    public string Description => "室温偏低时开启空调制热";
    public string ConditionLabel => $"室温低于 {TargetTemperature}℃ 且空调关机时，开启制热并设为 {TargetTemperature}℃。";
    public TimeSpan ExecutionTimeout => TimeSpan.FromSeconds(40);

    public bool SupportsTarget(string entityId) => options.Value.Enabled &&
        entityId?.StartsWith("climate.", StringComparison.Ordinal) == true && entityId == climate.PrimaryEntityId &&
        options.Value.Entities.Temperature?.StartsWith("sensor.", StringComparison.Ordinal) == true;

    public async Task<string> ExecuteAsync(string entityId, CancellationToken token)
    {
        if (!SupportsTarget(entityId)) return "target-not-configured";
        var mode = climate.BuildParameterCommand("climate_mode", "heat");
        var temperature = climate.BuildParameterCommand("climate_temperature", TargetTemperature) with
        {
            ExpectedEntityState = "heat"
        };

        var reason = await runner.SendIfAsync(mode, states => GetStartSkipReason(states, mode, temperature), token);
        if (reason is not null) return reason;

        try { await runner.VerifyParameterAsync(mode, token); }
        catch (InvalidOperationException) { return "climate-heat-mode-unconfirmed"; }

        try
        {
            reason = await runner.SendIfAsync(temperature, states =>
                CurrentState(states, entityId)?.State == "heat" ? null : "climate-heat-state-changed", token);
            if (reason is not null) return reason;
            await runner.VerifyParameterAsync(temperature, token);
            return "readback-confirmed";
        }
        catch (Exception error) when (error is not OperationCanceledException)
        {
            return "climate-heat-target-unconfirmed";
        }
    }

    private string? GetStartSkipReason(IReadOnlyList<HomeAssistantState> states, DeviceCommand mode, DeviceCommand temperature)
    {
        var sample = environment.Read(states);
        if (sample.Celsius is not { } celsius)
            return sample.Issue switch
            {
                IndoorTemperatureIssue.Stale => "temperature-stale",
                IndoorTemperatureIssue.Invalid => "temperature-invalid",
                _ => "temperature-unavailable"
            };
        if (celsius >= TargetTemperature) return "temperature-not-low";

        var state = CurrentState(states, mode.EntityId);
        if (state is null || !DeviceActionRunner.IsAvailable(state)) return "climate-unavailable";
        if (state.State != "off") return "climate-not-off";

        // 启动前同时校验制热模式和目标温度。
        try
        {
            mode.ValidateCurrentState!(state);
            temperature.ValidateCurrentState!(state);
            return null;
        }
        catch (InvalidOperationException) { return "climate-heat-unsupported"; }
    }

    private static HomeAssistantState? CurrentState(IReadOnlyList<HomeAssistantState> states, string entityId) =>
        states.FirstOrDefault(state => string.Equals(state.EntityId, entityId, StringComparison.OrdinalIgnoreCase));
}