using System.Globalization;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using HC_APTBS.Models;
using HC_APTBS.Services;

namespace HC_APTBS.ViewModels
{
    /// <summary>
    /// ViewModel for the bench Temperature Control panel:
    /// PID setpoint input and heater / deposit cooler / inlet cooler relay toggles.
    /// </summary>
    public sealed partial class TemperatureControlViewModel : ObservableObject
    {
        private readonly IBenchService _bench;
        private readonly IConfigurationService _config;

        /// <summary>Operator-entered PID setpoint in °C (text to allow invariant parsing).</summary>
        [ObservableProperty] private string _setpointText = "40";

        /// <summary>Tolerance ±°C applied when the setpoint is committed.</summary>
        [ObservableProperty] private string _toleranceText = "2";

        /// <summary>True when the deposit heater relay is energised.</summary>
        [ObservableProperty] private bool _isHeaterOn;

        /// <summary>True when the deposit cooler relay is energised.</summary>
        [ObservableProperty] private bool _isDepositCoolerOn;

        /// <summary>True when the T-in (inlet) cooler relay is energised.</summary>
        [ObservableProperty] private bool _isTinCoolerOn;

        /// <param name="benchService">Bench service for PID setpoint and relay control.</param>
        /// <param name="configService">Configuration service — seeds setpoint from <see cref="AppSettings"/>.</param>
        public TemperatureControlViewModel(IBenchService benchService, IConfigurationService configService)
        {
            _bench  = benchService;
            _config = configService;

            // Seed setpoint from global temperature band midpoint, tolerance from its half-width.
            int min = _config.Settings.TempMin;
            int max = _config.Settings.TempMax;
            int mid = (min + max) / 2;
            int tol = (max - min) / 2;
            SetpointText  = mid.ToString(CultureInfo.InvariantCulture);
            ToleranceText = tol.ToString(CultureInfo.InvariantCulture);
        }

        partial void OnIsHeaterOnChanged(bool value)
            => _bench.SetRelay(RelayNames.DepositHeater, value);

        partial void OnIsDepositCoolerOnChanged(bool value)
            => _bench.SetRelay(RelayNames.DepositCooler, value);

        partial void OnIsTinCoolerOnChanged(bool value)
            => _bench.SetRelay(RelayNames.TinCooler, value);

        /// <summary>Applies the PID setpoint entered by the operator.</summary>
        [RelayCommand]
        private void ApplySetpoint()
        {
            if (!double.TryParse(SetpointText, NumberStyles.Float, CultureInfo.InvariantCulture, out double sp))
                return;
            if (!double.TryParse(ToleranceText, NumberStyles.Float, CultureInfo.InvariantCulture, out double tol))
                tol = 2;
            _bench.SetTemperatureSetpoint(sp, tol);
        }
    }
}