// ReSharper disable MemberCanBePrivate.Global

using System;
using System.Collections.Generic;
using System.Threading;
using RGB.NET.Core;

namespace RGB.NET.Devices.WS281X;

/// <inheritdoc />
/// <summary>
/// Represents a device provider responsible for WS2812B- and WS2811-Led-devices.
/// </summary>
// ReSharper disable once InconsistentNaming
// ReSharper disable once UnusedType.Global
public sealed class WS281XDeviceProvider : AbstractRGBDeviceProvider
{
    #region Properties & Fields

    // ReSharper disable once InconsistentNaming
    private static readonly Lock _lock = new();

    private static WS281XDeviceProvider? _instance;
    /// <summary>
    /// Gets the singleton <see cref="WS281XDeviceProvider"/> instance.
    /// </summary>
    public static WS281XDeviceProvider Instance
    {
        get
        {
            lock (_lock)
                return _instance ?? new WS281XDeviceProvider();
        }
    }

    /// <summary>
    /// Gets a list of all defined device-definitions.
    /// </summary>
    // ReSharper disable once CollectionNeverUpdated.Global
    // ReSharper disable once ReturnTypeCanBeEnumerable.Global
    public List<IWS281XDeviceDefinition> DeviceDefinitions { get; } = [];

    #endregion

    #region Constructors

    /// <summary>
    /// Initializes a new instance of the <see cref="WS281XDeviceProvider"/> class.
    /// </summary>
    /// <exception cref="InvalidOperationException">Thrown if this constructor is called even if there is already an instance of this class.</exception>
    public WS281XDeviceProvider()
    {
        lock (_lock)
        {
            if (_instance != null) throw new InvalidOperationException($"There can be only one instance of type {nameof(WS281XDeviceProvider)}");
            _instance = this;
        }
    }

    #endregion

    #region Methods

    /// <summary>
    /// Adds the specified <see cref="IWS281XDeviceDefinition" /> to this device-provider.
    /// </summary>
    /// <param name="deviceDefinition">The <see cref="IWS281XDeviceDefinition"/> to add.</param>
    // ReSharper disable once UnusedMember.Global
    public void AddDeviceDefinition(IWS281XDeviceDefinition deviceDefinition) => DeviceDefinitions.Add(deviceDefinition);

    /// <inheritdoc />
    protected override void InitializeSDK() { }

    /// <inheritdoc />
    protected override IEnumerable<IRGBDevice> LoadDevices()
    {
        int i = 0;
        foreach (IWS281XDeviceDefinition deviceDefinition in DeviceDefinitions)
        {
            IDeviceUpdateTrigger updateTrigger = GetUpdateTrigger(i++);
            foreach (IRGBDevice device in deviceDefinition.CreateDevices(updateTrigger))
                yield return device;
        }
    }

    /// <inheritdoc />
    protected override void Dispose(bool disposing)
    {
        lock (_lock)
        {
            base.Dispose(disposing);

            DeviceDefinitions.Clear();

            _instance = null;
        }
    }

    #endregion
}