// ReSharper disable MemberCanBePrivate.Global
// ReSharper disable UnusedMember.Global

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

namespace RGB.NET.Devices.Debug
{
    /// <inheritdoc />
    /// <summary>
    /// Represents a device provider responsible for debug devices.
    /// </summary>
    public class DebugDeviceProvider : AbstractRGBDeviceProvider
    {
        #region Properties & Fields

        private static DebugDeviceProvider? _instance;
        /// <summary>
        /// Gets the singleton <see cref="DebugDeviceProvider"/> instance.
        /// </summary>
        public static DebugDeviceProvider Instance => _instance ?? new DebugDeviceProvider();

        private List<(IDeviceLayout layout, Action<IEnumerable<Led>>? updateLedsAction)> _fakeDeviceDefinitions = new();

        #endregion

        #region Constructors

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

        #endregion

        #region Methods

        /// <summary>
        /// Adds a new fake device definition.
        /// </summary>
        /// <param name="layout">The path of the layout file to be used.</param>
        /// <param name="updateLedsAction">A action emulating led-updates.</param>
        public void AddFakeDeviceDefinition(IDeviceLayout layout, Action<IEnumerable<Led>>? updateLedsAction = null)
            => _fakeDeviceDefinitions.Add((layout, updateLedsAction));

        /// <summary>
        /// Removes all previously added fake device definitions.
        /// </summary>
        public void ClearFakeDeviceDefinitions() => _fakeDeviceDefinitions.Clear();

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

        /// <inheritdoc />
        protected override IEnumerable<IRGBDevice> LoadDevices()
        {
            foreach ((IDeviceLayout layout, Action<IEnumerable<Led>>? updateLedsAction) in _fakeDeviceDefinitions)
                yield return new DebugRGBDevice(layout, updateLedsAction);
        }

        /// <inheritdoc />
        public override void Dispose()
        {
            base.Dispose();

            _fakeDeviceDefinitions.Clear();
        }

        #endregion
    }
}