using Hi.Disp;
using System;
using System.Collections.Concurrent;
using System.Threading;
using System.Windows.Forms;
using System.ComponentModel;

namespace Hi.WinForm.Disp
{
    /// <summary>
    /// A <see cref="Form"/> contains <see cref="Disp.RenderingCanvas"/>.
    /// This class is usually used for debug due to its simplicity.
    /// </summary>
    public partial class RenderingForm : Form, IGetDispEngine
    {
        static readonly Form seedForm = new Form();
        private static readonly ConcurrentDictionary<string, RenderingForm> displayerMap
            = new ConcurrentDictionary<string, RenderingForm>(4, 4);
        /// <summary>
        /// See <see cref="Call(string, IDisplayee[])"/> to get the information.
        /// </summary>
        public static ConcurrentDictionary<string, RenderingForm> DisplayerMap { get => displayerMap; }
        /// <summary>
        /// Ctor.
        /// </summary>
        /// <param name="displayees">displayees</param>
        internal RenderingForm(params IDisplayee[] displayees)
        {
            InitializeComponent();
            RenderingCanvas = new RenderingCanvas(displayees);
            this.Controls.Add(RenderingCanvas);
            //Displayer.DispEngine.Start();
        }
        /// <summary>
        /// The contained <see cref="Disp.RenderingCanvas"/>.
        /// </summary>
        public RenderingCanvas RenderingCanvas { get; }
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
        public IDisplayee Displayee
        {
            get => GetDispEngine().Displayee;
            set
            {
                var preDisplayee = GetDispEngine().Displayee;
                GetDispEngine().Displayee = value;
                if (preDisplayee == null)
                    RenderingCanvas.DispEngine.SetViewToHomeView();
            }
        }
        /// <summary>
        /// Create and obtain a <see cref="RenderingForm"/> if the key has not existed; Otherwise, the old one is obtained.
        /// <paramref name="displayees"/> are set to the obtained <see cref="RenderingForm"/>.
        /// The dictionary of this function is <see cref="DisplayerMap"/>.
        /// </summary>
        /// <param name="key">key</param>
        /// <param name="displayees">The displayees set to the obtained <see cref="RenderingForm"/>.</param>
        /// <returns>A <see cref="RenderingForm"/> obtained by the key.</returns>
        public static RenderingForm Call(string key, params IDisplayee[] displayees)
        {
            if (displayerMap.TryGetValue(key, out RenderingForm f))
            {
                f.RenderingCanvas.DispEngine.Displayee = new DispList(displayees);
                return f;
            }
            else
            {
                _ = seedForm.Handle;
                seedForm.Invoke(new Action(() =>
                {
                    RenderingForm ff = new RenderingForm(displayees)
                    {
                        Text = key,
                        Visible = true
                    };
                    displayerMap.TryAdd(key, ff);
                }));

                RenderingForm fff = null;
                while (!displayerMap.TryGetValue(key, out fff))
                    Thread.Sleep(1);
                return fff;
            }
        }
        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                RenderingCanvas.Dispose();
                components.Dispose();
            }
            base.Dispose(disposing);
        }
        /// <inheritdoc/>
        public DispEngine GetDispEngine()
        {
            return RenderingCanvas.DispEngine;
        }
    }
}