using System;
using System.Diagnostics;
using System.Text;
using FlaxEngine;
using FlaxEngine.GUI;

namespace Game;

[ExecuteInEditMode]
public class PerformanceWidget : Script
{
    private const double updateInterval = 0.2;

    public UIControl control;
    private Label label;

    private Stopwatch stopwatch;
    private Stopwatch stopwatch2;

    private double updateTimeAvg;
    private double updateTimeAvg2;
    private ulong updateTimeCount;
    private ulong updateTimeCount2;

    public override void OnAwake()
    {
        label = (Label)control.Control;
        label.Text = $"0fps";
        control.HideFlags = HideFlags.None;

        stopwatch = Stopwatch.StartNew();
        stopwatch2 = Stopwatch.StartNew();
    }

    public override void OnUpdate()
    {
        updateTimeCount2++;
        double elapsed2 = stopwatch2.Elapsed.TotalSeconds;
        if (elapsed2 >= updateInterval * 10)
        {
            stopwatch2.Restart();
            updateTimeAvg2 = elapsed2 / updateTimeCount2;
            updateTimeCount2 = 0;
        }

        updateTimeCount++;
        double elapsed = stopwatch.Elapsed.TotalSeconds;
        if (elapsed >= updateInterval)
        {
            stopwatch.Restart();
            updateTimeAvg = elapsed / updateTimeCount;
            updateTimeCount = 0;

            StringBuilder text = new StringBuilder(10);

#if true
            long triangles = 0;
            long drawCalls = 0;

#if BUILD_DEBUG || BUILD_DEVELOPMENT
            var gpuEvents = ProfilingTools.EventsGPU;
            if (gpuEvents.Length > 0)
            {
	                triangles = gpuEvents[0].Stats.Triangles;
	                drawCalls = gpuEvents[0].Stats.DrawCalls;
            }
#endif

            text.AppendLine($"{triangles} tris\n {drawCalls} drawcalls");
            text.AppendLine($"{(int)Math.Round(1.0f / updateTimeAvg2)}fps2");
#endif
            text.Append($"{(int)Math.Round(1.0f / updateTimeAvg)}fps");

            label.Text = text.ToString();
        }

#if false
#if BUILD_DEVELOPMENT
			var nameOffset = Marshal.OffsetOf(typeof(ProfilerCPU.Event), "Name0");
			foreach (var eventsCpu in FlaxEngine.ProfilingTools.EventsCPU)
			{
				sb.Append("\nName: " + eventsCpu.Name + " ");
				foreach (var eventt in eventsCpu.Events)
				{
#if FLAX_EDITOR
					string eventName = eventt.Name;
#else
					string eventName;
					unsafe
					{
						var ptr1 = &eventt;
						char* ptr2 = (char*)(new IntPtr((byte*)ptr1 + nameOffset.ToInt64()));
						//fixed (char* name = &eventt)
						{
							eventName = new string(ptr2);
						}
					}
#endif

					sb.Append(eventName + " " + (eventt.End-eventt.Start) + "ms, ");
				}

			}
#endif
#endif
    }
}