using System.Collections.Generic;
using UnityEngine;

namespace Amanotes
{
    internal class RuntimeOverlay
    {
        private readonly List<float> fpsValues = new List<float>
            { 0, 1, 5, 10, 15, 20, 30, 45, 50, 60, 75, 90, 120, 240, 360, 480, 720, 960, 1000, 1200 };

        private readonly List<float> timeScaleValues = new List<float>
            { 0f, 0.1f, 0.2f, 0.5f, 1f, 2f, 5f, 10f };

        internal void OnGUI()
        {
            float fps = Application.targetFrameRate;
            if (DrawSlider("Target FPS", ref fps, fpsValues))
                Application.targetFrameRate = (int)fps;

            float ts = Time.timeScale;
            if (DrawSlider("Time Scale", ref ts, timeScaleValues))
                Time.timeScale = ts;
        }

        private static bool DrawSlider(string label, ref float v, List<float> values)
        {
            int idx1 = values.IndexOf(v);
            if (idx1 == -1) { values.Add(v); values.Sort(); idx1 = values.IndexOf(v); }

            GUILayout.BeginHorizontal();
            GUILayout.Label(label, GUILayout.Width(100f));
            int idx2 = Mathf.RoundToInt(GUILayout.HorizontalSlider(idx1, 0, values.Count - 1));
            GUILayout.Label($"{v}", GUILayout.Width(50f));
            GUILayout.EndHorizontal();

            if (idx2 == idx1) return false;
            v = values[idx2];
            return true;
        }
    }
}