using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Text;
using Luneraria.Core;
using NUnit.Framework;
using UnityEngine;
using UnityEngine.TestTools;

namespace Luneraria.View.Tests
{
    /// <summary>
    /// U2C in the real scene: the bot match of seed 2 runs with every view attached while the
    /// player loop runs at 30, 60, 120 FPS and unlimited (Application.targetFrameRate, VSync off).
    /// Each run must reproduce the core's fingerprint. The measured frame rates show that the
    /// frame timing really differed. Writes docs/port/logs/u2c/scene-frame-rates.json.
    /// </summary>
    public sealed class SceneFrameRateTests
    {
        const float Speed = 24f;

        [UnityTest]
        public IEnumerator SceneMatchIsTheSameAtRealFrameRates()
        {
            var options = new MatchOptions { Seed = 2, HumanSlot = -1 };
            LuneTrace core = LuneTrace.RunCore(options, 1, 0, "");
            var report = new StringBuilder("{\n  \"match\": \"seed 2, bots, speed " + Speed + "x\",\n  \"core_hash\": \"" + core.Hash.ToString("X16") + "\",\n  \"core_steps\": " + core.Steps + ",\n  \"runs\": [\n");
            var failures = new List<string>();
            int[] rates = { 30, 60, 120, -1 };
            for (int index = 0; index < rates.Length; index++)
            {
                QualitySettings.vSyncCount = 0;
                Application.targetFrameRate = rates[index];
                yield return PlayModeSupport.Load();
                var driver = Object.FindAnyObjectByType<LuneMatchDriver>();
                driver.Seed = 2;
                driver.StartRound = 1;
                driver.ExtraGold = 0;
                driver.Speed = Speed;
                driver.Restart();
                driver.Runner.PlanningSeconds = .5;
                driver.Runner.SettledSeconds = .5;
                var rig = Object.FindAnyObjectByType<LuneCameraRig>();
                rig.Interactive = false;
                rig.LookAt(new Vec2(0, 0), 60f, true);
                float start = Time.realtimeSinceStartup;
                int frames = 0;
                int maxSteps = 0;
                while (driver.Runner.Current != LuneMatchRunner.Stage.Over && Time.realtimeSinceStartup - start < 600f)
                {
                    yield return null;
                    frames++;
                    maxSteps = Mathf.Max(maxSteps, driver.Runner.StepsThisFrame);
                }
                float seconds = Time.realtimeSinceStartup - start;
                LuneTrace trace = driver.Runner.Trace;
                string label = rates[index] > 0 ? rates[index] + " fps" : "unlimited";
                bool same = trace.Hash == core.Hash && trace.Steps == core.Steps;
                if (!same)
                    failures.Add(label + ": " + trace.Hash.ToString("X16") + " / " + trace.Steps + " steps");
                Debug.Log(string.Format("LUNE_SCENE_FPS {0}: {1} frames in {2:0.0} s = {3:0.0} fps, up to {4} steps per frame, hash {5:X16}, same={6}", label, frames, seconds, frames / seconds, maxSteps, trace.Hash, same));
                report.AppendFormat("    {{\"target\": \"{0}\", \"frames\": {1}, \"seconds\": {2}, \"measured_fps\": {3}, \"max_steps_per_frame\": {4}, \"steps\": {5}, \"hash\": \"{6:X16}\", \"winner\": {7}, \"same_as_core\": {8}}}{9}\n",
                    label, frames, PlayModeSupport.Number(seconds), PlayModeSupport.Number(frames / seconds), maxSteps, trace.Steps, trace.Hash, driver.Runner.Match.Winner, same ? "true" : "false", index < rates.Length - 1 ? "," : "");
            }
            Application.targetFrameRate = -1;
            report.Append("  ]\n}\n");
            string logs = PlayModeSupport.Evidence("logs", "u2c");
            Directory.CreateDirectory(logs);
            File.WriteAllText(Path.Combine(logs, "scene-frame-rates.json"), report.ToString());
            Assert.IsEmpty(failures, string.Join("\n", failures));
        }
    }
}