using System;
using System.Collections;
using System.Collections.Generic;
using NUnit.Framework;
using UnityEngine;
using UnityEngine.TestTools;

namespace AibisDream.FrameAnimation.Tests.PlayMode
{
    /// <summary>
    /// 帧动画组件的最小运行时集成测试。
    /// 时间推进细节由 EditMode 的 PlaybackSession 契约覆盖。
    /// </summary>
    public sealed class FrameAnimationPlayerTests
    {
        private readonly List<UnityEngine.Object> createdObjects =
            new List<UnityEngine.Object>();

        [TearDown]
        public void TearDown()
        {
            for (var index = createdObjects.Count - 1; index >= 0; index--)
            {
                if (createdObjects[index] != null)
                    UnityEngine.Object.DestroyImmediate(createdObjects[index]);
            }

            createdObjects.Clear();
        }

        [Test]
        public void GraphPlayer_RendersAndAppliesTerminalBehavior()
        {
            var first = CreateSprite(Color.red);
            var second = CreateSprite(Color.blue);
            var clip = CreateClip(
                "Clip",
                FrameClipEndBehavior.Clear,
                first,
                second);
            var graph = CreateGraph(clip);
            var gameObject = Track(new GameObject("Graph Player"));
            var renderer = gameObject.AddComponent<SpriteRenderer>();
            var player = gameObject.AddComponent<FrameAnimationPlayer>();
            player.ConfigureForAuthoring(graph, false, 1f);

            var handle = player.Play(clip.Id);
            Assert.That(renderer.sprite, Is.SameAs(first));

            player.EvaluateForTests(0.2d);

            Assert.That(handle.Result.Reason,
                Is.EqualTo(FrameAnimationCompletionReason.Completed));
            Assert.That(renderer.sprite, Is.Null);
            Assert.That(renderer.enabled, Is.True);
        }

        [Test]
        public void StandalonePlayer_PlaysConfiguredClipWithoutGraph()
        {
            var first = CreateSprite(Color.magenta);
            var second = CreateSprite(Color.cyan);
            var clip = CreateClip(
                "Standalone",
                FrameClipEndBehavior.HoldLastFrame,
                first,
                second);
            var gameObject = Track(new GameObject("Standalone Player"));
            var renderer = gameObject.AddComponent<SpriteRenderer>();
            var player = gameObject.AddComponent<FrameClipPlayer>();
            player.ConfigureForAuthoring(clip, false, 1f);

            var handle = player.Play();
            Assert.That(player.CurrentClip, Is.SameAs(clip));
            player.EvaluateForTests(0.2d);

            Assert.That(handle.Result.Reason,
                Is.EqualTo(FrameAnimationCompletionReason.Completed));
            Assert.That(renderer.sprite, Is.SameAs(second));
        }

        [Test]
        public void PlayRequest_FailureKeepsActiveAndSuccessReplacesIt()
        {
            var first = CreateClip(
                "First",
                FrameClipEndBehavior.Loop,
                CreateSprite(Color.white));
            var second = CreateClip(
                "Second",
                FrameClipEndBehavior.Loop,
                CreateSprite(Color.black));
            var graph = CreateGraph(first, second);
            var gameObject = Track(new GameObject("Request Arbitration"));
            gameObject.AddComponent<SpriteRenderer>();
            var player = gameObject.AddComponent<FrameAnimationPlayer>();
            player.ConfigureForAuthoring(graph, false, 1f);

            var active = player.Play(first.Id);
            var failed = player.Play("Missing");

            Assert.That(failed.Result.Error.Code,
                Is.EqualTo(FrameAnimationPlaybackErrorCode.PlayableNotFound));
            Assert.That(active.IsCompleted, Is.False);
            Assert.That(player.CurrentPlayableId, Is.EqualTo(first.Id));

            var replacement = player.Play(second.Id);

            Assert.That(active.Result.Reason,
                Is.EqualTo(FrameAnimationCompletionReason.Replaced));
            Assert.That(replacement.IsCompleted, Is.False);
            Assert.That(player.CurrentPlayableId, Is.EqualTo(second.Id));
        }

        [Test]
        public void RestoreTerminalState_RebuildsSavedVisualState()
        {
            var terminalSprite = CreateSprite(Color.green);
            var hold = CreateClip(
                "Hold",
                FrameClipEndBehavior.HoldLastFrame,
                CreateSprite(Color.red),
                terminalSprite);
            var hidden = CreateClip(
                "Hidden",
                FrameClipEndBehavior.HideTarget,
                CreateSprite(Color.blue));
            var graph = CreateGraph(hold, hidden);
            var gameObject = Track(new GameObject("Restore Terminal State"));
            var renderer = gameObject.AddComponent<SpriteRenderer>();
            var player = gameObject.AddComponent<FrameAnimationPlayer>();
            player.ConfigureForAuthoring(graph, false, 1f);

            var holdResult = player.RestoreTerminalState(hold.Id);

            Assert.That(holdResult.Result.Reason,
                Is.EqualTo(FrameAnimationCompletionReason.Completed));
            Assert.That(renderer.sprite, Is.SameAs(terminalSprite));
            Assert.That(renderer.enabled, Is.True);

            player.RestoreTerminalState(hidden.Id);

            Assert.That(renderer.enabled, Is.False);
        }

        [UnityTest]
        public IEnumerator Disable_SettlesActiveRequestAsStopped()
        {
            var clip = CreateClip(
                "Loop",
                FrameClipEndBehavior.Loop,
                CreateSprite(Color.white));
            var gameObject = Track(new GameObject("Disable Player"));
            gameObject.AddComponent<SpriteRenderer>();
            var player = gameObject.AddComponent<FrameAnimationPlayer>();
            player.ConfigureForAuthoring(CreateGraph(clip), false, 1f);
            var handle = player.Play(clip.Id);

            player.enabled = false;
            yield return null;

            Assert.That(handle.Result.Reason,
                Is.EqualTo(FrameAnimationCompletionReason.Stopped));
            Assert.That(player.State, Is.EqualTo(FrameAnimationPlaybackState.Stopped));
        }

        private FrameClip CreateClip(
            string id,
            FrameClipEndBehavior endBehavior,
            params Sprite[] sprites)
        {
            var clip = Track(ScriptableObject.CreateInstance<FrameClip>());
            var frames = new List<FrameAnimationFrame>();
            for (var index = 0; index < sprites.Length; index++)
            {
                frames.Add(new FrameAnimationFrame(
                    sprites[index],
                    100,
                    $"frame_{index}",
                    index));
            }

            clip.Configure(id, id, frames, 1f, endBehavior);
            return clip;
        }

        private FrameAnimationGraph CreateGraph(params FrameClip[] clips)
        {
            var graph = Track(ScriptableObject.CreateInstance<FrameAnimationGraph>());
            graph.Configure(
                "Graph",
                "Graph",
                clips,
                Array.Empty<AnimationNode>(),
                Array.Empty<AnimationEdge>(),
                Array.Empty<AnimationFlow>(),
                clips[0].Id);
            return graph;
        }

        private Sprite CreateSprite(Color color)
        {
            var texture = Track(new Texture2D(2, 2));
            texture.SetPixels(new[] { color, color, color, color });
            texture.Apply();
            return Track(Sprite.Create(
                texture,
                new Rect(0, 0, 2, 2),
                new Vector2(0.5f, 0.5f)));
        }

        private T Track<T>(T value) where T : UnityEngine.Object
        {
            createdObjects.Add(value);
            return value;
        }
    }
}