using System;
using System.Collections.Generic;
using System.Linq;
using UnityEditor;
using UnityEditor.SceneManagement;
using UnityEngine;
using UnityEngine.SceneManagement;
using UnityEngine.UI;

namespace AibisDream.FrameAnimation.Editor
{
    public static class FrameAnimationRuntimeSampleBuilder
    {
        private const string SourceTexturePath =
            "Assets/GameContent/Test/AnimatorRaw/手接树叶特写.png";
        private const string SampleFolder = "Assets/GameContent/Test/FrameAnimation";
        private const string IntroClipPath = SampleFolder + "/Intro.asset";
        private const string IdleClipPath = SampleFolder + "/Idle.asset";
        private const string FlowGraphPath = SampleFolder + "/FlowSampleGraph.asset";
        private const string DirectGraphPath = SampleFolder + "/DirectSampleGraph.asset";
        private const string ScenePath = "Assets/Scenes/FrameAnimationRuntimeTest.unity";

        [MenuItem("Tools/Frame Animation/Rebuild Runtime Sample")]
        private static void BuildFromMenu()
        {
            if (!EditorSceneManager.SaveCurrentModifiedScenesIfUserWantsTo())
            {
                return;
            }

            BuildFromCommandLine();
        }

        public static void BuildFromCommandLine()
        {
            EnsureFolder(SampleFolder);
            var sprites = AssetDatabase.LoadAllAssetsAtPath(SourceTexturePath)
                .OfType<Sprite>()
                .OrderBy(sprite => ExtractFrameNumber(sprite.name))
                .ToArray();
            if (sprites.Length < 21)
            {
                throw new InvalidOperationException(
                    $"样例源 Texture 需要至少 21 个 Sprite，当前只找到 {sprites.Length} 个。");
            }

            var introClip = CreateOrLoadAsset<FrameClip>(IntroClipPath);
            introClip.Configure(
                "Intro",
                "Intro",
                CreateFrames(sprites, 0, 5),
                1f,
                FrameClipEndBehavior.HoldLastFrame);
            EditorUtility.SetDirty(introClip);

            var idleClip = CreateOrLoadAsset<FrameClip>(IdleClipPath);
            idleClip.Configure(
                "Idle",
                "Idle",
                CreateFrames(sprites, 5, 16),
                1f,
                FrameClipEndBehavior.Loop);
            EditorUtility.SetDirty(idleClip);

            var flowGraph = CreateOrLoadAsset<FrameAnimationGraph>(FlowGraphPath);
            var introNodeId = FindExistingNodeId(flowGraph, introClip.Id);
            var idleNodeId = FindExistingNodeId(flowGraph, idleClip.Id);
            var introNode = new AnimationNode(introClip.Id, "Intro", internalId: introNodeId);
            var idleNode = new AnimationNode(
                idleClip.Id,
                "Idle Loop",
                FrameClipEndBehavior.Loop,
                internalId: idleNodeId);
            var flow = new AnimationFlow("IntroToIdle", "Intro To Idle", introNode.InternalId);
            flowGraph.Configure(
                "FlowSampleGraph",
                "Flow Sample Graph",
                new[] { introClip, idleClip },
                new[] { introNode, idleNode },
                new[] { new AnimationEdge(introNode.InternalId, idleNode.InternalId) },
                new[] { flow },
                flow.Id);
            EditorUtility.SetDirty(flowGraph);

            var directGraph = CreateOrLoadAsset<FrameAnimationGraph>(DirectGraphPath);
            directGraph.Configure(
                "DirectSampleGraph",
                "Direct Sample Graph",
                new[] { introClip, idleClip },
                Array.Empty<AnimationNode>(),
                Array.Empty<AnimationEdge>(),
                Array.Empty<AnimationFlow>(),
                idleClip.Id);
            EditorUtility.SetDirty(directGraph);

            AssetDatabase.SaveAssets();
            BuildScene(flowGraph, directGraph);
            AssetDatabase.SaveAssets();
            AssetDatabase.Refresh();
            Debug.Log($"Frame Animation runtime sample rebuilt: {ScenePath}");
        }

        private static IEnumerable<FrameAnimationFrame> CreateFrames(
            IReadOnlyList<Sprite> sprites,
            int startIndex,
            int count)
        {
            for (var offset = 0; offset < count; offset++)
            {
                var sourceIndex = startIndex + offset;
                var sprite = sprites[sourceIndex];
                yield return new FrameAnimationFrame(sprite, 250, sprite.name, sourceIndex);
            }
        }

        private static void BuildScene(
            FrameAnimationGraph flowGraph,
            FrameAnimationGraph directGraph)
        {
            var scene = EditorSceneManager.NewScene(NewSceneSetup.EmptyScene, NewSceneMode.Single);

            var cameraObject = new GameObject("Main Camera", typeof(Camera));
            cameraObject.tag = "MainCamera";
            cameraObject.transform.position = new Vector3(0f, 0f, -10f);
            var camera = cameraObject.GetComponent<Camera>();
            camera.orthographic = true;
            camera.orthographicSize = 6f;
            camera.clearFlags = CameraClearFlags.SolidColor;
            camera.backgroundColor = new Color(0.08f, 0.09f, 0.12f, 1f);

            var spriteObject = new GameObject("Flow Sample - SpriteRenderer", typeof(SpriteRenderer));
            spriteObject.transform.position = new Vector3(-3.5f, 0f, 0f);
            spriteObject.transform.localScale = Vector3.one * 0.45f;
            var spritePlayer = spriteObject.AddComponent<FrameAnimationPlayer>();
            spritePlayer.ConfigureForAuthoring(flowGraph, true, 1f);

            var canvasObject = new GameObject(
                "Direct Clip Sample Canvas",
                typeof(Canvas),
                typeof(CanvasScaler),
                typeof(GraphicRaycaster));
            var canvas = canvasObject.GetComponent<Canvas>();
            canvas.renderMode = RenderMode.ScreenSpaceOverlay;
            var scaler = canvasObject.GetComponent<CanvasScaler>();
            scaler.uiScaleMode = CanvasScaler.ScaleMode.ScaleWithScreenSize;
            scaler.referenceResolution = new Vector2(1280f, 720f);

            var imageObject = new GameObject(
                "Direct Idle - Image",
                typeof(RectTransform),
                typeof(CanvasRenderer),
                typeof(Image));
            imageObject.transform.SetParent(canvasObject.transform, false);
            var rectTransform = imageObject.GetComponent<RectTransform>();
            rectTransform.sizeDelta = new Vector2(384f, 216f);
            rectTransform.anchoredPosition = new Vector2(300f, 0f);
            var image = imageObject.GetComponent<Image>();
            image.preserveAspect = true;
            var imagePlayer = imageObject.AddComponent<FrameAnimationPlayer>();
            imagePlayer.ConfigureForAuthoring(directGraph, true, 1f);

            EditorSceneManager.MarkSceneDirty(scene);
            if (!EditorSceneManager.SaveScene(scene, ScenePath))
            {
                throw new InvalidOperationException($"无法保存样例场景：{ScenePath}");
            }
        }

        private static T CreateOrLoadAsset<T>(string path) where T : ScriptableObject
        {
            var asset = AssetDatabase.LoadAssetAtPath<T>(path);
            if (asset != null)
            {
                return asset;
            }

            asset = ScriptableObject.CreateInstance<T>();
            AssetDatabase.CreateAsset(asset, path);
            return asset;
        }

        private static string FindExistingNodeId(FrameAnimationGraph graph, string clipId)
        {
            var existing = graph.Nodes.FirstOrDefault(node => node != null && node.ClipId == clipId);
            return existing != null && FrameAnimationValueUtility.IsValidInternalId(existing.InternalId)
                ? existing.InternalId
                : null;
        }

        private static int ExtractFrameNumber(string spriteName)
        {
            if (string.IsNullOrEmpty(spriteName))
            {
                return int.MaxValue;
            }

            var spaceIndex = spriteName.LastIndexOf(' ');
            var dotIndex = spriteName.LastIndexOf('.');
            if (spaceIndex >= 0 && dotIndex > spaceIndex &&
                int.TryParse(spriteName.Substring(spaceIndex + 1, dotIndex - spaceIndex - 1), out var number))
            {
                return number;
            }

            return int.MaxValue;
        }

        private static void EnsureFolder(string path)
        {
            var segments = path.Split('/');
            var current = segments[0];
            for (var index = 1; index < segments.Length; index++)
            {
                var next = current + "/" + segments[index];
                if (!AssetDatabase.IsValidFolder(next))
                {
                    AssetDatabase.CreateFolder(current, segments[index]);
                }
                current = next;
            }
        }
    }
}