using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;

using UnityEngine;

using UnityEditor;

using UnityEditor.Animations;

using Colosseum.Skills;
using Colosseum.Enemy;

/// <summary>
/// 스킬/보스/애니메이션 컨트롤러에서 참조 중인 FBX 내장 AnimationClip을 개별 .anim으로 추출하고,
/// 모든 참조를 갱신한 뒤 원본 FBX를 삭제하는 에디터 도구입니다.
/// </summary>
public static class AnimationClipExtractor
{
    private const string MenuPathExtract = "Tools/Animation/Extract Clips from FBX";
    private const string MenuPathRelink = "Tools/Animation/Relink Clips to Extracted .anim";

    // ─────────────────────────────────────────────
    // Extract + Relink + Delete FBX (메인 진입점)
    // ─────────────────────────────────────────────

    [MenuItem(MenuPathExtract)]
    public static void ExtractAndRelink()
    {
        // ── 1. 참조 중인 클립 수집 (SkillData + BossPhaseData + AnimatorController) ──
        HashSet<AnimationClip> referencedClips = CollectReferencedClips();

        if (referencedClips.Count == 0)
        {
            EditorUtility.DisplayDialog(
                "Animation Clip Extractor",
                "스킬/보스/컨트롤러에서 참조 중인 AnimationClip이 없습니다.",
                "확인");
            return;
        }

        // ── 2. FBX 서브에셋인 클립만 필터링 ──
        var extractPlan = new List<(string fbxPath, AnimationClip clip, string clipName, string outputPath)>();
        int skipStandalone = 0;
        int skipExisting = 0;

        foreach (AnimationClip clip in referencedClips)
        {
            if (clip == null) continue;

            string assetPath = AssetDatabase.GetAssetPath(clip);

            if (assetPath.EndsWith(".anim", StringComparison.OrdinalIgnoreCase))
            {
                skipStandalone++;
                continue;
            }

            if (!assetPath.EndsWith(".fbx", StringComparison.OrdinalIgnoreCase))
            {
                skipStandalone++;
                continue;
            }

            string fbxDir = Path.GetDirectoryName(assetPath).Replace("\\", "/");
            string fbxName = Path.GetFileNameWithoutExtension(assetPath);
            string outputPath = $"{fbxDir}/{fbxName}.anim";

            if (AssetDatabase.AssetPathToGUID(outputPath) != string.Empty)
            {
                skipExisting++;
                continue;
            }

            extractPlan.Add((assetPath, clip, fbxName, outputPath));
        }

        // ── 3. 요약 ──
        string summary = $"참조 중인 클립: {referencedClips.Count}개\n"
            + $"추출 대상: {extractPlan.Count}개\n";

        if (skipStandalone > 0)
            summary += $"이미 독립 파일: {skipStandalone}개 (건너뜀)\n";
        if (skipExisting > 0)
            summary += $"이미 추출됨: {skipExisting}개 (건너뜀)\n";

        if (extractPlan.Count == 0)
        {
            bool doRelink = EditorUtility.DisplayDialog(
                "Animation Clip Extractor",
                $"{summary}\n추출할 클립이 없습니다.\n\n기존 추출된 .anim으로 참조를 갱신하시겠습니까?",
                "Relink", "취소");

            if (doRelink)
            {
                int relinked = PerformRelink();
                PerformDeleteFbx();
                EditorUtility.DisplayDialog("Animation Clip Extractor",
                    $"Relink: {relinked}개 참조 갱신", "확인");
            }

            return;
        }

        summary += "\n── 추출 대상 ──\n";
        foreach (var (fbxPath, clip, clipName, _) in extractPlan)
            summary += $"  {clip.name} → {clipName}.anim\n";

        // 삭제될 FBX 목록 (중복 제거)
        var fbxsToDelete = new HashSet<string>(extractPlan.Select(e => e.fbxPath));
        summary += $"\n── 삭제될 FBX ({fbxsToDelete.Count}개) ──\n";
        foreach (string fbx in fbxsToDelete.OrderBy(p => p))
            summary += $"  {Path.GetFileName(fbx)}\n";

        summary += "\n추출 → 참조 갱신 → FBX 삭제 순서로 진행합니다.";

        if (!EditorUtility.DisplayDialog(
            "Animation Clip Extractor",
            $"{summary}\n진행하시겠습니까?",
            "진행", "취소"))
        {
            return;
        }

        // ── 4. 클립 추출 ──
        AssetDatabase.StartAssetEditing();
        int successCount = 0;
        int errorCount = 0;

        try
        {
            foreach (var (fbxPath, sourceClip, clipName, outputPath) in extractPlan)
            {
                try
                {
                    AnimationClip extractedClip = ExtractClip(sourceClip, clipName);
                    string savePath = AssetDatabase.GenerateUniqueAssetPath(outputPath);

                    AssetDatabase.CreateAsset(extractedClip, savePath);
                    Debug.Log($"[AnimationClipExtractor] 추출: {sourceClip.name} → {savePath}");
                    successCount++;
                }
                catch (Exception e)
                {
                    Debug.LogError($"[AnimationClipExtractor] 추출 실패: {sourceClip.name} ({fbxPath})\n{e}");
                    errorCount++;
                }
            }
        }
        finally
        {
            AssetDatabase.StopAssetEditing();
            AssetDatabase.SaveAssets();
            AssetDatabase.Refresh();
        }

        // ── 5. Relink (모든 참조 소스) ──
        int relinkCount = PerformRelink();

        // ── 6. FBX 삭제 ──
        int deletedCount = PerformDeleteFbx();

        // ── 7. 결과 ──
        string resultMsg = $"추출: {successCount}개 성공";
        if (errorCount > 0) resultMsg += $", {errorCount}개 실패";
        resultMsg += $"\nRelink: {relinkCount}개 참조 갱신";
        resultMsg += $"\nFBX 삭제: {deletedCount}개";

        Debug.Log($"[AnimationClipExtractor] {resultMsg}");
        EditorUtility.DisplayDialog("Animation Clip Extractor", resultMsg, "확인");
    }

    [MenuItem(MenuPathExtract, true)]
    public static bool ValidateExtract()
    {
        return !EditorApplication.isPlayingOrWillChangePlaymode;
    }

    // ─────────────────────────────────────────────
    // Relink Only (별도 메뉴)
    // ─────────────────────────────────────────────

    [MenuItem(MenuPathRelink)]
    public static void RelinkOnly()
    {
        int count = PerformRelink();
        PerformDeleteFbx();

        EditorUtility.DisplayDialog(
            "Animation Clip Relink",
            $"{count}개 참조를 갱신했습니다.",
            "확인");
    }

    [MenuItem(MenuPathRelink, true)]
    public static bool ValidateRelink()
    {
        return !EditorApplication.isPlayingOrWillChangePlaymode;
    }

    // ─────────────────────────────────────────────
    // FBX 삭제
    // ─────────────────────────────────────────────

    /// <summary>
    /// 추출 완료된 FBX를 삭제합니다.
    /// {FBX이름}.anim이 동일 폴더에 존재하면, 해당 FBX의 모든 서브에셋 클립이
    /// 추출된 것으로 간주하고 삭제합니다.
    /// </summary>
    /// <returns>삭제된 FBX 수</returns>
    private static int PerformDeleteFbx()
    {
        var fbxToAnimMap = BuildFbxToAnimMap();
        int deletedCount = 0;

        AssetDatabase.StartAssetEditing();

        try
        {
            foreach (var (fbxPath, _) in fbxToAnimMap)
            {
                // FBX 내의 서브에셋 클립이 모두 .anim으로 교체되었는지 확인
                UnityEngine.Object[] subAssets = AssetDatabase.LoadAllAssetsAtPath(fbxPath);
                AnimationClip[] clips = subAssets.OfType<AnimationClip>().ToArray();

                if (clips.Length == 0)
                    continue;

                // 모든 클립이 추출된 .anim으로 relink되었는지 확인
                bool allRelinked = true;
                foreach (AnimationClip clip in clips)
                {
                    string clipAssetPath = AssetDatabase.GetAssetPath(clip);

                    // FBX 서브에셋 클립이 여전히 FBX에만 있는지 확인
                    if (clipAssetPath == fbxPath)
                    {
                        // 이 클립이 누군가 참조하고 있는지 확인
                        if (IsClipReferencedByAnyAsset(clip))
                        {
                            allRelinked = false;
                            break;
                        }
                    }
                }

                if (!allRelinked)
                {
                    Debug.LogWarning($"[AnimationClipExtractor] FBX 삭제 스킵 (아직 참조 중인 클립이 있음): {fbxPath}");
                    continue;
                }

                AssetDatabase.DeleteAsset(fbxPath);
                Debug.Log($"[AnimationClipExtractor] FBX 삭제: {fbxPath}");
                deletedCount++;
            }
        }
        finally
        {
            AssetDatabase.StopAssetEditing();
            AssetDatabase.SaveAssets();
            AssetDatabase.Refresh();
        }

        return deletedCount;
    }

    /// <summary>
    /// 지정한 클립이 프로젝트 내 어떤 에셋에서 참조되고 있는지 확인합니다.
    /// </summary>
    private static bool IsClipReferencedByAnyAsset(AnimationClip clip)
    {
        if (clip == null) return false;

        string clipPath = AssetDatabase.GetAssetPath(clip);
        int clipInstanceId = clip.GetInstanceID();

        // SkillData에서 참조 확인
        string[] skillGuids = AssetDatabase.FindAssets("t:SkillData");
        foreach (string guid in skillGuids)
        {
            string path = AssetDatabase.GUIDToAssetPath(guid);
            string[] deps = AssetDatabase.GetDependencies(path, false);
            if (deps.Contains(clipPath))
                return true;
        }

        // BossPhaseData에서 참조 확인
        string[] phaseGuids = AssetDatabase.FindAssets("t:BossPhaseData");
        foreach (string guid in phaseGuids)
        {
            string path = AssetDatabase.GUIDToAssetPath(guid);
            string[] deps = AssetDatabase.GetDependencies(path, false);
            if (deps.Contains(clipPath))
                return true;
        }

        // AnimatorController에서 참조 확인
        string[] controllerGuids = AssetDatabase.FindAssets("t:AnimatorController", new[] { "Assets/_Game" });
        foreach (string guid in controllerGuids)
        {
            string path = AssetDatabase.GUIDToAssetPath(guid);
            string[] deps = AssetDatabase.GetDependencies(path, false);
            if (deps.Contains(clipPath))
                return true;
        }

        return false;
    }

    // ─────────────────────────────────────────────
    // Relink 핵심 로직
    // ─────────────────────────────────────────────

    /// <summary>
    /// SkillData / BossPhaseData / AnimatorController에서 FBX 서브에셋 클립 참조를
    /// 추출된 .anim 파일로 교체합니다.
    /// </summary>
    /// <returns>갱신된 참조 수</returns>
    private static int PerformRelink()
    {
        var fbxToAnimMap = BuildFbxToAnimMap();

        if (fbxToAnimMap.Count == 0)
        {
            Debug.LogWarning("[AnimationClipExtractor] 매핑 가능한 FBX→.anim 쌍이 없습니다.");
            return 0;
        }

        int relinkCount = 0;

        AssetDatabase.StartAssetEditing();

        try
        {
            // ── SkillData relink ──
            string[] skillGuids = AssetDatabase.FindAssets("t:SkillData");
            foreach (string guid in skillGuids)
            {
                string path = AssetDatabase.GUIDToAssetPath(guid);
                SkillData skillData = AssetDatabase.LoadAssetAtPath<SkillData>(path);
                if (skillData == null) continue;

                SerializedObject so = new SerializedObject(skillData);
                bool modified = false;

                if (TryRemapClip(so.FindProperty("skillClip"), fbxToAnimMap, path, "skillClip"))
                {
                    modified = true;
                    relinkCount++;
                }

                if (TryRemapClip(so.FindProperty("endClip"), fbxToAnimMap, path, "endClip"))
                {
                    modified = true;
                    relinkCount++;
                }

                if (modified)
                    so.ApplyModifiedProperties();
            }

            // ── BossPhaseData relink ──
            string[] phaseGuids = AssetDatabase.FindAssets("t:BossPhaseData");
            foreach (string guid in phaseGuids)
            {
                string path = AssetDatabase.GUIDToAssetPath(guid);
                BossPhaseData phaseData = AssetDatabase.LoadAssetAtPath<BossPhaseData>(path);
                if (phaseData == null) continue;

                SerializedObject so = new SerializedObject(phaseData);

                if (TryRemapClip(so.FindProperty("phaseStartAnimation"), fbxToAnimMap, path, "phaseStartAnimation"))
                {
                    so.ApplyModifiedProperties();
                    relinkCount++;
                }
            }

            // ── AnimatorController relink ──
            string[] controllerGuids = AssetDatabase.FindAssets("t:AnimatorController", new[] { "Assets/_Game" });
            foreach (string guid in controllerGuids)
            {
                string path = AssetDatabase.GUIDToAssetPath(guid);
                AnimatorController controller = AssetDatabase.LoadAssetAtPath<AnimatorController>(path);
                if (controller == null) continue;

                int remapped = RemapControllerClips(controller, fbxToAnimMap, path);
                if (remapped > 0)
                {
                    EditorUtility.SetDirty(controller);
                    relinkCount += remapped;
                }
            }
        }
        finally
        {
            AssetDatabase.StopAssetEditing();
            AssetDatabase.SaveAssets();
        }

        if (relinkCount > 0)
            Debug.Log($"[AnimationClipExtractor] Relink 완료: {relinkCount}개 참조 갱신됨");

        return relinkCount;
    }

    /// <summary>
    /// AnimatorController의 모든 상태에서 FBX 서브에셋 클립을 .anim으로 교체합니다.
    /// </summary>
    private static int RemapControllerClips(
        AnimatorController controller,
        Dictionary<string, AnimationClip> fbxToAnimMap,
        string controllerPath)
    {
        int count = 0;

        // 컨트롤러의 모든 StateMachine과 State를 순회
        foreach (AnimatorControllerLayer layer in controller.layers)
        {
            if (layer.stateMachine == null) continue;
            count += RemapStateMachineClips(layer.stateMachine, fbxToAnimMap, controllerPath);
        }

        return count;
    }

    /// <summary>
    /// StateMachine 내의 모든 상태에서 클립 참조를 교체합니다.
    /// </summary>
    private static int RemapStateMachineClips(
        AnimatorStateMachine stateMachine,
        Dictionary<string, AnimationClip> fbxToAnimMap,
        string controllerPath)
    {
        int count = 0;

        // 일반 State
        foreach (ChildAnimatorState childState in stateMachine.states)
        {
            count += TryRemapMotion(childState.state, fbxToAnimMap, controllerPath);
        }

        // BlendTree (하위 상태 머신 포함)
        foreach (ChildAnimatorStateMachine childSm in stateMachine.stateMachines)
        {
            count += TryRemapMotion(childSm.stateMachine.states[0].state, fbxToAnimMap, controllerPath);

            // 하위 StateMachine 재귀
            if (childSm.stateMachine != null)
                count += RemapStateMachineClips(childSm.stateMachine, fbxToAnimMap, controllerPath);
        }

        return count;
    }

    /// <summary>
    /// AnimatorState의 Motion(AnimationClip)을 .anim으로 교체합니다.
    /// </summary>
    private static int TryRemapMotion(
        AnimatorState state,
        Dictionary<string, AnimationClip> fbxToAnimMap,
        string controllerPath)
    {
        if (state == null || state.motion == null)
            return 0;

        AnimationClip currentClip = state.motion as AnimationClip;
        if (currentClip == null)
            return 0;

        string clipPath = AssetDatabase.GetAssetPath(currentClip);

        // 이미 .anim이거나 FBX 서브에셋이 아니면 스킵
        if (clipPath.EndsWith(".anim", StringComparison.OrdinalIgnoreCase))
            return 0;
        if (!clipPath.EndsWith(".fbx", StringComparison.OrdinalIgnoreCase))
            return 0;

        if (!fbxToAnimMap.TryGetValue(clipPath, out AnimationClip replacementClip))
            return 0;

        state.motion = replacementClip;
        Debug.Log($"[AnimationClipExtractor] Controller Relink: {Path.GetFileName(controllerPath)}"
            + $" | {currentClip.name} → {replacementClip.name}");

        return 1;
    }

    /// <summary>
    /// FBX 경로 → 추출된 .anim AnimationClip 매핑을 구축합니다.
    /// </summary>
    private static Dictionary<string, AnimationClip> BuildFbxToAnimMap()
    {
        var map = new Dictionary<string, AnimationClip>();

        string[] animGuids = AssetDatabase.FindAssets("t:AnimationClip", new[] { "Assets/_Game" });

        foreach (string guid in animGuids)
        {
            string animPath = AssetDatabase.GUIDToAssetPath(guid);
            if (!animPath.EndsWith(".anim", StringComparison.OrdinalIgnoreCase))
                continue;

            string animName = Path.GetFileNameWithoutExtension(animPath);
            string fbxPath = $"{Path.GetDirectoryName(animPath).Replace("\\", "/")}/{animName}.fbx";

            if (AssetDatabase.AssetPathToGUID(fbxPath) != string.Empty)
            {
                AnimationClip animClip = AssetDatabase.LoadAssetAtPath<AnimationClip>(animPath);
                if (animClip != null)
                    map[fbxPath] = animClip;
            }
        }

        return map;
    }

    /// <summary>
    /// SerializedProperty의 AnimationClip 참조가 FBX 서브에셋이면 교체합니다.
    /// </summary>
    private static bool TryRemapClip(
        SerializedProperty clipProperty,
        Dictionary<string, AnimationClip> fbxToAnimMap,
        string assetPath,
        string fieldName)
    {
        if (clipProperty == null || clipProperty.propertyType != SerializedPropertyType.ObjectReference)
            return false;

        AnimationClip currentClip = clipProperty.objectReferenceValue as AnimationClip;
        if (currentClip == null) return false;

        string clipAssetPath = AssetDatabase.GetAssetPath(currentClip);

        if (clipAssetPath.EndsWith(".anim", StringComparison.OrdinalIgnoreCase))
            return false;
        if (!clipAssetPath.EndsWith(".fbx", StringComparison.OrdinalIgnoreCase))
            return false;
        if (!fbxToAnimMap.TryGetValue(clipAssetPath, out AnimationClip replacementClip))
            return false;

        clipProperty.objectReferenceValue = replacementClip;
        Debug.Log($"[AnimationClipExtractor] Relink: {Path.GetFileName(assetPath)}.{fieldName}"
            + $" | {currentClip.name} → {replacementClip.name}");

        return true;
    }

    // ─────────────────────────────────────────────
    // 참조 클립 수집
    // ─────────────────────────────────────────────

    /// <summary>
    /// 프로젝트 내 SkillData, BossPhaseData, AnimatorController에서 참조 중인 AnimationClip을 수집합니다.
    /// </summary>
    private static HashSet<AnimationClip> CollectReferencedClips()
    {
        var clips = new HashSet<AnimationClip>();

        // ── SkillData ──
        string[] skillGuids = AssetDatabase.FindAssets("t:SkillData");
        foreach (string guid in skillGuids)
        {
            string path = AssetDatabase.GUIDToAssetPath(guid);
            SkillData skillData = AssetDatabase.LoadAssetAtPath<SkillData>(path);
            if (skillData == null) continue;

            if (skillData.SkillClip != null) clips.Add(skillData.SkillClip);
            if (skillData.EndClip != null) clips.Add(skillData.EndClip);
        }

        // ── BossPhaseData ──
        string[] phaseGuids = AssetDatabase.FindAssets("t:BossPhaseData");
        foreach (string guid in phaseGuids)
        {
            string path = AssetDatabase.GUIDToAssetPath(guid);
            BossPhaseData phaseData = AssetDatabase.LoadAssetAtPath<BossPhaseData>(path);
            if (phaseData == null) continue;

            if (phaseData.PhaseStartAnimation != null) clips.Add(phaseData.PhaseStartAnimation);
        }

        // ── AnimatorController ──
        string[] controllerGuids = AssetDatabase.FindAssets("t:AnimatorController", new[] { "Assets/_Game" });
        foreach (string guid in controllerGuids)
        {
            string path = AssetDatabase.GUIDToAssetPath(guid);
            AnimatorController controller = AssetDatabase.LoadAssetAtPath<AnimatorController>(path);
            if (controller == null) continue;

            CollectClipsFromController(controller, clips);
        }

        return clips;
    }

    /// <summary>
    /// AnimatorController의 모든 상태에서 AnimationClip을 수집합니다.
    /// </summary>
    private static void CollectClipsFromController(AnimatorController controller, HashSet<AnimationClip> clips)
    {
        foreach (AnimatorControllerLayer layer in controller.layers)
        {
            if (layer.stateMachine == null) continue;
            CollectClipsFromStateMachine(layer.stateMachine, clips);
        }
    }

    /// <summary>
    /// StateMachine 내의 모든 상태에서 AnimationClip을 수집합니다.
    /// </summary>
    private static void CollectClipsFromStateMachine(AnimatorStateMachine stateMachine, HashSet<AnimationClip> clips)
    {
        foreach (ChildAnimatorState childState in stateMachine.states)
        {
            if (childState.state?.motion is AnimationClip clip)
                clips.Add(clip);
        }

        foreach (ChildAnimatorStateMachine childSm in stateMachine.stateMachines)
        {
            if (childSm.stateMachine != null)
                CollectClipsFromStateMachine(childSm.stateMachine, clips);
        }
    }

    // ─────────────────────────────────────────────
    // 클립 추출
    // ─────────────────────────────────────────────

    /// <summary>
    /// 소스 클립의 모든 커브와 이벤트를 복사한 독립 AnimationClip을 생성합니다.
    /// </summary>
    private static AnimationClip ExtractClip(AnimationClip source, string clipName)
    {
        AnimationClip extracted = new AnimationClip
        {
            name = clipName,
            frameRate = source.frameRate,
            legacy = source.legacy,
            wrapMode = source.wrapMode,
            localBounds = source.localBounds
        };

        EditorCurveBinding[] bindings = AnimationUtility.GetCurveBindings(source);
        foreach (EditorCurveBinding binding in bindings)
        {
            AnimationCurve curve = AnimationUtility.GetEditorCurve(source, binding);
            if (curve == null || curve.keys.Length == 0)
                continue;

            extracted.SetCurve(binding.path, binding.type, binding.propertyName, curve);
        }

        AnimationEvent[] events = AnimationUtility.GetAnimationEvents(source);
        if (events.Length > 0)
        {
            AnimationEvent[] copiedEvents = new AnimationEvent[events.Length];
            for (int i = 0; i < events.Length; i++)
            {
                copiedEvents[i] = new AnimationEvent
                {
                    time = events[i].time,
                    functionName = events[i].functionName,
                    floatParameter = events[i].floatParameter,
                    intParameter = events[i].intParameter,
                    stringParameter = events[i].stringParameter,
                    objectReferenceParameter = events[i].objectReferenceParameter,
                    messageOptions = events[i].messageOptions
                };
            }

            AnimationUtility.SetAnimationEvents(extracted, copiedEvents);
        }

        return extracted;
    }
}