// UTF-8 with BOM — required for Chinese character paths
using System.Collections.Generic;
using System.IO;
using System.Text;
using BrewMonster.Scripts.ECModel;
using UnityEditor;
using UnityEngine;

public class CombineActionSOAssigner : EditorWindow
{
    // Fixed — this is always where the weapon prefabs live
    private const string PrefabRootPath = "Assets/ModelRenderer/Art/Models/models/weapons";

    // Log files land next to the project's Logs/ folder
    private static readonly string LogDir = Path.GetFullPath("Logs/SOAssigner");

    private string _soRootPath = "Assets/ModelRenderer/Art/Models/models/weapons";
    private bool _isDryRun = true;
    private Vector2 _scrollPos;
    private readonly List<string> _log = new();
    private string _lastLogFile;

    private static readonly GUIStyle HeaderStyle = new(EditorStyles.boldLabel)
    {
        fontSize = 14
    };

    [MenuItem("Tools/Brew Monster/Combine Action SO Assigner")]
    public static void ShowWindow()
    {
        var win = GetWindow<CombineActionSOAssigner>(false, "SO Assigner", true);
        win.minSize = new Vector2(520, 480);
    }

    private void OnGUI()
    {
        DrawHeader();
        DrawConfig();
        DrawButtons();
        DrawLog();
    }

    // ── UI sections ──────────────────────────────────────────────────────────

    private void DrawHeader()
    {
        EditorGUILayout.Space(6);
        EditorGUILayout.LabelField("Combine Action SO Assigner", HeaderStyle);
        EditorGUILayout.LabelField("Batch-assigns CombinedActionSO assets to weapon prefabs.", EditorStyles.miniLabel);
        DrawSeparator();
    }

    private void DrawConfig()
    {
        EditorGUILayout.LabelField("Paths", EditorStyles.boldLabel);

        using (new EditorGUI.DisabledScope(true))
            EditorGUILayout.TextField("Prefab Root (fixed)", PrefabRootPath);

        _soRootPath = EditorGUILayout.TextField("SO Root Path", _soRootPath);

        EditorGUILayout.HelpBox(
            "SO Root must mirror the prefab folder tree.\n" +
            "e.g.  SO: {SO Root}/人物/刀剑/15品单刀/15品单刀.asset\n" +
            "      Prefab: " + PrefabRootPath + "/人物/刀剑/15品单刀/15品单刀.prefab",
            MessageType.Info);

        DrawSeparator();

        EditorGUILayout.LabelField("Options", EditorStyles.boldLabel);
        _isDryRun = EditorGUILayout.Toggle("Dry Run (no writes)", _isDryRun);

        if (_isDryRun)
            EditorGUILayout.HelpBox("Dry Run ON — matches will be logged but nothing will be saved to disk.", MessageType.Warning);
        else
            EditorGUILayout.HelpBox("Dry Run OFF — prefabs WILL be modified and saved.", MessageType.Error);

        DrawSeparator();
    }

    private void DrawButtons()
    {
        EditorGUILayout.BeginHorizontal();

        if (GUILayout.Button("Orphan Check", GUILayout.Height(30)))
            RunOrphanCheck();

        GUI.backgroundColor = _isDryRun ? Color.yellow : Color.red;
        if (GUILayout.Button(_isDryRun ? "Run (Dry)" : "Run (LIVE — writes disk)", GUILayout.Height(30)))
            RunAssignment();
        GUI.backgroundColor = Color.white;

        EditorGUILayout.EndHorizontal();

        EditorGUILayout.Space(4);
    }

    private void DrawLog()
    {
        EditorGUILayout.BeginHorizontal();
        EditorGUILayout.LabelField("Log", EditorStyles.boldLabel);
        if (!string.IsNullOrEmpty(_lastLogFile) && GUILayout.Button("Open Log File", GUILayout.Width(100)))
            EditorUtility.RevealInFinder(_lastLogFile);
        if (GUILayout.Button("Clear", GUILayout.Width(60)))
        {
            _log.Clear();
            _lastLogFile = null;
        }
        EditorGUILayout.EndHorizontal();

        if (!string.IsNullOrEmpty(_lastLogFile))
            EditorGUILayout.LabelField(_lastLogFile, EditorStyles.miniLabel);

        _scrollPos = EditorGUILayout.BeginScrollView(_scrollPos, GUILayout.ExpandHeight(true));
        foreach (var line in _log)
            EditorGUILayout.LabelField(line, EditorStyles.wordWrappedLabel);
        EditorGUILayout.EndScrollView();
    }

    private static void DrawSeparator()
    {
        EditorGUILayout.Space(4);
        Rect r = EditorGUILayout.GetControlRect(false, 1);
        EditorGUI.DrawRect(r, new Color(0.5f, 0.5f, 0.5f, 0.5f));
        EditorGUILayout.Space(4);
    }

    // ── Core logic ───────────────────────────────────────────────────────────

    private void RunOrphanCheck()
    {
        _log.Clear();
        _log.Add("=== ORPHAN CHECK ===");

        string[] guids = AssetDatabase.FindAssets("t:Prefab", new[] { PrefabRootPath });
        int orphans = 0;
        var fileLines = new List<string> { $"=== ORPHAN CHECK  {Timestamp()} ===" };

        foreach (string guid in guids)
        {
            string prefabPath = AssetDatabase.GUIDToAssetPath(guid);
            string soPath = BuildSOPath(prefabPath);

            if (AssetDatabase.LoadAssetAtPath<CombinedActionSO>(soPath) == null)
            {
                string line1 = $"[ORPHAN]  {Path.GetFileNameWithoutExtension(prefabPath)}";
                string line2 = $"          expected SO: {soPath}";
                _log.Add(line1);
                _log.Add(line2);
                fileLines.Add(line1);
                fileLines.Add(line2);
                orphans++;
            }
        }

        string summary = $"=== {orphans} orphan(s) out of {guids.Length} prefab(s) ===";
        _log.Add(summary);
        fileLines.Add(summary);

        _lastLogFile = WriteLogFile("OrphanCheck", fileLines);
        Debug.Log($"[SO Assigner] Orphan Check — {orphans}/{guids.Length} orphans. Log: {_lastLogFile}");
        Repaint();
    }

    private void RunAssignment()
    {
        _log.Clear();
        string header = _isDryRun ? "=== DRY RUN ===" : "=== LIVE RUN ===";
        _log.Add(header);

        string[] guids = AssetDatabase.FindAssets("t:Prefab", new[] { PrefabRootPath });
        int matched = 0, skipped = 0, failed = 0;

        var fileLines = new List<string> { $"{header}  {Timestamp()}" };

        try
        {
            for (int i = 0; i < guids.Length; i++)
            {
                string prefabPath = AssetDatabase.GUIDToAssetPath(guids[i]);
                string prefabName = Path.GetFileNameWithoutExtension(prefabPath);
                string soPath = BuildSOPath(prefabPath);

                EditorUtility.DisplayProgressBar(
                    "Assigning CombinedActionSO",
                    prefabName,
                    (float)i / guids.Length);

                CombinedActionSO so = AssetDatabase.LoadAssetAtPath<CombinedActionSO>(soPath);
                if (so == null)
                {
                    string skipLine = $"[SKIP]  {prefabName}  →  {soPath}";
                    fileLines.Add(skipLine);
                    if (!_isDryRun)
                        _log.Add(skipLine); // window only gets skips in live mode
                    skipped++;
                    continue;
                }

                if (_isDryRun)
                {
                    // File gets every match; window stays quiet
                    fileLines.Add($"[MATCH]  {prefabName}  →  {soPath}");
                    matched++;
                }
                else
                {
                    if (!TryAssign(prefabPath, so, out string error))
                    {
                        string errLine = $"[ERROR]  {prefabName}  —  {error}";
                        _log.Add(errLine);
                        fileLines.Add(errLine);
                        failed++;
                    }
                    else
                    {
                        fileLines.Add($"[OK]  {prefabName}");
                        matched++;
                    }
                }

                // Memory management every 100 items
                if (i > 0 && i % 100 == 0)
                {
                    Resources.UnloadUnusedAssets();
                    System.GC.Collect();
                }
            }
        }
        finally
        {
            EditorUtility.ClearProgressBar();
        }

        if (!_isDryRun)
            AssetDatabase.SaveAssets();

        string summary = $"matched: {matched}, skipped: {skipped}, failed: {failed} (total: {guids.Length})";
        string summaryLine = $"=== DONE — {summary} ===";
        _log.Add(summaryLine);
        fileLines.Add(summaryLine);

        _lastLogFile = WriteLogFile(_isDryRun ? "DryRun" : "LiveRun", fileLines);

        Debug.Log($"[SO Assigner] {(_isDryRun ? "DRY RUN" : "LIVE")} — {summary}  |  Log: {_lastLogFile}");

        if (skipped > 0)
            Debug.LogWarning($"[SO Assigner] {skipped} unmatched prefab(s) — see log file for details: {_lastLogFile}");

        Repaint();
    }

    private static bool TryAssign(string prefabPath, CombinedActionSO so, out string error)
    {
        error = null;
        GameObject root = null;
        try
        {
            root = PrefabUtility.LoadPrefabContents(prefabPath);

            CombineActHolder holder = root.GetComponent<CombineActHolder>();
            if (holder == null)
            {
                error = "CombineActHolder not found on root GameObject";
                return false;
            }

            using SerializedObject serializedHolder = new(holder);
            SerializedProperty prop = serializedHolder.FindProperty("combinedActionSO");
            if (prop == null)
            {
                error = "SerializedProperty 'combinedActionSO' not found";
                return false;
            }

            prop.objectReferenceValue = so;
            serializedHolder.ApplyModifiedPropertiesWithoutUndo();

            PrefabUtility.SaveAsPrefabAsset(root, prefabPath);
            return true;
        }
        catch (System.Exception ex)
        {
            error = ex.Message;
            return false;
        }
        finally
        {
            if (root != null)
                PrefabUtility.UnloadPrefabContents(root);
        }
    }

    // ── File logging ─────────────────────────────────────────────────────────

    private static string WriteLogFile(string prefix, List<string> lines)
    {
        Directory.CreateDirectory(LogDir);
        string fileName = $"{prefix}_{System.DateTime.Now:yyyy-MM-dd_HH-mm-ss}.log";
        string fullPath = Path.Combine(LogDir, fileName);
        File.WriteAllLines(fullPath, lines, new UTF8Encoding(encoderShouldEmitUTF8Identifier: true));
        return fullPath;
    }

    private static string Timestamp() =>
        System.DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");

    // ── Path helpers ─────────────────────────────────────────────────────────

    /// <summary>
    /// Maps a prefab path to its expected SO path using mirror structure.
    /// Prefab: Assets/ModelRenderer/Art/Models/models/weapons/X/Y/Z.prefab
    /// SO:     {_soRootPath}/X/Y/Z.asset
    /// </summary>
    private string BuildSOPath(string prefabPath)
    {
        string relative = prefabPath.Substring(PrefabRootPath.Length).TrimStart('/');
        string assetRelative = Path.ChangeExtension(relative, ".asset").Replace('\\', '/');
        return _soRootPath.TrimEnd('/') + "/" + assetRelative;
    }
}