using System.Collections.Generic;
using System.Text;
using AlicizaX.Editor;
using UnityEditor;
using UnityEngine;
using UnityEngine.UIElements;
using UnityEditorInternal;

namespace AlicizaX.Localization.Editor
{
    internal class LocalizationSettingsProvider : UnityEditor.SettingsProvider
    {
        private SerializedObject _serializedObject;
        private SerializedProperty _languageTypes;
        private ReorderableList _languageList;
        private SerializedProperty _genLangaugeTypePath;
        private SerializedProperty generateScriptCodeFirstConfig;
        private List<string> popConfig = new List<string>();

        // Track original state for comparison
        private List<string> _originalLanguages = new List<string>();
        private bool _hasUnsavedChanges = false;

        public LocalizationSettingsProvider() : base("Project/Localization Settings", SettingsScope.Project)
        {
        }

        public override void OnActivate(string searchContext, VisualElement rootElement)
        {
            InitGUI();
        }

        private void InitGUI()
        {
            var setting = LocalizationConfiguration.Instance;
            _serializedObject?.Dispose();
            _serializedObject = new SerializedObject(setting);
            _languageTypes = _serializedObject.FindProperty("LanguageTypes");
            _genLangaugeTypePath = _serializedObject.FindProperty("_genLangaugeTypePath");
            generateScriptCodeFirstConfig = _serializedObject.FindProperty("generateScriptCodeFirstConfig");

            // Store original language list
            _originalLanguages.Clear();
            for (int i = 0; i < _languageTypes.arraySize; i++)
            {
                _originalLanguages.Add(_languageTypes.GetArrayElementAtIndex(i).stringValue);
            }

            // 自定义 ReorderableList
            _languageList = new ReorderableList(_serializedObject, _languageTypes,
                draggable: false,
                displayHeader: true,
                displayAddButton: true,
                displayRemoveButton: true);

            _languageList.drawHeaderCallback = rect => { EditorGUI.LabelField(rect, "Language Types"); };

            _languageList.drawElementCallback = (rect, index, isActive, isFocused) =>
            {
                var element = _languageTypes.GetArrayElementAtIndex(index);
                rect.y += 2;

                if (index < 2) // 前两个（中文、英文）禁止修改
                {
                    EditorGUI.BeginDisabledGroup(true);
                    EditorGUI.TextField(
                        new Rect(rect.x, rect.y, rect.width, EditorGUIUtility.singleLineHeight),
                        element.stringValue);
                    EditorGUI.EndDisabledGroup();
                }
                else
                {
                    EditorGUI.BeginChangeCheck();
                    string newValue = EditorGUI.TextField(
                        new Rect(rect.x, rect.y, rect.width, EditorGUIUtility.singleLineHeight),
                        element.stringValue);
                    if (EditorGUI.EndChangeCheck())
                    {
                        element.stringValue = newValue;
                        _hasUnsavedChanges = true;
                    }
                }
            };

            // 禁止删除前两个
            _languageList.onCanRemoveCallback = list =>
            {
                return list.index >= 2; // 只有索引 >=2 的项才能删除
            };

            // Hook for when a language is added
            _languageList.onAddCallback = list =>
            {
                int newIndex = _languageTypes.arraySize;
                _languageTypes.InsertArrayElementAtIndex(newIndex);
                var newElement = _languageTypes.GetArrayElementAtIndex(newIndex);
                newElement.stringValue = "NewLanguage";
                _hasUnsavedChanges = true;
            };

            // Hook for when a language is removed
            _languageList.onRemoveCallback = list =>
            {
                if (list.index < 2)
                {
                    EditorUtility.DisplayDialog("Cannot Remove", "The first two languages (ChineseSimplified and English) cannot be removed.", "OK");
                    return;
                }

                // Just remove from the list, no immediate sync
                _languageTypes.DeleteArrayElementAtIndex(list.index);
                _hasUnsavedChanges = true;
            };

            popConfig.Clear();
            if (setting.LanguageTypeNames.Count > 0)
            {
                foreach (var lang in setting.LanguageTypeNames)
                {
                    string name = lang.Or("Unknown");
                    popConfig.Add(name);
                }
            }
        }

        public override void OnGUI(string searchContext)
        {
            if (_serializedObject == null || !_serializedObject.targetObject)
            {
                InitGUI();
            }

            _serializedObject.Update();
            EditorGUI.BeginChangeCheck();

            EditorGUILayout.PropertyField(_genLangaugeTypePath);
            EditorDrawing.DrawStringSelectPopup(new GUIContent("Gen Lang"), new GUIContent("None"), popConfig.ToArray(), generateScriptCodeFirstConfig.stringValue,
                (e) =>
                {
                    generateScriptCodeFirstConfig.stringValue = e;
                    _serializedObject.ApplyModifiedProperties();
                    LocalizationConfiguration.Save();
                });
            if (GUILayout.Button("Generate Language Types"))
            {
                RegenerateLanguageTypes();
            }

            _languageList.DoLayoutList();

            if (EditorGUI.EndChangeCheck())
            {
                _serializedObject.ApplyModifiedProperties();
                LocalizationConfiguration.Save();
            }

            // Add Save button
            EditorGUILayout.Space(10);
            EditorGUILayout.BeginHorizontal();
            GUILayout.FlexibleSpace();

            using (new EditorGUI.DisabledGroupScope(!_hasUnsavedChanges))
            {
                if (GUILayout.Button("Save Language Changes", GUILayout.Width(200), GUILayout.Height(30)))
                {
                    ApplyLanguageChanges();
                }
            }

            GUILayout.FlexibleSpace();
            EditorGUILayout.EndHorizontal();

            if (_hasUnsavedChanges)
            {
                EditorGUILayout.HelpBox("You have unsaved language changes. Click 'Save Language Changes' to apply them to all GameLocalizationTable assets.", MessageType.Warning);
            }
        }

        private void RegenerateLanguageTypes()
        {
            StringBuilder sb = new StringBuilder();

            sb.AppendLine("using System.Collections.Generic;");
            sb.AppendLine("");
            sb.AppendLine("/// <summary>");
            sb.AppendLine("/// AutoGenerate");
            sb.AppendLine("/// </summary>");
            sb.AppendLine("public static class LanguageTypes");
            sb.AppendLine("{");
            for (int i = 0; i < LocalizationConfiguration.Instance.LanguageTypeNames.Count; i++)
            {
                sb.AppendLine($"\tpublic const string {LocalizationConfiguration.Instance.LanguageTypeNames[i]} = \"{LocalizationConfiguration.Instance.LanguageTypeNames[i]}\";");
            }

            sb.AppendLine("");
            sb.AppendLine("\tpublic static readonly IReadOnlyList<string> Languages = new List<string>");
            sb.AppendLine("\t{");
            for (int i = 0; i < LocalizationConfiguration.Instance.LanguageTypeNames.Count; i++)
            {
                sb.AppendLine($"\t\t\"{LocalizationConfiguration.Instance.LanguageTypeNames[i]}\",");
            }

            sb.AppendLine("\t};");

            sb.AppendLine("");
            sb.AppendLine("\tpublic static string IndexToString(int index)");
            sb.AppendLine("\t{");
            sb.AppendLine("\t\tif (index < 0 || index >= Languages.Count) return \"Unknown\";");
            sb.AppendLine("\t\treturn Languages[index];");
            sb.AppendLine("\t}");
            sb.AppendLine("");
            sb.AppendLine("\tpublic static int StringToIndex(string s)");
            sb.AppendLine("\t{");
            sb.AppendLine("\t\tint index = -1;");
            sb.AppendLine("\t\tfor (int i = 0; i < Languages.Count; i++)");
            sb.AppendLine("\t\t{");
            sb.AppendLine("\t\t\tif (Languages[i] == s)");
            sb.AppendLine("\t\t\t{");
            sb.AppendLine("\t\t\t\tindex = i;");
            sb.AppendLine("\t\t\t\tbreak;");
            sb.AppendLine("\t\t\t}");
            sb.AppendLine("\t\t}");
            sb.AppendLine("");
            sb.AppendLine("\t\treturn index;");
            sb.AppendLine("\t}");
            sb.AppendLine("");
            sb.AppendLine("}");

            System.IO.File.WriteAllText(_genLangaugeTypePath.stringValue, sb.ToString());
            AssetDatabase.Refresh();
        }

        public override void OnDeactivate()
        {
            base.OnDeactivate();
            LocalizationConfiguration.Save();
        }

        private void ApplyLanguageChanges()
        {
            // Get current language list
            List<string> currentLanguages = new List<string>();
            for (int i = 0; i < _languageTypes.arraySize; i++)
            {
                currentLanguages.Add(_languageTypes.GetArrayElementAtIndex(i).stringValue);
            }

            // Detect changes
            List<string> addedLanguages = new List<string>();
            List<string> removedLanguages = new List<string>();
            Dictionary<string, string> renamedLanguages = new Dictionary<string, string>(); // old -> new

            // Find added languages
            foreach (var lang in currentLanguages)
            {
                if (!_originalLanguages.Contains(lang))
                {
                    addedLanguages.Add(lang);
                }
            }

            // Find removed languages
            foreach (var lang in _originalLanguages)
            {
                if (!currentLanguages.Contains(lang))
                {
                    removedLanguages.Add(lang);
                }
            }

            // Detect renames (same index, different name)
            for (int i = 0; i < Mathf.Min(_originalLanguages.Count, currentLanguages.Count); i++)
            {
                if (_originalLanguages[i] != currentLanguages[i])
                {
                    // Check if this is a rename (not an add/remove)
                    if (!addedLanguages.Contains(currentLanguages[i]) && !removedLanguages.Contains(_originalLanguages[i]))
                    {
                        renamedLanguages[_originalLanguages[i]] = currentLanguages[i];
                    }
                }
            }

            // Apply changes to all tables
            string[] guids = AssetDatabase.FindAssets("t:GameLocaizationTable");
            int tablesUpdated = 0;

            foreach (string guid in guids)
            {
                string assetPath = AssetDatabase.GUIDToAssetPath(guid);
                GameLocaizationTable table = AssetDatabase.LoadAssetAtPath<GameLocaizationTable>(assetPath);

                if (table == null)
                    continue;

                bool tableModified = false;

                // Handle renames first
                foreach (var rename in renamedLanguages)
                {
                    LocalizationLanguage language = table.Languages.Find(lang => lang.LanguageName == rename.Key);
                    if (language != null)
                    {
                        language.LanguageName = rename.Value;
                        language.name = rename.Value;
                        tableModified = true;
                    }
                }

                // Handle additions
                foreach (var newLang in addedLanguages)
                {
                    // Skip if already exists
                    if (table.Languages.Exists(lang => lang.LanguageName == newLang))
                        continue;

                    // Create new LocalizationLanguage asset
                    LocalizationLanguage newLanguage = ScriptableObject.CreateInstance<LocalizationLanguage>();
                    newLanguage.name = newLang;
                    newLanguage.LanguageName = newLang;
                    newLanguage.Strings = new List<LocalizationLanguage.LocalizationString>();

                    // Synchronize keys from existing table structure
                    foreach (var section in table.TableSheet)
                    {
                        foreach (var item in section.SectionSheet)
                        {
                            string sectionKey = section.SectionName.Replace(" ", "");
                            string itemKey = item.Key.Replace(" ", "");
                            string fullKey = sectionKey + "." + itemKey;

                            newLanguage.Strings.Add(new LocalizationLanguage.LocalizationString
                            {
                                SectionId = section.Id,
                                EntryId = item.Id,
                                Key = fullKey,
                                Value = string.Empty
                            });
                        }
                    }

                    AssetDatabase.AddObjectToAsset(newLanguage, table);
                    table.Languages.Add(newLanguage);
                    tableModified = true;
                }

                // Handle removals
                foreach (var removedLang in removedLanguages)
                {
                    LocalizationLanguage languageToDelete = table.Languages.Find(lang => lang.LanguageName == removedLang);
                    if (languageToDelete != null)
                    {
                        table.Languages.Remove(languageToDelete);
                        UnityEngine.Object.DestroyImmediate(languageToDelete, true);
                        tableModified = true;
                    }
                }

                if (tableModified)
                {
                    EditorUtility.SetDirty(table);
                    tablesUpdated++;
                }
            }

            AssetDatabase.SaveAssets();
            AssetDatabase.Refresh();

            // Update original languages list
            _originalLanguages.Clear();
            _originalLanguages.AddRange(currentLanguages);
            _hasUnsavedChanges = false;

            // Log results
            if (addedLanguages.Count > 0)
                Debug.Log($"Added {addedLanguages.Count} language(s) to {tablesUpdated} table(s): {string.Join(", ", addedLanguages)}");
            if (removedLanguages.Count > 0)
                Debug.Log($"Removed {removedLanguages.Count} language(s) from {tablesUpdated} table(s): {string.Join(", ", removedLanguages)}");
            if (renamedLanguages.Count > 0)
                Debug.Log($"Renamed {renamedLanguages.Count} language(s) in {tablesUpdated} table(s)");

            EditorUtility.DisplayDialog("Success", $"Language changes applied to {tablesUpdated} GameLocalizationTable(s).", "OK");
        }

        static LocalizationSettingsProvider s_provider;

        [SettingsProvider]
        public static SettingsProvider CreateMyCustomSettingsProvider()
        {
            if (s_provider == null)
            {
                s_provider = new LocalizationSettingsProvider();
            }

            return s_provider;
        }
    }
}