import AsyncStorage from '@/utils/kvStore';
import { logger } from '@/utils/logger';
import { createSelector, createSlice, PayloadAction } from '@reduxjs/toolkit';
import type { RootState } from './index';

// Tab 配置接口
export interface TabConfig {
  id: string;              // tab 标识符
  icon: string;            // SF Symbol 图标名
  titleKey: string;        // i18n 翻译 key
  enabled: boolean;        // 是否启用
  canBeDisabled: boolean;  // 是否可以被禁用
  order: number;           // 显示顺序
}

// State 接口
interface TabBarConfigState {
  configs: TabConfig[];
  isInitialized: boolean;
}

// 默认配置
export const DEFAULT_TAB_CONFIGS: TabConfig[] = [
  {
    id: 'statistics',
    icon: 'chart.pie.fill',
    titleKey: 'statistics.tabs.health',
    enabled: true,
    canBeDisabled: false,
    order: 1,
  },
  {
    id: 'medications',
    icon: 'pills.fill',
    titleKey: 'statistics.tabs.medications',
    enabled: true,
    canBeDisabled: false,
    order: 2,
  },
  {
    id: 'fasting',
    icon: 'timer',
    titleKey: 'statistics.tabs.fasting',
    enabled: true,
    canBeDisabled: true, // 只有断食可以被关闭
    order: 3,
  },
  {
    id: 'challenges',
    icon: 'trophy.fill',
    titleKey: 'statistics.tabs.challenges',
    enabled: true,
    canBeDisabled: false,
    order: 4,
  },
  {
    id: 'personal',
    icon: 'person.fill',
    titleKey: 'statistics.tabs.personal',
    enabled: true,
    canBeDisabled: false,
    order: 5,
  },
];

// AsyncStorage key
const STORAGE_KEY = 'tab_bar_config';

// 初始状态
const initialState: TabBarConfigState = {
  configs: DEFAULT_TAB_CONFIGS,
  isInitialized: false,
};

const tabBarConfigSlice = createSlice({
  name: 'tabBarConfig',
  initialState,
  reducers: {
    // 设置配置（用于从 AsyncStorage 恢复）
    setConfigs: (state, action: PayloadAction<TabConfig[]>) => {
      state.configs = action.payload;
      state.isInitialized = true;
    },
    
    // 切换 tab 启用状态
    toggleTabEnabled: (state, action: PayloadAction<string>) => {
      const tabId = action.payload;
      const config = state.configs.find(c => c.id === tabId);
      
      if (config && config.canBeDisabled) {
        config.enabled = !config.enabled;
        // 自动持久化到 AsyncStorage
        saveConfigsToStorage(state.configs);
      }
    },
    
    // 更新 tab 顺序（拖拽后）
    reorderTabs: (state, action: PayloadAction<TabConfig[]>) => {
      // 更新顺序，同时保持其他属性不变
      const newConfigs = action.payload.map((config, index) => ({
        ...config,
        order: index + 1,
      }));
      state.configs = newConfigs;
      // 自动持久化到 AsyncStorage
      saveConfigsToStorage(newConfigs);
    },
    
    // 恢复默认配置
    resetToDefault: (state) => {
      state.configs = DEFAULT_TAB_CONFIGS;
      // 持久化到 AsyncStorage
      saveConfigsToStorage(DEFAULT_TAB_CONFIGS);
    },
    
    // 标记已初始化
    markInitialized: (state) => {
      state.isInitialized = true;
    },
  },
});

// 持久化配置到 AsyncStorage
const saveConfigsToStorage = async (configs: TabConfig[]) => {
  try {
    await AsyncStorage.setItem(STORAGE_KEY, JSON.stringify(configs));
    logger.info('底部栏配置已保存');
  } catch (error) {
    logger.error('保存底部栏配置失败:', error);
  }
};

// 从 AsyncStorage 加载配置
export const loadTabBarConfigs = () => async (dispatch: any) => {
  try {
    const stored = await AsyncStorage.getItem(STORAGE_KEY);
    
    if (stored) {
      const configs = JSON.parse(stored) as TabConfig[];
      
      // 验证配置有效性
      if (Array.isArray(configs) && configs.length > 0) {
        // 合并默认配置，确保新增的 tab 也能显示
        const mergedConfigs = mergeWithDefaults(configs);
        dispatch(setConfigs(mergedConfigs));
        logger.info('底部栏配置已加载');
        return;
      }
    }
    
    // 如果没有存储或无效，使用默认配置
    dispatch(setConfigs(DEFAULT_TAB_CONFIGS));
    dispatch(markInitialized());
  } catch (error) {
    logger.error('加载底部栏配置失败:', error);
    // 出错时使用默认配置
    dispatch(setConfigs(DEFAULT_TAB_CONFIGS));
    dispatch(markInitialized());
  }
};

// 合并存储的配置和默认配置
const mergeWithDefaults = (storedConfigs: TabConfig[]): TabConfig[] => {
  const merged = [...storedConfigs];
  
  // 检查是否有新增的默认 tab
  DEFAULT_TAB_CONFIGS.forEach(defaultConfig => {
    const exists = merged.find(c => c.id === defaultConfig.id);
    if (!exists) {
      // 新增的 tab，添加到末尾
      merged.push({
        ...defaultConfig,
        order: merged.length + 1,
      });
    }
  });
  
  // 按 order 排序
  return merged.sort((a, b) => a.order - b.order);
};

// Actions
export const {
  setConfigs,
  toggleTabEnabled,
  reorderTabs,
  resetToDefault,
  markInitialized,
} = tabBarConfigSlice.actions;

// Selectors
export const selectTabBarConfigs = (state: RootState) => state.tabBarConfig.configs;

// ✅ 使用 createSelector 进行记忆化，避免不必要的重渲染
export const selectEnabledTabs = createSelector(
  [selectTabBarConfigs],
  (configs) => configs
    .filter(config => config.enabled)
    .sort((a, b) => a.order - b.order)
);

export const selectIsInitialized = (state: RootState) => state.tabBarConfig.isInitialized;

// 按 id 获取配置
export const selectTabConfigById = (tabId: string) => (state: RootState) => 
  state.tabBarConfig.configs.find(config => config.id === tabId);

export default tabBarConfigSlice.reducer;