import { foodLibraryApi } from '@/services/foodLibraryApi';
import type {
  FoodCategory,
  FoodCategoryDto,
  FoodItem,
  FoodItemDto,
  FoodLibraryState
} from '@/types/food';
import { createAsyncThunk, createSlice, PayloadAction } from '@reduxjs/toolkit';

// 数据转换工具函数
const transformFoodItemDto = (dto: FoodItemDto): FoodItem => ({
  id: dto.id.toString(),
  name: dto.name,
  emoji: '🍽️', // 默认 emoji，可以根据分类或其他逻辑设置
  calories: dto.caloriesPer100g || 0,
  unit: '100克',
  description: dto.description,
  protein: dto.proteinPer100g,
  carbohydrate: dto.carbohydratePer100g,
  fat: dto.fatPer100g,
  fiber: dto.fiberPer100g,
  sugar: dto.sugarPer100g,
  sodium: dto.sodiumPer100g,
  additionalNutrition: dto.additionalNutrition,
  imageUrl: dto.imageUrl,
});

const transformFoodCategoryDto = (dto: FoodCategoryDto): FoodCategory => ({
  id: dto.key,
  name: dto.name,
  foods: dto.foods.map(transformFoodItemDto),
  icon: dto.icon,
  sortOrder: dto.sortOrder,
  isSystem: dto.isSystem,
});

// 异步 thunks
export const fetchFoodLibrary = createAsyncThunk(
  'foodLibrary/fetchFoodLibrary',
  async (_, { rejectWithValue }) => {
    try {
      const response = await foodLibraryApi.getFoodLibrary();
      return response;
    } catch (error: any) {
      return rejectWithValue(error.message || '获取食物库失败');
    }
  }
);

export const searchFoods = createAsyncThunk(
  'foodLibrary/searchFoods',
  async (keyword: string, { rejectWithValue }) => {
    try {
      const response = await foodLibraryApi.searchFoods(keyword);
      return response;
    } catch (error: any) {
      return rejectWithValue(error.message || '搜索食物失败');
    }
  }
);

export const getFoodById = createAsyncThunk(
  'foodLibrary/getFoodById',
  async (id: number, { rejectWithValue }) => {
    try {
      const response = await foodLibraryApi.getFoodById(id);
      return response;
    } catch (error: any) {
      return rejectWithValue(error.message || '获取食物详情失败');
    }
  }
);

// 初始状态
const initialState: FoodLibraryState = {
  categories: [],
  loading: false,
  error: null,
  searchResults: [],
  searchLoading: false,
  lastUpdated: null,
};

// 创建 slice
const foodLibrarySlice = createSlice({
  name: 'foodLibrary',
  initialState,
  reducers: {
    // 清除错误
    clearError: (state) => {
      state.error = null;
    },
    // 清除搜索结果
    clearSearchResults: (state) => {
      state.searchResults = [];
    },
    // 添加自定义食物到指定分类
    addCustomFood: (state, action: PayloadAction<{ categoryId: string; food: FoodItem }>) => {
      const { categoryId, food } = action.payload;
      const category = state.categories.find(cat => cat.id === categoryId);
      if (category) {
        category.foods.push(food);
      }
    },
    // 从指定分类移除食物
    removeFoodFromCategory: (state, action: PayloadAction<{ categoryId: string; foodId: string }>) => {
      const { categoryId, foodId } = action.payload;
      const category = state.categories.find(cat => cat.id === categoryId);
      if (category) {
        category.foods = category.foods.filter(food => food.id !== foodId);
      }
    },
    // 添加食物到收藏
    addToFavorites: (state, action: PayloadAction<FoodItem>) => {
      const favoriteCategory = state.categories.find(cat => cat.id === 'favorite');
      if (favoriteCategory) {
        // 检查是否已存在
        const exists = favoriteCategory.foods.some(food => food.id === action.payload.id);
        if (!exists) {
          favoriteCategory.foods.push(action.payload);
        }
      }
    },
    // 从收藏移除食物
    removeFromFavorites: (state, action: PayloadAction<string>) => {
      const favoriteCategory = state.categories.find(cat => cat.id === 'favorite');
      if (favoriteCategory) {
        favoriteCategory.foods = favoriteCategory.foods.filter(food => food.id !== action.payload);
      }
    },
  },
  extraReducers: (builder) => {
    // 获取食物库
    builder
      .addCase(fetchFoodLibrary.pending, (state) => {
        state.loading = true;
        state.error = null;
      })
      .addCase(fetchFoodLibrary.fulfilled, (state, action) => {
        state.loading = false;
        state.categories = action.payload.categories.map(transformFoodCategoryDto);
        state.lastUpdated = Date.now();
        state.error = null;
      })
      .addCase(fetchFoodLibrary.rejected, (state, action) => {
        state.loading = false;
        state.error = action.payload as string;
      });

    // 搜索食物
    builder
      .addCase(searchFoods.pending, (state) => {
        state.searchLoading = true;
        state.error = null;
      })
      .addCase(searchFoods.fulfilled, (state, action) => {
        state.searchLoading = false;
        state.searchResults = action.payload.map(transformFoodItemDto);
        state.error = null;
      })
      .addCase(searchFoods.rejected, (state, action) => {
        state.searchLoading = false;
        state.error = action.payload as string;
        state.searchResults = [];
      });

    // 获取食物详情
    builder
      .addCase(getFoodById.pending, (state) => {
        state.loading = true;
        state.error = null;
      })
      .addCase(getFoodById.fulfilled, (state, action) => {
        state.loading = false;
        state.error = null;
        // 可以在这里处理获取到的食物详情，比如更新缓存等
      })
      .addCase(getFoodById.rejected, (state, action) => {
        state.loading = false;
        state.error = action.payload as string;
      });
  },
});

// 导出 actions
export const {
  clearError,
  clearSearchResults,
  addCustomFood,
  removeFoodFromCategory,
  addToFavorites,
  removeFromFavorites,
} = foodLibrarySlice.actions;

// 选择器
export const selectFoodLibrary = (state: { foodLibrary: FoodLibraryState }) => state.foodLibrary;
export const selectFoodCategories = (state: { foodLibrary: FoodLibraryState }) => state.foodLibrary.categories;
export const selectFoodLibraryLoading = (state: { foodLibrary: FoodLibraryState }) => state.foodLibrary.loading;
export const selectFoodLibraryError = (state: { foodLibrary: FoodLibraryState }) => state.foodLibrary.error;
export const selectSearchResults = (state: { foodLibrary: FoodLibraryState }) => state.foodLibrary.searchResults;
export const selectSearchLoading = (state: { foodLibrary: FoodLibraryState }) => state.foodLibrary.searchLoading;

// 复合选择器
export const selectFoodCategoryById = (categoryId: string) =>
  (state: { foodLibrary: FoodLibraryState }) =>
    state.foodLibrary.categories.find(cat => cat.id === categoryId);

export const selectFoodById = (foodId: string) =>
  (state: { foodLibrary: FoodLibraryState }) => {
    for (const category of state.foodLibrary.categories) {
      const food = category.foods.find(f => f.id === foodId);
      if (food) return food;
    }
    return null;
  };

export const selectFavoritesFoods = (state: { foodLibrary: FoodLibraryState }) =>
  state.foodLibrary.categories.find(cat => cat.id === 'favorite')?.foods || [];

export const selectCommonFoods = (state: { foodLibrary: FoodLibraryState }) =>
  state.foodLibrary.categories.find(cat => cat.id === 'common')?.foods || [];

// 导出 reducer
export default foodLibrarySlice.reducer;