/**
 * 菜单控制器
 *
 * 功能：处理菜单管理的业务逻辑
 */

const Menu = require('../models/Menu');
const Dish = require('../models/Dish');
const { validateRequired, validateBatch } = require('../utils/validator');
const { success } = require('../utils/response');
const { BusinessError, ValidationError } = require('../middleware/errorHandler');

/**
 * 获取菜单列表（分页、筛选）
 * GET /api/menus
 */
const getMenus = async (req, res, next) => {
  try {
    const {
      page = 1,
      pageSize = 10,
      type,
      is_active
    } = req.query;

    const result = await Menu.findAll({
      page: parseInt(page),
      pageSize: parseInt(pageSize),
      type,
      is_active: is_active !== undefined ? parseInt(is_active) : undefined
    });

    res.json(success({
      list: result.list,
      pagination: {
        total: result.total,
        page: result.page,
        pageSize: result.pageSize,
        totalPages: Math.ceil(result.total / result.pageSize)
      }
    }, '获取菜单列表成功'));
  } catch (err) {
    next(err);
  }
};

/**
 * 获取单个菜单详情
 * GET /api/menus/:id
 */
const getMenuById = async (req, res, next) => {
  try {
    const { id } = req.params;

    const menu = await Menu.findById(id);
    if (!menu) {
      throw new BusinessError('菜单不存在', 404);
    }

    res.json(success(menu, '获取菜单详情成功'));
  } catch (err) {
    next(err);
  }
};

/**
 * 创建菜单
 * POST /api/menus
 * 需要管理员权限
 */
const createMenu = async (req, res, next) => {
  try {
    const { name, type, menu_type, start_date, end_date, is_active } = req.body;

    // Use menu_type if provided, otherwise use type
    const menuType = menu_type || type;

    // 数据验证
    const validation = validateBatch([
      validateRequired(name, '菜单名称'),
      validateRequired(menuType, '菜单类型')
    ]);

    if (!validation.valid) {
      throw new ValidationError('数据验证失败', validation.errors);
    }

    // 验证菜单类型
    const validTypes = ['lunch', 'dinner', 'holiday'];
    if (!validTypes.includes(menuType)) {
      throw new ValidationError('菜单类型必须是 lunch、dinner 或 holiday');
    }

    // 验证日期范围
    if (start_date && end_date && new Date(start_date) > new Date(end_date)) {
      throw new ValidationError('开始日期不能晚于结束日期');
    }

    const menu = await Menu.create({
      name,
      type: menuType,
      start_date: start_date || null,
      end_date: end_date || null,
      is_active: is_active !== undefined ? (is_active ? 1 : 0) : 1
    });

    res.status(201).json(success(menu, '创建菜单成功'));
  } catch (err) {
    next(err);
  }
};

/**
 * 更新菜单
 * PUT /api/menus/:id
 * 需要管理员权限
 */
const updateMenu = async (req, res, next) => {
  try {
    const { id } = req.params;
    const { name, type, menu_type, start_date, end_date, is_active } = req.body;

    // Use menu_type if provided, otherwise use type
    const menuType = menu_type || type;

    // 检查菜单是否存在
    const menu = await Menu.findById(id);
    if (!menu) {
      throw new BusinessError('菜单不存在', 404);
    }

    // 验证菜单类型
    if (menuType) {
      const validTypes = ['lunch', 'dinner', 'holiday'];
      if (!validTypes.includes(menuType)) {
        throw new ValidationError('菜单类型必须是 lunch、dinner 或 holiday');
      }
    }

    // 验证日期范围
    const newStartDate = start_date || menu.start_date;
    const newEndDate = end_date || menu.end_date;
    if (newStartDate && newEndDate && new Date(newStartDate) > new Date(newEndDate)) {
      throw new ValidationError('开始日期不能晚于结束日期');
    }

    const updatedMenu = await Menu.update(id, {
      name,
      type: menuType,
      start_date: start_date !== undefined ? start_date : undefined,
      end_date: end_date !== undefined ? end_date : undefined,
      is_active: is_active !== undefined ? (is_active ? 1 : 0) : undefined
    });

    res.json(success(updatedMenu, '更新菜单成功'));
  } catch (err) {
    next(err);
  }
};

/**
 * 删除菜单
 * DELETE /api/menus/:id
 * 需要管理员权限
 */
const deleteMenu = async (req, res, next) => {
  try {
    const { id } = req.params;

    // 检查菜单是否存在
    const menu = await Menu.findById(id);
    if (!menu) {
      throw new BusinessError('菜单不存在', 404);
    }

    await Menu.delete(id);

    res.json(success(null, '删除菜单成功'));
  } catch (err) {
    next(err);
  }
};

/**
 * 获取菜单中的菜品列表
 * GET /api/menus/:id/dishes
 */
const getMenuDishes = async (req, res, next) => {
  try {
    const { id } = req.params;

    // 检查菜单是否存在
    const menu = await Menu.findById(id);
    if (!menu) {
      throw new BusinessError('菜单不存在', 404);
    }

    const dishes = await Menu.getMenuDishes(id);

    res.json(success({
      menu: {
        id: menu.id,
        name: menu.name,
        type: menu.type,
        start_date: menu.start_date,
        end_date: menu.end_date,
        is_active: menu.is_active
      },
      dishes
    }, '获取菜单菜品成功'));
  } catch (err) {
    next(err);
  }
};

/**
 * 为菜单添加菜品
 * POST /api/menus/:id/dishes
 * 需要管理员权限
 */
const addDishToMenu = async (req, res, next) => {
  try {
    const { id } = req.params;
    const { dish_id, special_price } = req.body;

    // 数据验证
    const validation = validateBatch([
      validateRequired(dish_id, '菜品ID')
    ]);

    if (!validation.valid) {
      throw new ValidationError('数据验证失败', validation.errors);
    }

    // 检查菜单是否存在
    const menu = await Menu.findById(id);
    if (!menu) {
      throw new BusinessError('菜单不存在', 404);
    }

    // 检查菜品是否存在
    const dish = await Dish.findById(dish_id);
    if (!dish) {
      throw new BusinessError('菜品不存在', 404);
    }

    // 验证特价
    if (special_price !== undefined && special_price !== null) {
      if (parseFloat(special_price) <= 0) {
        throw new ValidationError('特价必须大于0');
      }
    }

    const addedDish = await Menu.addDish(
      id,
      dish_id,
      special_price ? parseFloat(special_price) : null
    );

    res.status(201).json(success(addedDish, '添加菜品到菜单成功'));
  } catch (err) {
    next(err);
  }
};

/**
 * 从菜单移除菜品
 * DELETE /api/menus/:id/dishes/:dishId
 * 需要管理员权限
 */
const removeDishFromMenu = async (req, res, next) => {
  try {
    const { id, dishId } = req.params;

    // 检查菜单是否存在
    const menu = await Menu.findById(id);
    if (!menu) {
      throw new BusinessError('菜单不存在', 404);
    }

    await Menu.removeDish(id, dishId);

    res.json(success(null, '从菜单移除菜品成功'));
  } catch (err) {
    next(err);
  }
};

/**
 * 更新菜单中菜品的特价
 * PUT /api/menus/:id/dishes/:dishId/price
 * 需要管理员权限
 */
const updateMenuDishPrice = async (req, res, next) => {
  try {
    const { id, dishId } = req.params;
    const { special_price } = req.body;

    // 验证特价
    if (special_price !== undefined && special_price !== null) {
      if (parseFloat(special_price) <= 0) {
        throw new ValidationError('特价必须大于0');
      }
    }

    // 检查菜单是否存在
    const menu = await Menu.findById(id);
    if (!menu) {
      throw new BusinessError('菜单不存在', 404);
    }

    await Menu.updateDishPrice(
      id,
      dishId,
      special_price ? parseFloat(special_price) : null
    );

    res.json(success(null, '更新菜品特价成功'));
  } catch (err) {
    next(err);
  }
};

/**
 * 批量添加菜品到菜单
 * POST /api/menus/:id/dishes/batch
 * 需要管理员权限
 */
const addDishesToMenu = async (req, res, next) => {
  try {
    const { id } = req.params;
    const { dishes } = req.body;

    // 数据验证
    if (!Array.isArray(dishes) || dishes.length === 0) {
      throw new ValidationError('请提供菜品数组');
    }

    // 检查菜单是否存在
    const menu = await Menu.findById(id);
    if (!menu) {
      throw new BusinessError('菜单不存在', 404);
    }

    const successCount = await Menu.addDishes(id, dishes);

    res.json(success({
      total: dishes.length,
      success: successCount,
      failed: dishes.length - successCount
    }, `成功添加${successCount}个菜品到菜单`));
  } catch (err) {
    next(err);
  }
};

/**
 * 获取当前有效的菜单
 * GET /api/menus/active
 */
const getActiveMenus = async (req, res, next) => {
  try {
    const { type } = req.query;

    const menus = await Menu.getActiveMenus(type);

    res.json(success(menus, '获取有效菜单成功'));
  } catch (err) {
    next(err);
  }
};

// 导出所有控制器函数
module.exports = {
  getMenus,
  getMenuById,
  createMenu,
  updateMenu,
  deleteMenu,
  getMenuDishes,
  addDishToMenu,
  removeDishFromMenu,
  updateMenuDishPrice,
  addDishesToMenu,
  getActiveMenus
};