/**
 * [MOCK-010] 库存模块DataSource
 * AI注意: 这是Mock实现，不是真实业务逻辑
 * 仅在USE_MOCK=true时启用
 */

import { Inventory } from '../types/inventory';

// 库存数据接口
export interface InventoryDataSource {
  list(params?: {
    page?: number;
    pageSize?: number;
    productId?: string;
    status?: string;
    warehouseId?: string;
  }): Promise<{ data: Inventory[]; total: number }>;
  
  get(id: string): Promise<Inventory | null>;
  
  create(inventory: Omit<Inventory, 'id' | 'createdAt' | 'updatedAt'>): Promise<Inventory>;
  
  update(id: string, inventory: Partial<Inventory>): Promise<Inventory | null>;
  
  updateStock(id: string, quantity: number): Promise<Inventory | null>;
  
  getByProductId(productId: string): Promise<Inventory[]>;
  
  getByWarehouseId(warehouseId: string): Promise<Inventory[]>;
  
  getLowStockAlerts(threshold: number): Promise<Inventory[]>;
  
  getInventoryStatistics(): Promise<{
    totalItems: number;
    totalStock: number;
    lowStockItems: number;
    outOfStockItems: number;
    warehouseDistribution: Record<string, number>;
  }>;
}

// 库存DataSource实现
export class InventoryDataSourceImpl implements InventoryDataSource {
  async list(params?: {
    page?: number;
    pageSize?: number;
    productId?: string;
    status?: string;
    warehouseId?: string;
  }): Promise<{ data: Inventory[]; total: number }> {
    // 这里应该调用实际的API
    // 暂时返回Mock数据
    const mockInventory: Inventory[] = [
      {
        id: 'inv_1',
        productId: '1',
        productName: '智能手表',
        quantity: 100,
        threshold: 20,
        status: 'in_stock',
        warehouseId: 'warehouse_1',
        warehouseName: '北京仓库',
        lastStockUpdate: new Date('2026-03-10'),
        createdAt: new Date('2026-02-01'),
        updatedAt: new Date('2026-03-10'),
      },
      {
        id: 'inv_2',
        productId: '2',
        productName: '无线耳机',
        quantity: 200,
        threshold: 30,
        status: 'in_stock',
        warehouseId: 'warehouse_1',
        warehouseName: '北京仓库',
        lastStockUpdate: new Date('2026-03-11'),
        createdAt: new Date('2026-02-02'),
        updatedAt: new Date('2026-03-11'),
      },
      {
        id: 'inv_3',
        productId: '3',
        productName: '运动鞋',
        quantity: 150,
        threshold: 25,
        status: 'in_stock',
        warehouseId: 'warehouse_2',
        warehouseName: '上海仓库',
        lastStockUpdate: new Date('2026-03-12'),
        createdAt: new Date('2026-02-03'),
        updatedAt: new Date('2026-03-12'),
      },
      {
        id: 'inv_4',
        productId: '4',
        productName: '智能手机',
        quantity: 5,
        threshold: 10,
        status: 'low_stock',
        warehouseId: 'warehouse_1',
        warehouseName: '北京仓库',
        lastStockUpdate: new Date('2026-03-09'),
        createdAt: new Date('2026-02-04'),
        updatedAt: new Date('2026-03-09'),
      },
      {
        id: 'inv_5',
        productId: '5',
        productName: '平板电脑',
        quantity: 0,
        threshold: 15,
        status: 'out_of_stock',
        warehouseId: 'warehouse_2',
        warehouseName: '上海仓库',
        lastStockUpdate: new Date('2026-03-08'),
        createdAt: new Date('2026-02-05'),
        updatedAt: new Date('2026-03-08'),
      },
    ];

    let filteredInventory = mockInventory;
    
    if (params?.productId) {
      filteredInventory = filteredInventory.filter(i => i.productId === params.productId);
    }
    
    if (params?.status) {
      filteredInventory = filteredInventory.filter(i => i.status === params.status);
    }
    
    if (params?.warehouseId) {
      filteredInventory = filteredInventory.filter(i => i.warehouseId === params.warehouseId);
    }

    const page = params?.page || 1;
    const pageSize = params?.pageSize || 10;
    const start = (page - 1) * pageSize;
    const end = start + pageSize;
    const paginatedInventory = filteredInventory.slice(start, end);

    return {
      data: paginatedInventory,
      total: filteredInventory.length,
    };
  }

  async get(id: string): Promise<Inventory | null> {
    // 这里应该调用实际的API
    // 暂时返回Mock数据
    const mockInventory: Inventory[] = [
      {
        id: 'inv_1',
        productId: '1',
        productName: '智能手表',
        quantity: 100,
        threshold: 20,
        status: 'in_stock',
        warehouseId: 'warehouse_1',
        warehouseName: '北京仓库',
        lastStockUpdate: new Date('2026-03-10'),
        createdAt: new Date('2026-02-01'),
        updatedAt: new Date('2026-03-10'),
      },
      {
        id: 'inv_2',
        productId: '2',
        productName: '无线耳机',
        quantity: 200,
        threshold: 30,
        status: 'in_stock',
        warehouseId: 'warehouse_1',
        warehouseName: '北京仓库',
        lastStockUpdate: new Date('2026-03-11'),
        createdAt: new Date('2026-02-02'),
        updatedAt: new Date('2026-03-11'),
      },
    ];

    const inventory = mockInventory.find(i => i.id === id);
    return inventory || null;
  }

  async create(inventory: Omit<Inventory, 'id' | 'createdAt' | 'updatedAt'>): Promise<Inventory> {
    // 这里应该调用实际的API
    // 暂时返回Mock数据
    const newInventory: Inventory = {
      ...inventory,
      id: `inv_${Date.now()}`,
      createdAt: new Date(),
      updatedAt: new Date(),
    };

    return newInventory;
  }

  async update(id: string, inventory: Partial<Inventory>): Promise<Inventory | null> {
    // 这里应该调用实际的API
    // 暂时返回Mock数据
    const existingInventory = await this.get(id);
    if (!existingInventory) {
      return null;
    }

    const updatedInventory: Inventory = {
      ...existingInventory,
      ...inventory,
      updatedAt: new Date(),
    };

    return updatedInventory;
  }

  async updateStock(id: string, quantity: number): Promise<Inventory | null> {
    // 这里应该调用实际的API
    // 暂时返回Mock数据
    const existingInventory = await this.get(id);
    if (!existingInventory) {
      return null;
    }

    const newQuantity = existingInventory.quantity + quantity;
    let status: 'in_stock' | 'low_stock' | 'out_of_stock';
    
    if (newQuantity <= 0) {
      status = 'out_of_stock';
    } else if (newQuantity < existingInventory.threshold) {
      status = 'low_stock';
    } else {
      status = 'in_stock';
    }

    const updatedInventory: Inventory = {
      ...existingInventory,
      quantity: newQuantity,
      status,
      lastStockUpdate: new Date(),
      updatedAt: new Date(),
    };

    return updatedInventory;
  }

  async getByProductId(productId: string): Promise<Inventory[]> {
    // 这里应该调用实际的API
    // 暂时返回Mock数据
    const mockInventory: Inventory[] = [
      {
        id: 'inv_1',
        productId: '1',
        productName: '智能手表',
        quantity: 100,
        threshold: 20,
        status: 'in_stock',
        warehouseId: 'warehouse_1',
        warehouseName: '北京仓库',
        lastStockUpdate: new Date('2026-03-10'),
        createdAt: new Date('2026-02-01'),
        updatedAt: new Date('2026-03-10'),
      },
      {
        id: 'inv_2',
        productId: '2',
        productName: '无线耳机',
        quantity: 200,
        threshold: 30,
        status: 'in_stock',
        warehouseId: 'warehouse_1',
        warehouseName: '北京仓库',
        lastStockUpdate: new Date('2026-03-11'),
        createdAt: new Date('2026-02-02'),
        updatedAt: new Date('2026-03-11'),
      },
    ];

    return mockInventory.filter(i => i.productId === productId);
  }

  async getByWarehouseId(warehouseId: string): Promise<Inventory[]> {
    // 这里应该调用实际的API
    // 暂时返回Mock数据
    const mockInventory: Inventory[] = [
      {
        id: 'inv_1',
        productId: '1',
        productName: '智能手表',
        quantity: 100,
        threshold: 20,
        status: 'in_stock',
        warehouseId: 'warehouse_1',
        warehouseName: '北京仓库',
        lastStockUpdate: new Date('2026-03-10'),
        createdAt: new Date('2026-02-01'),
        updatedAt: new Date('2026-03-10'),
      },
      {
        id: 'inv_2',
        productId: '2',
        productName: '无线耳机',
        quantity: 200,
        threshold: 30,
        status: 'in_stock',
        warehouseId: 'warehouse_1',
        warehouseName: '北京仓库',
        lastStockUpdate: new Date('2026-03-11'),
        createdAt: new Date('2026-02-02'),
        updatedAt: new Date('2026-03-11'),
      },
      {
        id: 'inv_3',
        productId: '3',
        productName: '运动鞋',
        quantity: 150,
        threshold: 25,
        status: 'in_stock',
        warehouseId: 'warehouse_2',
        warehouseName: '上海仓库',
        lastStockUpdate: new Date('2026-03-12'),
        createdAt: new Date('2026-02-03'),
        updatedAt: new Date('2026-03-12'),
      },
    ];

    return mockInventory.filter(i => i.warehouseId === warehouseId);
  }

  async getLowStockAlerts(threshold: number): Promise<Inventory[]> {
    // 这里应该调用实际的API
    // 暂时返回Mock数据
    const mockInventory: Inventory[] = [
      {
        id: 'inv_1',
        productId: '1',
        productName: '智能手表',
        quantity: 100,
        threshold: 20,
        status: 'in_stock',
        warehouseId: 'warehouse_1',
        warehouseName: '北京仓库',
        lastStockUpdate: new Date('2026-03-10'),
        createdAt: new Date('2026-02-01'),
        updatedAt: new Date('2026-03-10'),
      },
      {
        id: 'inv_4',
        productId: '4',
        productName: '智能手机',
        quantity: 5,
        threshold: 10,
        status: 'low_stock',
        warehouseId: 'warehouse_1',
        warehouseName: '北京仓库',
        lastStockUpdate: new Date('2026-03-09'),
        createdAt: new Date('2026-02-04'),
        updatedAt: new Date('2026-03-09'),
      },
      {
        id: 'inv_5',
        productId: '5',
        productName: '平板电脑',
        quantity: 0,
        threshold: 15,
        status: 'out_of_stock',
        warehouseId: 'warehouse_2',
        warehouseName: '上海仓库',
        lastStockUpdate: new Date('2026-03-08'),
        createdAt: new Date('2026-02-05'),
        updatedAt: new Date('2026-03-08'),
      },
    ];

    return mockInventory.filter(i => i.quantity <= threshold);
  }

  async getInventoryStatistics(): Promise<{
    totalItems: number;
    totalStock: number;
    lowStockItems: number;
    outOfStockItems: number;
    warehouseDistribution: Record<string, number>;
  }> {
    // 这里应该调用实际的API
    // 暂时返回Mock数据
    const mockInventory: Inventory[] = [
      {
        id: 'inv_1',
        productId: '1',
        productName: '智能手表',
        quantity: 100,
        threshold: 20,
        status: 'in_stock',
        warehouseId: 'warehouse_1',
        warehouseName: '北京仓库',
        lastStockUpdate: new Date('2026-03-10'),
        createdAt: new Date('2026-02-01'),
        updatedAt: new Date('2026-03-10'),
      },
      {
        id: 'inv_2',
        productId: '2',
        productName: '无线耳机',
        quantity: 200,
        threshold: 30,
        status: 'in_stock',
        warehouseId: 'warehouse_1',
        warehouseName: '北京仓库',
        lastStockUpdate: new Date('2026-03-11'),
        createdAt: new Date('2026-02-02'),
        updatedAt: new Date('2026-03-11'),
      },
      {
        id: 'inv_3',
        productId: '3',
        productName: '运动鞋',
        quantity: 150,
        threshold: 25,
        status: 'in_stock',
        warehouseId: 'warehouse_2',
        warehouseName: '上海仓库',
        lastStockUpdate: new Date('2026-03-12'),
        createdAt: new Date('2026-02-03'),
        updatedAt: new Date('2026-03-12'),
      },
      {
        id: 'inv_4',
        productId: '4',
        productName: '智能手机',
        quantity: 5,
        threshold: 10,
        status: 'low_stock',
        warehouseId: 'warehouse_1',
        warehouseName: '北京仓库',
        lastStockUpdate: new Date('2026-03-09'),
        createdAt: new Date('2026-02-04'),
        updatedAt: new Date('2026-03-09'),
      },
      {
        id: 'inv_5',
        productId: '5',
        productName: '平板电脑',
        quantity: 0,
        threshold: 15,
        status: 'out_of_stock',
        warehouseId: 'warehouse_2',
        warehouseName: '上海仓库',
        lastStockUpdate: new Date('2026-03-08'),
        createdAt: new Date('2026-02-05'),
        updatedAt: new Date('2026-03-08'),
      },
    ];

    const totalItems = mockInventory.length;
    const totalStock = mockInventory.reduce((sum, item) => sum + item.quantity, 0);
    const lowStockItems = mockInventory.filter(i => i.status === 'low_stock').length;
    const outOfStockItems = mockInventory.filter(i => i.status === 'out_of_stock').length;

    const warehouseDistribution: Record<string, number> = {};
    mockInventory.forEach(item => {
      warehouseDistribution[item.warehouseName] = (warehouseDistribution[item.warehouseName] || 0) + item.quantity;
    });

    return {
      totalItems,
      totalStock,
      lowStockItems,
      outOfStockItems,
      warehouseDistribution,
    };
  }
}

// 导出DataSource实例
export const inventoryDataSource = new InventoryDataSourceImpl();