/**
 * [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, InventoryStatus } from '../types/inventory';

export interface Warehouse {
  id: string;
  name: string;
  code: string;
  address: string;
  city: string;
  country: string;
  capacity: number;
  currentUsage: number;
  status: 'active' | 'inactive' | 'maintenance';
  manager: string;
  phone: string;
  email: string;
  createdAt: string;
  updatedAt: string;
}

export interface InventoryForecast {
  id: string;
  productId: string;
  productName: string;
  sku: string;
  currentStock: number;
  forecastedDemand: number;
  recommendedOrder: number;
  leadTime: number;
  riskLevel: 'low' | 'medium' | 'high';
  date: string;
}

export interface InventoryQueryParams {
  productId?: string;
  status?: InventoryStatus;
  warehouseId?: string;
  page?: number;
  pageSize?: number;
}

export interface InventoryDataSource {
  list(params?: InventoryQueryParams): 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>;
  }>;
  fetchWarehouses(): Promise<Warehouse[]>;
  getInventoryForecasts(): Promise<InventoryForecast[]>;
}

export class InventoryDataSourceImpl implements InventoryDataSource {
  async list(params?: InventoryQueryParams): Promise<{ data: Inventory[]; total: number }> {
    const mockInventory: Inventory[] = [
      {
        id: 'inv_1',
        productId: '1',
        productName: '智能手表',
        quantity: 100,
        threshold: 20,
        status: InventoryStatus.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: InventoryStatus.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: InventoryStatus.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: InventoryStatus.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: InventoryStatus.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> {
    const mockInventory: Inventory[] = [
      {
        id: 'inv_1',
        productId: '1',
        productName: '智能手表',
        quantity: 100,
        threshold: 20,
        status: InventoryStatus.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: InventoryStatus.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> {
    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> {
    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> {
    const existingInventory = await this.get(id);
    if (!existingInventory) {
      return null;
    }

    const newQuantity = existingInventory.quantity + quantity;
    let status: InventoryStatus;
    
    if (newQuantity <= 0) {
      status = InventoryStatus.OUT_OF_STOCK;
    } else if (newQuantity < existingInventory.threshold) {
      status = InventoryStatus.LOW_STOCK;
    } else {
      status = InventoryStatus.IN_STOCK;
    }

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

    return updatedInventory;
  }

  async getByProductId(productId: string): Promise<Inventory[]> {
    const mockInventory: Inventory[] = [
      {
        id: 'inv_1',
        productId: '1',
        productName: '智能手表',
        quantity: 100,
        threshold: 20,
        status: InventoryStatus.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: InventoryStatus.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[]> {
    const mockInventory: Inventory[] = [
      {
        id: 'inv_1',
        productId: '1',
        productName: '智能手表',
        quantity: 100,
        threshold: 20,
        status: InventoryStatus.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: InventoryStatus.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: InventoryStatus.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[]> {
    const mockInventory: Inventory[] = [
      {
        id: 'inv_1',
        productId: '1',
        productName: '智能手表',
        quantity: 100,
        threshold: 20,
        status: InventoryStatus.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: InventoryStatus.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: InventoryStatus.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>;
  }> {
    const mockInventory: Inventory[] = [
      {
        id: 'inv_1',
        productId: '1',
        productName: '智能手表',
        quantity: 100,
        threshold: 20,
        status: InventoryStatus.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: InventoryStatus.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: InventoryStatus.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: InventoryStatus.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: InventoryStatus.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 === InventoryStatus.LOW_STOCK).length;
    const outOfStockItems = mockInventory.filter(i => i.status === InventoryStatus.OUT_OF_STOCK).length;

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

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

  async fetchWarehouses(): Promise<Warehouse[]> {
    return [
      {
        id: 'warehouse_1',
        name: '北京仓库',
        code: 'BJ-WH-001',
        address: '北京市朝阳区建国路88号',
        city: '北京',
        country: '中国',
        capacity: 10000,
        currentUsage: 7500,
        status: 'active',
        manager: '张三',
        phone: '010-12345678',
        email: 'zhangsan@example.com',
        createdAt: '2026-01-01',
        updatedAt: '2026-03-15',
      },
      {
        id: 'warehouse_2',
        name: '上海仓库',
        code: 'SH-WH-001',
        address: '上海市浦东新区张江路100号',
        city: '上海',
        country: '中国',
        capacity: 15000,
        currentUsage: 12000,
        status: 'active',
        manager: '李四',
        phone: '021-87654321',
        email: 'lisi@example.com',
        createdAt: '2026-01-15',
        updatedAt: '2026-03-16',
      },
    ];
  }

  async getInventoryForecasts(): Promise<InventoryForecast[]> {
    return [
      {
        id: 'forecast_1',
        productId: '1',
        productName: '智能手表',
        sku: 'WATCH-001',
        currentStock: 100,
        forecastedDemand: 150,
        recommendedOrder: 50,
        leadTime: 7,
        riskLevel: 'low',
        date: '2026-03-21',
      },
      {
        id: 'forecast_2',
        productId: '2',
        productName: '无线耳机',
        sku: 'EARPHONE-001',
        currentStock: 200,
        forecastedDemand: 180,
        recommendedOrder: 0,
        leadTime: 5,
        riskLevel: 'low',
        date: '2026-03-21',
      },
      {
        id: 'forecast_3',
        productId: '4',
        productName: '智能手机',
        sku: 'PHONE-001',
        currentStock: 5,
        forecastedDemand: 50,
        recommendedOrder: 45,
        leadTime: 10,
        riskLevel: 'high',
        date: '2026-03-21',
      },
    ];
  }
}

export const inventoryDataSource = new InventoryDataSourceImpl();