import { Injectable } from '@nestjs/common';
import { DataSource } from 'typeorm';

import { Warehouse } from './entities/warehouse.entity';
import { WarehouseInventory } from './entities/warehouse-inventory.entity';

export interface WarehouseDashboard {
  totalWarehouses: number;
  totalInventory: number;
  receivedToday: number;
  stored: number;
  reserved: number;
  readyForLoading: number;
  loaded: number;
  dispatched: number;
}

@Injectable()
export class WarehouseDashboardService {
  constructor(private readonly dataSource: DataSource) {}

  async getDashboard(): Promise<WarehouseDashboard> {
    const warehouseRepo = this.dataSource.getRepository(Warehouse);
    const inventoryRepo = this.dataSource.getRepository(WarehouseInventory);

    const startOfToday = new Date();
    startOfToday.setHours(0, 0, 0, 0);

    const [totalWarehouses, totalInventory, stored, reserved, readyForLoading, loaded, dispatched, receivedToday] =
      await Promise.all([
        warehouseRepo.count(),
        inventoryRepo.count(),
        inventoryRepo.count({ where: { status: 'STORED' } }),
        inventoryRepo.count({ where: { status: 'RESERVED' } }),
        inventoryRepo.count({ where: { status: 'READY_FOR_LOADING' } }),
        inventoryRepo.count({ where: { status: 'LOADED' } }),
        inventoryRepo.count({ where: { status: 'DISPATCHED' } }),
        inventoryRepo
          .createQueryBuilder('inv')
          .where('inv.arrived_at >= :start', { start: startOfToday })
          .getCount(),
      ]);

    return {
      totalWarehouses,
      totalInventory,
      receivedToday,
      stored,
      reserved,
      readyForLoading,
      loaded,
      dispatched,
    };
  }
}