refactor: inventory cost to nestjs

packages/server-nest/src/modules/InventoryCost/commands/InventoryAverageCostMethod.service.ts

@@ -0,0 +1,97 @@
+import { pick } from 'lodash';
+import { Knex } from 'knex';
+import { InventoryTransaction } from '../models/InventoryTransaction';
+import { InventoryItemOpeningAvgCostService } from './InventoryItemOpeningAvgCost.service';
+import { Inject, Injectable } from '@nestjs/common';
+import { InventoryAverageCostMethod } from './InventoryAverageCostMethod';
+import { StoreInventoryLotsCostService } from './StoreInventortyLotsCost.service';
+import { TenantModelProxy } from '../../System/models/TenantBaseModel';
+
+@Injectable()
+export class InventoryAverageCostMethodService {
+  constructor(
+    private readonly itemOpeningAvgCostService: InventoryItemOpeningAvgCostService,
+    private readonly storeInventoryLotsCostService: StoreInventoryLotsCostService,
+
+    @Inject(InventoryTransaction.name)
+    private readonly inventoryTransactionModel: TenantModelProxy<
+      typeof InventoryTransaction
+    >,
+  ) {}
+
+  /**
+   * Retrieves the inventory cost lots.
+   * @param {Date} startingDate
+   * @param {number} itemId
+   * @param {number} openingQuantity
+   * @param {number} openingCost
+   * @returns {Promise<any[]>}
+   */
+  async getInventoryCostLots(
+    startingDate: Date,
+    itemId: number,
+    openingQuantity: number,
+    openingCost: number,
+  ) {
+    const afterInvTransactions = await this.inventoryTransactionModel()
+      .query()
+      .modify('filterDateRange', startingDate)
+      .orderBy('date', 'ASC')
+      .orderByRaw("FIELD(direction, 'IN', 'OUT')")
+      .orderBy('createdAt', 'ASC')
+      .where('item_id', itemId)
+      .withGraphFetched('item');
+
+    const avgCostTracker = new InventoryAverageCostMethod();
+
+    // Tracking inventroy transactions and retrieve cost transactions based on
+    // average rate cost method.
+    return avgCostTracker.trackingCostTransactions(
+      afterInvTransactions,
+      openingQuantity,
+      openingCost,
+    );
+  }
+  /**
+   * Computes items costs from the given date using average cost method.
+   * ----------
+   * - Calculate the items average cost in the given date.
+   * - Remove the journal entries that associated to the inventory transacions
+   *   after the given date.
+   * - Re-compute the inventory transactions and re-write the journal entries
+   *   after the given date.
+   * ----------
+   * @param {Date} startingDate
+   * @param {number} itemId
+   * @param {Knex.Transaction} trx
+   */
+  public async computeItemCost(
+    startingDate: Date,
+    itemId: number,
+    trx?: Knex.Transaction,
+  ) {
+    const { openingQuantity, openingCost } =
+      await this.itemOpeningAvgCostService.getOpeningAverageCost(
+        startingDate,
+        itemId,
+      );
+    // Retrieves the new calculated inventory cost lots.
+    const inventoryCostLots = await this.getInventoryCostLots(
+      startingDate,
+      itemId,
+      openingQuantity,
+      openingCost,
+    );
+    // Revert the inveout out lots transactions
+    await this.storeInventoryLotsCostService.revertInventoryCostLotTransactions(
+      startingDate,
+      itemId,
+      trx,
+    );
+    // Store inventory lots cost transactions.
+    await this.storeInventoryLotsCostService.storeInventoryLotsCost(
+      inventoryCostLots,
+      trx,
+    );
+  }
+}