fleet

apps/edr-freight-api/src/modules/procurement/procurement.service.ts

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+import { Injectable } from '@nestjs/common';
+import { ProcurementRepository } from './procurement.repository';
+import { Vendor } from './entities/vendor.entity';
+import { AssetAcquisition } from './entities/asset-acquisition.entity';
+import { AssetDisposal } from './entities/asset-disposal.entity';
+import {
+  CreateVendorDto,
+  UpdateVendorDto,
+  CreateAcquisitionDto,
+  UpdateAcquisitionDto,
+  CreateDisposalDto,
+} from './dto/procurement.dto';
+
+export interface DepreciationResult {
+  method: 'STRAIGHT_LINE';
+  cost: number;
+  salvageValue: number;
+  usefulLifeMonths: number;
+  monthsElapsed: number;
+  monthlyDepreciation: number;
+  bookValue: number;
+}
+
+export interface LifecycleResult {
+  vehicleId: string;
+  acquisition: AssetAcquisition | null;
+  disposal: AssetDisposal | null;
+  depreciation: DepreciationResult | null;
+}
+
+@Injectable()
+export class ProcurementService {
+  constructor(private readonly procurementRepository: ProcurementRepository) {}
+
+  // ---- Vendors ----
+  async createVendor(dto: CreateVendorDto): Promise<Vendor> {
+    return this.procurementRepository.createVendor(dto);
+  }
+
+  async listVendors(): Promise<Vendor[]> {
+    return this.procurementRepository.findVendors();
+  }
+
+  async updateVendor(id: string, dto: UpdateVendorDto): Promise<Vendor | null> {
+    return this.procurementRepository.updateVendor(id, dto);
+  }
+
+  async deleteVendor(id: string): Promise<{ success: boolean }> {
+    await this.procurementRepository.softDeleteVendor(id);
+    return { success: true };
+  }
+
+  // ---- Acquisitions ----
+  async createAcquisition(dto: CreateAcquisitionDto): Promise<AssetAcquisition> {
+    return this.procurementRepository.createAcquisition(dto);
+  }
+
+  async listAcquisitions(vehicleId?: string): Promise<AssetAcquisition[]> {
+    return this.procurementRepository.findAcquisitions(vehicleId);
+  }
+
+  async getAcquisition(id: string): Promise<AssetAcquisition | null> {
+    return this.procurementRepository.findAcquisitionById(id);
+  }
+
+  async updateAcquisition(id: string, dto: UpdateAcquisitionDto): Promise<AssetAcquisition | null> {
+    return this.procurementRepository.updateAcquisition(id, dto);
+  }
+
+  async deleteAcquisition(id: string): Promise<{ success: boolean }> {
+    await this.procurementRepository.softDeleteAcquisition(id);
+    return { success: true };
+  }
+
+  // ---- Disposals ----
+  async createDisposal(dto: CreateDisposalDto): Promise<AssetDisposal> {
+    return this.procurementRepository.createDisposal(dto);
+  }
+
+  async listDisposals(): Promise<AssetDisposal[]> {
+    return this.procurementRepository.findDisposals();
+  }
+
+  async deleteDisposal(id: string): Promise<{ success: boolean }> {
+    await this.procurementRepository.softDeleteDisposal(id);
+    return { success: true };
+  }
+
+  // ---- Lifecycle ----
+  async lifecycle(vehicleId: string): Promise<LifecycleResult> {
+    const acquisition = await this.procurementRepository.findLatestAcquisitionByVehicle(vehicleId);
+    const disposal = await this.procurementRepository.findLatestDisposalByVehicle(vehicleId);
+
+    return {
+      vehicleId,
+      acquisition,
+      disposal,
+      depreciation: this.computeStraightLineDepreciation(acquisition),
+    };
+  }
+
+  /**
+   * Straight-line depreciation. Requires a cost and a positive useful life.
+   * monthlyDep = (cost - salvageValue) / usefulLifeMonths
+   * bookValue  = cost - monthlyDep * monthsElapsedSinceAcquisition, floored at salvageValue.
+   */
+  private computeStraightLineDepreciation(
+    acquisition: AssetAcquisition | null,
+  ): DepreciationResult | null {
+    if (!acquisition) return null;
+
+    const cost = acquisition.cost != null ? Number(acquisition.cost) : null;
+    const usefulLifeMonths =
+      acquisition.usefulLifeMonths != null ? Number(acquisition.usefulLifeMonths) : null;
+
+    if (cost == null || usefulLifeMonths == null || usefulLifeMonths <= 0) {
+      return null;
+    }
+
+    const salvageValue = acquisition.salvageValue != null ? Number(acquisition.salvageValue) : 0;
+    const monthlyDepreciation = (cost - salvageValue) / usefulLifeMonths;
+
+    const acquiredAt = new Date(acquisition.acquisitionDate);
+    const now = new Date();
+    const monthsElapsed = Math.max(
+      0,
+      (now.getFullYear() - acquiredAt.getFullYear()) * 12 +
+        (now.getMonth() - acquiredAt.getMonth()),
+    );
+
+    const bookValue = Math.max(cost - monthlyDepreciation * monthsElapsed, salvageValue);
+
+    return {
+      method: 'STRAIGHT_LINE',
+      cost,
+      salvageValue,
+      usefulLifeMonths,
+      monthsElapsed,
+      monthlyDepreciation,
+      bookValue,
+    };
+  }
+}