Update backend API configuration and schema for improved functionality

- Modified TypeScript configuration to disable strict mode and allow importing TypeScript extensions.
- Updated Prisma schema to enhance the User model with a new debtAccounts field and refined asset/liability types.
- Adjusted environment variable parsing for PORT to use coercion for better type handling.
- Refactored various controllers and repositories to utilize type imports for better clarity and maintainability.
- Enhanced service layers with new methods for retrieving assets by type and calculating invoice statistics.
- Introduced new types for invoice statuses and asset types to ensure consistency across the application.

backend-api/src/services/AssetService.ts

@@ -1,6 +1,9 @@
-import {Asset, AssetType} from '@prisma/client';
+import type {Asset} from '@prisma/client';
 import {AssetRepository} from '../repositories/AssetRepository';
-import {NotFoundError, ForbiddenError, ValidationError} from '../utils/errors';
+import {NotFoundError, ValidationError} from '../utils/errors';
+
+type AssetType = 'cash' | 'investment' | 'property' | 'vehicle' | 'other';
+const VALID_ASSET_TYPES: AssetType[] = ['cash', 'investment', 'property', 'vehicle', 'other'];
 
 interface CreateAssetDTO {
   name: string;
@@ -54,7 +57,7 @@ export class AssetService {
     if (data.value !== undefined || data.name !== undefined || data.type !== undefined) {
       this.validateAssetData({
         name: data.name || asset.name,
-        type: data.type || asset.type,
+        type: (data.type || asset.type) as AssetType,
         value: data.value !== undefined ? data.value : asset.value,
       });
     }
@@ -75,6 +78,18 @@ export class AssetService {
     return this.assetRepository.getTotalValue(userId);
   }
 
+  async getByType(userId: string): Promise<Record<string, Asset[]>> {
+    const assets = await this.assetRepository.findAllByUser(userId);
+    return assets.reduce((acc, asset) => {
+      const type = asset.type;
+      if (!acc[type]) {
+        acc[type] = [];
+      }
+      acc[type].push(asset);
+      return acc;
+    }, {} as Record<string, Asset[]>);
+  }
+
   private validateAssetData(data: CreateAssetDTO): void {
     if (!data.name || data.name.trim().length === 0) {
       throw new ValidationError('Asset name is required');
@@ -84,7 +99,7 @@ export class AssetService {
       throw new ValidationError('Asset value cannot be negative');
     }
 
-    if (!Object.values(AssetType).includes(data.type)) {
+    if (!VALID_ASSET_TYPES.includes(data.type)) {
       throw new ValidationError('Invalid asset type');
     }
   }

backend-api/src/services/InvoiceService.ts

@@ -1,7 +1,9 @@
-import {Invoice, InvoiceStatus, Prisma} from '@prisma/client';
+import type {Invoice, Prisma} from '@prisma/client';
 import {InvoiceRepository} from '../repositories/InvoiceRepository';
 import {NotFoundError, ValidationError} from '../utils/errors';
 
+type InvoiceStatus = 'draft' | 'sent' | 'paid' | 'overdue' | 'cancelled';
+
 interface InvoiceLineItemDTO {
   description: string;
   quantity: number;
@@ -26,6 +28,17 @@ interface UpdateInvoiceDTO {
   notes?: string;
 }
 
+interface InvoiceStats {
+  total: number;
+  draft: number;
+  sent: number;
+  paid: number;
+  overdue: number;
+  totalAmount: number;
+  paidAmount: number;
+  outstandingAmount: number;
+}
+
 /**
  * Invoice Service
  * Handles invoice business logic including calculations
@@ -37,6 +50,10 @@ export class InvoiceService {
     return this.invoiceRepository.findAllByUser(userId, filters) as unknown as Invoice[];
   }
 
+  async getAllByUser(userId: string, filters?: {status?: string; clientId?: string}): Promise<Invoice[]> {
+    return this.invoiceRepository.findAllByUser(userId, filters) as unknown as Invoice[];
+  }
+
   async getById(id: string, userId: string): Promise<Invoice> {
     const invoice = await this.invoiceRepository.findByIdAndUser(id, userId);
     if (!invoice) {
@@ -72,7 +89,7 @@ export class InvoiceService {
 
     return this.invoiceRepository.create({
       invoiceNumber,
-      status: data.status || InvoiceStatus.DRAFT,
+      status: data.status || 'draft',
       issueDate: data.issueDate,
       dueDate: data.dueDate,
       subtotal,
@@ -136,6 +153,50 @@ export class InvoiceService {
     await this.invoiceRepository.delete(id);
   }
 
+  async getStats(userId: string): Promise<InvoiceStats> {
+    const invoices = await this.invoiceRepository.findAllByUser(userId);
+    
+    const stats: InvoiceStats = {
+      total: invoices.length,
+      draft: 0,
+      sent: 0,
+      paid: 0,
+      overdue: 0,
+      totalAmount: 0,
+      paidAmount: 0,
+      outstandingAmount: 0,
+    };
+
+    for (const inv of invoices) {
+      stats.totalAmount += inv.total;
+      
+      switch (inv.status) {
+        case 'draft':
+          stats.draft++;
+          break;
+        case 'sent':
+          stats.sent++;
+          stats.outstandingAmount += inv.total;
+          break;
+        case 'paid':
+          stats.paid++;
+          stats.paidAmount += inv.total;
+          break;
+        case 'overdue':
+          stats.overdue++;
+          stats.outstandingAmount += inv.total;
+          break;
+      }
+    }
+
+    return stats;
+  }
+
+  async getOverdueInvoices(userId: string): Promise<Invoice[]> {
+    const invoices = await this.invoiceRepository.findAllByUser(userId, {status: 'overdue'});
+    return invoices as unknown as Invoice[];
+  }
+
   private validateInvoiceData(data: CreateInvoiceDTO): void {
     if (!data.clientId) {
       throw new ValidationError('Client ID is required');