Fix/api 13/pagination

.env.example

@@ -10,4 +10,6 @@ PGADMIN_DEFAULT_EMAIL=
 PGADMIN_DEFAULT_PASSWORD=
 # JWT
 JWT_SECRET=
-JWT_EXPIRES_IN=7d
+JWT_EXPIRES_IN=7d
+# API
+API_URL=

src/products/dto/find-products.dto.ts

@@ -1,20 +1,5 @@
 import { ApiProperty } from '@nestjs/swagger';
-
-class UUIDBaseDTO {
-  @ApiProperty({ example: '123e4567-e89b-12d3-a456-426614174006' })
-  id: string;
-}
-
-export class BaseDTO extends UUIDBaseDTO {
-  @ApiProperty()
-  createdAt: Date;
-
-  @ApiProperty()
-  updatedAt: Date;
-
-  @ApiProperty({ example: null })
-  deletedAt: Date;
-}
+import { BaseDTO, UUIDBaseDTO } from 'src/utils/dto/base.dto';
 
 export class ManufacturerDTO extends BaseDTO {
   @ApiProperty()
@@ -24,7 +9,7 @@ export class ManufacturerDTO extends BaseDTO {
   description: string;
 }
 
-export class ImagesDTO extends BaseDTO {
+export class ImageDTO extends BaseDTO {
   @ApiProperty()
   url: string;
 }
@@ -34,7 +19,7 @@ export class LotDTO extends BaseDTO {
   expirationDate: Date;
 }
 
-export class CategorieDTO extends UUIDBaseDTO {
+export class CategoryDTO extends UUIDBaseDTO {
   @ApiProperty()
   name: string;
 
@@ -56,15 +41,15 @@ export class PresentationDTO extends BaseDTO {
   meansurementUnit: string;
 }
 
-export class PresentationsDTO extends BaseDTO {
+export class ProductPresentationDTO extends BaseDTO {
   @ApiProperty()
   price: number;
 
   @ApiProperty()
   presentation: PresentationDTO;
 }
 
-export class ProductListDTO extends BaseDTO {
+export class ProductDTO extends BaseDTO {
   @ApiProperty()
   name: string;
 
@@ -80,15 +65,12 @@ export class ProductListDTO extends BaseDTO {
   @ApiProperty({ type: ManufacturerDTO })
   manufacturer: ManufacturerDTO;
 
-  @ApiProperty({ type: ImagesDTO })
-  images: ImagesDTO[];
-
-  @ApiProperty({ type: [LotDTO] })
-  lot: LotDTO[];
+  @ApiProperty({ type: ImageDTO })
+  images: ImageDTO[];
 
-  @ApiProperty({ type: [CategorieDTO] })
-  categories: CategorieDTO[];
+  @ApiProperty({ type: [CategoryDTO] })
+  categories: CategoryDTO[];
 
-  @ApiProperty({ type: [PresentationsDTO] })
-  presentations: PresentationsDTO[];
+  @ApiProperty({ type: [ProductPresentationDTO] })
+  presentations: ProductPresentationDTO[];
 }

src/products/products.controller.ts

@@ -4,30 +4,60 @@ import {
   Get,
   ParseIntPipe,
   Query,
+  Req,
 } from '@nestjs/common';
 import { ProductsService } from './products.service';
-import { ApiOperation, ApiResponse } from '@nestjs/swagger';
-import { ProductListDTO } from './dto/find-products.dto';
+import {
+  ApiExtraModels,
+  ApiOkResponse,
+  ApiOperation,
+  getSchemaPath,
+} from '@nestjs/swagger';
+import { ProductDTO } from './dto/find-products.dto';
+import { Request } from 'express';
+import { ConfigService } from '@nestjs/config';
+import { getPaginationUrl } from 'src/utils/pagination-urls';
+import { PaginationDTO } from 'src/utils/dto/pagination.dto';
 
 @Controller('product')
+@ApiExtraModels(PaginationDTO, ProductDTO)
 export class ProductsController {
-  constructor(private productsServices: ProductsService) {}
+  constructor(
+    private productsServices: ProductsService,
+    private configService: ConfigService,
+  ) {}
 
   @Get()
   @ApiOperation({
     summary: 'List all available products',
     description:
       'returns all available products (deletedAt is NULL). It will include their images, lots, presentations, manufacturers and categories.',
   })
-  @ApiResponse({
-    status: 200,
+  @ApiOkResponse({
     description: 'Products obtained correctly.',
-    type: [ProductListDTO],
+    schema: {
+      allOf: [
+        { $ref: getSchemaPath(PaginationDTO) },
+        {
+          properties: {
+            results: {
+              type: 'array',
+              items: { $ref: getSchemaPath(ProductDTO) },
+            },
+          },
+        },
+      ],
+    },
   })
-  getProducts(
+  async getProducts(
     @Query('page', new DefaultValuePipe(1), ParseIntPipe) page: number,
     @Query('limit', new DefaultValuePipe(10), ParseIntPipe) limit: number,
+    @Req() req: Request,
   ) {
-    return this.productsServices.getProducts(page, limit);
+    const baseUrl = this.configService.get<string>('API_URL') + `${req.path}`;
+    const count = await this.productsServices.countProducts();
+    const { next, previous } = getPaginationUrl(baseUrl, page, limit, count);
+    const products = await this.productsServices.getProducts(page, limit);
+    return { products, count, next, previous };
   }
 }

src/products/products.service.ts

@@ -6,48 +6,34 @@ import { Repository } from 'typeorm';
 @Injectable()
 export class ProductsService {
   constructor(
-    @InjectRepository(Product) private productRepository: Repository<Product>,
+    @InjectRepository(Product)
+    private productRepository: Repository<Product>,
   ) {}
 
-  async getProducts(
-    page: number,
-    limit: number,
-  ): Promise<{
-    totalItems: number;
-    totalPages: number;
-    currentPage: number;
-    products: Product[];
-  }> {
-    const totalItems = await this.productRepository
+  async countProducts(): Promise<number> {
+    return await this.productRepository
       .createQueryBuilder('product')
       .where('product.deletedAt IS NULL')
       .getCount();
+  }
 
-    const totalPages = Math.ceil(totalItems / limit);
-
+  async getProducts(page: number, limit: number): Promise<Product[]> {
     const products = await this.productRepository
       .createQueryBuilder('product')
       .leftJoinAndSelect('product.images', 'images')
-      .leftJoinAndSelect('product.lot', 'lot')
       .leftJoinAndSelect('product.manufacturer', 'manufacturer')
       .leftJoinAndSelect('product.categories', 'categories')
       .leftJoinAndSelect('product.presentations', 'productPresentation')
       .leftJoinAndSelect('productPresentation.presentation', 'presentation')
       .where('product.deletedAt IS NULL')
       .andWhere('manufacturer.deletedAt IS NULL')
       .andWhere('images.deletedAt IS NULL')
-      .andWhere('lot.deletedAt IS NULL')
       .andWhere('productPresentation.deletedAt IS NULL')
       .andWhere('presentation.deletedAt IS NULL')
       .skip((page - 1) * limit)
       .take(limit)
       .getMany();
 
-    return {
-      totalItems,
-      totalPages,
-      currentPage: page,
-      products,
-    };
+    return products;
   }
 }

src/utils/dto/base.dto.ts

@@ -0,0 +1,17 @@
+import { ApiProperty } from '@nestjs/swagger';
+
+export class UUIDBaseDTO {
+  @ApiProperty({ example: '123e4567-e89b-12d3-a456-426614174006' })
+  id: string;
+}
+
+export class BaseDTO extends UUIDBaseDTO {
+  @ApiProperty()
+  createdAt: Date;
+
+  @ApiProperty()
+  updatedAt: Date;
+
+  @ApiProperty({ example: null })
+  deletedAt: Date;
+}

src/utils/dto/pagination.dto.ts

@@ -0,0 +1,15 @@
+import { ApiProperty } from '@nestjs/swagger';
+
+export class PaginationDTO<T> {
+  @ApiProperty()
+  results: T[];
+
+  @ApiProperty()
+  count: number;
+
+  @ApiProperty()
+  next: string | null;
+
+  @ApiProperty()
+  previous: string | null;
+}

src/utils/pagination-urls.ts

@@ -0,0 +1,22 @@
+type PaginationURL = {
+  next: string | null;
+  previous: string | null;
+};
+
+export function getPaginationUrl(
+  baseUrl: string,
+  page: number,
+  limit: number,
+  count: number,
+): PaginationURL {
+  const startIndex = (page - 1) * limit;
+  const endIndex = page * limit;
+
+  const next =
+    endIndex < count ? `${baseUrl}?page=${page + 1}&limit=${limit}` : null;
+
+  const previous =
+    startIndex > 0 ? `${baseUrl}?page=${page - 1}&limit=${limit}` : null;
+
+  return { next, previous };
+}