feat: implement article management features with CRUD operations

src/lib/feature/article/article.service.ts

@@ -0,0 +1,177 @@
+import { getRepository } from '@/lib/db/client';
+import { ArticleEntity } from '@/lib/feature/article/article.entity';
+import {
+    ArticleModel,
+    CreateArticleModel,
+    PaginatedArticlesResult,
+    UpdateArticleModel,
+} from '@/lib/feature/article/article.model';
+import { UUIDv4 } from '@/utils/types/uuid';
+
+export const articleEntityToModel = (
+    articleEntity: ArticleEntity
+): ArticleModel => {
+    return {
+        id: articleEntity.id,
+        title: articleEntity.title,
+        slug: articleEntity.slug,
+        description: articleEntity.description,
+        coverImageUrl: articleEntity.coverImageUrl,
+        content: articleEntity.content,
+        authorId: articleEntity.authorId,
+        externalId: articleEntity.externalId,
+    };
+};
+
+/** Retrieves an artible by its external ID.
+ * @param externalId - The external ID of the article to retrieve.
+ * @returns {Promise<ArticleModel | null>} The article model if found, otherwise null.
+ * */
+export const getArticleByExternalId = async (
+    externalId: UUIDv4
+): Promise<ArticleModel | null> => {
+    const articleRepository = await getRepository(ArticleEntity);
+
+    const articleEntity = await articleRepository.findOneBy({
+        externalId: externalId,
+    });
+
+    if (!articleEntity) {
+        return null;
+    }
+
+    return articleEntityToModel(articleEntity);
+};
+
+/**
+ * Retrieves an article by its slug.
+ * @param slug - The slug of the article to retrieve.
+ * @returns {Promise<ArticleModel | null>} The article model if found, otherwise null.
+ */
+export const getArticleBySlug = async (
+    slug: string
+): Promise<ArticleModel | null> => {
+    const articleRepository = await getRepository(ArticleEntity);
+
+    const articleEntity = await articleRepository.findOneBy({ slug });
+
+    if (!articleEntity) {
+        return null;
+    }
+
+    return articleEntityToModel(articleEntity);
+};
+
+/**
+ * Retrieves all articles by a given author ID.
+ * @param authorId - The ID of the author.
+ * @returns {Promise<ArticleModel[]>} A list of article models.
+ */
+export const getArticlesByAuthorId = async (
+    authorId: string
+): Promise<ArticleModel[]> => {
+    const articleRepository = await getRepository(ArticleEntity);
+
+    const articleEntities = await articleRepository.findBy({ authorId });
+
+    return articleEntities.map(articleEntityToModel);
+};
+
+/**
+ * Retrieves a paginated list of articles ordered by creation date descending.
+ * @param page - The page number (1-based).
+ * @param pageSize - The number of articles per page.
+ * @returns {Promise<PaginatedArticlesResult>} The paginated result.
+ */
+export const getArticlesPaginated = async (
+    page: number = 1,
+    pageSize: number = 10
+): Promise<PaginatedArticlesResult> => {
+    const articleRepository = await getRepository(ArticleEntity);
+
+    const [articleEntities, total] = await articleRepository.findAndCount({
+        order: { createdAt: 'DESC' },
+        skip: (page - 1) * pageSize,
+        take: pageSize,
+    });
+
+    return {
+        data: articleEntities.map(articleEntityToModel),
+        total,
+        page,
+        pageSize,
+        totalPages: Math.ceil(total / pageSize),
+    };
+};
+
+/**
+ * Saves a new article to the database.
+ * @param article - The article data to save.
+ * @returns {Promise<ArticleModel>} The saved article model.
+ * @throws {Error} If an article with the same slug already exists.
+ */
+export const saveArticle = async (
+    article: CreateArticleModel
+): Promise<ArticleModel> => {
+    const articleRepository = await getRepository(ArticleEntity);
+
+    if (!article.authorId) {
+        throw new Error('Author ID is required to save an article');
+    }
+
+    if (!!(await articleRepository.findOneBy({ slug: article.slug }))) {
+        throw new Error(`Article with slug ${article.slug} already exists`);
+    }
+
+    const newArticle = articleRepository.create(article);
+    return articleEntityToModel(await articleRepository.save(newArticle));
+};
+
+/**
+ * Updates an existing article in the database.
+ * @param articleId - The ID of the article to update.
+ * @param article - The new article data.
+ * @returns {Promise<ArticleModel>} The updated article model.
+ * @throws {Error} If the article with the given ID does not exist.
+ */
+export const updateArticle = async (
+    articleId: string,
+    article: UpdateArticleModel
+): Promise<ArticleModel> => {
+    const articleRepository = await getRepository(ArticleEntity);
+
+    const existingArticle = await articleRepository.findOneBy({
+        id: articleId,
+    });
+    if (!existingArticle) {
+        throw new Error(`Article with ID ${articleId} not found`);
+    }
+
+    if (!!article.title) existingArticle.title = article.title;
+    if (!!article.slug) existingArticle.slug = article.slug;
+    if (!!article.description)
+        existingArticle.description = article.description;
+    if (!!article.coverImageUrl)
+        existingArticle.coverImageUrl = article.coverImageUrl;
+    if (!!article.content) existingArticle.content = article.content;
+
+    return articleEntityToModel(await articleRepository.save(existingArticle));
+};
+
+/**
+ * Deletes an article from the database.
+ * @param articleId - The ID of the article to delete.
+ * @throws {Error} If the article with the given ID does not exist.
+ */
+export const deleteArticle = async (articleId: string): Promise<void> => {
+    const articleRepository = await getRepository(ArticleEntity);
+
+    const existingArticle = await articleRepository.findOneBy({
+        id: articleId,
+    });
+    if (!existingArticle) {
+        throw new Error(`Article with ID ${articleId} not found`);
+    }
+
+    await articleRepository.remove(existingArticle);
+};