Books API by Helene Westrin

.gitignore

@@ -5,4 +5,5 @@ node_modules
 .env.development.local
 .env.test.local
 .env.production.local
-package-lock.json
+package-lock.json
+.vercel

README.md

@@ -1,13 +1,98 @@
-# Project Express API
+# My Books API using Express.js
 
-Replace this readme with your own information about your project.
+In this project I created my first API using Express.js. It's a small API without a database that has a fixed amount of data about some books.
 
-Start by briefly describing the assignment in a sentence or two. Keep it short and to the point.
+## **Endpoints**
 
-## The problem
+### **1. List All Books**
 
-Describe how you approached to problem, and what tools and techniques you used to solve it. How did you plan? What technologies did you use? If you had more time, what would be next?
+**GET** `/api/books`
+
+Retrieves all books in the "database". Supports filtering and sorting through query parameters.
+
+| Query Parameter | Description                                  | Example                              |
+| --------------- | -------------------------------------------- | ------------------------------------ |
+| `author`        | Filter books by author name                  | `/api/books?author=Rowling`          |
+| `startsWith`    | Filter books by title starting with a letter | `/api/books?startsWith=H`            |
+| `language`      | Filter books by language code                | `/api/books?language=eng`            |
+| `minRating`     | Filter books by minimum average rating       | `/api/books?minRating=4.5`           |
+| `sortBy`        | Sort books by a field (e.g., `title`)        | `/api/books?sortBy=title`            |
+| `order`         | Sort order (`asc` or `desc`)                 | `/api/books?sortBy=title&order=desc` |
+
+---
+
+### **2. Get a Book by ID**
+
+**GET** `/api/books/:id`
+
+Retrieve a specific book by its unique `bookID`.
+
+**Example**:
+
+```plaintext
+GET /api/books/1461
+```
+
+---
+
+### **3. Add a New Book**
+
+**POST** `/api/books`
+
+Add a new book to the JSON file. The `bookID` is auto-generated. You must provide the following fields in the request body:
+
+| Field                | Type     | Description                 |
+| -------------------- | -------- | --------------------------- |
+| `title`              | `string` | Title of the book           |
+| `authors`            | `string` | Author(s) of the book       |
+| `average_rating`     | `number` | Average rating of the book  |
+| `isbn`               | `number` | ISBN of the book            |
+| `isbn13`             | `number` | ISBN-13 of the book         |
+| `language_code`      | `string` | Language code of the book   |
+| `num_pages`          | `number` | Number of pages in the book |
+| `ratings_count`      | `number` | Total ratings of the book   |
+| `text_reviews_count` | `number` | Number of text reviews      |
+
+**Example Request Body**:
+
+```json
+{
+  "title": "New Book Title",
+  "authors": "Author Name",
+  "average_rating": 4.7,
+  "isbn": 123456789,
+  "isbn13": 9781234567890,
+  "language_code": "eng",
+  "num_pages": 250,
+  "ratings_count": 100,
+  "text_reviews_count": 20
+}
+```
+
+---
+
+### **4. Filter Books**
+
+Use query parameters to filter books based on criteria. Combine multiple filters as needed.
+
+**Examples**:
+
+- By author: `/api/books?author=Rowling`
+- By title starting with "H": `/api/books?startsWith=H`
+- By language: `/api/books?language=eng`
+- By minimum rating: `/api/books?minRating=4.5`
+
+---
+
+### **5. Sort Books**
+
+Use `sortBy` and `order` query parameters to sort books.
+
+**Examples**:
+
+- Sort by title (ascending): `/api/books?sortBy=title`
+- Sort by rating (descending): `/api/books?sortBy=average_rating&order=desc`
 
 ## View it live
 
-Every project should be deployed somewhere. Be sure to include the link to the deployed project so that the viewer can click around and see what it's all about.
+[Try it out for yourself »](https://project-express-api-ivory.vercel.app/)

constants/constants.js

@@ -0,0 +1,7 @@
+export const ERRORS = {
+  BOOK_NOT_FOUND: "A book with this bookID does not exist.",
+  AUTHOR_NOT_FOUND: "No books found for the given author.",
+  DUPLICATE_BOOK: "Book with this bookID already exists.",
+  DUPLICATE_ISBN: "A book with this ISBN already exists.",
+  ADD_BOOK_ERROR: "An error occurred while adding the book.",
+};

controllers/bookController.js

@@ -0,0 +1,101 @@
+import fs from "fs";
+import path from "path";
+import { ERRORS } from "../constants/constants";
+import { generateID } from "../utils/utils";
+
+// Get absolute path to the JSON file
+const booksFilePath = path.resolve("data/books.json");
+
+// Helper function to load data
+const loadBooks = () => {
+  try {
+    const data = fs.readFileSync(booksFilePath, "utf-8");
+    return JSON.parse(data);
+  } catch (error) {
+    console.error("Error loading books:", error);
+    return [];
+  }
+};
+
+// Save books
+const saveBooks = (books) => {
+  fs.writeFileSync(booksFilePath, JSON.stringify(books, null, 2));
+};
+
+// Get all books
+export const getBooks = (req, res) => {
+  const { author, startsWith, language, minRating, sortBy, order } = req.query;
+  let books = loadBooks();
+
+  // Apply all filters in a single loop
+  books = books.filter((book) => {
+    if (author && !book.authors.toLowerCase().includes(author.toLowerCase()))
+      return false;
+    if (
+      startsWith &&
+      book.title.charAt(0).toLowerCase() !== startsWith.toLowerCase()
+    )
+      return false;
+    if (language && book.language_code !== language) return false;
+    if (minRating && book.average_rating < parseFloat(minRating)) return false;
+    return true;
+  });
+
+  // Sort the results
+  if (sortBy) {
+    books.sort((a, b) => {
+      const orderFactor = order === "desc" ? -1 : 1;
+
+      if (sortBy === "average_rating") {
+        return (a.average_rating - b.average_rating) * orderFactor;
+      }
+
+      if (sortBy === "title") {
+        return a.title.localeCompare(b.title) * orderFactor;
+      }
+
+      return 0; // Default: no sorting if field not recognized
+    });
+  }
+
+  // Return all, filtered and/or sorted books
+  res.json(books);
+};
+
+// Get a specific book by ID
+export const getBookByID = (req, res) => {
+  const books = loadBooks();
+  const id = req.params.id;
+
+  const book = books.find((book) => book.bookID === +id);
+
+  if (book) {
+    res.json(book);
+  } else {
+    return res.status(404).json({ error: ERRORS.BOOK_NOT_FOUND });
+  }
+};
+
+// Add a new book
+export const addBook = (req, res) => {
+  try {
+    const newBook = req.body;
+    const books = loadBooks();
+
+    // Generate a unique ID
+    newBook.bookID = generateID(books);
+
+    // Ensure no duplicate ISBNs
+    if (books.some((book) => book.isbn === newBook.isbn)) {
+      return res.status(400).json({ error: ERRORS.DUPLICATE_ISBN });
+    }
+
+    books.push(newBook);
+    saveBooks(books);
+
+    res.status(201).json(newBook);
+  } catch (error) {
+    console.error("Error adding book:", error);
+    res.status(500).json({ error: ERRORS.ADD_BOOK_ERROR });
+  }
+};