northwind-rest-api/backend/business-logic/categories-logic.js

Local REST API Exposing 'Northwind Traders' Database.

const dal = require("../data-access-layer/dal");
const imageHelper = require("../helpers/image-helper");

async function getAllCategories() {
    const categories = await dal.getAllCategories();
    return categories;
};

async function getOneCategory(id) {
    const categories = await dal.getAllCategories();
    const category = categories.find(c => c.id === id);
    return category;
};

async function addCategory(category, image) {
    const categories = await dal.getAllCategories();
    const maxId = categories.reduce((maxId, c) => c.id > maxId ? c.id : maxId, 0);
    category.id = maxId + 1;
    const fileName = await imageHelper.saveCategoryImage(image);
    category.imageUrl = fileName ? "http://localhost:3030/api/categories/images/" + fileName : null;
    categories.push(category);
    await dal.saveAllCategories(categories);
    return category;
};

async function updateCategory(newCategory, image) {
    const categories = await dal.getAllCategories();
    const existingCategory = categories.find(c => c.id === newCategory.id);
    if (!existingCategory) return null;
    for (const prop in newCategory) {
        if (newCategory[prop] !== undefined) {
            existingCategory[prop] = newCategory[prop];
        }
    }
    const currentFileName = existingCategory.imageUrl ? existingCategory.imageUrl.substring(existingCategory.imageUrl.lastIndexOf("/") + 1) : null;
    const newFileName = await imageHelper.updateCategoryImage(currentFileName, image);
    if(newFileName) {
        existingCategory.imageUrl = "http://localhost:3030/api/categories/images/" + newFileName;
    }
    await dal.saveAllCategories(categories);
    return existingCategory;
};

async function deleteCategory(id) {
    const categories = await dal.getAllCategories();
    const index = categories.findIndex(c => c.id === id);
    if (index === -1) return;
    const existingCategory = categories[index];
    const currentFileName = existingCategory.imageUrl ? existingCategory.imageUrl.substring(existingCategory.imageUrl.lastIndexOf("/") + 1) : null;
    await imageHelper.deleteCategoryImage(currentFileName)
    categories.splice(index, 1);
    await dal.saveAllCategories(categories);
};

module.exports = {
    getAllCategories,
    getOneCategory,
    addCategory,
    updateCategory,
    deleteCategory
};