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

Local REST API Exposing Northwind Database.

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

async function getAllSuppliers() {
    const suppliers = await dal.getAllSuppliers();
    return suppliers;
};

async function getOneSupplier(id) {
    const suppliers = await dal.getAllSuppliers();
    const supplier = suppliers.find(s => s.id === id);
    return supplier;
};

async function addSupplier(supplier, image) {
    const suppliers = await dal.getAllSuppliers();
    const maxId = suppliers.reduce((maxId, s) => s.id > maxId ? s.id : maxId, 0);
    supplier.id = maxId + 1;
    const fileName = await imageHelper.saveSupplierImage(image);
    supplier.imageUrl = fileName ? "http://localhost:3030/api/suppliers/images/" + fileName : null;
    suppliers.push(supplier);
    await dal.saveAllSuppliers(suppliers);
    return supplier;
};

async function updateSupplier(newSupplier, image) {
    const suppliers = await dal.getAllSuppliers();
    const existingSupplier = suppliers.find(s => s.id === newSupplier.id);
    if (!existingSupplier) return null;
    for (const prop in newSupplier) {
        if (newSupplier[prop] !== undefined) {
            existingSupplier[prop] = newSupplier[prop];
        }
    }
    const currentFileName = existingSupplier.imageUrl ? existingSupplier.imageUrl.substring(existingSupplier.imageUrl.lastIndexOf("/") + 1) : null;
    const newFileName = await imageHelper.updateSupplierImage(currentFileName, image);
    if(newFileName) {
        existingSupplier.imageUrl = "http://localhost:3030/api/suppliers/images/" + newFileName;
    }
    await dal.saveAllSuppliers(suppliers);
    return existingSupplier;
};

async function deleteSupplier(id) {
    const suppliers = await dal.getAllSuppliers();
    const index = suppliers.findIndex(s => s.id === id);
    if (index === -1) return;
    const existingSupplier = suppliers[index];
    const currentFileName = existingSupplier.imageUrl ? existingSupplier.imageUrl.substring(existingSupplier.imageUrl.lastIndexOf("/") + 1) : null;
    await imageHelper.deleteSupplierImage(currentFileName)
    suppliers.splice(index, 1);
    await dal.saveAllSuppliers(suppliers);
};

module.exports = {
    getAllSuppliers,
    getOneSupplier,
    addSupplier,
    updateSupplier,
    deleteSupplier
};