wbs_rechner/backend_nodejs/wbs_rechner_express.js

const express = require('express');
const app = express();
app.use(express.json()); // for parsing JSON data

// Swagger Setup
const swaggerJsdoc = require('swagger-jsdoc');
const swaggerUi = require('swagger-ui-express');

const options = {
    definition: {
        openapi: '3.0.0',
        info: {
            title: 'WBS RECHNER',
            version: '1.0.0',
            description: 'An API for calculating total income and granting WBS.',
        },
    },
    apis: ['wbs_rechner_express.js'],
};

const specs = swaggerJsdoc(options);
app.use('/api', swaggerUi.serve, swaggerUi.setup(specs));

/**
 * @swagger
 * /calculate:
 *   post:
 *     summary: Calculates whether a WBS can be granted based on the provided incomes
 *     requestBody:
 *       required: true
 *       content:
 *         application/json:
 *           schema:
 *             type: object
 *             properties:
 *               persons:
 *                 type: array
 *                 items:
 *                   type: object
 *                   properties:
 *                     incomes:
 *                       type: array
 *                       items:
 *                         type: object
 *                         properties:
 *                           amount:
 *                             type: number
 *                           frequency:
 *                             type: number
 *                           advertisingCosts:
 *                             type: number
 *             example:
 *               persons:
 *                 - incomes:
 *                     - amount: 500
 *                       frequency: 12
 *                       advertisingCosts: 500
 *                     - amount: 200
 *                       frequency: 1
 *                       advertisingCosts: 0
 *                 - incomes:
 *                     - amount: 1200
 *                       frequency: 12
 *                       advertisingCosts: 200
 *                     - amount: 2000
 *                       frequency: 1
 *                       advertisingCosts: 0
 *     responses:
 *       200:
 *         description: WBS calculation result
 *         content:
 *           application/json:
 *             schema:
 *               type: object
 *               properties:
 *                 wbsGranted:
 *                   type: boolean
 *       400:
 *         description: Bad Request
 *       500:
 *         description: Internal Server Error
 */
app.post('/calculate', (req, res) => {
    /**
     * Calculates whether a WBS can be granted based on the provided incomes.
     * @param {object[]} persons - An array of persons.
     * @param {object[]} persons.incomes - An array of incomes for each person.
     * @param {number} persons.incomes[].amount - The amount of income.
     * @param {number} persons.incomes[].frequency - The frequency of income.
     * @param {number} persons.incomes[].advertisingCosts - The advertising costs for the income.
     * @returns {object} - The result object containing the wbsGranted property.
     */
    let totalIncome = 0;
    const persons = req.body.persons;
    for (const person of persons) {
        for (const income of person.incomes) {
            let annualIncome = income.amount * income.frequency;
            annualIncome -= income.advertisingCosts;
            totalIncome += annualIncome;
        }
    }

    // Example calculation does not correspond to the WBS calculation
    let maxIncome = persons.length * 12000;
    let wbsGranted = totalIncome <= maxIncome;

    res.send({ wbsGranted: wbsGranted });
});

/**
 * @swagger
 * /frequencies:
 *   get:
 *     summary: Retrieves all possible frequencies of income
 *     responses:
 *       200:
 *         description: An array of frequency objects
 *         content:
 *           application/json:
 *             schema:
 *               type: array
 *               items:
 *                 type: object
 *                 properties:
 *                   value:
 *                     type: number
 *                   description:
 *                     type: string
 *             example:
 *               - value: 365
 *                 description: "täglich"
 *               - value: 12
 *                 description: "monatlich"
 *               - value: 4
 *                 description: "vierteljährlich"
 *               - value: 1
 *                 description: "jährlich"
 *       400:
 *         description: Bad Request
 *       500:
 *         description: Internal Server Error
 */
app.get('/frequencies', (req, res) => {
    /**
     * Retrieves all possible frequencies of income.
     * @returns {object[]} - An array of frequency objects.
     * @property {number} value - The value of the frequency.
     * @property {string} description - The description of the frequency.
     */
    const frequencies = [
        { value: 365, description: 'täglich' },
        { value: 12, description: 'monatlich' },
        { value: 4, description: 'vierteljährlich' },
        { value: 1, description: 'jährlich' }
        // etc...
    ];
    res.send(frequencies);
});

/**
 * @swagger
 * /types:
 *   get:
 *     summary: Retrieves all types of income
 *     responses:
 *       200:
 *         description: An array of income type objects
 *         content:
 *           application/json:
 *             schema:
 *               type: array
 *               items:
 *                 type: object
 *                 properties:
 *                   value:
 *                     type: string
 *                   description:
 *                     type: string
 *             example:
 *               - value: 'work'
 *                 description: 'als Arbeitnehmer'
 *               - value: 'pensioner'
 *                 description: 'als Rentner'
 *               - value: 'social'
 *                 description: 'Einnahme aus Sozialeistungen'
 *               - value: 'entertains'
 *                 description: 'Unterhalt'
 *       400:
 *         description: Bad Request
 *       500:
 *         description: Internal Server Error
 */
app.get('/types', (req, res) => {
    /**
     * Retrieves all types of income.
     * @returns {object[]} - An array of income type objects.
     * @property {string} value - The value of the income type.
     * @property {string} description - The description of the income type.
     */
    const types = [
        { value: 'work', description: 'als Arbeitnehmer' },
        { value: 'pensioner', description: 'als Rentner' },
        { value: 'social', description: 'Einnahme aus Sozialeistungen' },
        { value: 'entertains', description: 'Unterhalt' }
        // etc...
    ];
    res.send(types);
});

const port = process.env.PORT || 3000;
app.listen(port, () => console.log(`Server läuft auf Port ${port}...`));