blinky/libs/server.js

const config = require('../config.json');
const logger = require('./logger.js');
const controller = require('./controller.js');
const parser = require('./parser.js');
const constants = require('./constants.js');
const path = require('path');

const express = require('express');
const favicon = require('serve-favicon');
const bodyparser = require('body-parser');

const app = express();
app.use(favicon(path.join(path.dirname(__dirname), 'public', 'favicon.ico')));
app.use(bodyparser.json());
app.use(bodyparser.urlencoded({extended: true}));

const html = require('./index.js').get();

// run the express http server and handle gets/posts
async function start() {
    return await new Promise(function (resolve, reject) {
        app.listen(config.server.port, config.server.listen)
            .on('listening', function () {
                resolve('server listening on ' + config.server.listen + ':' + config.server.port + '...')
            })
            .on('error', function (err) {
                reject('error starting server (' + err + ')');
            });
    });
}

function handleRequests() {
    // GET html page
    app.get('*', (request, response) => {
        logger.http(request);
        response.send(html);
        response.end();
    });
    // POST '/set'
    app.post('/' + constants.MODE_SET, (request, response) => {
        logger.http(request);
        handleSimpleAnimation(parser.parseRequest(request.body, constants.MODE_SET), response);
    });
    // POST '/morph'
    app.post('/' + constants.MODE_MORPH, (request, response) => {
        logger.http(request);
        handleSimpleAnimation(parser.parseRequest(request.body, constants.MODE_MORPH), response);
    });
    // POST '/blink'
    app.post('/' + constants.MODE_BLINK, (request, response) => {
        logger.http(request);
        handleComplexAnimation(parser.parseRequest(request.body, constants.MODE_BLINK), response);
    });
    // POST '/pulse'
    app.post('/' + constants.MODE_PULSE, (request, response) => {
        logger.http(request);
        handleComplexAnimation(parser.parseRequest(request.body, constants.MODE_PULSE), response);
    });
    // POST '/poweroff'
    app.post('/' + constants.MODE_POWEROFF, (request, response) => {
        logger.http(request);
        handlePowerOff(parser.parseRequest(request.body, constants.MODE_POWEROFF), response);
    });
}

async function handleSimpleAnimation(config, response) {
    try {
        response.end(JSON.stringify(await controller.simple(config)));
    } catch (err) {
        logger.error(err);
        response.status(500);
        response.end(JSON.stringify({status: 'error', error: err.message}));
    }
}

async function handleComplexAnimation(config, response) {
    if (controller.isInfiniteAnimation(config)) {
        response.end(JSON.stringify({status: 'ok', time: 'infinite'}));
        response = undefined;
    }
    try {
        const result = await controller.complex(config);
        if (response === undefined) {
            return;
        }
        response.end(JSON.stringify(result));
    } catch (err) {
        if (response === undefined) {
            return;
        }
        logger.error(err);
        response.status(500);
        response.end(JSON.stringify({status: 'error', error: err.message}));
    }
}

async function handlePowerOff(config, response) {
    try {
        response.end(JSON.stringify(await controller.powerOff(config)));
    } catch (err) {
        response.status(500);
        response.end(JSON.stringify({status: 'error', error: err.message}));
    }
}

// exports
module.exports = {
    start,
    handleRequests
};