const logger = require('./logger.js');
const commands = require('./commands.js');
const http = require('http');

let server;
let api;

async function start() {
    const listen = global.config?.server?.listen || '0.0.0.0';
    const port = global.config?.server?.port;
    setupAPI();
    if (server === undefined) {
        server = http.createServer();
    }
    return new Promise((resolve, reject) => {
        server.listen(port, listen)
            .on('listening', function () {
                logger.debug('server listening on ' + config.server.listen + ':' + config.server.port + '...');
                handleRequests();
                resolve();
            });
    });
}

function handleRequests() {
    server.on('request', (request, response) => {
        request.timestamp = new Date().getTime();
        respond(request, response, api.get(request.url));
    });
}

async function respond(request, response, endpoint) {
    if (response === undefined) {
        return;
    }
    let data = {
        status: 'ok',
        command: endpoint.command,
        args: endpoint.args
    };
    if (endpoint.detached === true) {
        data.detached = true;
    }
    let code = 200;
    if (endpoint === undefined) {
        code = 501;
        data.status = 'error';
        data.msg = 'endpoint not defined';
    } else if (request.method.toLowerCase() !== (endpoint.type.toLowerCase())) {
        code = 405;
        data.status = 'error';
        data.msg = 'endpoint does not support ' + request.method + ' requests';
    } else {
        try {
            const result = await commands.execute(endpoint);
            if (result !== undefined) {
                data.result = result;
            }
        } catch (err) {
            code = 501;
            data.status = 'error';
            data.msg = err.toString();
        }
    }
    data.time = new Date().getTime() - request.timestamp + 'ms';
    const json = JSON.stringify(data);
    response.writeHead(code);
    response.end(json);
    logger.http({ request: request, code: code, data: json });
}

function setupAPI() {
    const apiConfig = global.config?.api;
    if (apiConfig === undefined || apiConfig.length === 0) {
        throw new Error('no api endpoints configured - aborting');
    }
    api = new Map();
    config.api.forEach(function (endpoint) {
        let url = endpoint.url;
        let tmp = endpoint;
        delete tmp.url;
        api.set(url, tmp);
    });
}

module.exports = {
    start
}