const express = require("express")
    , expressLogging = require("express-logging")
    , logger = require("logops")
    , hostname = require('os').hostname()
    , browser = require('./src/service/HeadlessService')
    , port = 32101
    , { NoSuchSessionError } = require("selenium-webdriver/lib/error")
// , { puppeteerErrors } = require("puppeteer-core/lib/cjs/puppeteer/common/Errors");


logger.getContext = function getContext() {
    return {
        // hostname: hostname,
        // pid: process.pid,
        // port: port,
        app: 'Browser'
    };
}
var app = express();
app.use(express.json());
app.use(expressLogging(logger));
app.use((req, res, next) => {
    logger.debug(Object.assign(req.body, req.query, req.params), 'Request params')
    next()
})
app.listen(port, () => {
    logger.info({ app: 'Headless browser' }, 'Startup');
});


// process.stdin.resume();//so the program will not close instantly

exitHandler = (options, exitCode) => {
    if (options.cleanup) logger.info('cleanup')
    if (exitCode || exitCode === 0) logger.info('exit code :', exitCode)
    browser.close().then(() => process.exit());
}

/**
 * Process shutdown events handling
 */
//do something when app is closing
process.on('exit', exitHandler.bind(null, { cleanup: true }));

//catches ctrl+c event
process.on('SIGINT', exitHandler.bind(null, { exit: true }));

process.on('SIGTERM', exitHandler.bind(null, { cleanup: true }));

// setTimeout(() => {
//     process.on('SIGKILL', exitHandler.bind(null, {exit:true}));
// }, 2000)


// catches "kill pid" (for example: nodemon restart)
// process.on('SIGUSR1', exitHandler.bind(null, {exit:true}));
// process.on('SIGUSR2', exitHandler.bind(null, {exit:true}));

//catches uncaught exceptions
// process.on('uncaughtException', exitHandler.bind(null, {exit:true}));

/**
 * request handler
 */
app.post('/', async (req, res, next) => {
    browser.get(req.body).then(html => {
        if (html) res.send(html)
        else throw new Error('Emtpy html')
    }).catch(e => {
        if (e instanceof NoSuchSessionError) {
            logger.error({ reason: e.message, url: req.url }, 'Browser session expired')
        } else {
            logger.error({ reason: e.message, url: req.url }, 'Browser error occured')
        }
        res.status(500).send({ code: 500, message: e.message })
    })
})