let fs = require('fs');
let { logger } = require('./logging');

function toISODateString(d) {
    function pad(n) { return n < 10 ? '0' + n : n }
    return d.getUTCFullYear() + '-'
        + pad(d.getUTCMonth() + 1) + '-'
        + pad(d.getUTCDate()) + 'T'
        + pad(d.getUTCHours()) + ':'
        + pad(d.getUTCMinutes()) + ':'
        + pad(d.getUTCSeconds()) + 'Z'
}

function getBuildInfo(buildInfoPath) {
    try {
        return fs.readFileSync(buildInfoPath, "utf8");
    } catch (err) {
        if (err.code === 'ENOENT') {
            return "UNKNOWN_" + toISODateString(new Date());
        } else {
            logger.error("Unexpected Error!", err);
        }
    }
}

function sleep(ms) {
    return new Promise(resolve => {
        setTimeout(resolve, ms)
    })
}

exports.toISODateString = toISODateString;
exports.getBuildInfo = getBuildInfo;
exports.sleep = sleep;