const streams = require('streamroller');

const os = require('os');

const eol = os.EOL;

function openTheStream(filename, pattern, options) {

const stream = new streams.DateRollingFileStream(filename, pattern, options);

stream.on('error', (err) => {

// eslint-disable-next-line no-console

console.error(

'log4js.dateFileAppender - Writing to file %s, error happened ',

filename,

err

);

});

stream.on('drain', () => {

process.emit('log4js:pause', false);

});

return stream;

}

/**

* File appender that rolls files according to a date pattern.

* @param filename base filename.

* @param pattern the format that will be added to the end of filename when rolling,

* also used to check when to roll files - defaults to '.yyyy-MM-dd'

* @param layout layout function for log messages - defaults to basicLayout

* @param options - options to be passed to the underlying stream

* @param timezoneOffset - optional timezone offset in minutes (default system local)

*/

function appender(filename, pattern, layout, options, timezoneOffset) {

// the options for file appender use maxLogSize, but the docs say any file appender

// options should work for dateFile as well.

options.maxSize = options.maxLogSize;

const writer = openTheStream(filename, pattern, options);

const app = function (logEvent) {

if (!writer.writable) {

return;

}

if (!writer.write(layout(logEvent, timezoneOffset) + eol, 'utf8')) {

process.emit('log4js:pause', true);

}

};

app.shutdown = function (complete) {

writer.end('', 'utf-8', complete);

};

return app;

}

function configure(config, layouts) {

let layout = layouts.basicLayout;

if (config.layout) {

layout = layouts.layout(config.layout.type, config.layout);

}

if (!config.alwaysIncludePattern) {

config.alwaysIncludePattern = false;

}

// security default (instead of relying on streamroller default)

config.mode = config.mode || 0o600;

return appender(

config.filename,

config.pattern,

layout,

config,

config.timezoneOffset

);

}

module.exports.configure = configure;