/**
 * Formats log4js's pattern based on the information available,
 * configures the perf log level, and allows easy access to logger instance methods.
 * Also adds perfStart and perfEnd methods, which allow easy performance logging.
 */

import log4js from 'log4js';

const DEV_PATTERN = '[ %[%-5p%] | %[%-10.10f{1}%] %3l:%-2o ] %[%m%]';
const BUILD_PATTERN = '[ %d | %[%-5p%] ] %[%m%]';

const dev = !__filename.startsWith('/snapshot');
const pattern = dev ? DEV_PATTERN : BUILD_PATTERN;

log4js.configure({
	levels: { PERF: { value: log4js.levels.TRACE.level, colour: 'yellow' } } as any,
	appenders: { out: { type: 'stdout', layout: { type: 'pattern', pattern } } },
	categories: { default: { appenders: ['out'], level: 'info', enableCallStack: dev } }
});

const logger = log4js.getLogger();

const activePerfs: Record<string, bigint> = {};

const perfStart = (identifier: string) => {
	activePerfs[identifier] = process.hrtime.bigint();
};

const perfEnd = (identifier: string) => {
	let start = activePerfs[identifier];
	if (!start) logger.warn('Attempted to perf invalid identifier \'%s\'.', identifier);
	else {
		const elapsed = Number((process.hrtime.bigint() - start) / BigInt(10000)) / 100;
		// @ts-ignore
		logger.perf('%s took %s ms.', identifier, elapsed.toFixed(3));
		delete activePerfs[identifier];
	}
};

export default {
	// @ts-ignore
	perf: logger.perf.bind(logger),
	perfStart: perfStart,
	perfEnd: perfEnd,
	info: logger.info.bind(logger),
	debug: logger.debug.bind(logger),
	error: logger.error.bind(logger),
	warn: logger.warn.bind(logger),
	fatal: logger.fatal.bind(logger),
	trace: logger.trace.bind(logger),
	setLogLevel: (level: string) => logger.level = level
};