import * as winston from 'winston';
import {LeveledLogMethod} from 'winston';
import {RequestHandler} from 'express';
import * as colors from 'colors';
import {DefaultConfig} from '.';
import prune = require('json-prune');


const logger = winston.createLogger({
	level: DefaultConfig.isProduction ? 'info' : 'silly',
	format: winston.format.json(),
	transports: [
		new winston.transports.Console({
			format: winston.format.simple(),
		}),
	],
});

export const levels = ['error', 'warn', 'info', 'http', 'verbose', 'debug', 'silly'] as const;
export type LogLevels = typeof levels[number]|'log';
const wrapper = (original: LeveledLogMethod) => {
	return (...args: unknown[]) => {
		return original(args.map((obj) => typeof obj === 'string' ? obj : prune(obj)).join(' '));
	};
};

export const Logger = {
} as {[level in LogLevels]: ReturnType<typeof wrapper>};

for (const level of levels) {
	Logger[level] = wrapper(logger[level]);
}
Logger.log = wrapper(logger['silly']);

export const HttpLogger: RequestHandler = (req, res, next) => {
	const start = Date.now();
	const path = req.path;
	type Callback = (() => void)|undefined;
	const end = res.end;
	res.end = function(...args: [Callback] & [unknown, Callback] & [unknown, BufferEncoding, Callback]) {
		const statusCode = res.statusCode;
		const colorFunction = statusCode >= 500 ? colors.red
			: statusCode >= 400 ? colors.yellow
				: statusCode >= 300 ? colors.cyan
					: statusCode >= 200 ? colors.green
						: colors.gray;
		const status = colorFunction(res.statusCode.toString(10));
		const method = req.method.toUpperCase().padEnd(6, ' ');
		const responseTime = (Date.now()-start).toString(10).padStart(3, ' ');
		if (!req.noHttpLogging)
			Logger.http(`${status} ${method} ${responseTime}ms ${path}`);
		end.apply(res, args);
	};
	next();
};