controller.js

const fs = require('fs');
function addMapping(router, mapping) {
	for (var url in mapping) {
		if (url.startsWith("GET ")) {
			var path = url.substring(4);
			router.get(path, mapping[url]);
		}
        else if(url.startsWith("POST ")) {
            var path = url.substring(5);
            router.post(path, mapping[url]);
            
        }
		else {
			consol.log(`invalid URL: ${url}`);
		}
	}
}

function addControllers(router){
	var files = fs.readdirSync(__dirname + '/controllers');
	var js_files = files.filter((f) => {
			return f.endsWith('.js');
	});
	for (var f of js_files) {
		let mapping = require(__dirname + '/controllers/' + f);
		addMapping(router, mapping);
	}
}
module.exports = function (dir) {
	let controllers_dir = dir || 'controllers',
		router = require('koa-router')();
	addControllers(router, controllers_dir);
	return router.routes();
}