const fs = require("fs")
const os = require('os');

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

function addControllers(router, controllers_dir) {
    let ostype = os.type() == "Windows_NT"
    let dir;
    if (ostype) {
        dir = __dirname.replace("\\bin", "")
    } else {
        dir = __dirname.replace("/bin", "")
    }

    var files = fs.readdirSync(dir + "/" + controllers_dir);
    var js_files = files.filter((f) => {
        return f.endsWith('.js');
    });

    for (var f of js_files) {
        console.log(`process controller: ${f}...`);
        let mapping = require(dir + `/${controllers_dir}/` + f);
        addMapping(router, mapping);
    }
}
module.exports = function (dir) {
    let
        controllers_dir = dir || 'controllers', // 如果不传参数，扫描目录默认为'controllers'
        router = require('koa-router')();
    addControllers(router, controllers_dir);
    return router.routes();
    // return 1;
};