const path = require('path');
const Koa = require('koa');
const mountRoutes = require('koa-mount-routes');

const app = new Koa();
mountRoutes(app, path.join(__dirname, 'controllers'), {
  urlPrefix: '/api/v1/'
});

app.listen(3000, () => {
  console.log('Example app listening on port 3000!');
});

mountRoutes(
  app, // A Koa2 instance;
  dirPath, // *absolute* path to the controllers dir
  {
    // optional parameters, and the 3rd param for this function is not required
    ignore, // files you want to ignore while scanning controllers dir such as index.js, see parameter options of module glob(https://github.com/isaacs/node-glob#options) for more infomation. Default value: ''
    urlPrefix, // prefix for routes, such as /api/v1/. Default value: '/'
    autoPlural, // whether apply pluralized file name as part of routes automatically. Default value: true
    allowedMethods // it is for koa-router, see https://github.com/alexmingoia/koa-router#routerallowedmethodsoptions--function for more information. As here, you can assign it to `[options]` parameter of koa-router#router.allowedMethods such as `{ throw: true }`. Default value: null, that's to say, we do not execute `app.use(router.allowedMethods());` by default.
  }
);

// FileName: controllers/weibo.js

module.exports = {
  // when value is a function or an array of functions, the HTTP method would be default value GET
  '/': async ctx => {
    ctx.body = 'Weibos Index';
  },
  // also you can provide one more handlers with an array of functions: these handlers except last one are called middlerwares in Koa
  '/getArr': [
    async ctx => {
      ctx.body = 'GET for one more handlers';
    }
  ],
  // also you can make URL params
  '/:id': {
    // explicitly identifing an HTTP method can never be wrong
    get: ctx => {
      ctx.body = `get weibo: ${ctx.params.id}`;
    },
    post: async ctx => {
      ctx.body = `post weibo: ${ctx.params.id}`;
    }
  },
  // another example for usage of middlerwares
  '/temp': {
    delete: [
      async (ctx, next) => {
        ctx.myOwnVar = 'this is a middleware.';
        await next();
      },
      async ctx => {
        ctx.body = `${ctx.myOwnVar}ordinary api`;
      }
    ]
  }
};