'use strict';
/*jslint node:true*/
//from koa
const http = require('http');
const Koa = require('koa');
const convert = require('koa-convert');
const logger = require('koa-logger');
const session = require('koa-generic-session');
const bodyParser = require('koa-bodyparser');
const csrf = require('koa-csrf');
const cors = require('koa-cors');
const range = require('koa-range');
const statics = require('koa-static');
const Router = require('koa-66');
const io = require('socket.io');

//util
const co = require('co');

//from fs
const fsDc = require('fs-dc');
const fsLogger = require('fs-logger');

function scaffold(config) {
    const defaultConfig = require('./config.js');
    const app = new Koa();
    csrf(app);
    const router = new Router();
    config = config || defaultConfig;
    if (config.mws && config.mws.length) {//k8s探针用，去掉鉴权
        config.mws = config.mws.map(v => {
            if (v.opts && v.opts.exclude) {
                if ('*' != v.opts.exclude[0]) {
                    v.opts.exclude.push({ p: '/healthz', o: 'GET' })
                }
            }
            return v;
        });
    }
    app.keys = ["it is a secret"];
    app.use(convert(cors({
        credentials: true
    })));
    app.use(co.wrap(errorHandler()));
    app.use(range);
    if (config.staticDirs && Array.isArray(config.staticDirs)) {
        config.staticDirs.forEach(function (s) {
            app.use(convert(statics(s)));
        });
    }
    app.use(convert(logger()));
    app.use(convert(session({ key: 'fs-sid', cookie: { maxAge: null } }, app)));
    app.use(convert(bodyParser({
        'formLimit': '80mb',
        'jsonLimit': '80mb',
        'textLimit': '80mb',
    })));
    //init fs.logger and inject it into app(app.fs.logger) and runtime ctx(ctx.fs.logger)
    app.use(co.wrap(fsLogger(app, config.logger)));
    //init fs.dc and inject it into app(app.fs.dc) and runtime ctx(app.fs.dc)
    if (config.dc) {
        app.use(co.wrap(fsDc(app, config.dc)));
    }
    const socketRegEvent = []
    app.socket = {
        on: function (evt, callback) {
            socketRegEvent.push([evt, callback]);
        }
    }

    config.mws.forEach(function (mv) {
        if (typeof mv.entry === 'function') {
            try {
                mv.entry(app, router, mv.opts);
            } catch (err) {
                app.fs.logger.log('error', '[app]', err)
            }
        }
    });

    app.use(router.routes());
    router.get('/healthz', async function (ctx, next) {//k8s探针用
        try {
            ctx.status = 200;
            ctx.body = 'ok';
        } catch (err) {
            ctx.fs.logger.log('error', '[app]', err)
        }
    });

    function errorHandler() {
        return function* (ctx, next) {
            try {
                yield next();
            } catch (err) {
                app.fs.logger.log("error", "[FS-ERRHD]", err);
                //simple process.
                //@Todo 500 page; 400...
                ctx.status = 500;
                ctx.body = 'internal server error';
            }
        };
    }
    const server = http.createServer(app.callback());
    const socket = io(server);

    app.socket = socket;

    socketRegEvent.forEach(function (reg) {
        socket.on(reg[0], reg[1]);
    });

    app.server = server.listen(config.port || 4000);
    // app.server = app.listen(config.port || 4000);
    //for test
    app.router = router;
    return app;
}

module.exports = scaffold;