/**
 * Created by TaoHuang on 2017/2/21.
 */

'use strict';

const fs = require('fs');
const _ = require('lodash');
const path = require('path');

const curDir = __dirname;
const files = fs.readdirSync(curDir);

let domainRules = {};

files.forEach((file) => {
    let info = fs.statSync(path.resolve(curDir, file));

    if (info.isDirectory() && file !== '.git') {
        domainRules[file] = require(path.resolve(curDir, file));
    }
});

module.exports = () => {
    return (req, res, next) => {
        let curDomainRules = domainRules[req.subdomains[0]];

        if (!curDomainRules) {
            return next();
        }

        for (let i = 0; i < curDomainRules.length; i++) {
            let rule = curDomainRules[i];

            if (
                (_.isRegExp(rule.origin) && !_.isEmpty(rule.origin.exec(req.url))) ||
                (_.isFunction(rule.origin) && rule.origin(req))
            ) {
                let newUrl = req.url;

                if (_.isRegExp(rule.origin)) {
                    if (_.isFunction(rule.target)) {
                        newUrl = req.url.replace(rule.origin, _.partial(rule.target, req));
                    } else if (_.isString(rule.target)) {
                        newUrl = req.url.replace(rule.origin, req.target);
                    }
                } else if (_.isFunction(rule.origin)) {
                    if (_.isFunction(rule.target)) {
                        newUrl = rule.target(req);
                    } else if (_.isString(rule.target)) {
                        newUrl = rule.target;
                    }
                }

                if (rule.type === '301') {
                    return res.redirect(301, newUrl);
                } else if (rule.type === 'rewrite') {
                    req.url = newUrl;
                    return next();
                }

                break;
            }
        }

        return next();
    };
};