/**
 * 控制路由请求次数
 * @date: 2018/03/05
 */
'use strict';

const _ = require('lodash');
const cache = global.yoho.cache.master;
const helpers = global.yoho.helpers;
const pathToRegexp = require('path-to-regexp');
const logger = global.yoho.logger;
const md5 = require('md5');

const statusCode = {
    code: 4403,
    data: {},
    message: '亲，您的访问次数过多，请稍后再试哦...'
};

const INVALIDTIME = 3600 * 24; // 24h
const IP_WHITE_LIST = [
    '106.38.38.146',
    '106.38.38.147',
    '106.39.86.227',
    '218.94.75.58',
    '218.94.75.50',
    '218.94.77.166'
];

const _jumpUrl = (req, res, next, result) => {
    if (result.code === 4403) {
        if (req.xhr) {
            res.set({
                'Cache-Control': 'no-cache',
                Pragma: 'no-cache',
                Expires: (new Date(1900, 0, 1, 0, 0, 0, 0)).toUTCString()
            });
            return res.status(403).json(result);
        }
        return res.redirect(`${result.data.url}&refer=${req.originalUrl}`);
    }

    return next();
};

module.exports = () => {
    return (req, res, next) => {
        // default open
        if (_.get(req.app.locals.pc, 'close.risk', false)) {
            return next();
        }

        let ip = _.get(req.yoho, 'clientIp', '');
        let path = req.path || '';
        let risks = _.get(req.app.locals.pc, 'json.risk', []);
        let router = {};

        logger.debug(`risk => risks: ${JSON.stringify(risks)}, path: ${path}, ip: ${ip}`); // eslint-disable-line
        if (_.isEmpty(path) || _.isEmpty(risks) || IP_WHITE_LIST.indexOf(ip) > -1) {
            return next();
        }

        _.isArray(risks) && risks.some(item => {
            if (item.state === 'off') {
                return false;
            }

            if (!item.regRoute) {
                item.regRoute = pathToRegexp(item.route);
                item.interval = parseInt(item.interval, 10);
                item.requests = parseInt(item.requests, 10);
            }

            if (item.regRoute.test(path)) {
                router = item;
                return true;
            }

            return false;
        });

        logger.debug(`risk => router: ${JSON.stringify(router)}, path: ${path}`); // eslint-disable-line
        if (_.isEmpty(router)) {
            return next();
        }

        let keyPath = md5(`${router.regRoute}`);
        let limitKey = `pc:risk:limit:${keyPath}:${ip}`;
        let configKey = `pc:risk:${keyPath}:${ip}`;
        let checkUrl = helpers.urlFormat('/3party/check', {
            pid: `pc:risk:limit:${keyPath}`
        });

        return Promise.all([
            cache.getAsync(limitKey),
            cache.getAsync(configKey),
        ]).then(inters => {
            logger.debug(`risk => getCache: ${JSON.stringify(inters)}, path: ${path}`); // eslint-disable-line
            if (inters[0]) {
                return Object.assign({}, statusCode, {data: {url: checkUrl}});
            }

            if (typeof inters[1] === 'undefined') {
                cache.setAsync(configKey, 1, router.interval || 300);
                return {code: 200};
            }

            inters[1] = parseInt(`0${inters[1]}`, 10);
            if (inters[1] <= router.requests) {
                router = [];
                cache.incrAsync(configKey, 1);
                return {code: 200};
            }

            return Promise.all([
                cache.setAsync(limitKey, 1, INVALIDTIME),
                cache.delAsync(configKey)
            ]).then(() => {
                return Object.assign({}, statusCode, {data: {url: checkUrl}});
            });
        }).then(result => {
            logger.debug(`risk => result: ${JSON.stringify(result)}, path: ${path}`); // eslint-disable-line
            return _jumpUrl(req, res, next, result);
        }).catch(e => {
            console.log(`risk => path: ${path}, err: ${e.message}`);
            return next();
        });
    };
};