/**
 * 微信工具类
 *
 * Created by lyr-pc on 2016/11/25.
 */
"use strict"
var log = require('./log');
var configFile = require('../include/commons').CONFIG_FILE;
var config = require('../resources/config/' + configFile);
var wxTokenRepo = require('../repository/mysql/wechat.token.repo.js');
var https = require('https');

/**
 * 发送微信模板消息
 *
 * @param message {"touser":"","template_id":"","url":"","data":{"firts":{"value":"","color":""}}}
 */
function sendWxTemplateMessage(message, handler) {
    getWxAccessToken(function (err, token) {
        if (err) {
            log.error("get access_token failed:" + err);
            return;
        }

        var opt = {
            host: 'api.weixin.qq.com',
            path: '/cgi-bin/message/template/send?access_token=' + token,
            method: 'POST'
        };

        var msg = JSON.stringify(message);
        log.info("sending wechat template message:" + msg);
        // 发送模板消息
        var req = https.request(opt, function (res) {
            res.setEncoding('utf8');
            var data = "";
            res.on('data', (d) => {
                data += d;
            });
            res.on('end', () => {
                var result = JSON.parse(data);

                if (result && result.errcode === 0) {
                    log.info("send wechat template message success:" + msg);
                    if (handler) {
                        handler(null, result);
                    }
                } else {
                    log.error("send wechat template message failed:" + msg);
                    if (handler) {
                        handler(result, null);
                    }
                }
            });
            res.on('error', function (err) {
                log.error('send wechat template message failed: ' + err.message);
                if (handler) {
                    handler(err, null);
                }
            });
        }).on('error', (e) => {
            log.error("send wechat template message failed:" + e.message);
            if (handler) {
                handler(e, null);
            }
        });

        req.end(msg);
    });
};

/**
 * 获取微信access_token
 *
 * @param handler 回调函数
 */
function getWxAccessToken(handler) {
    wxTokenRepo.getAccessToken(function (err, result) {
        if (err) {
            log.error("get wechat accessToken failed", err);
            return;
        }

        var data = result && result.length > 0 ? result[0] : null;
        var accessToken = "";

        if (data) {
            // 判断access_token是否有效
            if ((new Date().getTime() - data.add_timestamp) < (data.expires_in * 1000)) {
                accessToken = data.access_token;
            }
        }

        // access_token为空时从微信重新获取并执行回调，否则直接执行回调
        if (!accessToken) {
            var token_url = "https://api.weixin.qq.com/cgi-bin/token?";
            var params = "grant_type=client_credential&appid=" + config.wechatConfig.appId
                + "&secret=" + config.wechatConfig.appSecret;

            // 从微信获取access_token
            https.get(token_url + params, function (res) {
                var data = '';
                res.on('data', (d) => {
                    data += d;
                });
                res.on('end', () => {
                    data = data ? JSON.parse(data) : {};
                    if (data.access_token) {
                        accessToken = data.access_token;
                        var expiresIn = data.expires_in;

                        if (handler) {
                            // 执行回调
                            handler(null, accessToken);
                        }

                        var tokenData = [accessToken, new Date().getTime(), expiresIn, new Date()];
                        // 保存access_token
                        wxTokenRepo.saveAccessToken(tokenData, function (err, result) {
                            if (err) {
                                log.error("insert wechat access_token failed:" + err.message);
                            }
                        })
                    } else {
                        log.error("get wechat access_token failed:" + data);
                        if (handler) {
                            // 执行回调
                            handler(data, null);
                        }
                    }
                });
            }).on('error', (e) => {
                log.error("get wechat access_token from wechat failed:" + e.message);
                if (handler) {
                    // 执行回调
                    handler(e, null);
                }
            });
        } else {
            if (handler) {
                // 执行回调
                handler(null, accessToken);
            }
        }
    });
};

exports.sendWxTemplateMessage = sendWxTemplateMessage;
exports.getWxAccessToken = getWxAccessToken;