//aws polly tts
const AWS = require('aws-sdk');
const fs=require('fs');
const { LineClient } = require('messaging-api-line');
require("dotenv").config({path : '.env'});

var express = require('express');
var app = express();
const line = require('@line/bot-sdk');

//papago api
var request = require('request');

//번역 api_url
var translate_api_url = 'https://openapi.naver.com/v1/papago/n2mt';

//언어감지 api_url
var languagedetect_api_url = 'https://openapi.naver.com/v1/papago/detectLangs';

// 검색 기능 api_url
var search_api_url = 'https://openapi.naver.com/v1/search/encyc.json';

//polly
const Polly =new AWS.Polly({
    signatureVersion: 'v4',
    region: 'ap-northeast-2',
    accessKeyId:process.env.accesskeyid,
    secretAccessKey:process.env.secretaccesskey
});

// Naver Auth Key
//새로 발급받은 naver papago api id, pw 입력
var client_id = process.env.client_id;
var client_secret = process.env.client_secret;
const config = {
  channelAccessToken: process.env.channelAccessToken,
  channelSecret: process.env.channelSecret,
};


// create LINE SDK client
const client = new line.Client(config);
const for_audio_client=LineClient.connect({
    accessToken: process.env.channelAccessToken,
    channelSecret: process.env.channelSecret,
});
// create Express app
// about Express itself: https://expressjs.com/

// register a webhook handler with middleware
// about the middleware, please refer to doc
app.use(express.static('public'));
app.post('/webhook', line.middleware(config), (req, res) => {
  Promise
    .all(req.body.events.map(handleEvent))
    .then((result) => res.json(result))
    .catch((err) => {
      console.error(err);
      res.status(200).end();
    });
});

// event handler
function handleEvent(event) {
  if (event.type !== 'message' || event.message.type !== 'text') {
    // ignore non-text-message event
    return Promise.resolve(null);
  }

  // 검색 기능
  else if(event.message.text.substr(0,4) == "!검색 "){
    return new Promise(function(resolve, reject) {
      var text_len = event.message.text;

      var search_options = {
        url : search_api_url,
        form : {'query': event.message.text.substr(4, text_len - 4), 'display': 1},
        headers: {'X-Naver-Client-Id': client_id, 'X-Naver-Client-Secret': client_secret}
      };
      request.get(search_options, function(error, response, body){
        console.log(response);
      })
    })
  }

  // 번역 기능 & 음성 기능
  return new Promise(function(resolve, reject) {
    //언어 감지 option
    var detect_options = {
      url : languagedetect_api_url,
      form : {'query': event.message.text},
      headers: {'X-Naver-Client-Id': client_id, 'X-Naver-Client-Secret': client_secret}
    };
    //papago 언어 감지
    request.post(detect_options,function(error,response,body){
      console.log(response.statusCode);
      if(!error && response.statusCode == 200){
        var detect_body = JSON.parse(response.body);
        var source = '';
        var target = '';
        var result = { type: 'text', text:''};
        //언어 감지가 제대로 됐는지 확인
        console.log(detect_body.langCode);
        if(detect_options.form.query=='음성'){
            console.log('audio streaming');
            if (!error && response.statusCode == 200){
                console.log(response.statusCode);
                for_audio_client.replyAudio(event.replyToken,{
                    "originalContentUrl": "https://panguin.ml/speech.m4a",
                    "duration": 24000
                }).then(resolve).catch(reject);
            }
        }
        //번역은 한국어->영어 / 영어->한국어만 지원
        else if(detect_body.langCode == 'ko'||detect_body.langCode == 'en'){
          source = detect_body.langCode == 'ko' ? 'ko':'en';
          target = source == 'ko' ? 'en':'ko';
          //papago 번역 option
          var options = {
              url:  translate_api_url,
              // 한국어(source : ko), 영어(target: en), 카톡에서 받는 메시지(text)
              form: {'source':source, 'target':target, 'text':event.message.text},
              headers: {'X-Naver-Client-Id': client_id, 'X-Naver-Client-Secret': client_secret}
          };

          // Naver Post API
          request.post(options, function(error, response, body){
              // Translate API Sucess
              if(!error && response.statusCode == 200){
                  // JSON
                  var objBody = JSON.parse(response.body);
                  result.text = objBody.message.result.translatedText;
                  //번역된 문자 audio로 저장
                  let audio_options={
                      'Text': result.text,
                      'OutputFormat': 'mp3',
                      'VoiceId':'Amy'
                  };
                  Polly.synthesizeSpeech(audio_options, (err, data) => {
                      console.log("check");
                      if (err) {
                          throw err;
                      } else if (data) {
                          if (data.AudioStream instanceof Buffer) {
                              fs.writeFile("public/speech.m4a", data.AudioStream, function(err) {
                                  if (err) {
                                      return console.log(err);
                                  }
                                  console.log("The file was saved!");
                              });
                          }
                      }
                  });
                  // Message 잘 찍히는지 확인
                  console.log(result.text);
                  //번역된 문장 보내기
                  client.replyMessage(event.replyToken,result).then(resolve).catch(reject);
              }
          });
        }
        // 메시지의 언어가 영어 또는 한국어가 아닐 경우
        else{
          result.text = '언어를 감지할 수 없습니다. \n 번역 언어는 한글 또는 영어만 가능합니다.';
          client.replyMessage(event.replyToken,result).then(resolve).catch(reject);
        }

      }

    });

  });
}

app.listen(80, function () {
  console.log('Linebot listening on port 80!');
});