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

const config = require('./config');

//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';


// create LINE SDK client
const client = new line.Client(config);

// create Express app
// about Express itself: https://expressjs.com/
// register a webhook handler with middleware
// about the middleware, please refer to doc
app.post("/webhook", line.middleware(config.line_config), (req, res) => {
  // res.status(200).end();
  Promise.all(req.body.events.map(handleEvent)).then(result =>
      res.json(result)
  );
});

function handleImgEvent(event) {

  switch (event) {
    case event.type = 'image':
    async function detectText(fileName) {
      // [START vision_text_detection]
      const vision = require('@google-cloud/vision');

      // Creates a client
      const client = new vision.ImageAnnotatorClient();

      /**
       * TODO(developer): Uncomment the following line before running the sample.
       */
          // const fileName = 'Local image file, e.g. /path/to/image.png';

          // Performs text detection on the local file
      const [result] = await client.textDetection(fileName);
      const detections = result.textAnnotations;
      console.log('Text:');
      detections.forEach(text => console.log(text));
      // [END vision_text_detection]
    }
      break;
    case event.type = 'message':
      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}
      }
      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);
          //번역은 한국어->영어 / 영어->한국어만 지원
          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);
                // Message 잘 찍히는지 확인

                result.text = objBody.message.result.translatedText;
                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);
          }
          break;


        }
      })
  }
}
app.listen(3000, function () {
  console.log('Linebot listening on port 3000!');
})