var amazonHelper = require('./helpers/amazon');
var databaseHelper = require('./helpers/database');

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

require('isomorphic-fetch');

var express = require('express');
var alexa = require('alexa-app');

var bodyParser = require('body-parser');

var MongoClient = require ('mongodb').MongoClient;
var ObjectID = require ('mongodb').ObjectID;

const router = express.Router ();

router.get ('/getSkill/:id', async (req, res, next) => {
  try {
    const id = req.params.id;

    if (id.length !== 24){
      res.json([]);
      throw("error");
    }

    db.collection ('skill_list').find({_id: ObjectID(id)}).toArray((err,result)=>{
      if (err){
        throw err;
        res.json([]);
      }else{
        res.json(result);
      }
    });
    
  } catch (e) {
    console.log ('error:', e);
    next (e);
  }
});

router.get ('/deleteSkill/:skillID', async (req, res, next) => {
  try {
    let id = req.params.id;
    let result = db.collection('skill_list').remove({_id: ObjectID(id)},(err,result)=>{
      if (err) throw err;
      res.json(result);
    });
  } catch (e) {
    console.log ('error:', e);
    next (e);
  }
});

router.post ('/updateSkill/:id', async (req, res, next) => {
  
    let id = req.params.id;
    let skill = req.body;
    delete skill._id;
    if (id !== '-1'){
      amazonHelper.updateSkill(skill,db).then(amazonResult=>{
        if (amazonResult===200 || amazonResult===202){
          //Skill uploaded, it's ok to update database
          let result = db.collection('skill_list').update({_id: ObjectID(id)}, skill,{upsert:true}, (err, result)=>{
            if (JSON.parse(result).nModified===1){
              //database update ok
              res.json({result:0, message:'ok'});
            }else{
              res.json({result:-1, message:'ok'});
            }
          });
        }else{
          res.json({result:-1, message:'Amazon result ' + amazonResult});
        }
      }).catch(e=>{
        //skill upload went wrong, don't update database, send error
        res.json({result:-1, message:e});
      });

    }else{
      //no new skills for now
    }
});

var skillID = 'amzn1.ask.skill.7115bfc9-313e-4728-830b-ebd19ce96cb3';
var skillDbID = '5a232fb86ce046c749739455'; //_id in database 

var app = express();

// ALWAYS setup the alexa app and attach it to express before anything else.
var alexaApp = new alexa.app('step3'); // this means we still work with one skill

alexaApp.express({
  expressApp: app,

  // verifies requests come from amazon alexa. Must be enabled for production.
  // You can disable this if you're running a dev environment and want to POST
  // things to test behavior. enabled by default.
  checkCert: false,

  // sets up a GET route when set to true. This is handy for testing in
  // development, but not recommended for production. disabled by default
  debug: true
});

// now POST calls to /test in express will be handled by the app.request() function

// from here on you can setup any other express routes or middlewares as normal

alexaApp.launch(function(request, response) {
  const skill = db.collection('skill_list').findOne({_id: ObjectID(skillDbID)}, (err,result)=>{
    if (err){
      response.say("I could not find desired skill")
    }else{
      response.say(skill.invocationAnswer);
    }
  });
});

var findElementByAttr = function (data, attr, val){
  for(var i = 0; i < data.length; i ++) {
    if(data[i][attr] === val) {
        return i;
    }
  }
  return -1;
}

alexaApp.request = (jsonRequest) => {
  const alexaRequest = new alexa.request(jsonRequest);
  if (alexaRequest.type() === "IntentRequest") {
    const skill = db.collection('skill_list').findOne({
      _id: skillDbID
    });
    if (skill) {
      let intentId = findElementByAttr(skill.intents, 'intentName', alexaRequest.data.request.intent.name);
      const response = new alexa.response(alexaRequest.getSession());
      if (intentId !== -1){
        return response.say(skill.intents[intentId].answer);
      }else{
        return response.say('Sorry, I could not find desired intent');
      }
    }
  }
};

app.use (function (req, res, next) {
  res.header ('Access-Control-Allow-Origin', '*');
  res.header (
    'Access-Control-Allow-Headers',
    'Origin, Content-Type'
  );
  res.header ('Access-Control-Allow-Methods', 'GET, POST, OPTIONS');
  res.header ('Access-Control-Allow-Credentials', 'true');
  next ();
});

app.use (bodyParser.json ());
app.use ('/', router);


MongoClient.connect (config.dbURL).then (database => {
  db = database;
  db.collection ('intent_list');
  
  databaseHelper.initModule(db);
  
  app.listen (config.PORT, () =>{
    console.log ('Express server running on port ' + config.PORT);
    databaseHelper.loadTokens();
  });
}).catch(e=>{
  console.log("error : " + e);
});