var currentQuestion = 0;
var score = 0;
var totQuestions = questions.length;

var container = document.getElementById('quizContainer');
var questionEl = document.getElementById('question');
var opt1 = document.getElementById('opt1');
var opt2 = document.getElementById('opt2');
var opt3 = document.getElementById('opt3');
var opt4 = document.getElementById('opt4');
var nextButton = document.getElementById('nextButton');
var resultCont = document.getElementById('result');
var previousButton = document.getElementById('previousButton')
var restartButton = document.getElementById('restartButton')
var answerButton = document.getElementById('answerButton')


function loadQuestion (questionIndex) {
    var q = questions[questionIndex];
    questionEl.textContent = (questionIndex + 1) + '. ' + q.question;
    opt1.textContent = q.option1;
    opt2.textContent = q.option2;
    opt3.textContent = q.option3;
    opt4.textContent = q.option4;
};


function loadpreviousQuestion () {
    var selectedOption = document.querySelector('input[type=radio]:checked');
    if(!selectedOption){
        alert('Please select your answer!');
        return;
    }
    var answer = selectedOption.value;
    /*if(questions[currentQuestion].answer == answer){
        score += 1;
    }*/
    selectedOption.checked = false;
    currentQuestion--;
    if(currentQuestion == totQuestions - 1){
        nextButton.textContent = 'Finish';
    }
    if(currentQuestion == totQuestions){
        container.style.display = 'none';

        resultCont.style.display = '';
        resultCont.textContent = 'Your Score: ' + score + ' out of 10';

        showAnswers();

        return;
    }

loadQuestion(currentQuestion);

}

function loadNextQuestion () {
    var selectedOption = document.querySelector('input[type=radio]:checked');
    if(!selectedOption){
        alert('Please select your answer!');
        return;
    }
    var answer = selectedOption.value;
    if(questions[currentQuestion].answer == answer){
        score += 1;
    }
    selectedOption.checked = false;
    currentQuestion++;
    if(currentQuestion == totQuestions - 1){
        nextButton.textContent = 'Finish';
    }
    if(currentQuestion == totQuestions){

        container.style.display = 'none';
        resultCont.style.display = '';
        resultCont.textContent = 'Your Score: ' + score + ' out of 10';
        answerButton.style.display='block';
        //restartButton.style.display='block';

        //showAnswers();
        return;
    }
    loadQuestion(currentQuestion);
}

loadQuestion(currentQuestion);


 function resetquiz() {
    container.style.display = '';
resultCont.style.display = 'none';
score = 0;
currentQuestion = 0;
 loadQuestion(currentQuestion)
 answerButton.style.display='none';
 nextButton.textContent = 'Next Question';

 }

function showAnswers() {
 for(var i = 0; i < questions.length; i++) {
  var info = questions[i];
  var el = document.createElement('div');
  var questionTxt = document.createTextNode((i + 1 ) + '. ' + questions[i].question);
  var answer = ' ' + info['option' + info.answer];
  var answerEl = document.createElement('strong');
  var answerTxt = document.createTextNode(answer);
  answerEl.appendChild(answerTxt);
  el.appendChild(questionTxt);
  el.appendChild(answerEl);
  resultCont.appendChild(el);
 }
}