{{ block title }}Task 3 (5 minutes){{ endblock }}

{{ block content }}
<div class="timer" id="timer-display">Time remaining: <span id="countdown"></span></div>
<div class="tally">Correct answers so far: <span id="tally">0</span></div>

<hr>

<div id="problem-area" class="my-3">
    <div class="task-addends" id="addend-list"></div>
    <div class="task-separator"></div>
    <div class="mt-2">
        <input type="number" id="answer-input" class="form-control" style="width:160px; display:inline-block;"
               placeholder="Your answer" autocomplete="off">
        <button class="btn btn-primary btn-answer" id="submit-btn">Submit</button>
    </div>
    <div class="feedback" id="feedback"></div>
</div>

<div id="task-complete" style="display:none;">
    <p class="text-muted">Time is up! Your responses are being saved...</p>
</div>

{{ endblock }}

{{ block scripts }}
<script>
(function () {
    var TASK_NUM = 3;
    var firstProblem = {{ first_problem|json }};
    var timeoutSeconds = {{ timeout_seconds }};

    var currentIdx = 0;
    var currentProblem = firstProblem;
    var tally = 0;
    var problemStartTime = Date.now();
    var submitting = false;

    function renderProblem(prob) {
        var container = document.getElementById('addend-list');
        container.innerHTML = '';
        prob.forEach(function (n) {
            var span = document.createElement('span');
            span.className = 'task-addend-row';
            span.textContent = n;
            container.appendChild(span);
        });
        document.getElementById('answer-input').value = '';
        document.getElementById('answer-input').focus();
        document.getElementById('feedback').textContent = '';
        document.getElementById('feedback').className = 'feedback';
        problemStartTime = Date.now();
    }

    function submitAnswer() {
        if (submitting) return;
        var raw = document.getElementById('answer-input').value.trim();
        if (raw === '') return;
        var answer = parseInt(raw, 10);
        if (isNaN(answer)) return;

        submitting = true;
        document.getElementById('submit-btn').disabled = true;
        var response_ms = Date.now() - problemStartTime;
        liveSend({ task: TASK_NUM, idx: currentIdx, answer: answer, response_ms: response_ms });
    }

    function liveRecv(data) {
        submitting = false;
        document.getElementById('submit-btn').disabled = false;

        if (data.correct) {
            tally++;
            document.getElementById('tally').textContent = tally;
            document.getElementById('feedback').textContent = '✓ Correct!';
            document.getElementById('feedback').className = 'feedback correct';
        } else {
            document.getElementById('feedback').textContent = '✗ Incorrect';
            document.getElementById('feedback').className = 'feedback incorrect';
        }

        if (data.next_problem) {
            currentIdx = data.next_idx;
            currentProblem = data.next_problem;
            setTimeout(function () { renderProblem(currentProblem); }, 300);
        } else {
            document.getElementById('problem-area').style.display = 'none';
            document.getElementById('task-complete').style.display = 'block';
        }
    }

    window.liveRecv = liveRecv;

    document.getElementById('answer-input').addEventListener('keydown', function (e) {
        if (e.key === 'Enter') { e.preventDefault(); submitAnswer(); }
    });
    document.getElementById('submit-btn').addEventListener('click', submitAnswer);

    var endTime = Date.now() + timeoutSeconds * 1000;
    function updateCountdown() {
        var remaining = Math.max(0, Math.ceil((endTime - Date.now()) / 1000));
        var m = Math.floor(remaining / 60);
        var s = remaining % 60;
        document.getElementById('countdown').textContent =
            m + ':' + (s < 10 ? '0' : '') + s;
        if (remaining === 0) {
            document.getElementById('problem-area').style.display = 'none';
            document.getElementById('task-complete').style.display = 'block';
        }
    }
    updateCountdown();
    setInterval(updateCountdown, 1000);

    renderProblem(firstProblem);
}());
</script>
{{ endblock }}