{{-- Shared "create exam" builder JS — included wherever the create-exam modal (_create_modal.blade.php) appears. --}}
{{-- The including page may define window.onExamPublished(res) before this include to react to a successful publish. --}}
var examQCount = 0;

function examOptionLetter(idx){
    return String.fromCharCode(65 + idx);
}

function markExamOptionCorrect(radio){
    var row = radio.closest('.opt-row');
    var wrap = row.parentElement;
    wrap.querySelectorAll('.opt-row').forEach(function(r){ r.classList.remove('is-correct'); });
    row.classList.add('is-correct');
}

function examOptionRowHtml(qId, idx, canRemove){
    return '<div class="opt-row mc-row' + (idx === 0 ? ' is-correct' : '') + '">' +
        '<input type="radio" name="questions[' + qId + '][correct]" value="' + idx + '" ' + (idx === 0 ? 'checked' : '') + ' onchange="markExamOptionCorrect(this)">' +
        '<span class="opt-letter">' + examOptionLetter(idx) + '</span>' +
        '<input type="text" name="questions[' + qId + '][options][]" placeholder="{{ trans('admin.Option') }} ' + (idx + 1) + '" required>' +
        '<button type="button" class="opt-remove" title="{{ trans('admin.Remove option') }}" ' + (canRemove ? '' : 'disabled') + ' onclick="removeExamOption(' + qId + ', this)">&times;</button>' +
    '</div>';
}

function examTfRowHtml(qId, idx, label){
    return '<div class="opt-row tf-row' + (idx === 0 ? ' is-correct' : '') + '">' +
        '<input type="radio" name="questions[' + qId + '][correct]" value="' + idx + '" ' + (idx === 0 ? 'checked' : '') + ' onchange="markExamOptionCorrect(this)">' +
        '<span class="opt-fixed-label">' + label + '</span>' +
        '<input type="hidden" name="questions[' + qId + '][options][]" value="' + label + '">' +
    '</div>';
}

function renderExamOptions(qId, type){
    var wrap = document.getElementById('opts-' + qId);
    var addBtn = document.getElementById('addOptBtn-' + qId);
    if (!wrap) return;

    if (type === 'true_false') {
        wrap.innerHTML = examTfRowHtml(qId, 0, "{{ trans('admin.True') }}") + examTfRowHtml(qId, 1, "{{ trans('admin.False') }}");
        if (addBtn) addBtn.style.display = 'none';
    } else {
        var html = '';
        for (var i = 0; i < 4; i++) {
            html += examOptionRowHtml(qId, i, true);
        }
        wrap.innerHTML = html;
        if (addBtn) addBtn.style.display = '';
        reindexExamOptions(qId);
    }
}

function reindexExamOptions(qId){
    var wrap = document.getElementById('opts-' + qId);
    if (!wrap) return;
    var rows = wrap.querySelectorAll('.opt-row');
    var hasChecked = false;

    rows.forEach(function(row, i){
        var radio = row.querySelector('input[type=radio]');
        radio.value = i;
        if (radio.checked) hasChecked = true;
        var letter = row.querySelector('.opt-letter');
        if (letter) letter.textContent = examOptionLetter(i);
        var removeBtn = row.querySelector('.opt-remove');
        if (removeBtn) removeBtn.disabled = rows.length <= 2;
    });

    if (!hasChecked && rows.length) {
        rows[0].querySelector('input[type=radio]').checked = true;
    }

    rows.forEach(function(row){
        row.classList.toggle('is-correct', row.querySelector('input[type=radio]').checked);
    });
}

function addExamOption(qId){
    var wrap = document.getElementById('opts-' + qId);
    if (!wrap) return;
    var idx = wrap.querySelectorAll('.opt-row').length;
    wrap.insertAdjacentHTML('beforeend', examOptionRowHtml(qId, idx, true));
    reindexExamOptions(qId);
}

function removeExamOption(qId, btn){
    var wrap = document.getElementById('opts-' + qId);
    if (!wrap || wrap.querySelectorAll('.opt-row').length <= 2) return;
    btn.closest('.opt-row').remove();
    reindexExamOptions(qId);
}

function changeExamQuestionType(qId, select){
    renderExamOptions(qId, select.value);
}

var EXAM_ATTACHMENT_ACCEPT = 'image/*,.pdf,.doc,.docx,.xls,.xlsx';

function examAttachmentBoxHtml(qId){
    return '<div class="field" style="margin-top:12px;">' +
        '<label>{{ trans('admin.Attachment') }}</label>' +
        '<div class="upload-box compact" onclick="document.getElementById(\'attachFile-' + qId + '\').click()">' +
            '<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.6"><path d="M12 16V4M7 9l5-5 5 5"/><path d="M4 16v3a2 2 0 002 2h12a2 2 0 002-2v-3"/></svg>' +
            '<div class="upload-file-info">' +
                '<b id="attachLabel-' + qId + '">{{ trans('admin.Click to upload or drag and drop') }}</b>' +
                '<span>{{ trans('admin.Attachment types hint') }}</span>' +
            '</div>' +
        '</div>' +
        '<input type="file" id="attachFile-' + qId + '" name="questions[' + qId + '][attachment]" accept="' + EXAM_ATTACHMENT_ACCEPT + '" style="display:none;" onchange="examAttachmentChanged(' + qId + ')">' +
    '</div>';
}

function examAttachmentChanged(qId){
    var input = document.getElementById('attachFile-' + qId);
    var label = document.getElementById('attachLabel-' + qId);
    label.textContent = input.files.length ? input.files[0].name : "{{ trans('admin.Click to upload or drag and drop') }}";
}

function addExamQuestion(){
    examQCount++;
    var n = examQCount;
    var id = 'q' + n;
    var wrap = document.getElementById('examQuestions');
    var div = document.createElement('div');
    div.className = 'q-card'; div.id = id;
    div.innerHTML =
        '<div class="q-card-head"><b>{{ trans('admin.Question') }} ' + n + '</b><button type="button" class="remove-q" onclick="document.getElementById(\'' + id + '\').remove()">{{ trans('admin.Remove') }}</button></div>' +
        '<div class="field q-type-row"><label>{{ trans('admin.Question type') }}</label><select name="questions[' + n + '][type]" onchange="changeExamQuestionType(' + n + ', this)">' +
            '<option value="multiple_choice" selected>{{ trans('admin.Multiple choice') }}</option>' +
            '<option value="true_false">{{ trans('admin.True / False') }}</option>' +
        '</select></div>' +
        '<div class="field" style="margin-bottom:12px;"><input type="text" name="questions[' + n + '][question]" placeholder="{{ trans('admin.Type the question') }}…" required></div>' +
        '<div id="opts-' + n + '"></div>' +
        '<button type="button" class="btn btn-soft btn-sm add-opt-btn" id="addOptBtn-' + n + '" onclick="addExamOption(' + n + ')">＋ {{ trans('admin.Add option') }}</button>' +
        '<div class="hint">{{ trans('admin.Select the correct answer hint') }}</div>' +
        examAttachmentBoxHtml(n);
    wrap.appendChild(div);
    renderExamOptions(n, 'multiple_choice');
}

function openExamBuilder(){
    $('#examForm')[0].reset();
    $('#examCourseSelect').trigger('reset-combo');
    $('#examQuestions').html('');
    examQCount = 0;
    addExamQuestion();
    $('#examErrors').html('');
    openModal('examModal');
}

function publishExam(status){
    $('#examErrors').html('');

    var formEl = document.getElementById('examForm');

    if (!$('#examQuestions').children().length) {
        $('#examErrors').html("{{ trans('admin.minimum questions required') }}");
        return;
    }

    if (!formEl.reportValidity()) {
        return;
    }

    $('#examPublishBtn, #examSaveDraftBtn').prop('disabled', true);

    var formData = new FormData(formEl);
    formData.append('status', status);

    $.ajax({
        url: "{{ route('dashboard.exams.store') }}",
        method: 'POST',
        data: formData,
        processData: false,
        contentType: false,
        success: function(res){
            closeModal('examModal');
            dashToast('✓', "{{ trans('admin.success') }}");
            if (typeof onExamPublished === 'function') onExamPublished(res);
        },
        error: function(xhr){
            if (xhr.status === 422) {
                var errors = xhr.responseJSON.errors;
                var html = '';
                $.each(errors, function(key, val){ html += val[0] + '<br>'; });
                $('#examErrors').html(html);
            } else {
                var msg = (xhr.responseJSON && xhr.responseJSON.message) || "{{ trans('admin.faild') }}";
                dashToast('✕', msg);
            }
        },
        complete: function(){
            $('#examPublishBtn, #examSaveDraftBtn').prop('disabled', false);
        }
    });
}


(function(){
    var field = $('#examCourseCombo');
    var select = $('#examCourseSelect');
    if (!field.length) return;

    var trigger = $('<button type="button" class="combo-trigger"></button>');
    var panel = $('<div class="combo-panel"><input type="text" class="combo-search" placeholder="{{ trans('admin.search') }}…" autocomplete="off"><ul class="combo-list"></ul></div>');
    var search = panel.find('.combo-search');
    var list = panel.find('.combo-list');
    select.before(trigger);
    field.append(panel);

    function renderTrigger(){ trigger.text(select.find('option:selected').text()); }

    function renderList(term){
        term = (term || '').toLowerCase();
        list.empty();
        select.find('option').each(function(){
            if (!this.value) return;
            var text = $(this).text();
            if (term && text.toLowerCase().indexOf(term) === -1) return;
            var li = $('<li></li>').text(text).attr('data-value', this.value);
            if (this.value === select.val()) li.addClass('sel');
            list.append(li);
        });
        if (!list.children().length) list.append($('<li class="empty"></li>').text("{{ __('admin.no_result') }}"));
    }

    function close(){ field.removeClass('open'); }

    trigger.on('click', function(){
        var opening = !field.hasClass('open');
        field.toggleClass('open', opening);
        if (opening) { search.val(''); renderList(''); setTimeout(function(){ search.trigger('focus'); }, 0); }
    });
    search.on('input', function(){ renderList(this.value); });
    search.on('keydown', function(e){
        if (e.key === 'Escape') { e.stopPropagation(); close(); trigger.trigger('focus'); }
        if (e.key === 'Enter') { e.preventDefault(); list.find('li').not('.empty').first().trigger('click'); }
    });
    list.on('click', 'li:not(.empty)', function(){
        select.val($(this).attr('data-value')).trigger('change');
        renderTrigger();
        close();
    });
    $(document).on('click', function(e){ if (!field.is(e.target) && !field.has(e.target).length) close(); });

    renderTrigger();
    select.on('reset-combo', function(){ renderTrigger(); close(); });
})();