// Bind Listeners

$("input[name='font-select']").change(function(){
    let $choice = $(this).val();
    set_font($choice);
});

$("input[name='font-size']").change(function(){
    let $choice = $(this).val();
    set_font_size($choice);
});

$("input[name='bg-select']").change(function(){
    let $choice = $(this).val();
    set_bg_colour($choice);
});

$(".bg-select-area").click(function(event){
    $(this).find("input[name='bg-select']").prop("checked", true).change();
});

$("#btn-toggle-navigator").click(function(event){
    check_answered();
    update_navigator();
    if ($quiz_navigator.is(":hidden")) {
        if ($quiz_settings.is(":visible")) {
            toggle_settings = true;
            $quiz_settings.fadeOut();
        }
        $quiz_render.fadeOut();
        $quiz_navigator.fadeIn();
        $(".navigator-text").fadeIn();
        $(".review-text").fadeOut();
        toggle_navigator = false;
        $(window).scrollTop(0);
    } else {
        $quiz_navigator.fadeOut();
        if (toggle_settings) {
            $quiz_settings.fadeIn();
            $(window).scrollTop(0);
            toggle_settings = false;
        } else {
            $quiz_render.fadeIn();
            $(window).scrollTop(0);
        }
    }
    event.preventDefault();
});

$("#btn-toggle-settings").click(function(event){
    if (($quiz_settings).is(":hidden")) {
        if ($quiz_navigator.is(":visible")) {
            toggle_navigator = true;
            $quiz_navigator.fadeOut();
        }
        $quiz_render.fadeOut();
        $quiz_settings.fadeIn();
        $(window).scrollTop(0);
        toggle_settings = false;
    } else {
        $quiz_settings.fadeOut();
        if (toggle_navigator) {
            $quiz_navigator.fadeIn();
            toggle_navigator = false;
            $(window).scrollTop(0);
        } else {
            $quiz_render.fadeIn();
            $(window).scrollTop(0);
        }
    }
    event.preventDefault();
});

$(".btn-quiz-return").click(function(event){
    $quiz_navigator.fadeOut();
    $quiz_settings.fadeOut();
    $quiz_render.fadeIn();
    $(window).scrollTop(0);
    toggle_settings = false;
    toggle_navigator = false;
    event.preventDefault();
});

$(".btn-dummy").click(function(event){
    event.preventDefault();
});

$("#navigator-container").on("click", ".q-navigator-button", function(event){
    check_answered();
    update_navigator();
    current_question = parseInt($(this).prop("name"));
    $quiz_navigator.fadeOut();
    $quiz_render.fadeIn();
    $question_title.focus();
    $(window).scrollTop(0);
    toggle_navigator = false;
    toggle_settings = false;
    render_question();
    check_flag();
    event.preventDefault();
});

$(".q-question-nav").click(function(event){
    check_answered();
    update_navigator();
    if ($(this).prop("id") == "q-nav-next") {
        if (current_question < questions.length) {
            current_question ++;
        }
    } else if ($(this).prop("id") == "q-nav-prev") {
        if (current_question > 0) {
            current_question --;
        }
    } else if ($(this).hasClass("q-navigator-button")) {
        current_question = $(this).prop("name");
        $quiz_render.fadeIn();
        $quiz_navigator.fadeOut();
        toggle_navigator = false;
        toggle_settings = false;
    }
    render_question();
    check_flag();
    event.preventDefault();
});

$("#q-nav-flag").click(function(event){
    if (question_status[current_question] != 1) {
        question_status[current_question] = 1;
        $(this).removeClass().addClass("btn btn-warning");
        $(this).prop("title", "Question Flagged for revision. Click to un-flag.");
    } else {
        question_status[current_question] = 0;
        $(this).removeClass().addClass("btn btn-secondary");
        $(this).prop("title", "Question Un-Flagged. Click to flag for revision.");
    }
    window.localStorage.setItem('question_status', JSON.stringify(question_status));
    update_navigator();
    event.preventDefault();
});

$("#btn-start-quiz").click(function(event){

    $.ajax({
        url: `/api/questions/`,
        type: 'POST',
        data: JSON.stringify({'id': id}),
        contentType: "application/json",
        success: function(response) {
            $(this).fadeOut();
            $(".btn-quiz-return").fadeIn();
            $(".quiz-console").fadeIn();
            $("#quiz-settings").fadeOut();
            $("#quiz-navigator").fadeOut();
            $(".quiz-start-text").fadeOut();
            time_limit = response.time_limit;
            start_time = response.start_time;
            questions = response.questions;
            total_questions = questions.length;
            window.localStorage.setItem('questions', JSON.stringify(questions));
            window.localStorage.setItem('start_time', JSON.stringify(start_time));
            window.localStorage.setItem('time_limit', JSON.stringify(time_limit));
            render_question();
            build_navigator();
            check_flag();
            if (time_limit != 'null' && time_limit != null) {
                $("#q-timer-widget").fadeIn();
                time_remaining = get_time_remaining();
                clock = setInterval(timer, 1000);
            }
            if (response.time_adjustment > 0) {
                const $alert = $("#alert-box");
                $alert.html(
                    `<div class="alert alert-primary alert-dismissible fade show" role="alert">
                    <i class="bi bi-exclamation-triangle-fill" title="Alert"></i>
                    User code validated. Extra time of ${response.time_adjustment} minutes added to the exam time limit.
                    <button type="button" class="btn-close" data-bs-dismiss="alert" aria-label="Close"></button>
                </div>
                `
                );
                $alert.focus();
            }
        },
        error: function(response) {
            error_response(response);
        }
    });

    event.preventDefault();
});

$("#quiz-question-options").on("change", ".quiz-option", function(event){
    $name = parseInt($(this).prop("name"));
    $value = $(this).prop("value");
    answers[$name] = $value;
    window.localStorage.setItem('answers', JSON.stringify(answers));
});

$("#q-review-answers").click(function(event){
    check_answered();
    update_navigator();
    if ($quiz_navigator.is(":hidden")) {
        if ($quiz_settings.is(":visible")) {
            toggle_settings = true;
            $quiz_settings.fadeOut();
        }
        $quiz_render.fadeOut();
        $quiz_navigator.fadeIn();
        $(".navigator-text").fadeOut();
        $(".review-text").fadeIn();
        toggle_navigator = false;
        $(window).scrollTop(0);
    } else {
        $quiz_navigator.fadeOut();
        if (toggle_settings) {
            $quiz_settings.fadeIn();
            toggle_settings = false;
        } else {
            $quiz_render.fadeIn();
        }
    }
    event.preventDefault();
});

$(".quiz-button-submit").click(function(event){
    let submission = {
        'id': id,
        'answers': answers
    }

    $.ajax({
        url: `/api/submit/`,
        type: 'POST',
        data: JSON.stringify(submission),
        contentType: "application/json",
        success: function(response) {
            window.localStorage.clear();
            window.location.href = `/result/`;
        },
        error: function(response) {
            error_response(response);
        }
    });

    event.preventDefault();
});

// Functions

function set_font(value = 'osdefault') {
    let font_styles = ['arial', 'comicsans', 'opendyslexic', 'tahoma', 'verdana']

    for (let i = 0; i < font_styles.length; i ++) {
        if (font_styles[i] != value) {
            $("body").removeClass( `q-f-${font_styles[i]}` );
        };
    };

    if (value != 'osdefault') {
        $("body").addClass(`q-f-${value}`);
    };
    
    display_settings['font-select'] = value;
    window.localStorage.setItem('display_settings', JSON.stringify(display_settings));
    $('input[name="font-select"][value="' + value + '"]').prop('checked', true);
}

function set_font_size(value = '14pt') {
    let font_sizes = ['12pt', '16pt', '18pt']

    for (let i = 0; i < font_sizes.length; i ++) {
        if (font_sizes[i] != value) {
            $("body").removeClass( `q-f-${font_sizes[i]}` );
        };
    };

    if (value != '14pt') {
        $("body").addClass(`q-f-${value}`);
    };

    display_settings['font-size'] = value;
    window.localStorage.setItem('display_settings', JSON.stringify(display_settings));
    $('input[name="font-size"][value="' + value + '"]').prop('checked', true);
}

function set_bg_colour(value = 'bg-light') {
    let backgrounds = ['bg-light', 'q-bg-light-1', 'q-bg-light-2', 'alert-primary', 'alert-secondary', 'alert-dark', 'bg-dark']

    for (let i = 0; i < backgrounds.length; i ++) {
        if (backgrounds[i] != value) {
            $("body").removeClass(backgrounds[i]);
            if (backgrounds[i] == 'bg-dark') {
                $("body").removeClass('text-light');
            };
            if (backgrounds[i] == 'alert-primary' || backgrounds[i] == 'alert-secondary' || backgrounds[i] == 'alert-dark') {
                $("body").removeClass('text-dark');
            };
        };
    };

    $("body").addClass(value);
    if (value == 'bg-dark') {
        $("body").addClass('text-light');
    };
    if (value == 'alert-primary' || value == 'alert-secondary' || value == 'alert-dark') {
        $("body").addClass('text-dark');
    };

    display_settings['bg-select'] = value;
    window.localStorage.setItem('display_settings', JSON.stringify(display_settings));
    $('input[name="bg-select"][value="' + value + '"]').prop('checked', true);
}

function get_settings_from_storage() {
    let display_settings = window.localStorage.getItem('display_settings')
    if (display_settings != null) {
        return JSON.parse(display_settings);
    };
    return {
        'font-select': 'osdefault',
        'font-size': '14pt',
        'bg-select': 'bg-light'
    }
}

function apply_settings(settings) {
    set_font(settings['font-select']);
    set_font_size(settings['font-size']);
    set_bg_colour(settings['bg-select']);
}

function render_question() {
    if (current_question == 0) {
        $nav_prev.addClass('disabled');
    }
    if (current_question == questions.length - 1) {
        $nav_next.addClass('disabled');
    }
    if ($nav_prev.hasClass('disabled') && current_question > 0) {
        $nav_prev.removeClass('disabled');
    }
    if ($nav_next.hasClass('disabled') && current_question < questions.length - 1) {
        $nav_next.removeClass('disabled');
    }
    var question = questions[current_question];
    let header_text = question.question_header;
    var block_length = 0;
    if ('block_length' in question) {
        block_length = question['block_length'];
    };
    var block_q_no = 0;
    if ('block_q_no' in question) {
        block_q_no = question['block_q_no'];
    }
    let remaining_qs = (block_length - block_q_no).toString();
    if (block_length - block_q_no > 1) {
        remaining_qs += ' questions';
    } else {
        remaining_qs += ' question';
    }
    header_text = header_text.replace('<block_remaining_questions>', remaining_qs);
    $question_header.html(header_text);
    $question_text.html(question.text);
    $question_title.html(`Question ${current_question + 1} of ${ questions.length }.`);

    var q_no = question['q_no'];
    var options = question.options;
    var options_output = '';
    for (let i = 0; i < options.length; i ++) {
        var add_checked = ''
        if (q_no in answers) {
            if (answers[q_no] == options[i][0]) {
                add_checked = 'checked';
            }
        }
        options_output += `<div class="form-check">
            <input type="radio" class="form-check-input quiz-option" id="q${current_question}-${i}" name="${q_no}" value="${options[i][0]}" ${add_checked}>
            <label for="q${current_question}-${i}" class="form-check-label">${options[i][1]}</label>
        </div>`;
    }
    $question_options.html(options_output);
    let skipped = count_questions(-1);
    let answered = count_questions(2);
    let flagged = count_questions(1);

    $progress_skipped.prop('title', `Skipped: ${skipped}`);
    $progress_skipped.prop('aria-valuenow', skipped);
    $progress_skipped.css('width', `${skipped}%`);
    $skipped_count.text(`Skipped: ${skipped}`);
    if (skipped < 1) {
        $skipped_count.fadeOut()
    } else {
        $skipped_count.fadeIn()
    }

    $progress_flagged.prop('title', `Flagged: ${flagged}`);
    $progress_flagged.prop('aria-valuenow', flagged);
    $progress_flagged.css('width', `${flagged}%`);
    $flagged_count.text(`Flagged: ${flagged}`);
    if (flagged < 1) {
        $flagged_count.fadeOut()
    } else {
        $flagged_count.fadeIn()
    }

    $progress_answered.prop('title', `Answered: ${answered}`);
    $progress_answered.prop('aria-valuenow', answered);
    $progress_answered.css('width', `${answered}%`);
    $answered_count.text(`Answered: ${answered}`);
    if (answered < 1) {
        $answered_count.fadeOut()
    } else {
        $answered_count.fadeIn()
    }

    $question_title.focus();
    $(window).scrollTop(0);
}

function check_answered() {
    var question = questions[current_question];
    var name = question.q_no;
    if (question_status[current_question] == 0 || question_status[current_question] == -1) {
        if (!$(`input[name='${name}']:checked`).val()) {
            question_status[current_question] = -1;
        } else {
            question_status[current_question] = 2;
        }
        window.localStorage.setItem('question_status', JSON.stringify(question_status));
    }
}

function check_flag() {
    if (!(current_question in question_status)) {
        question_status[current_question] = 0;
        window.localStorage.setItem('question_status', JSON.stringify(question_status));
    }
    switch (question_status[current_question]) {
        case -1:
            $nav_flag.removeClass().addClass('btn btn-danger progress-bar-striped');
            $nav_flag.prop("title", "Question Incomplete. Click to flag for revision.");
            break;
        case 1:
            $nav_flag.removeClass().addClass('btn btn-warning');
            $nav_flag.prop("title", "Question Flagged for revision. Click to un-flag.");
            break;
        case 2:
            $nav_flag.removeClass().addClass('btn btn-success');
            $nav_flag.prop("title", "Question Answered. Click to flag for revision.");
            break;
        default:
            $nav_flag.removeClass().addClass('btn btn-secondary');
            $nav_flag.prop("title", "Question Un-Flagged. Click to flag for revision.");
    }
}

function build_navigator() {
    $nav_container.html('')
    var output = ''
    for (let i = 0; i < questions.length; i ++) {
        let add_class, add_href, add_status = '';
        switch (question_status[i]) {
            case -1:
                add_class = 'btn-danger progress-bar-striped';
                add_href = 'href="#"';
                add_status = 'Incomplete';
                break;
            case 1:
                add_class = 'btn-warning';
                add_href = 'href="#"';
                add_status = 'Flagged';
                break;
            case 2:
                add_class = 'btn-success';
                add_href = 'href="#"';
                add_status = 'Answered';
                break;
            default:
                add_class = 'btn-secondary disabled';
                add_href = '';
                add_status = 'Unseen';
        }
        output += `<a ${add_href} class="q-navigator-button btn ${add_class}" name=${i} title="Question ${i+1}: ${add_status}">Q${i + 1}</a>`;
    }
    $nav_container.html(output);
}

function update_navigator() {
    let button = $(`.q-navigator-button[name=${current_question}]`)
    if (current_question in question_status) {
        switch (question_status[current_question]) {
            case -1:
                button.removeClass().addClass("q-navigator-button btn btn-danger progress-bar-striped");
                button.prop("title", `Question ${current_question + 1}: Incomplete`);
                break;
            case 1:
                button.removeClass().addClass("q-navigator-button btn btn-warning");
                button.prop("title", `Question ${current_question + 1}: Flagged`);
                break;
            case 2:
                button.removeClass().addClass("q-navigator-button btn btn-success");
                button.prop("title", `Question ${current_question + 1}: Answered`);
                break;
            default:
                button.removeClass().addClass("q-navigator-button btn btn-secondary disabled");
                button.prop("title", `Question ${current_question + 1}: Unseen`);
        }
    }
}

function start() {
    $("#btn-start-quiz").fadeOut();
    $(".btn-quiz-return").fadeIn();
    $(".quiz-console").fadeIn();
    $("#quiz-settings").fadeOut();
    $("#quiz-navigator").fadeOut();
    $(".quiz-start-text").fadeOut();

    questions = JSON.parse(window.localStorage.getItem('questions'));
    total_questions = questions.length;
    start_time = window.localStorage.getItem('start_time');
    time_limit = window.localStorage.getItem('time_limit');

    let get_answers = window.localStorage.getItem('answers');
    if (get_answers != null) {
        answers = JSON.parse(get_answers);
    }

    let get_status = window.localStorage.getItem('question_status');
    if (get_status != null) {
        question_status = JSON.parse(get_status);
    }

    render_question();
    build_navigator();
    check_flag();
    if (time_limit != 'null' && time_limit != null) {
        $("#q-timer-widget").fadeIn();
        time_remaining = get_time_remaining();
        clock = setInterval(timer, 1000);
    }
}

function check_started() {
    let questions = window.localStorage.getItem('questions');
    let time_limit = window.localStorage.getItem('time_limit');
    let start_time = window.localStorage.getItem('start_time')
    if (questions != null && start_time != null && time_limit != null) {
        start();
    }
}

function get_time_remaining() {
    var end_time = new Date(time_limit).getTime();
    var _start_time = new Date().getTime();
    return end_time - _start_time;
}

function timer() {
    var hours = Math.floor((time_remaining % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60));
    var minutes = Math.floor((time_remaining % (1000 * 60 * 60)) / (1000 * 60));
    var seconds = Math.floor((time_remaining % (1000 * 60)) / 1000);

    if (time_remaining > 0) {
        var timer_display = '';
        if (hours > 0) {
            timer_display = `${hours.toString()}:`;
        }
        if (minutes > 0 || hours > 0) {
            if (minutes < 10) {
                timer_display += `0${minutes.toString()}:`;
            } else {
                timer_display += `${minutes.toString()}:`;
            }
        }
        if (seconds < 10) {
            timer_display += `0${seconds.toString()}`;
        } else {
            timer_display += seconds.toString();
        }
        $timer.html(timer_display);
        time_remaining -= 1000
    } else {
        $timer.html('Expired');
        clearInterval(clock);
        stop()
    }
}

function stop() {
    $quiz_render.fadeOut();
    $quiz_navigator.fadeOut();
    $quiz_timeout.fadeIn();
    $("#btn-toggle-navigator").addClass('disabled');
    $("#btn-toggle-settings").addClass('disabled')
}

function count_questions(status) {
    output = 0;
    for (let i = 0; i < Object.keys(question_status).length; i++) {
        key = Object.keys(question_status)[i];
        if (question_status[key] == status){
            output ++;
        }
    }
    return output;
}

// Variable Definitions

const id = window.localStorage.getItem('id');

var current_question = 0;
var total_questions = 0;
var question_status = {};
var answers = {};
var questions = [];
var time_limit, start_time, time_remaining;

var display_settings = get_settings_from_storage();

const $quiz_settings = $("#quiz-settings");
const $quiz_navigator = $("#quiz-navigator");
const $quiz_render = $("#quiz-render");
const $quiz_timeout = $("#quiz-timeout");
const $nav_flag = $("#q-nav-flag");
const $nav_next = $("#q-nav-next");
const $nav_prev = $("#q-nav-prev");
const $nav_container = $("#navigator-container");
const $timer = $("#q-timer-display");
var clock

var toggle_settings = false;
var toggle_navigator = false;

const $question_title = $("#quiz-question-title");
const $question_header = $("#quiz-question-header");
const $question_text = $("#quiz-question-text");
const $question_options = $("#quiz-question-options");

const $progress_skipped = $("#skipped-bar");
const $progress_answered = $("#answered-bar");
const $progress_flagged = $("#flagged-bar");
const $skipped_count = $("#skipped-count");
const $answered_count = $("#answered-count");
const $flagged_count = $("#flagged-count");

// Execution on Load

apply_settings(display_settings);
check_started();