// 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) {
            $("#btn-start-quiz").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()