$(document).ready(function() {
    var currentPosition = 0;
    var slides = $('.slide');
    var slideWidth = 680;
    var numberOfSlides = slides.length;

    // Remove scrollbar in JS
    $('#sliderContainer').css({ 'overflow': 'hidden', 'height': slides.eq(0).height() });

    // Wrap all .slides with #slideInner div
    slides
    .wrapAll('<div id="slideInner"></div>')
    // Float left to display horizontally, readjust .slides width
    .css({
        'float': 'left',
        'width': slideWidth
    });

    // Set #slideInner width equal to total width of all slides
    $('#slideInner').css('width', slideWidth * numberOfSlides);

    // Insert left and right arrow controls in the DOM
    $('#slider')
    .prepend('<span class="control" id="leftControl">Move left</span>')
    .append('<span class="control" id="rightControl">Move right</span>');

    // Hide left arrow control on first load
    manageControls(currentPosition);

    // Create event listeners for .controls clicks
    $('.control')
    .bind('click', function() {
        // Determine new position
        currentPosition = ($(this).attr('id') == 'rightControl')
    ? currentPosition + 1 : currentPosition - 1;

        // Hide / show controls
        manageControls(currentPosition);
        // Move slideInner using margin-left
        $('#slideInner').animate({
            'marginLeft': slideWidth * (-currentPosition)
        });
    });

    $('.control').css({ opacity: 0.5, 'z-index'
    : '1' });
    
    $('.control')
    .hover(
        function() {
            $(this).css({ opacity : 1, 'z-index': '99' });
        },
        function() {
            $(this).css({ opacity: 0.5, 'z-index': '1' });
        }
    );

    // manageControls: Hides and shows controls depending on currentPosition
    function manageControls(position) {
        // Hide left arrow if position is first slide
        if (position == 0) { $('#leftControl').hide() }
        else { $('#leftControl').show() }
        // Hide right arrow if position is last slide
        if (position == numberOfSlides - 1) { $('#rightControl').hide() }
        else { $('#rightControl').show() }
    }
});