(function (root, factory) {
    'use strict';

    var $ = root.jQuery;

    if (typeof define === 'function' && define.amd) {
        // AMD
        if ($) {
            define([], factory.bind(null, $));
        } else {
            define(['jquery'], factory);
        }
    } else if (typeof exports === 'object') {
        // Node, CommonJS-like
        if ($) {
            module.exports = factory($);
        } else {
            module.exports = factory(require('jquery'));
        }
    } else {
        // Browser globals (root is window)
        if ($) {
            factory($); // no global needed as we store it as a jQuery plugin on jQuery.fn
        } else {
            throw 'Missing required jQuery dependency';
        }
    }
}(this, function ($) {
    var isDragging = false;
    var $currentHandle = null;

    function drawCircle($container, degreeStart, degreeEnd) {
        var
            $canvas = $container.find('canvas'),
            canvas = $canvas[0];

        var outerWidth = $container.outerWidth();
        var innerWidth = $container.innerWidth();
        var borderWidth = outerWidth - innerWidth;
        $canvas.css('left', borderWidth * -1);
        $canvas.css('top', borderWidth * -1);


        var radius = (outerWidth - borderWidth / 2) / 2;
        canvas.width = outerWidth + borderWidth;
        canvas.height = canvas.width;
        var context = canvas.getContext('2d');
        context.clearRect(0, 0, canvas.width, canvas.height);
        context.beginPath();



        context.arc(canvas.width / 2, canvas.width / 2, radius, degreesToRadians(degreeStart) - Math.PI / 2, degreesToRadians(degreeEnd) - Math.PI / 2, false);
        context.lineWidth = borderWidth / 2;
        context.strokeStyle = $canvas.css('color');
        context.stroke();
    }

    function degreesToRadians(degrees) {
        return degrees * (Math.PI / 180);
    }

    function updateWidget($container) {
        var $input = $container.find('input');
        var isSingleValue = _isSingleValue($input);
        var $handles = $container.find('.handle');
        var $handle1 = $container.find('.handle1');
        if (!isSingleValue) {
            var $handle2 = $container.find('.handle2');
        }

        var outerWidth = $container.outerWidth();
        var innerWidth = $container.innerWidth();
        var borderWidth = (outerWidth - innerWidth) / 2;

        var radius = (outerWidth - borderWidth) / 2;


        var minValue = parseFloat($input.attr('data-min')) || 0;
        var maxValue = parseFloat($input.attr('data-max')) || 360;
        var unit = $input.attr('data-unit') === undefined ? '°' : $input.attr('data-unit');
        var steps = maxValue - minValue;
        var stepSizeInDegrees = 360 / steps;

        $handles.each(function (idx, handle) {
            var $handle = $(handle);
            var value = parseFloat($handle.attr('data-value'));
            var deg = (value - minValue) * stepSizeInDegrees;

            var X = Math.round(radius + radius * Math.sin(deg * Math.PI / 180));
            var Y = Math.round(radius + radius * -Math.cos(deg * Math.PI / 180));
            $handle.css({
                left: X,
                top: Y
            });
            $container.find($handle.attr('data-value-target')).html($handle.attr('data-value') + unit);
        });

        var extraChangeEventParameters = [{
            source: 'lcnCircleRangeSelect'
        }];

        var value1 = $handle1.attr('data-value');
        if (isSingleValue) {
            $input.val(value1).trigger('change', extraChangeEventParameters);
        } else {
            var value2 = $handle2.attr('data-value');
            drawCircle($container, (value1 - minValue) * stepSizeInDegrees, (value2 - minValue) * stepSizeInDegrees);
            $input.val(value1 + ';' + value2).trigger('change', extraChangeEventParameters);
        }
    }

    function init($input) {
        var isSingleValue = _isSingleValue($input);
        if (isSingleValue) {
            var value1 = parseFloat($input.val() || 0);
        } else {
            var values = $input.val() || '0;0';
            values = values.split(';');
            var value1 = parseFloat(values[0]);
            var value2 = parseFloat(values[1]);
        }


        var $container = $('<div class="circle-range-select-wrapper"></div>');

        var backgroundImage = $input.attr('data-bg-image');
        if (backgroundImage) {
            $container.css({
                'background-image': 'url("' + backgroundImage + '")',
                'background-size': 'contain'
            });
        }

        $input.wrap($container);
        $container = $input.parent();

        $container.append('<div class="handle handle1" data-value="' + value1 + '" data-value-target=".value1"></div>');
        if (isSingleValue) {
            $container.append('<div class="values"><span class="value1"></span></div>');
        } else {
            $container.append('<div class="handle handle2" data-value="' + value2 + '" data-value-target=".value2"></div>');
            $container.append('<div class="values"><span class="value1"></span> - <span class="value2"></span></div>');
            $container.append('<canvas class="selected-range"></canvas>');
        }


        updateWidget($container);

        $container.on('mousedown touchstart', '.handle', function (e) {
            isDragging = true;
            e.preventDefault();
            $currentHandle = $(e.target);
            $(document).one('mouseup touchend', function () {
                isDragging = false;
                $currentHandle = null;
            });
        });

        $input.on('change', function (e, options) {
            if (options && typeof options === 'object' && options.source === 'lcnCircleRangeSelect') {
                return;
            }

            var $input = $container.find('input');
            var isSingleValue = _isSingleValue($input);
            var $handle1 = $container.find('.handle1');

            if (isSingleValue) {
                $handle1.attr('data-value', parseFloat($input.val() || 0));
            } else {
                var $handle2 = $container.find('.handle2');
                var values = $input.val() || '0;0';
                values = values.split(';');
                $handle1.attr('data-value', parseFloat(values[0]));
                $handle2.attr('data-value', parseFloat(values[1]));
            }

            updateWidget($container);
        });

        $(window).on('resize', updateWidget.bind(null, $container));
    }


    function _isSingleValue($input) {
        return $input.attr('data-single-value') !== undefined && $input.attr('data-single-value') !== 'false';
    }

    $(document).on('mousemove touchmove', function (e) {
        if (isDragging) {

            var $draggingTarget = $(e.target);

            $draggingWrapper = $draggingTarget.closest('.circle-range-select-wrapper');
            if ($draggingWrapper.length === 0) {
                return;
            }

            if ($currentHandle.hasClass('handle1')) {
                $draggingHandle = $draggingWrapper.find('.handle1');
            } else if ($currentHandle.hasClass('handle2')) {
                $draggingHandle = $draggingWrapper.find('.handle2');
            }

            if ($draggingHandle[0] !== $currentHandle[0]) {
                return;
            }


            var $container = $currentHandle.closest('.circle-range-select-wrapper');
            var radius = $container.width() / 2;

            if (!e.offsetX && e.originalEvent.touches) {
                // touch events
                var targetOffset = $draggingTarget.offset();
                e.offsetX = e.originalEvent.touches[0].pageX - targetOffset.left;
                e.offsetY = e.originalEvent.touches[0].pageY - targetOffset.top;
            } else if (typeof e.offsetX === "undefined" || typeof e.offsetY === "undefined") {
                // firefox compatibility
                var targetOffset = $draggingTarget.offset();
                e.offsetX = e.pageX - targetOffset.left;
                e.offsetY = e.pageY - targetOffset.top;
            }

            if ($draggingTarget.hasClass('handle')) {
                var mPos = {
                    x: e.target.offsetLeft + e.offsetX,
                    y: e.target.offsetTop + e.offsetY
                };
            } else {
                var mPos = {
                    x: e.offsetX,
                    y: e.offsetY
                };
            }

            var atan = Math.atan2(mPos.x - radius, mPos.y - radius);
            var deg = -atan / (Math.PI / 180) + 180; // final (0-360 positive) degrees from mouse position

            var $input = $container.find('input');
            var minValue = parseFloat($input.attr('data-min')) || 0;
            var maxValue = parseFloat($input.attr('data-max')) || 360;
            var steps = maxValue - minValue;
            var stepSize = 360 / steps;

            var value = minValue + Math.round(deg / stepSize);
            //if (value == maxValue) {
            //  value = minValue;
            //}


            $currentHandle.attr('data-value', value);

            updateWidget($container);
        }
    });


    $.fn.lcnCircleRangeSelect = function () {
        return this.each(function () {
            init($(this));
        });

    };

    $(function () {
        $('input.circle-range-select[data-auto-init]').lcnCircleRangeSelect();
    });

    return $.fn.lcnCircleRangeSelect;

}));