(function ($, window, document, undefined) {

    var move,
        ms = $.mobiscroll,
        classes = ms.classes,
        util = ms.util,
        pr = util.jsPrefix,
        has3d = util.has3d,
        hasFlex = util.hasFlex,
        getCoord = util.getCoord,
        constrain = util.constrain,
        testTouch = util.testTouch;

    ms.presetShort('scroller', 'Scroller', false);

    classes.Scroller = function (el, settings, inherit) {
        var $markup,
            btn,
            isScrollable,
            itemHeight,
            multiple,
            s,
            scrollDebounce,
            trigger,

            click,
            moved,
            start,
            startTime,
            stop,
            p,
            min,
            max,
            target,
            index,
            lines,
            timer,
            that = this,
            $elm = $(el),
            iv = {},
            pos = {},
            pixels = {},
            wheels = [];

        // Event handlers

        function onStart(ev) {
            // Scroll start
            if (testTouch(ev, this) && !move && !click && !btn && !isReadOnly(this)) {
                // Prevent touch highlight
                ev.preventDefault();
                // Better performance if there are tap events on document
                ev.stopPropagation();

                move = true;
                isScrollable = s.mode != 'clickpick';
                target = $('.dw-ul', this);
                setGlobals(target);
                moved = iv[index] !== undefined; // Don't allow tap, if still moving
                p = moved ? getCurrentPosition(target) : pos[index];
                start = getCoord(ev, 'Y');
                startTime = new Date();
                stop = start;
                scroll(target, index, p, 0.001);

                if (isScrollable) {
                    target.closest('.dwwl').addClass('dwa');
                }

                if (ev.type === 'mousedown') {
                    $(document).on('mousemove', onMove).on('mouseup', onEnd);
                }
            }
        }

        function onMove(ev) {
            if (move) {
                if (isScrollable) {
                    // Prevent scroll
                    ev.preventDefault();
                    ev.stopPropagation();
                    stop = getCoord(ev, 'Y');
                    if (Math.abs(stop - start) > 3 || moved) {
                        scroll(target, index, constrain(p + (start - stop) / itemHeight, min - 1, max + 1));
                        moved = true;
                    }
                }
            }
        }

        function onEnd(ev) {
            if (move) {
                var time = new Date() - startTime,
                    curr = constrain(Math.round(p + (start - stop) / itemHeight), min - 1, max + 1),
                    val = curr,
                    speed,
                    dist,
                    ttop = target.offset().top;

                // Better performance if there are tap events on document
                ev.stopPropagation();

                move = false;

                if (ev.type === 'mouseup') {
                    $(document).off('mousemove', onMove).off('mouseup', onEnd);
                }

                if (has3d && time < 300) {
                    speed = (stop - start) / time;
                    dist = (speed * speed) / s.speedUnit;
                    if (stop - start < 0) {
                        dist = -dist;
                    }
                } else {
                    dist = stop - start;
                }

                if (!moved) { // this is a "tap"
                    var idx = Math.floor((stop - ttop) / itemHeight),
                        li = $($('.dw-li', target)[idx]),
                        valid = li.hasClass('dw-v'),
                        hl = isScrollable;

                    time = 0.1;

                    if (trigger('onValueTap', [li]) !== false && valid) {
                        val = idx;
                    } else {
                        hl = true;
                    }

                    if (hl && valid) {
                        li.addClass('dw-hl'); // Highlight
                        setTimeout(function () {
                            li.removeClass('dw-hl');
                        }, 100);
                    }

                    if (!multiple && (s.confirmOnTap === true || s.confirmOnTap[index]) && li.hasClass('dw-sel')) {
                        that.select();
                        return;
                    }
                } else {
                    val = constrain(Math.round(p - dist / itemHeight), min, max);
                    time = speed ? Math.max(0.1, Math.abs((val - curr) / speed) * s.timeUnit) : 0.1;
                }

                if (isScrollable) {
                    calc(target, index, val, 0, time, true);
                }
            }
        }

        function onBtnStart(ev) {
            btn = $(this);
            // +/- buttons
            if (testTouch(ev, this)) {
                step(ev, btn.closest('.dwwl'), btn.hasClass('dwwbp') ? plus : minus);
            }
            if (ev.type === 'mousedown') {
                $(document).on('mouseup', onBtnEnd);
            }
        }

        function onBtnEnd(ev) {
            btn = null;
            if (click) {
                clearInterval(timer);
                click = false;
            }
            if (ev.type === 'mouseup') {
                $(document).off('mouseup', onBtnEnd);
            }
        }

        function onKeyDown(ev) {
            if (ev.keyCode == 38) { // up
                step(ev, $(this), minus);
            } else if (ev.keyCode == 40) { // down
                step(ev, $(this), plus);
            }
        }

        function onKeyUp() {
            if (click) {
                clearInterval(timer);
                click = false;
            }
        }

        function onScroll(ev) {
            if (!isReadOnly(this)) {
                ev.preventDefault();
                ev = ev.originalEvent || ev;

                var delta = ev.deltaY || ev.wheelDelta || ev.detail,
                    t = $('.dw-ul', this);

                setGlobals(t);

                scroll(t, index, constrain(((delta < 0 ? -20 : 20) - pixels[index]) / itemHeight, min - 1, max + 1));

                clearTimeout(scrollDebounce);
                scrollDebounce = setTimeout(function () {
                    calc(t, index, Math.round(pos[index]), delta > 0 ? 1 : 2, 0.1);
                }, 200);
            }
        }

        // Private functions

        function step(ev, w, func) {
            ev.stopPropagation();
            ev.preventDefault();
            if (!click && !isReadOnly(w) && !w.hasClass('dwa')) {
                click = true;
                // + Button
                var t = w.find('.dw-ul');

                setGlobals(t);
                clearInterval(timer);
                timer = setInterval(function () { func(t); }, s.delay);
                func(t);
            }
        }

        function isReadOnly(wh) {
            if ($.isArray(s.readonly)) {
                var i = $('.dwwl', $markup).index(wh);
                return s.readonly[i];
            }
            return s.readonly;
        }

        function generateWheelItems(i) {
            var html = '<div class="dw-bf">',
                w = wheels[i],
                l = 1,
                labels = w.labels || [],
                values = w.values || [],
                keys = w.keys || values;

            $.each(values, function (j, v) {
                if (l % 20 === 0) {
                    html += '</div><div class="dw-bf">';
                }
                html += '<div role="option" aria-selected="false" class="dw-li dw-v" data-val="' + keys[j] + '"' + (labels[j] ? ' aria-label="' + labels[j] + '"' : '') + ' style="height:' + itemHeight + 'px;line-height:' + itemHeight + 'px;">' +
                    '<div class="dw-i"' + (lines > 1 ? ' style="line-height:' + Math.round(itemHeight / lines) + 'px;font-size:' + Math.round(itemHeight / lines * 0.8) + 'px;"' : '') + '>' + v + '</div></div>';
                l++;
            });

            html += '</div>';
            return html;
        }

        function setGlobals(t) {
            multiple = t.closest('.dwwl').hasClass('dwwms');
            min = $('.dw-li', t).index($(multiple ? '.dw-li' : '.dw-v', t).eq(0));
            max = Math.max(min, $('.dw-li', t).index($(multiple ? '.dw-li' : '.dw-v', t).eq(-1)) - (multiple ? s.rows - (s.mode == 'scroller' ? 1 : 3) : 0));
            index = $('.dw-ul', $markup).index(t);
        }

        function formatHeader(v) {
            var t = s.headerText;
            return t ? (typeof t === 'function' ? t.call(el, v) : t.replace(/\{value\}/i, v)) : '';
        }

        function getCurrentPosition(t) {
            return Math.round(-util.getPosition(t, true) / itemHeight);
        }

        function ready(t, i) {
            clearTimeout(iv[i]);
            delete iv[i];
            t.closest('.dwwl').removeClass('dwa');
        }

        function scroll(t, index, val, time, active) {
            var px = -val * itemHeight,
                style = t[0].style;

            if (px == pixels[index] && iv[index]) {
                return;
            }

            //if (time && px != pixels[index]) {
            // Trigger animation start event
            //trigger('onAnimStart', [$markup, index, time]);
            //}

            pixels[index] = px;

            if (has3d) {
                style[pr + 'Transition'] = util.prefix + 'transform ' + (time ? time.toFixed(3) : 0) + 's ease-out';
                style[pr + 'Transform'] = 'translate3d(0,' + px + 'px,0)';
            } else {
                style.top = px + 'px';
            }

            if (iv[index]) {
                ready(t, index);
            }

            if (time && active) {
                t.closest('.dwwl').addClass('dwa');
                iv[index] = setTimeout(function () {
                    ready(t, index);
                }, time * 1000);
            }

            pos[index] = val;
        }

        function getValid(val, t, dir, multiple, select) {
            var selected,
                cell = $('.dw-li[data-val="' + val + '"]', t),
                cells = $('.dw-li', t),
                v = cells.index(cell),
                l = cells.length;

            if (multiple) {
                setGlobals(t);
            } else if (!cell.hasClass('dw-v')) { // Scroll to a valid cell
                var cell1 = cell,
                    cell2 = cell,
                    dist1 = 0,
                    dist2 = 0;

                while (v - dist1 >= 0 && !cell1.hasClass('dw-v')) {
                    dist1++;
                    cell1 = cells.eq(v - dist1);
                }

                while (v + dist2 < l && !cell2.hasClass('dw-v')) {
                    dist2++;
                    cell2 = cells.eq(v + dist2);
                }

                // If we have direction (+/- or mouse wheel), the distance does not count
                if (((dist2 < dist1 && dist2 && dir !== 2) || !dist1 || (v - dist1 < 0) || dir == 1) && cell2.hasClass('dw-v')) {
                    cell = cell2;
                    v = v + dist2;
                } else {
                    cell = cell1;
                    v = v - dist1;
                }
            }

            selected = cell.hasClass('dw-sel');

            if (select) {
                if (!multiple) {
                    $('.dw-sel', t).removeAttr('aria-selected');
                    cell.attr('aria-selected', 'true');
                }

                // Add selected class to cell
                $('.dw-sel', t).removeClass('dw-sel');
                cell.addClass('dw-sel');
            }

            return {
                selected: selected,
                v: multiple ? constrain(v, min, max) : v,
                val: cell.hasClass('dw-v') ? cell.attr('data-val') : null
            };
        }

        function scrollToPos(time, index, manual, dir, active) {
            // Call validation event
            if (trigger('validate', [$markup, index, time, dir]) !== false) {
                // Set scrollers to position
                $('.dw-ul', $markup).each(function (i) {
                    var t = $(this),
                        multiple = t.closest('.dwwl').hasClass('dwwms'),
                        sc = i == index || index === undefined,
                        res = getValid(that._tempWheelArray[i], t, dir, multiple, true),
                        selected = res.selected;

                    if (!selected || sc) {
                        // Set valid value
                        that._tempWheelArray[i] = res.val;

                        // Scroll to position
                        scroll(t, i, res.v, sc ? time : 0.1, sc ? active : false);
                    }
                });

                trigger('onValidated', []);

                // Reformat value if validation changed something
                that._tempValue = s.formatValue(that._tempWheelArray, that);

                if (that.live) {
                    that._hasValue = manual || that._hasValue;
                    setValue(manual, manual, 0, true);
                }

                that._header.html(formatHeader(that._tempValue));

                if (manual) {
                    trigger('onChange', [that._tempValue]);
                }
            }

        }

        function calc(t, idx, val, dir, time, active) {
            val = constrain(val, min, max);

            // Set selected scroller value
            that._tempWheelArray[idx] = $('.dw-li', t).eq(val).attr('data-val');

            scroll(t, idx, val, time, active);

            setTimeout(function () {
                // Validate
                scrollToPos(time, idx, true, dir, active);
            }, 10);
        }

        function plus(t) {
            var val = pos[index] + 1;
            calc(t, index, val > max ? min : val, 1, 0.1);
        }

        function minus(t) {
            var val = pos[index] - 1;
            calc(t, index, val < min ? max : val, 2, 0.1);
        }

        function setValue(fill, change, time, noscroll, temp) {
            if (that._isVisible && !noscroll) {
                scrollToPos(time);
            }

            that._tempValue = s.formatValue(that._tempWheelArray, that);

            if (!temp) {
                that._wheelArray = that._tempWheelArray.slice(0);
                that._value = that._hasValue ? that._tempValue : null;
            }

            if (fill) {

                trigger('onValueFill', [that._hasValue ? that._tempValue : '', change]);

                if (that._isInput) {
                    $elm.val(that._hasValue ? that._tempValue : '');
                }

                if (change) {
                    that._preventChange = true;
                    $elm.change();
                }
            }
        }

        // Call the parent constructor
        classes.Frame.call(this, el, settings, true);

        // Public functions

        /**
        * Gets the selected wheel values, formats it, and set the value of the scroller instance.
        * If input parameter is true, populates the associated input element.
        * @param {Array} values Wheel values.
        * @param {Boolean} [fill=false] Also set the value of the associated input element.
        * @param {Number} [time=0] Animation time
        * @param {Boolean} [temp=false] If true, then only set the temporary value.(only scroll there but not set the value)
        * @param {Boolean} [change=false] Trigger change on the input element
        */
        that.setVal = that._setVal = function (val, fill, change, temp, time) {
            that._hasValue = val !== null && val !== undefined;
            that._tempWheelArray = $.isArray(val) ? val.slice(0) : s.parseValue.call(el, val, that) || [];
            setValue(fill, change === undefined ? fill : change, time, false, temp);
        };

        /**
         * Returns the selected value
         */
        that.getVal = that._getVal = function (temp) {
            var val = that._hasValue || temp ? that[temp ? '_tempValue' : '_value'] : null;
            return util.isNumeric(val) ? +val : val;
        };

        /*
         * Sets the wheel values (passed as an array)
         */
        that.setArrayVal = that.setVal;

        /*
         * Returns the selected wheel values as an array
         */
        that.getArrayVal = function (temp) {
            return temp ? that._tempWheelArray : that._wheelArray;
        };

        // @deprecated since 2.14.0, backward compatibility code
        // ---

        that.setValue = function (val, fill, time, temp, change) {
            that.setVal(val, fill, change, temp, time);
        };

        /**
        * Return the selected wheel values.
        */
        that.getValue = that.getArrayVal;

        // ---

        /**
        * Changes the values of a wheel, and scrolls to the correct position
        * @param {Array} idx Indexes of the wheels to change.
        * @param {Number} [time=0] Animation time when scrolling to the selected value on the new wheel.
        * @param {Boolean} [manual=false] Indicates that the change was triggered by the user or from code.
        */
        that.changeWheel = function (idx, time, manual) {
            if ($markup) {
                var i = 0,
                    nr = idx.length;

                $.each(s.wheels, function (j, wg) {
                    $.each(wg, function (k, w) {
                        if ($.inArray(i, idx) > -1) {
                            wheels[i] = w;
                            $('.dw-ul', $markup).eq(i).html(generateWheelItems(i));
                            nr--;
                            if (!nr) {
                                that.position();
                                scrollToPos(time, undefined, manual);
                                return false;
                            }
                        }
                        i++;
                    });
                    if (!nr) {
                        return false;
                    }
                });
            }
        };

        /**
        * Returns the closest valid cell.
        */
        that.getValidCell = getValid;

        that.scroll = scroll;

        // Protected overrides

        that._generateContent = function () {
            var lbl,
                html = '',
                l = 0;

            $.each(s.wheels, function (i, wg) { // Wheel groups
                html += '<div class="mbsc-w-p dwc' + (s.mode != 'scroller' ? ' dwpm' : ' dwsc') + (s.showLabel ? '' : ' dwhl') + '">' +
                            '<div class="dwwc"' + (s.maxWidth ? '' : ' style="max-width:600px;"') + '>' +
                                (hasFlex ? '' : '<table class="dw-tbl" cellpadding="0" cellspacing="0"><tr>');

                $.each(wg, function (j, w) { // Wheels
                    wheels[l] = w;
                    lbl = w.label !== undefined ? w.label : j;
                    html += '<' + (hasFlex ? 'div' : 'td') + ' class="dwfl"' + ' style="' +
                                    (s.fixedWidth ? ('width:' + (s.fixedWidth[l] || s.fixedWidth) + 'px;') :
                                    (s.minWidth ? ('min-width:' + (s.minWidth[l] || s.minWidth) + 'px;') : 'min-width:' + s.width + 'px;') +
                                    (s.maxWidth ? ('max-width:' + (s.maxWidth[l] || s.maxWidth) + 'px;') : '')) + '">' +
                                '<div class="dwwl dwwl' + l + (w.multiple ? ' dwwms' : '') + '">' +
                                (s.mode != 'scroller' ?
                                    '<div class="dwb-e dwwb dwwbp ' + (s.btnPlusClass || '') + '" style="height:' + itemHeight + 'px;line-height:' + itemHeight + 'px;"><span>+</span></div>' + // + button
                                    '<div class="dwb-e dwwb dwwbm ' + (s.btnMinusClass || '') + '" style="height:' + itemHeight + 'px;line-height:' + itemHeight + 'px;"><span>&ndash;</span></div>' : '') + // - button
                                '<div class="dwl">' + lbl + '</div>' + // Wheel label
                                '<div tabindex="0" aria-live="off" aria-label="' + lbl + '" role="listbox" class="dwww">' +
                                    '<div class="dww" style="height:' + (s.rows * itemHeight) + 'px;">' +
                                        '<div class="dw-ul" style="margin-top:' + (w.multiple ? (s.mode == 'scroller' ? 0 : itemHeight) : s.rows / 2 * itemHeight - itemHeight / 2) + 'px;">';

                    // Create wheel values
                    html += generateWheelItems(l) +
                        '</div></div><div class="dwwo"></div></div><div class="dwwol"' +
                        (s.selectedLineHeight ? ' style="height:' + itemHeight + 'px;margin-top:-' + (itemHeight / 2 + (s.selectedLineBorder || 0)) + 'px;"' : '') + '></div></div>' +
                        (hasFlex ? '</div>' : '</td>');

                    l++;
                });

                html += (hasFlex ? '' : '</tr></table>') + '</div></div>';
            });

            return html;
        };

        that._attachEvents = function ($markup) {
            $markup
                .on('keydown', '.dwwl', onKeyDown)
                .on('keyup', '.dwwl', onKeyUp)
                .on('touchstart mousedown', '.dwwl', onStart)
                .on('touchmove', '.dwwl', onMove)
                .on('touchend', '.dwwl', onEnd)
                .on('touchstart mousedown', '.dwwb', onBtnStart)
                .on('touchend', '.dwwb', onBtnEnd);

            if (s.mousewheel) {
                $markup.on('wheel mousewheel', '.dwwl', onScroll);
            }
        };

        that._markupReady = function ($m) {
            $markup = $m;
            scrollToPos();
        };

        that._fillValue = function () {
            that._hasValue = true;
            setValue(true, true, 0, true);
        };

        that._readValue = function () {
            var v = $elm.val() || '';

            if (v !== '') {
                that._hasValue = true;
            }

            that._tempWheelArray = that._hasValue && that._wheelArray ? that._wheelArray.slice(0) : s.parseValue.call(el, v, that) || [];
            setValue();
        };

        that._processSettings = function () {
            s = that.settings;
            trigger = that.trigger;
            itemHeight = s.height;
            lines = s.multiline;

            that._isLiquid = (s.layout || (/top|bottom/.test(s.display) && s.wheels.length == 1 ? 'liquid' : '')) === 'liquid';

            // @deprecated since 2.15.0, backward compatibility code
            // ---
            if (s.formatResult) {
                s.formatValue = s.formatResult;
            }
            // ---

            if (lines > 1) {
                s.cssClass = (s.cssClass || '') + ' dw-ml';
            }

            // Ensure a minimum number of 3 items if clickpick buttons present
            if (s.mode != 'scroller') {
                s.rows = Math.max(3, s.rows);
            }
        };

        // Properties

        that._selectedValues = {};

        // Constructor
        if (!inherit) {
            that.init(settings);
        }
    };

    // Extend defaults
    classes.Scroller.prototype = {
        _hasDef: true,
        _hasTheme: true,
        _hasLang: true,
        _hasPreset: true,
        _class: 'scroller',
        _defaults: $.extend({}, classes.Frame.prototype._defaults, {
            // Options
            minWidth: 80,
            height: 40,
            rows: 3,
            multiline: 1,
            delay: 300,
            readonly: false,
            showLabel: true,
            confirmOnTap: true,
            wheels: [],
            mode: 'scroller',
            preset: '',
            speedUnit: 0.0012,
            timeUnit: 0.08,
            formatValue: function (d) {
                return d.join(' ');
            },
            parseValue: function (value, inst) {
                var val = [],
                    ret = [],
                    i = 0,
                    found,
                    keys;

                if (value !== null && value !== undefined) {
                    val = (value + '').split(' ');
                }

                $.each(inst.settings.wheels, function (j, wg) {
                    $.each(wg, function (k, w) {
                        keys = w.keys || w.values;
                        found = keys[0]; // Default to first wheel value if not found
                        $.each(keys, function (l, key) {
                            if (val[i] == key) { // Don't do strict comparison
                                found = key;
                                return false;
                            }
                        });
                        ret.push(found);
                        i++;
                    });
                });
                return ret;
            }
        })
    };

    ms.themes.scroller = ms.themes.frame;

})(jQuery, window, document);