// Copyright (c) 2005-2009 Marty Haught, Thomas Fuchs

//

// script.aculo.us is freely distributable under the terms of an MIT-style license.

// For details, see the script.aculo.us web site: http://script.aculo.us/



if (!Control) var Control = { };



// options:

//  axis: 'vertical', or 'horizontal' (default)

//

// callbacks:

//  onChange(value)

//  onSlide(value)

Control.Slider = Class.create({

  initialize: function(handle, track, options) {

    var slider = this;



    if (Object.isArray(handle)) {

      this.handles = handle.collect( function(e) { return $(e) });

    } else {

      this.handles = [$(handle)];

    }



    this.track   = $(track);

    this.options = options || { };



    this.axis      = this.options.axis || 'horizontal';

    this.increment = this.options.increment || 1;

    this.step      = parseInt(this.options.step || '1');

    this.range     = this.options.range || $R(0,1);



    this.value     = 0; // assure backwards compat

    this.values    = this.handles.map( function() { return 0 });

    this.spans     = this.options.spans ? this.options.spans.map(function(s){ return $(s) }) : false;

    this.options.startSpan = $(this.options.startSpan || null);

    this.options.endSpan   = $(this.options.endSpan || null);



    this.restricted = this.options.restricted || false;



    this.maximum   = this.options.maximum || this.range.end;

    this.minimum   = this.options.minimum || this.range.start;



    // Will be used to align the handle onto the track, if necessary

    this.alignX = parseInt(this.options.alignX || '0');

    this.alignY = parseInt(this.options.alignY || '0');



    this.trackLength = this.maximumOffset() - this.minimumOffset();



    this.handleLength = this.isVertical() ?

      (this.handles[0].offsetHeight != 0 ?

        this.handles[0].offsetHeight : this.handles[0].style.height.replace(/px$/,"")) :

      (this.handles[0].offsetWidth != 0 ? this.handles[0].offsetWidth :

        this.handles[0].style.width.replace(/px$/,""));



    this.active   = false;

    this.dragging = false;

    this.disabled = false;



    if (this.options.disabled) this.setDisabled();



    // Allowed values array

    this.allowedValues = this.options.values ? this.options.values.sortBy(Prototype.K) : false;

    if (this.allowedValues) {

      this.minimum = this.allowedValues.min();

      this.maximum = this.allowedValues.max();

    }



    this.eventMouseDown = this.startDrag.bindAsEventListener(this);

    this.eventMouseUp   = this.endDrag.bindAsEventListener(this);

    this.eventMouseMove = this.update.bindAsEventListener(this);



    // Initialize handles in reverse (make sure first handle is active)

    this.handles.each( function(h,i) {

      i = slider.handles.length-1-i;

      slider.setValue(parseFloat(

        (Object.isArray(slider.options.sliderValue) ?

          slider.options.sliderValue[i] : slider.options.sliderValue) ||

         slider.range.start), i);

      h.makePositioned().observe("mousedown", slider.eventMouseDown);

      h.observe("touchstart", slider.eventMouseDown);

    });



    this.track.observe("mousedown", this.eventMouseDown);

    this.track.observe("touchstart", this.eventMouseDown);

    document.observe("mouseup", this.eventMouseUp);

    document.observe("touchend", this.eventMouseUp);

    document.observe("mousemove", this.eventMouseMove);

    document.observe("touchmove", this.eventMouseMove);



    this.initialized = true;

  },

  dispose: function() {

    var slider = this;

    Event.stopObserving(this.track, "mousedown", this.eventMouseDown);

    Event.stopObserving(this.track, "touchstart", this.eventMouseDown);

    Event.stopObserving(document, "mouseup", this.eventMouseUp);

    Event.stopObserving(document, "touchend", this.eventMouseUp);

    Event.stopObserving(document, "mousemove", this.eventMouseMove);

    Event.stopObserving(document, "touchmove", this.eventMouseMove);

    this.handles.each( function(h) {

      Event.stopObserving(h, "mousedown", slider.eventMouseDown);

      Event.stopObserving(h, "touchstart", slider.eventMouseDown);

    });

  },

  setDisabled: function(){

    this.disabled = true;

  },

  setEnabled: function(){

    this.disabled = false;

  },

  getNearestValue: function(value){

    if (this.allowedValues){

      if (value >= this.allowedValues.max()) return(this.allowedValues.max());

      if (value <= this.allowedValues.min()) return(this.allowedValues.min());



      var offset = Math.abs(this.allowedValues[0] - value);

      var newValue = this.allowedValues[0];

      this.allowedValues.each( function(v) {

        var currentOffset = Math.abs(v - value);

        if (currentOffset <= offset){

          newValue = v;

          offset = currentOffset;

        }

      });

      return newValue;

    }

    if (value > this.range.end) return this.range.end;

    if (value < this.range.start) return this.range.start;

    return value;

  },

  setValue: function(sliderValue, handleIdx){

    if (!this.active) {

      this.activeHandleIdx = handleIdx || 0;

      this.activeHandle    = this.handles[this.activeHandleIdx];

      this.updateStyles();

    }

    handleIdx = handleIdx || this.activeHandleIdx || 0;

    if (this.initialized && this.restricted) {

      if ((handleIdx>0) && (sliderValue<this.values[handleIdx-1]))

        sliderValue = this.values[handleIdx-1];

      if ((handleIdx < (this.handles.length-1)) && (sliderValue>this.values[handleIdx+1]))

        sliderValue = this.values[handleIdx+1];

    }

    sliderValue = this.getNearestValue(sliderValue);

    this.values[handleIdx] = sliderValue;

    this.value = this.values[0]; // assure backwards compat



    this.handles[handleIdx].style[this.isVertical() ? 'top' : 'left'] =

      this.translateToPx(sliderValue);



    this.drawSpans();

    if (!this.dragging || !this.event) this.updateFinished();

  },

  setValueBy: function(delta, handleIdx) {

    this.setValue(this.values[handleIdx || this.activeHandleIdx || 0] + delta,

      handleIdx || this.activeHandleIdx || 0);

  },

  translateToPx: function(value) {

    return Math.round(

      ((this.trackLength-this.handleLength)/(this.range.end-this.range.start)) *

      (value - this.range.start)) + "px";

  },

  translateToValue: function(offset) {

    return ((offset/(this.trackLength-this.handleLength) *

      (this.range.end-this.range.start)) + this.range.start);

  },

  getRange: function(range) {

    var v = this.values.sortBy(Prototype.K);

    range = range || 0;

    return $R(v[range],v[range+1]);

  },

  minimumOffset: function(){

    return(this.isVertical() ? this.alignY : this.alignX);

  },

  maximumOffset: function(){

    return(this.isVertical() ?

      (this.track.offsetHeight != 0 ? this.track.offsetHeight :

        this.track.style.height.replace(/px$/,"")) - this.alignY :

      (this.track.offsetWidth != 0 ? this.track.offsetWidth :

        this.track.style.width.replace(/px$/,"")) - this.alignX);

  },

  isVertical:  function(){

    return (this.axis == 'vertical');

  },

  drawSpans: function() {

    var slider = this;

    if (this.spans)

      $R(0, this.spans.length-1).each(function(r) { slider.setSpan(slider.spans[r], slider.getRange(r)) });

    if (this.options.startSpan)

      this.setSpan(this.options.startSpan,

        $R(0, this.values.length>1 ? this.getRange(0).min() : this.value ));

    if (this.options.endSpan)

      this.setSpan(this.options.endSpan,

        $R(this.values.length>1 ? this.getRange(this.spans.length-1).max() : this.value, this.maximum));

  },

  setSpan: function(span, range) {

    if (this.isVertical()) {

      span.style.top = this.translateToPx(range.start);

      span.style.height = this.translateToPx(range.end - range.start + this.range.start);

    } else {

      span.style.left = this.translateToPx(range.start);

      span.style.width = this.translateToPx(range.end - range.start + this.range.start);

    }

  },

  updateStyles: function() {

    this.handles.each( function(h){ Element.removeClassName(h, 'selected') });

    Element.addClassName(this.activeHandle, 'selected');

  },

  startDrag: function(event) {

    if (Event.isLeftClick(event) || event.touches) {

      if (!this.disabled){

        this.active = true;



        var handle = Event.element(event);

        var pointer = (event.touches ? [event.touches[0].clientX, event.touches[0].clientY] : [Event.pointerX(event), Event.pointerY(event)]);

        var track = handle;

        if (track==this.track) {

          var offsets  = this.track.cumulativeOffset();

          this.event = event;

          this.setValue(this.translateToValue(

           (this.isVertical() ? pointer[1]-offsets[1] : pointer[0]-offsets[0])-(this.handleLength/2)

          ));

          var offsets  = this.activeHandle.cumulativeOffset();

          this.offsetX = (pointer[0] - offsets[0]);

          this.offsetY = (pointer[1] - offsets[1]);

        } else {

          // find the handle (prevents issues with Safari)

          while((this.handles.indexOf(handle) == -1) && handle.parentNode)

            handle = handle.parentNode;



          if (this.handles.indexOf(handle)!=-1) {

            this.activeHandle    = handle;

            this.activeHandleIdx = this.handles.indexOf(this.activeHandle);

            this.updateStyles();



            var offsets  = this.activeHandle.cumulativeOffset();

            this.offsetX = (pointer[0] - offsets[0]);

            this.offsetY = (pointer[1] - offsets[1]);

          }

        }

      }

      Event.stop(event);

    }

  },

  update: function(event) {

   if (this.active) {

      if (!this.dragging) this.dragging = true;

      this.draw(event);

      if (Prototype.Browser.WebKit && !event.touches) window.scrollBy(0,0);

      Event.stop(event);

   }

  },

  draw: function(event) {

    var pointer = (event.touches ? [event.touches[0].clientX, event.touches[0].clientY] : [Event.pointerX(event), Event.pointerY(event)]);

    var offsets = this.track.cumulativeOffset();

    pointer[0] -= this.offsetX + offsets[0];

    pointer[1] -= this.offsetY + offsets[1];

    this.event = event;

    this.setValue(this.translateToValue( this.isVertical() ? pointer[1] : pointer[0] ));

    if (this.initialized && this.options.onSlide)

      this.options.onSlide(this.values.length>1 ? this.values : this.value, this);

  },

  endDrag: function(event) {

    if (this.active && this.dragging) {

      this.finishDrag(event, true);

      Event.stop(event);

    }

    this.active = false;

    this.dragging = false;

  },

  finishDrag: function(event, success) {

    this.active = false;

    this.dragging = false;

    this.updateFinished();

  },

  updateFinished: function() {

    if (this.initialized && this.options.onChange)

      this.options.onChange(this.values.length>1 ? this.values : this.value, this);

    this.event = null;

  }

});