'use strict';

!function($) {

/**
 * Slider module.
 * @module foundation.slider
 * @requires foundation.util.motion
 * @requires foundation.util.triggers
 * @requires foundation.util.keyboard
 * @requires foundation.util.touch
 */

class Slider {
  /**
   * Creates a new instance of a drilldown menu.
   * @class
   * @param {jQuery} element - jQuery object to make into an accordion menu.
   * @param {Object} options - Overrides to the default plugin settings.
   */
  constructor(element, options) {
    this.$element = element;
    this.options = $.extend({}, Slider.defaults, this.$element.data(), options);

    this._init();

    Foundation.registerPlugin(this, 'Slider');
    Foundation.Keyboard.register('Slider', {
      'ltr': {
        'ARROW_RIGHT': 'increase',
        'ARROW_UP': 'increase',
        'ARROW_DOWN': 'decrease',
        'ARROW_LEFT': 'decrease',
        'SHIFT_ARROW_RIGHT': 'increase_fast',
        'SHIFT_ARROW_UP': 'increase_fast',
        'SHIFT_ARROW_DOWN': 'decrease_fast',
        'SHIFT_ARROW_LEFT': 'decrease_fast'
      },
      'rtl': {
        'ARROW_LEFT': 'increase',
        'ARROW_RIGHT': 'decrease',
        'SHIFT_ARROW_LEFT': 'increase_fast',
        'SHIFT_ARROW_RIGHT': 'decrease_fast'
      }
    });
  }

  /**
   * Initilizes the plugin by reading/setting attributes, creating collections and setting the initial position of the handle(s).
   * @function
   * @private
   */
  _init() {
    this.inputs = this.$element.find('input');
    this.handles = this.$element.find('[data-slider-handle]');

    this.$handle = this.handles.eq(0);
    this.$input = this.inputs.length ? this.inputs.eq(0) : $(`#${this.$handle.attr('aria-controls')}`);
    this.$fill = this.$element.find('[data-slider-fill]').css(this.options.vertical ? 'height' : 'width', 0);

    var isDbl = false,
        _this = this;
    if (this.options.disabled || this.$element.hasClass(this.options.disabledClass)) {
      this.options.disabled = true;
      this.$element.addClass(this.options.disabledClass);
    }
    if (!this.inputs.length) {
      this.inputs = $().add(this.$input);
      this.options.binding = true;
    }
    this._setInitAttr(0);
    this._events(this.$handle);

    if (this.handles[1]) {
      this.options.doubleSided = true;
      this.$handle2 = this.handles.eq(1);
      this.$input2 = this.inputs.length > 1 ? this.inputs.eq(1) : $(`#${this.$handle2.attr('aria-controls')}`);

      if (!this.inputs[1]) {
        this.inputs = this.inputs.add(this.$input2);
      }
      isDbl = true;

      this._setHandlePos(this.$handle, this.options.initialStart, true, function() {

        _this._setHandlePos(_this.$handle2, _this.options.initialEnd, true);
      });
      // this.$handle.triggerHandler('click.zf.slider');
      this._setInitAttr(1);
      this._events(this.$handle2);
    }

    if (!isDbl) {
      this._setHandlePos(this.$handle, this.options.initialStart, true);
    }
  }

  /**
   * Sets the position of the selected handle and fill bar.
   * @function
   * @private
   * @param {jQuery} $hndl - the selected handle to move.
   * @param {Number} location - floating point between the start and end values of the slider bar.
   * @param {Function} cb - callback function to fire on completion.
   * @fires Slider#moved
   * @fires Slider#changed
   */
  _setHandlePos($hndl, location, noInvert, cb) {
  //might need to alter that slightly for bars that will have odd number selections.
    location = parseFloat(location);//on input change events, convert string to number...grumble.

    // prevent slider from running out of bounds, if value exceeds the limits set through options, override the value to min/max
    if (location < this.options.start) { location = this.options.start; }
    else if (location > this.options.end) { location = this.options.end; }

    var isDbl = this.options.doubleSided;

    if (isDbl) { //this block is to prevent 2 handles from crossing eachother. Could/should be improved.
      if (this.handles.index($hndl) === 0) {
        var h2Val = parseFloat(this.$handle2.attr('aria-valuenow'));
        location = location >= h2Val ? h2Val - this.options.step : location;
      } else {
        var h1Val = parseFloat(this.$handle.attr('aria-valuenow'));
        location = location <= h1Val ? h1Val + this.options.step : location;
      }
    }

    //this is for single-handled vertical sliders, it adjusts the value to account for the slider being "upside-down"
    //for click and drag events, it's weird due to the scale(-1, 1) css property
    if (this.options.vertical && !noInvert) {
      location = this.options.end - location;
    }

    var _this = this,
        vert = this.options.vertical,
        hOrW = vert ? 'height' : 'width',
        lOrT = vert ? 'top' : 'left',
        handleDim = $hndl[0].getBoundingClientRect()[hOrW],
        elemDim = this.$element[0].getBoundingClientRect()[hOrW],
        //percentage of bar min/max value based on click or drag point
        pctOfBar = percent(location - this.options.start, this.options.end - this.options.start).toFixed(2),
        //number of actual pixels to shift the handle, based on the percentage obtained above
        pxToMove = (elemDim - handleDim) * pctOfBar,
        //percentage of bar to shift the handle
        movement = (percent(pxToMove, elemDim) * 100).toFixed(this.options.decimal);
        //fixing the decimal value for the location number, is passed to other methods as a fixed floating-point value
        location = parseFloat(location.toFixed(this.options.decimal));
        // declare empty object for css adjustments, only used with 2 handled-sliders
    var css = {};

    this._setValues($hndl, location);

    // TODO update to calculate based on values set to respective inputs??
    if (isDbl) {
      var isLeftHndl = this.handles.index($hndl) === 0,
          //empty variable, will be used for min-height/width for fill bar
          dim,
          //percentage w/h of the handle compared to the slider bar
          handlePct =  ~~(percent(handleDim, elemDim) * 100);
      //if left handle, the math is slightly different than if it's the right handle, and the left/top property needs to be changed for the fill bar
      if (isLeftHndl) {
        //left or top percentage value to apply to the fill bar.
        css[lOrT] = `${movement}%`;
        //calculate the new min-height/width for the fill bar.
        dim = parseFloat(this.$handle2[0].style[lOrT]) - movement + handlePct;
        //this callback is necessary to prevent errors and allow the proper placement and initialization of a 2-handled slider
        //plus, it means we don't care if 'dim' isNaN on init, it won't be in the future.
        if (cb && typeof cb === 'function') { cb(); }//this is only needed for the initialization of 2 handled sliders
      } else {
        //just caching the value of the left/bottom handle's left/top property
        var handlePos = parseFloat(this.$handle[0].style[lOrT]);
        //calculate the new min-height/width for the fill bar. Use isNaN to prevent false positives for numbers <= 0
        //based on the percentage of movement of the handle being manipulated, less the opposing handle's left/top position, plus the percentage w/h of the handle itself
        dim = movement - (isNaN(handlePos) ? this.options.initialStart/((this.options.end-this.options.start)/100) : handlePos) + handlePct;
      }
      // assign the min-height/width to our css object
      css[`min-${hOrW}`] = `${dim}%`;
    }

    this.$element.one('finished.zf.animate', function() {
                    /**
                     * Fires when the handle is done moving.
                     * @event Slider#moved
                     */
                    _this.$element.trigger('moved.zf.slider', [$hndl]);
                });

    //because we don't know exactly how the handle will be moved, check the amount of time it should take to move.
    var moveTime = this.$element.data('dragging') ? 1000/60 : this.options.moveTime;

    Foundation.Move(moveTime, $hndl, function() {
      //adjusting the left/top property of the handle, based on the percentage calculated above
      $hndl.css(lOrT, `${movement}%`);

      if (!_this.options.doubleSided) {
        //if single-handled, a simple method to expand the fill bar
        _this.$fill.css(hOrW, `${pctOfBar * 100}%`);
      } else {
        //otherwise, use the css object we created above
        _this.$fill.css(css);
      }
    });

    /**
     * Fires when the value has not been change for a given time.
     * @event Slider#changed
     */    
    clearTimeout(_this.timeout);
    _this.timeout = setTimeout(function(){
      _this.$element.trigger('changed.zf.slider', [$hndl]);
    }, _this.options.changedDelay);
  }

  /**
   * Sets the initial attribute for the slider element.
   * @function
   * @private
   * @param {Number} idx - index of the current handle/input to use.
   */
  _setInitAttr(idx) {
    var id = this.inputs.eq(idx).attr('id') || Foundation.GetYoDigits(6, 'slider');
    this.inputs.eq(idx).attr({
      'id': id,
      'max': this.options.end,
      'min': this.options.start,
      'step': this.options.step
    });
    this.handles.eq(idx).attr({
      'role': 'slider',
      'aria-controls': id,
      'aria-valuemax': this.options.end,
      'aria-valuemin': this.options.start,
      'aria-valuenow': idx === 0 ? this.options.initialStart : this.options.initialEnd,
      'aria-orientation': this.options.vertical ? 'vertical' : 'horizontal',
      'tabindex': 0
    });
  }

  /**
   * Sets the input and `aria-valuenow` values for the slider element.
   * @function
   * @private
   * @param {jQuery} $handle - the currently selected handle.
   * @param {Number} val - floating point of the new value.
   */
  _setValues($handle, val) {
    var idx = this.options.doubleSided ? this.handles.index($handle) : 0;
    this.inputs.eq(idx).val(val);
    $handle.attr('aria-valuenow', val);
  }

  /**
   * Handles events on the slider element.
   * Calculates the new location of the current handle.
   * If there are two handles and the bar was clicked, it determines which handle to move.
   * @function
   * @private
   * @param {Object} e - the `event` object passed from the listener.
   * @param {jQuery} $handle - the current handle to calculate for, if selected.
   * @param {Number} val - floating point number for the new value of the slider.
   * TODO clean this up, there's a lot of repeated code between this and the _setHandlePos fn.
   */
  _handleEvent(e, $handle, val) {
    var value, hasVal;
    if (!val) {//click or drag events
      e.preventDefault();
      var _this = this,
          vertical = this.options.vertical,
          param = vertical ? 'height' : 'width',
          direction = vertical ? 'top' : 'left',
          pageXY = vertical ? e.pageY : e.pageX,
          halfOfHandle = this.$handle[0].getBoundingClientRect()[param] / 2,
          barDim = this.$element[0].getBoundingClientRect()[param],
          barOffset = (this.$element.offset()[direction] -  pageXY),
          //if the cursor position is less than or greater than the elements bounding coordinates, set coordinates within those bounds
          barXY = barOffset > 0 ? -halfOfHandle : (barOffset - halfOfHandle) < -barDim ? barDim : Math.abs(barOffset),
          offsetPct = percent(barXY, barDim);
      value = (this.options.end - this.options.start) * offsetPct + this.options.start;

      // turn everything around for RTL, yay math!
      if (Foundation.rtl() && !this.options.vertical) {value = this.options.end - value;}

      value = _this._adjustValue(null, value);
      //boolean flag for the setHandlePos fn, specifically for vertical sliders
      hasVal = false;

      if (!$handle) {//figure out which handle it is, pass it to the next function.
        var firstHndlPos = absPosition(this.$handle, direction, barXY, param),
            secndHndlPos = absPosition(this.$handle2, direction, barXY, param);
            $handle = firstHndlPos <= secndHndlPos ? this.$handle : this.$handle2;
      }

    } else {//change event on input
      value = this._adjustValue(null, val);
      hasVal = true;
    }

    this._setHandlePos($handle, value, hasVal);
  }

  /**
   * Adjustes value for handle in regard to step value. returns adjusted value
   * @function
   * @private
   * @param {jQuery} $handle - the selected handle.
   * @param {Number} value - value to adjust. used if $handle is falsy
   */
  _adjustValue($handle, value) {
    var val,
      step = this.options.step,
      div = parseFloat(step/2),
      left, prev_val, next_val;
    if (!!$handle) {
      val = parseFloat($handle.attr('aria-valuenow'));
    }
    else {
      val = value;
    }
    left = val % step;
    prev_val = val - left;
    next_val = prev_val + step;
    if (left === 0) {
      return val;
    }
    val = val >= prev_val + div ? next_val : prev_val;
    return val;
  }

  /**
   * Adds event listeners to the slider elements.
   * @function
   * @private
   * @param {jQuery} $handle - the current handle to apply listeners to.
   */
  _events($handle) {
    if (this.options.disabled) { return false; }

    var _this = this,
        curHandle,
        timer;

      this.inputs.off('change.zf.slider').on('change.zf.slider', function(e) {
        var idx = _this.inputs.index($(this));
        _this._handleEvent(e, _this.handles.eq(idx), $(this).val());
      });

      if (this.options.clickSelect) {
        this.$element.off('click.zf.slider').on('click.zf.slider', function(e) {
          if (_this.$element.data('dragging')) { return false; }

          if (!$(e.target).is('[data-slider-handle]')) {
            if (_this.options.doubleSided) {
              _this._handleEvent(e);
            } else {
              _this._handleEvent(e, _this.$handle);
            }
          }
        });
      }

    if (this.options.draggable) {
      this.handles.addTouch();

      var $body = $('body');
      $handle
        .off('mousedown.zf.slider')
        .on('mousedown.zf.slider', function(e) {
          $handle.addClass('is-dragging');
          _this.$fill.addClass('is-dragging');//
          _this.$element.data('dragging', true);

          curHandle = $(e.currentTarget);

          $body.on('mousemove.zf.slider', function(e) {
            e.preventDefault();

            _this._handleEvent(e, curHandle);

          }).on('mouseup.zf.slider', function(e) {
            _this._handleEvent(e, curHandle);

            $handle.removeClass('is-dragging');
            _this.$fill.removeClass('is-dragging');
            _this.$element.data('dragging', false);

            $body.off('mousemove.zf.slider mouseup.zf.slider');
          });
      });
    }

    $handle.off('keydown.zf.slider').on('keydown.zf.slider', function(e) {
      var _$handle = $(this),
          idx = _this.options.doubleSided ? _this.handles.index(_$handle) : 0,
          oldValue = parseFloat(_this.inputs.eq(idx).val()),
          newValue;

      // handle keyboard event with keyboard util
      Foundation.Keyboard.handleKey(e, 'Slider', {
        decrease: function() {
          newValue = oldValue - _this.options.step;
        },
        increase: function() {
          newValue = oldValue + _this.options.step;
        },
        decrease_fast: function() {
          newValue = oldValue - _this.options.step * 10;
        },
        increase_fast: function() {
          newValue = oldValue + _this.options.step * 10;
        },
        handled: function() { // only set handle pos when event was handled specially
          e.preventDefault();
          _this._setHandlePos(_$handle, newValue, true);
        }
      });
      /*if (newValue) { // if pressed key has special function, update value
        e.preventDefault();
        _this._setHandlePos(_$handle, newValue);
      }*/
    });
  }

  /**
   * Destroys the slider plugin.
   */
  destroy() {
    this.handles.off('.zf.slider');
    this.inputs.off('.zf.slider');
    this.$element.off('.zf.slider');

    Foundation.unregisterPlugin(this);
  }
}

Slider.defaults = {
  /**
   * Minimum value for the slider scale.
   * @option
   * @example 0
   */
  start: 0,
  /**
   * Maximum value for the slider scale.
   * @option
   * @example 100
   */
  end: 100,
  /**
   * Minimum value change per change event.
   * @option
   * @example 1
   */
  step: 1,
  /**
   * Value at which the handle/input *(left handle/first input)* should be set to on initialization.
   * @option
   * @example 0
   */
  initialStart: 0,
  /**
   * Value at which the right handle/second input should be set to on initialization.
   * @option
   * @example 100
   */
  initialEnd: 100,
  /**
   * Allows the input to be located outside the container and visible. Set to by the JS
   * @option
   * @example false
   */
  binding: false,
  /**
   * Allows the user to click/tap on the slider bar to select a value.
   * @option
   * @example true
   */
  clickSelect: true,
  /**
   * Set to true and use the `vertical` class to change alignment to vertical.
   * @option
   * @example false
   */
  vertical: false,
  /**
   * Allows the user to drag the slider handle(s) to select a value.
   * @option
   * @example true
   */
  draggable: true,
  /**
   * Disables the slider and prevents event listeners from being applied. Double checked by JS with `disabledClass`.
   * @option
   * @example false
   */
  disabled: false,
  /**
   * Allows the use of two handles. Double checked by the JS. Changes some logic handling.
   * @option
   * @example false
   */
  doubleSided: false,
  /**
   * Potential future feature.
   */
  // steps: 100,
  /**
   * Number of decimal places the plugin should go to for floating point precision.
   * @option
   * @example 2
   */
  decimal: 2,
  /**
   * Time delay for dragged elements.
   */
  // dragDelay: 0,
  /**
   * Time, in ms, to animate the movement of a slider handle if user clicks/taps on the bar. Needs to be manually set if updating the transition time in the Sass settings.
   * @option
   * @example 200
   */
  moveTime: 200,//update this if changing the transition time in the sass
  /**
   * Class applied to disabled sliders.
   * @option
   * @example 'disabled'
   */
  disabledClass: 'disabled',
  /**
   * Will invert the default layout for a vertical<span data-tooltip title="who would do this???"> </span>slider.
   * @option
   * @example false
   */
  invertVertical: false,
  /**
   * Milliseconds before the `changed.zf-slider` event is triggered after value change. 
   * @option
   * @example 500
   */
  changedDelay: 500
};

function percent(frac, num) {
  return (frac / num);
}
function absPosition($handle, dir, clickPos, param) {
  return Math.abs(($handle.position()[dir] + ($handle[param]() / 2)) - clickPos);
}

// Window exports
Foundation.plugin(Slider, 'Slider');

}(jQuery);

//*********this is in case we go to static, absolute positions instead of dynamic positioning********
// this.setSteps(function() {
//   _this._events();
//   var initStart = _this.options.positions[_this.options.initialStart - 1] || null;
//   var initEnd = _this.options.initialEnd ? _this.options.position[_this.options.initialEnd - 1] : null;
//   if (initStart || initEnd) {
//     _this._handleEvent(initStart, initEnd);
//   }
// });

//***********the other part of absolute positions*************
// Slider.prototype.setSteps = function(cb) {
//   var posChange = this.$element.outerWidth() / this.options.steps;
//   var counter = 0
//   while(counter < this.options.steps) {
//     if (counter) {
//       this.options.positions.push(this.options.positions[counter - 1] + posChange);
//     } else {
//       this.options.positions.push(posChange);
//     }
//     counter++;
//   }
//   cb();
// };
