content: 'use strict';
  
  import React from 'react';
  import ReactDOM from 'react-dom';
  import {getTrackCSS, getTrackLeft, getTrackAnimateCSS} from './trackHelper';
  import assign from 'object-assign';
  
  var helpers = {
    initialize: function (props) {
      const slickList = ReactDOM.findDOMNode(this.list);
  
      var slideCount = React.Children.count(props.children);
      var listWidth = this.getWidth(slickList);
      var trackWidth = this.getWidth(ReactDOM.findDOMNode(this.track));
      var slideWidth;
  
      if (!props.vertical) {
        var centerPaddingAdj = props.centerMode && (parseInt(props.centerPadding) * 2);
        slideWidth = (this.getWidth(ReactDOM.findDOMNode(this)) - centerPaddingAdj)/props.slidesToShow;
      } else {
        slideWidth = this.getWidth(ReactDOM.findDOMNode(this));
      }
  
      const slideHeight = this.getHeight(slickList.querySelector('[data-index="0"]'));
      const listHeight = slideHeight * props.slidesToShow;
  
      var currentSlide = props.rtl ? slideCount - 1 - props.initialSlide : props.initialSlide;
  
      this.setState({
        slideCount,
        slideWidth,
        listWidth,
        trackWidth,
        currentSlide,
        slideHeight,
        listHeight,
      }, function () {
  
        var targetLeft = getTrackLeft(assign({
          slideIndex: this.state.currentSlide,
          trackRef: this.track
        }, props, this.state));
        // getCSS function needs previously set state
        var trackStyle = getTrackCSS(assign({left: targetLeft}, props, this.state));
  
        this.setState({trackStyle: trackStyle});
  
        this.autoPlay(); // once we're set up, trigger the initial autoplay.
      });
    },
    update: function (props) {
      const slickList = ReactDOM.findDOMNode(this.list);
      // This method has mostly same code as initialize method.
      // Refactor it
      var slideCount = React.Children.count(props.children);
      var listWidth = this.getWidth(slickList);
      var trackWidth = this.getWidth(ReactDOM.findDOMNode(this.track));
      var slideWidth;
  
      if (!props.vertical) {
        var centerPaddingAdj = props.centerMode && (parseInt(props.centerPadding) * 2);
        slideWidth = (this.getWidth(ReactDOM.findDOMNode(this)) - centerPaddingAdj)/props.slidesToShow;
      } else {
        slideWidth = this.getWidth(ReactDOM.findDOMNode(this));
      }
  
      const slideHeight = this.getHeight(slickList.querySelector('[data-index="0"]'));
      const listHeight = slideHeight * props.slidesToShow;
  
      // pause slider if autoplay is set to false
      if(props.autoplay) {
        this.pause();
      } else {
        this.autoPlay();
      }
  
      this.setState({
        slideCount,
        slideWidth,
        listWidth,
        trackWidth,
        slideHeight,
        listHeight,
      }, function () {
  
        var targetLeft = getTrackLeft(assign({
          slideIndex: this.state.currentSlide,
          trackRef: this.track
        }, props, this.state));
        // getCSS function needs previously set state
        var trackStyle = getTrackCSS(assign({left: targetLeft}, props, this.state));
  
        this.setState({trackStyle: trackStyle});
      });
    },
    getWidth: function getWidth(elem) {
      return elem.getBoundingClientRect().width || elem.offsetWidth || 0;
    },
    getHeight(elem) {
      return elem.getBoundingClientRect().height || elem.offsetHeight || 0;
    },
    adaptHeight: function () {
      if (this.props.adaptiveHeight) {
        var selector = '[data-index="' + this.state.currentSlide +'"]';
        if (this.list) {
          var slickList = ReactDOM.findDOMNode(this.list);
          slickList.style.height = slickList.querySelector(selector).offsetHeight + 'px';
        }
      }
    },
    canGoNext: function (opts){
      var canGo = true;
      if (!opts.infinite) {
        if (opts.centerMode) {
          // check if current slide is last slide
          if (opts.currentSlide >= (opts.slideCount - 1)) {
            canGo = false;
          }
        } else {
          // check if all slides are shown in slider
          if (opts.slideCount <= opts.slidesToShow ||
            opts.currentSlide >= (opts.slideCount - opts.slidesToShow)) {
            canGo = false;
          }
        }
      }
      return canGo;
    },
    slideHandler: function (index) {
      // Functionality of animateSlide and postSlide is merged into this function
      // console.log('slideHandler', index);
      var targetSlide, currentSlide;
      var targetLeft, currentLeft;
      var callback;
  
      if (this.props.waitForAnimate && this.state.animating) {
        return;
      }
  
      if (this.props.fade) {
        currentSlide = this.state.currentSlide;
  
        // Don't change slide if it's not infite and current slide is the first or last slide.
        if(this.props.infinite === false &&
          (index < 0 || index >= this.state.slideCount)) {
          return;
        }
  
        //  Shifting targetSlide back into the range
        if (index < 0) {
          targetSlide = index + this.state.slideCount;
        } else if (index >= this.state.slideCount) {
          targetSlide = index - this.state.slideCount;
        } else {
          targetSlide = index;
        }
  
        if (this.props.lazyLoad && this.state.lazyLoadedList.indexOf(targetSlide) < 0) {
          this.setState({
            lazyLoadedList: this.state.lazyLoadedList.concat(targetSlide)
          });
        }
  
        callback = () => {
          this.setState({
            animating: false
          });
          if (this.props.afterChange) {
            this.props.afterChange(targetSlide);
          }
          delete this.animationEndCallback;
        };
  
        this.setState({
          animating: true,
          currentSlide: targetSlide
        }, function () {
          this.animationEndCallback = setTimeout(callback, this.props.speed);
        });
  
        if (this.props.beforeChange) {
          this.props.beforeChange(this.state.currentSlide, targetSlide);
        }
  
        this.autoPlay();
        return;
      }
  
      targetSlide = index;
      if (targetSlide < 0) {
        if(this.props.infinite === false) {
          currentSlide = 0;
        } else if (this.state.slideCount % this.props.slidesToScroll !== 0) {
          currentSlide = this.state.slideCount - (this.state.slideCount % this.props.slidesToScroll);
        } else {
          currentSlide = this.state.slideCount + targetSlide;
        }
      } else if (targetSlide >= this.state.slideCount) {
        if(this.props.infinite === false) {
          currentSlide = this.state.slideCount - this.props.slidesToShow;
        } else if (this.state.slideCount % this.props.slidesToScroll !== 0) {
          currentSlide = 0;
        } else {
          currentSlide = targetSlide - this.state.slideCount;
        }
      } else {
        currentSlide = targetSlide;
      }
  
      targetLeft = getTrackLeft(assign({
        slideIndex: targetSlide,
        trackRef: this.track
      }, this.props, this.state));
  
      currentLeft = getTrackLeft(assign({
        slideIndex: currentSlide,
        trackRef: this.track
      }, this.props, this.state));
  
      if (this.props.infinite === false) {
        targetLeft = currentLeft;
      }
  
      if (this.props.beforeChange) {
        this.props.beforeChange(this.state.currentSlide, currentSlide);
      }
  
      if (this.props.lazyLoad) {
        var loaded = true;
        var slidesToLoad = [];
        for (var i = targetSlide; i < targetSlide + this.props.slidesToShow; i++ ) {
          loaded = loaded && (this.state.lazyLoadedList.indexOf(i) >= 0);
          if (!loaded) {
            slidesToLoad.push(i);
          }
        }
        if (!loaded) {
          this.setState({
            lazyLoadedList: this.state.lazyLoadedList.concat(slidesToLoad)
          });
        }
      }
  
      // Slide Transition happens here.
      // animated transition happens to target Slide and
      // non - animated transition happens to current Slide
      // If CSS transitions are false, directly go the current slide.
  
      if (this.props.useCSS === false) {
  
        this.setState({
          currentSlide: currentSlide,
          trackStyle: getTrackCSS(assign({left: currentLeft}, this.props, this.state))
        }, function () {
          if (this.props.afterChange) {
            this.props.afterChange(currentSlide);
          }
        });
  
      } else {
  
        var nextStateChanges = {
          animating: false,
          currentSlide: currentSlide,
          trackStyle: getTrackCSS(assign({left: currentLeft}, this.props, this.state)),
          swipeLeft: null
        };
  
        callback = () => {
          this.setState(nextStateChanges);
          if (this.props.afterChange) {
            this.props.afterChange(currentSlide);
          }
          delete this.animationEndCallback;
        };
  
        this.setState({
          animating: true,
          currentSlide: currentSlide,
          trackStyle: getTrackAnimateCSS(assign({left: targetLeft}, this.props, this.state))
        }, function () {
          this.animationEndCallback = setTimeout(callback, this.props.speed);
        });
  
      }
  
      this.autoPlay();
    },
    swipeDirection: function (touchObject) {
      var xDist, yDist, r, swipeAngle;
  
      xDist = touchObject.startX - touchObject.curX;
      yDist = touchObject.startY - touchObject.curY;
      r = Math.atan2(yDist, xDist);
  
      swipeAngle = Math.round(r * 180 / Math.PI);
      if (swipeAngle < 0) {
          swipeAngle = 360 - Math.abs(swipeAngle);
      }
      if ((swipeAngle <= 45) && (swipeAngle >= 0) || (swipeAngle <= 360) && (swipeAngle >= 315)) {
          return (this.props.rtl === false ? 'left' : 'right');
      }
      if ((swipeAngle >= 135) && (swipeAngle <= 225)) {
          return (this.props.rtl === false ? 'right' : 'left');
      }
      if (this.props.verticalSwiping === true) {
        if ((swipeAngle >= 35) && (swipeAngle <= 135)) {
          return 'down';
        } else {
          return 'up';
        }
      }
  
      return 'vertical';
    },
    play: function(){
      var nextIndex;
  
      if (!this.state.mounted) {
        return false
      }
  
      if (this.props.rtl) {
        nextIndex = this.state.currentSlide - this.props.slidesToScroll;
      } else {
        if (this.canGoNext(Object.assign({}, this.props,this.state))) {
          nextIndex = this.state.currentSlide + this.props.slidesToScroll;
        } else {
          return false;
        }
      }
  
      this.slideHandler(nextIndex);
    },
    autoPlay: function () {
      if (this.state.autoPlayTimer) {
        clearTimeout(this.state.autoPlayTimer);
      }
      if (this.props.autoplay) {
        this.setState({
          autoPlayTimer: setTimeout(this.play, this.props.autoplaySpeed)
        });
      }
    },
    pause: function () {
      if (this.state.autoPlayTimer) {
        clearTimeout(this.state.autoPlayTimer);
        this.setState({
          autoPlayTimer: null
        });
      }
    }
  };
  
  export default helpers;
  