define(function(require, exports, module) {
"use strict";
var Util = require('../util');
var Base = require('../base');
//transform
var transform = Util.prefixStyle("transform");
// default render function for position:sticky elements
var defaultStickyRenderFunc = function(e) {
  var stickyElement = e.stickyElement;
  var curStickyElement = e.curStickyElement;
  var xscroll = e.xscroll;
  var _ = e._;
  var infinite = xscroll.getPlugin("infinite");
  if (infinite) {
    infinite.userConfig.renderHook.call(self, stickyElement, curStickyElement);
    stickyElement.setAttribute("xs-guid", curStickyElement.guid);
    Util.addClass(stickyElement, curStickyElement.className);
    for (var attrName in curStickyElement.style) {
      if (attrName != "display" && attrName != "position") {
        //copy styles
        stickyElement.style[attrName] = attrName == _.height ? curStickyElement.style[attrName] + 'px' : curStickyElement.style[attrName];
      }
    }
  } else {
    var style = curStickyElement.getAttribute("style");
    stickyElement.innerHTML = curStickyElement.innerHTML;
    stickyElement.className = curStickyElement.className;
    style && stickyElement.setAttribute("style", style);
  }
}

var Sticky = function(cfg) {
  Sticky.superclass.constructor.call(this, cfg);
  this.userConfig = Util.mix({
    stickyRenderTo: undefined,
    forceSticky: true,
    prefix: "xs-sticky-container",
    stickyRenderFunc: defaultStickyRenderFunc,
    zoomType: "y"
  }, cfg);
  this.init();
}

Util.extend(Sticky, Base, {
  init: function() {
    var self = this,
      userConfig = self.userConfig,
      xscroll = self.xscroll = userConfig.xscroll;
    var isY = self.isY = !!(userConfig.zoomType == "y");
    self._ = {
      top: self.isY ? "top" : "left",
      left: self.isY ? "left" : "bottom",
      right: self.isY ? "right" : "top",
      height: self.isY ? "height" : "width",
      width: self.isY ? "width" : "height"
    };
    self.stickyRenderTo = Util.getNode(userConfig.stickyRenderTo);
    self._handlers = [];
    return self;
  },
  getStickiesPos: function() {
    var self = this;
    var xscroll = self.xscroll;
    var isInfinite = self.isInfinite;
    var isY = self.isY;
    var _ = self._;
    var stickiesPos = [];
    var getPos = function(sticky) {
      var pos = {};
      if (isInfinite) {
        pos[_.top] = isY ? sticky._top : sticky._left;
        pos[_.height] = isY ? sticky._height : sticky._width;
      } else {
        pos[_.top] = self.isY ? Util.getOffsetTop(sticky) : Util.getOffsetLeft(sticky);
        pos[_.height] = self.isY ? sticky.offsetHeight : sticky.offsetWidth;
      }
      return pos;
    }
    for (var i = 0; i < self.stickiesNum; i++) {
      var pos = getPos(self.stickyElements[i]);
      self._handlers[i] = self._handlers[i] || self.createStickyEl();
      pos.el = self._handlers[i];
      pos.isRender = false;
      stickiesPos.push(pos);
    }
    return stickiesPos
  },
  getStickyElements: function() {
    var self = this;
    var xscroll = self.xscroll;
    var userConfig = self.userConfig;
    var isInfinite = self.isInfinite;
    var infinite = xscroll.getPlugin("infinite");
    if (infinite) {
      var stickyElements = [],
        serializedData = infinite.__serializedData;
      for (var i in serializedData) {
        var rowData = serializedData[i];
        if (rowData && rowData.style && "sticky" == rowData.style.position) {
          stickyElements.push(rowData);
        }
      }
      return stickyElements;
    } else {
      return Util.getNodes(xscroll.userConfig.stickyElements, xscroll.content);
    }
  },
  render: function(force) {
    var self = this;
    var userConfig = self.userConfig;
    var xscroll = self.xscroll;
    self.isInfinite = !!xscroll.getPlugin("infinite");
    var _ = self._;
    self.stickyElements = self.getStickyElements();
    self.stickiesNum = self.stickyElements && self.stickyElements.length;
    if (!self.stickiesNum) return;
    if (!self.stickyRenderTo) {
      self.stickyRenderTo = document.createElement('div');
      xscroll.renderTo.appendChild(self.stickyRenderTo);
    }
    self.stickiesPos = self.getStickiesPos();
    var stickyRenderTo = self.stickyRenderTo;
    stickyRenderTo.style[_.top] = 0;
    stickyRenderTo.style[_.left] = 0;
    stickyRenderTo.style[_.right] = 0;
    stickyRenderTo.style.position = xscroll.userConfig.useOriginScroll ? "fixed" : "absolute";
    Util.addClass(self.stickyRenderTo, userConfig.prefix);
    self.stickyHandler(force);
    self._bindEvt();
  },
  createStickyEl: function() {
    var self = this;
    var el = document.createElement('div');
    el.style.display = "none";
    Util.addClass(el, "xs-sticky-handler");
    self.stickyRenderTo.appendChild(el);
    return el;
  },
  _bindEvt: function() {
    var self = this,
      xscroll = self.xscroll;
    xscroll.on("scroll", self.stickyHandler, self);
  },
  stickyHandler: function(force) {
    var self = this;
    var xscroll = self.xscroll;
    var userConfig = self.userConfig;
    var scrollTop = self.isY ? xscroll.getScrollTop() : xscroll.getScrollLeft();
    var stickiesPos = self.stickiesPos;
    var _ = self._;
    var indexes = [];
    for (var i = 0, l = stickiesPos.length; i < l; i++) {
      var top = stickiesPos[i][_.top];
      if (scrollTop > top) {
        indexes.push(i);
      }
    }
    if (!indexes.length) {
      if (self.stickyElement) {
        self.stickyElement.style.display = "none";
      }
      self.curStickyIndex = undefined;
      return;
    }

    var curStickyIndex = Math.max.apply(null, indexes);
    if (self.curStickyIndex != curStickyIndex || force) {
      var prevStickyIndex = self.curStickyIndex;
      self.curStickyIndex = curStickyIndex;
      self.curStickyElement = self.stickyElements[curStickyIndex];
      self.curStickyPos = stickiesPos[curStickyIndex];
      self.stickyElement = self.curStickyPos.el;
      for (var i = 0, l = stickiesPos.length; i < l; i++) {
        stickiesPos[i].el.style.display = "none";
      }
      var eventsObj = {
        stickyElement: self.stickyElement,
        curStickyIndex: self.curStickyIndex,
        prevStickyIndex: prevStickyIndex,
        curStickyPos: self.curStickyPos,
        isRender: self.curStickyPos.isRender
      };
      xscroll.trigger("beforestickychange", eventsObj);
      self._stickyRenderFunc(self);
      xscroll.trigger("stickychange", eventsObj);
    }

    var trans = 0;
    if (self.stickiesPos[self.curStickyIndex + 1]) {
      var cur = self.stickiesPos[self.curStickyIndex];
      var next = self.stickiesPos[self.curStickyIndex + 1];
      if (scrollTop + cur[_.height] > next[_.top] && scrollTop + cur[_.height] < next[_.top] + cur[_.height]) {
        trans = cur[_.height] + scrollTop - next[_.top];
      } else {
        trans = 0;
      }
    }
    self.stickyElement.style[transform] = self.isY ? "translateY(-" + (trans) + "px) translateZ(0)" : "translateX(-" + (trans) + "px) translateZ(0)";
  },
  _stickyRenderFunc: function(e) {
    var self = this;
    var _ = self._;
    var stickyRenderFunc = self.userConfig.stickyRenderFunc;
    var el = self.curStickyPos.el;
    if (!self.curStickyPos.isRender) {
      el.style[_.left] = 0;
      el.style[_.right] = 0;
      stickyRenderFunc && stickyRenderFunc.call(self, e);
    }
    el.style.display = "block";
    self.curStickyPos.isRender = true;
  },
  destroy: function() {
    var self = this;
    self.stickyElements = undefined;
    self.stickiesNum = undefined;
    self.stickiesPos = undefined;
    Util.remove(self.stickyElement);
    self.stickyElement = undefined;
  }
});

if (typeof module == 'object' && module.exports) {
  module.exports = Sticky;
}
/** ignored by jsdoc **/
else {
  return Sticky;
}
});