/*!
 * @preserve
 *
 * readmore.js jquery plugin
 * author: @jed_foster
 * project home: http://jedfoster.github.io/readmore.js
 * licensed under the mit license
 *
 * debounce function from http://davidwalsh.name/javascript-debounce-function
 */

/* global jquery */
//在$(function)里面的都是一次性对象发函数
(function(factory) {

  if (typeof define === 'function' && define.amd) {
    // amd
    define(['jquery'], factory);
  } else if (typeof exports === 'object') {
    // commonjs
    module.exports = factory(require('jquery'));
  } else {
    // browser globals
    factory(jquery);
  }
}(function($) {
  'use strict';

  var readmore = 'readmore',
      defaults = {
        speed: 100,
        collapsedheight: 200,
        heightmargin: 16,
        morelink: '<a href="#">read more</a>',
        lesslink: '<a href="#">close</a>',
        embedcss: true,
        blockcss: 'display: block; width: 100%;',
        startopen: false,

        // callbacks
        blockprocessed: function() {},
        beforetoggle: function() {},
        aftertoggle: function() {}
      },
      cssembedded = {},
      uniqueidcounter = 0;

  function debounce(func, wait, immediate) {
    var timeout;

    return function() {
      var context = this, args = arguments;
      var later = function() {
        timeout = null;
        if (! immediate) {
          func.apply(context, args);
        }
      };
      var callnow = immediate && !timeout;

      cleartimeout(timeout);
      timeout = settimeout(later, wait);

      if (callnow) {
        func.apply(context, args);
      }
    };
  }

  function uniqueid(prefix) {
    var id = ++uniqueidcounter;

    return string(prefix == null ? 'rmjs-' : prefix) + id;
  }

  function setboxheights(element) {
    var el = element.clone().css({
          height: 'auto',
          width: element.width(),
          maxheight: 'none',
          overflow: 'hidden'
        }).insertafter(element),
        expandedheight = el.outerheight(true),
        cssmaxheight = parseint(el.css({maxheight: ''}).css('max-height').replace(/[^-\d\.]/g, ''), 10),
        defaultheight = element.data('defaultheight');

    el.remove();

    var collapsedheight = cssmaxheight || element.data('collapsedheight') || defaultheight;

    if (element.data('expandedheight') != undefined && element.data('expandedheight') != '' && element.data('expandedheight') != null) {
      expandedheight = number(expandedheight) > number(element.data('expandedheight')) ? expandedheight : element.data('expandedheight');
    }

    // store our measurements.
    element.data({
      expandedheight: expandedheight,
      maxheight: cssmaxheight,
      collapsedheight: collapsedheight
    })
    // and disable any `max-height` property set in css
    .css({
      maxheight: 'none'
    });
  }

  var resizeboxes = debounce(function() {
    $('[data-readmore]').each(function() {
      var current = $(this),
          isexpanded = (current.attr('aria-expanded') === 'true');

      setboxheights(current);

      current.css({
        height: current.data( (isexpanded ? 'expandedheight' : 'collapsedheight') )
      });
    });
  }, 100);

  function embedcss(options) {
    if (! cssembedded[options.selector]) {
      var styles = ' ';

      if (options.embedcss && options.blockcss !== '') {
        styles += options.selector + ' + [data-readmore-toggle], ' +
          options.selector + '[data-readmore]{' +
            options.blockcss +
          '}';
      }

      // include the transition css even if embedcss is false
      styles += options.selector + '[data-readmore]{' +
        'transition: height ' + options.speed + 'ms;' +
        'overflow: hidden;' +
      '}';

      (function(d, u) {
        var css = d.createelement('style');
        css.type = 'text/css';

        if (css.stylesheet) {
          css.stylesheet.csstext = u;
        }
        else {
          css.appendchild(d.createtextnode(u));
        }

        d.getelementsbytagname('head')[0].appendchild(css);
      }(document, styles));

      cssembedded[options.selector] = true;
    }
  }

  function readmore(element, options) {

    this.element = element;

    this.options = $.extend({}, defaults, options);

    embedcss(this.options);

    this._defaults = defaults;
    this._name = readmore;

    this.init();

    // ie8 chokes on `window.addeventlistener`, so need to test for support.
    if (window.addeventlistener) {
      // need to resize boxes when the page has fully loaded.
      window.addeventlistener('load', resizeboxes);
      window.addeventlistener('resize', resizeboxes);
    }
    else {
      window.attachevent('load', resizeboxes);
      window.attachevent('resize', resizeboxes);
    }
  }


  readmore.prototype = {
    init: function() {
      var current = $(this.element);

      current.data({
        defaultheight: this.options.collapsedheight,
        heightmargin: this.options.heightmargin
      });

      setboxheights(current);

      var collapsedheight = current.data('collapsedheight'),
          heightmargin = current.data('heightmargin');

      if (current.outerheight(true) <= collapsedheight + heightmargin) {
        // the block is shorter than the limit, so there's no need to truncate it.
        if (this.options.blockprocessed && typeof this.options.blockprocessed === 'function') {
          this.options.blockprocessed(current, false);
        }
        return true;
      }
      else {
        var id = current.attr('id') || uniqueid(),
            uselink = this.options.startopen ? this.options.lesslink : this.options.morelink;

        current.attr({
          'data-readmore': '',
          'aria-expanded': this.options.startopen,
          'id': id
        });

        current.after($(uselink)
          .on('click', (function(_this) {
            return function(event) {
              _this.toggle(this, current[0], event);
            };
          })(this))
          .attr({
            'data-readmore-toggle': id,
            'aria-controls': id
          }));

        if (! this.options.startopen) {
          current.css({
            height: collapsedheight
          });
        }

        if (this.options.blockprocessed && typeof this.options.blockprocessed === 'function') {
          this.options.blockprocessed(current, true);
        }
      }
    },

    toggle: function(trigger, element, event) {
      if (event) {
        event.preventdefault();
      }

      if (! trigger) {
        trigger = $('[aria-controls="' + this.element.id + '"]')[0];
      }

      if (! element) {
        element = this.element;
      }

      var $element = $(element),
          newheight = '',
          newlink = '',
          expanded = false,
          collapsedheight = $element.data('collapsedheight');

      if ($element.height() <= collapsedheight) {
        newheight = $element.data('expandedheight') + 'px';
        newlink = 'lesslink';
        expanded = true;
      }
      else {
        newheight = collapsedheight;
        newlink = 'morelink';
      }

      // fire beforetoggle callback
      // since we determined the new "expanded" state above we're now out of sync
      // with our true current state, so we need to flip the value of `expanded`
      if (this.options.beforetoggle && typeof this.options.beforetoggle === 'function') {
        this.options.beforetoggle(trigger, $element, ! expanded);
      }
      // debugger
      // if(window.innerwidth<768){
        
      //   number(newheight.replace('px','')-300)+'px'

      // };
      $element.css({'height': newheight});

      // fire aftertoggle callback
      $element.on('transitionend', (function(_this) {
        return function() {
          if (_this.options.aftertoggle && typeof _this.options.aftertoggle === 'function') {
            _this.options.aftertoggle(trigger, $element, expanded);
          }

          $(this).attr({
            'aria-expanded': expanded
          }).off('transitionend');
        }
      })(this));

      $(trigger).replacewith($(this.options[newlink])
        .on('click', (function(_this) {
            return function(event) {
              _this.toggle(this, element, event);
            };
          })(this))
        .attr({
          'data-readmore-toggle': $element.attr('id'),
          'aria-controls': $element.attr('id')
        }));
    },

    destroy: function() {
      $(this.element).each(function() {
        var current = $(this);

        current.attr({
          'data-readmore': null,
          'aria-expanded': null
        })
          .css({
            maxheight: '',
            height: ''
          })
          .next('[data-readmore-toggle]')
          .remove();

        current.removedata();
      });
    }
  };


  $.fn.readmore = function(options) {
    var args = arguments,
        selector = this.selector;

    options = options || {};

    if (typeof options === 'object') {
      return this.each(function() {
        if ($.data(this, 'plugin_' + readmore)) {
          var instance = $.data(this, 'plugin_' + readmore);
          instance.destroy.apply(instance);
        }

        options.selector = selector;

        $.data(this, 'plugin_' + readmore, new readmore(this, options));
      });
    }
    else if (typeof options === 'string' && options[0] !== '_' && options !== 'init') {
      return this.each(function () {
        var instance = $.data(this, 'plugin_' + readmore);
        if (instance instanceof readmore && typeof instance[options] === 'function') {
          instance[options].apply(instance, array.prototype.slice.call(args, 1));
        }
      });
    }
  };

}));