/*
 * jQuery history plugin
 *
 * sample page: http://www.serpere.info/jquery-history-plugin/samples/
 *
 * Copyright (c) 2006-2009 Taku Sano (Mikage Sawatari)
 * Copyright (c) 2010 Takayuki Miwa
 * Licensed under the MIT License:
 *   http://www.opensource.org/licenses/mit-license.php
 */

;(function($) {
  var locationWrapper = {
    put: function(hash, win) {
      (win || window).location.hash = hash
    },

    get: function(win) {
      return (win || window).location.hash.replace(/^#/, '')
    }
  }

  var iframeWrapper = {
    id: '__jQuery_history',
    init: function() {
      var html = '<iframe id="'+ this.id +'" style="display:none" src="javascript:false" />'
      $('body').prepend(html)
      return this
    },

    _document: function() {
      return $('#' + this.id)[0].contentWindow.document
    },

    put: function(hash) {
      var doc = this._document()

      doc.open()
      doc.close()
      locationWrapper.put(hash, doc)
    },

    get: function() {
      return locationWrapper.get(this._document())
    }
  }

  var _ = {
    appState: undefined,
    callback: undefined,
    init:  function(callback) {},
    check: function() {},
    load:  function(hash) {}
  }

  $.history = _

  var SimpleImpl = {
    init: function(callback) {
      _.callback = callback
      var current_hash = locationWrapper.get()
      _.appState = current_hash
      _.callback(current_hash)
      setInterval(_.check, 100)
    },

    check: function() {
      var current_hash = locationWrapper.get()
      if (current_hash != _.appState) {
        _.appState = current_hash
        _.callback(current_hash)
      }
    },

    load: function(hash) {
      //if (hash != _.appState) {
        locationWrapper.put(hash)
        _.appState = hash
        _.callback(hash)
      //}
    }
  }

  var IframeImpl = {
    init: function(callback) {
      _.callback = callback
      var current_hash = locationWrapper.get()
      _.appState = current_hash
      iframeWrapper.init().put(current_hash)
      _.callback(current_hash)
      setInterval(_.check, 100)
    },

    check: function() {
      var current_hash = iframeWrapper.get()
      if (current_hash != _.appState) {
        locationWrapper.put(current_hash)
        _.appState = current_hash
        _.callback(current_hash)
      }
    },

    load: function(hash) {
      if (hash != _.appState) {
        locationWrapper.put(hash)
        iframeWrapper.put(hash)
        _.appState = hash
        _.callback(hash)
      }
    }
  }

  if ($.browser.msie && ($.browser.version < 8 || document.documentMode < 8))
    $.extend(_, IframeImpl)
  else
    $.extend(_, SimpleImpl)
})(jQuery)