/* Measures app names and checks if there is enough space to display them */
var MAX_APP_LIST_END = 275;


/*****
 * Allows reordering of the side nav links
 *
 * TODO: make this extensibleOB
 *
 * By Julie
 *
 */


var MAX_SIDENAV_LINKS = 7;
var MOVING_THRESHOLD = 10; //pixels
var saved_message = null;


/* object is the container which holds the handle, icon and link */
function track_moveable(container_obj, link_obj) {
  this.listContainer=container_obj;
  this.link = link_obj;
  this.listContainer.onmousedown=function(e) { return this._onclick(e?e:window.event);}.bind(this);
}

track_moveable.prototype._onclick=function(e) { 
  this.clickMouseY = mouseY(e);
  document.onselectstart = function(e) { return false; };
  document.onmousemove = function(e){return this._track_move(e?e:window.event)}.bind(this);
  document.onmouseup = function(e) { this._track_drop(e?e:window.event) }.bind(this);
  return false;
}

track_moveable.prototype._track_move=function(e) { 
  if (Math.abs(mouseY(e)-this.clickMouseY) > MOVING_THRESHOLD) {
    var moveable = new moveable_app(this.listContainer, this.link);
    moveable._onclick(null, this.clickMouseY);
  }
}

track_moveable.prototype._track_drop=function(e) {
  document.onmouseout=document.onmouseup=document.onmousemove=document.onclick=null;
  this.link.onclick = function(e) { return true; };
}

/* object is the container which holds the handle, icon and link */ 
function moveable_app(container_obj, link_obj) { 
  this.listContainer=container_obj;
  this.link = link_obj;
  this.listContainer.onmousedown=function(e) { return this._onclick(e?e:window.event);}.bind(this);
}

moveable_app.prototype._onclick=function(e, mouseYCoord) {
  // make it nice and transparent
  add_css_class_name(this.listContainer, 'floating_container');
  
  // calculate the bounds of how far we can move the item up and down
  var app_list_node = ge('app_list');
  this.listContainer.lowerBoundY = elementY(app_list_node.firstChild ? app_list_node.firstChild : app_list_node);
  this.oldListID = this.listContainer.parentNode.parentNode.id;
  this.justOpened = false;

  var app_non_nav_list_node = ge('app_non_nav_list');  

  this.listContainer.upperBoundY = elementY(app_non_nav_list_node.lastChild? app_non_nav_list_node.lastChild : app_non_nav_list_node); 

  var listContainerHeight =  (isIE() || isSafari()) ? this.listContainer.offsetHeight : this.listContainer.offsetHeight-1;

  // make the empty space keep the height of the container that is floating
  this.listContainer.parentNode.style.height = (listContainerHeight) + 'px';

  // initialize position variables
  this.listContainer.top = elementY(this.listContainer);
  mouseYCoord = mouseYCoord ? mouseYCoord : mouseY(e);
  this.mouseOffset = mouseYCoord - this.listContainer.top;
  this.listContainer.style.top = this.listContainer.top + 'px';

  document.onmousemove = function(e){return this._move(e?e:window.event)}.bind(this);
  document.onmouseup=function(e){this._drop(e?e:window.event)}.bind(this);

  this._calculateBoundaries();

  return false;
}


/* Figure out at what lower and upper pixel boundaries to
 * switch the placeholder of the floating element
 */
moveable_app.prototype._calculateBoundaries = function() {

  var list = this.listContainer.parentNode.parentNode;
  
  var previousListItem = this.listContainer.parentNode.previousSibling;
  this.listContainer.prevList = null;
  this.listContainer.previousNodeY = null;

  if (previousListItem) {
   this.listContainer.previousNodeY = elementY(previousListItem) + 7; 
   this.newList = false;
  } else if (list.id == 'app_non_nav_list') {
     this.listContainer.prevList = ge('app_list');
     var elementPos = null;
     if (this.listContainer.prevList.lastChild) {
       elementPos = this.listContainer.prevList.lastChild;
     } else {
       elementPos = this.listContainer.prevList;
     }
     this.newList = true;
     this.listContainer.previousNodeY = elementY(elementPos) + 20;
  }

  var nextListItem = this.listContainer.parentNode.nextSibling;
  this.listContainer.nextList = null;
  this.listContainer.nextNodeY = null;
  if (nextListItem) {
     this.listContainer.nextNodeY = elementY(nextListItem) - 7;
     this.newList = false;
  } else if (list.id == 'app_list') {

     this.listContainer.nextList = ge('app_non_nav_list');
     var elementPos = null;
     this.newList = true;
     if (this.listContainer.nextList.parentNode.style.display == 'none') {
       this.justOpened = true;
       this.listContainer.nextNodeY = elementY(ge('more_link')) - 18;
     } else {
       if (this.listContainer.nextList.firstChild) {
         elementPos = this.listContainer.nextList.firstChild;
       } else {
         elementPos = this.listContainer.nextList;
       }
       this.listContainer.nextNodeY = elementY(elementPos) - 20;
     }
  }
}


moveable_app.prototype._move = function(e) {
    this.listContainer.top = mouseY(e) - this.mouseOffset;     
    var oldParent = this.listContainer.parentNode;

    // move downwards
    if (this.listContainer.nextNodeY && this.listContainer.top > this.listContainer.nextNodeY) {
      if (this.listContainer.nextList == null) {
        var newParent = oldParent.nextSibling;
        newParent.appendChild(this.listContainer);
        oldParent.style.height = null;
        oldParent.appendChild(newParent.firstChild);
      } else { // create a div if none exists
        if (this.newList) {
          expand_more_list();
          var newParent = document.createElement('div');
          newParent.className = 'list_item';
          this.listContainer.nextList.insertBefore(newParent, this.listContainer.nextList.firstChild);
          newParent.appendChild(this.listContainer);
          oldParent.parentNode.removeChild(oldParent);
        }
      }
    }      
    // move upwards
    else if (this.listContainer.previousNodeY && this.listContainer.top < this.listContainer.previousNodeY) {
       if (this.listContainer.prevList == null) {
          var newParent = oldParent.previousSibling; 
          newParent.appendChild(this.listContainer);
          oldParent.style.height = null;
          oldParent.appendChild(newParent.firstChild);
       } else {
          var newParent = document.createElement('div');
          newParent.className = 'list_item';
          this.listContainer.prevList.appendChild(newParent);
          newParent.appendChild(this.listContainer);
          oldParent.parentNode.removeChild(oldParent);
       }
    }

    if (this.listContainer.parentNode != oldParent) {
      oldParent.style.height = null;
      this.listContainer.parentNode.style.height = (this.listContainer.offsetHeight - 1 )+ 'px'; 
      this._calculateBoundaries();   
    }
    
    /* limit how far up/down you can drag the thing */
    if ((is_first_child(this.listContainer.parentNode, 'app_list') && this.listContainer.top < elementY(this.listContainer.parentNode)) || 
        (is_last_child(this.listContainer.parentNode, 'app_non_nav_list') && this.listContainer.top > elementY(this.listContainer.parentNode))) {
      this.listContainer.style.top = (elementY(this.listContainer.parentNode) + 1) + 'px';
    } else {
      this.listContainer.style.top= this.listContainer.top + 'px';
    }
    return false;
}


function is_first_child(elem, parent) {
  return (elem.parentNode.id == parent) && (elem.parentNode.firstChild == elem);
}


function is_last_child(elem, parent) {
  return (elem.parentNode.id == parent) && (elem.parentNode.lastChild == elem);
}

function onload_side_nav_check() {
  enforce_app_list_limits_and_save(false);
}

function  enforce_app_list_limits_and_save(force_save) {
  var display_list = '';
  var app_list_node = ge('app_list');
 
  var more_apps_node = ge('app_non_nav_list');
  var more_list = '';

  var max_reached = false;
  var extra_pixel_amount = 0;

  // account for editapp.php page's rearrange message
  var rearrange_message = ge('rearrange_message');
  if (rearrange_message) {
    extra_pixel_amount = rearrange_message.offsetHeight + 6; // 6 is the margin amount on the rearrange message;
  }

  var threshold = MAX_APP_LIST_END + elementY(ge('sidebar')) + extra_pixel_amount;

  // Drop a link from the main list into the more list if there are more than the max number of links
  while (elementY(app_list_node) + app_list_node.offsetHeight > threshold || app_list_node.childNodes.length > MAX_SIDENAV_LINKS) {
    if (more_apps_node.firstChild) {
      more_apps_node.insertBefore(app_list_node.lastChild, more_apps_node.firstChild);
    } else {
      more_apps_node.appendChild(app_list_node.lastChild);
    }
    max_reached = true;
  }

  if (max_reached || force_save) {

    // get the app orders of the main list
    for (var i=0; i< app_list_node.childNodes.length; i++) {
      if (i!=0) {
        display_list += ':';
      }
      display_list += app_list_node.childNodes[i].firstChild.id;
    }
    
    // get the app orders of the display list
    for (var i=0; i< more_apps_node.childNodes.length; i++) {
      if (i!=0) {
        more_list += ':';
      }
      more_list += more_apps_node.childNodes[i].firstChild.id;
    }
    
    var ajax=new Ajax(
                      function(obj, text) {
                        eval(text);
                      }
                      );
    
    var post_vars = { 'display_list' : display_list, 'more_list' : more_list };
    ajax.post('/ajax/apps_menu.php', post_vars);
  }
}


moveable_app.prototype._drop = function(e) {

  remove_css_class_name(this.listContainer, 'floating_container');
  this.listContainer.style.top = null;
  this.listContainer.parentNode.style.height = null;

  // enforce app list length and save
  enforce_app_list_limits_and_save(true);

  if (this.listContainer.parentNode.parentNode.id != 'app_non_nav_list' && this.justOpened) {
    window.setTimeout('close_more_list()', 500);
  }

  document.onmouseout=document.onmouseup=document.onmousemove=document.onclick=null;
  if (this.link) {
    this.link.onclick = function (e) { return false; };
  }
  
  return false;
}


function change_status_message(className, messageContent) {
  var message = ge('rearrange_message');
  message.className = className; 
  message.innerHTML = messageContent;
}


/*  Change function for how a list item looks in moving from the non-menu to   
 *  the apps menu
 */
function change_to_apps_menu(list_item) { 
    var container = list_item.firstChild;
    var action_link = container.firstChild;
    
    action_link.setAttribute('onclick', 'move_lists(this.parentNode.parentNode, \'app_non_nav_list\', change_to_non_menu, true); return false;');
    action_link.setAttribute('class', 'action_item');
    action_link.innerHTML= "remove";

    /* add a draggable handle */ 
    var handle = document.createElement('div');
    handle.setAttribute('class', 'handle');
    handle.setAttribute('onmousedown', 'new moveable_app(this.parentNode);');
    container.insertBefore(handle, container.firstChild.nextSibling);
}


function change_to_non_menu(list_item) {
    var container = list_item.firstChild;
    var action_link = container.firstChild;
    var handle = container.firstChild.nextSibling;

    /* remove draggable handle */
    container.removeChild(handle); 

        
    action_link.setAttribute('onclick', 'move_lists(this.parentNode.parentNode, \'app_list\', change_to_apps_menu); return false;');
    action_link.setAttribute('class', 'action_item_add');
    action_link.innerHTML= "add to menu";   
}


/* Moves a list item from its current list to the back of a new list with id 'to_list_id'
 * If the list item properties need to change in the move, that can be defined in the 
 * optional changeFunction function parameter. 
 * if boolean front_of_list is defined, the item is inserted at the front rather than the back
 */
function move_lists(obj, to_list_id, changeFunction, front_of_list) {
    to_list_obj = ge(to_list_id);
    if (changeFunction) {
      changeFunction(obj);
    }

    if (front_of_list) {
      to_list_obj.insertBefore(obj, to_list_obj.firstChild);   
    } else {
      to_list_obj.appendChild(obj);
    }
}