--- Tags -------------------- -------------------- -------------------

/* --- Tags ----------------------------------------------------------------  */

/*
  These are sorted unique tags. Each tag is mapped to the array of notes
  tagged with it. A note is described with ID of the corresponding HTML element
  having 'note' class.
  
  We may use this associative array to perform some kind of optimization.
*/
Tags = {
    "emacs":new Array(
      "3078076044"
    ),
    "Qt":new Array(
      "3078076812"
    ),
    "style guide":new Array(
      "3078077068"
    ),
    "win32":new Array(
      "3078076940"
    ),
    "XML":new Array(
      "3078076556","3078077196"
    ),
    "XML Schema":new Array(
      "3078076556"
    ),
    "XSLT":new Array(
      "3078076172","3078077196"
    ),
    "zvon.org":new Array(
      "3078076172"
    ),
    "валидатор":new Array(
      "3078076556"
    ),
    "веб-разработка":new Array(
      "3078076428"
    ),
    "вёрстка":new Array(
      "3078076428"
    ),
    "книга":new Array(
      "3078076684"
    ),
    "программирование":new Array(
      "3078076812","3078076940"
    ),
    "сайт":new Array(
      "3078075884","3078076300","3078076556","3078076684","3078077196"
    ),
    "софт":new Array(
      "3078077324"
    ),
};

/* --- Utils ---------------------------------------------------------------- */

jQuery.fn.exists = function(fn){
  var ret = false;
  $(this).each(function(){
    this.fn = fn; // 'this' must be available in 'fn'
    if (this.fn()){
      ret = true;
      return false; // break from 'each'
    }
  });
  return ret;
}

jQuery.fn.existsText = function(text){
  return $(this).exists(function(){
    return $(this).text() == text;
  });
}

jQuery.fn.select = function(fn, callback){
  $(this).each(function(){
    this.fn = fn; // 'this' must be available in 'fn'
    if (this.fn()){
      this.callback = callback;
      return this.callback(); // 'this' must be available in 'callback'
    }
  });
}

function array_remove(array, element){
  for(i in array)
    if (element == array[i])
      array.splice(i, 1);
}

/* --- Cloud ---------------------------------------------------------------- */

var Cloud = new function(){

  this.addTag = function(tag, size){
    var code = "<a href='' class='note_tag tag_size_" + size + "'>" + tag + "</a> "

    $("#all_tags").append(code);
    tag_setClickHandler($("#all_tags > .note_tag").slice(-1));
      // "#all_tags > .note_tag :last" does not work
      
    if (size < 3){
      $("#popular_tags").append("<a href='' class='note_tag tag_size_" + size + "'>" + tag + "</a> ");
      tag_setClickHandler($("#popular_tags > .note_tag").slice(-1));
        // "#popular_tags > .note_tag :last" does not work
    }
  }

  this.recalculate = function(){

    $("#all_tags .note_tag").remove();
    $("#popular_tags .note_tag").remove();

    var tags = new Object();
    for (tag in Tags)
      if (!Filter.isTagChosen(tag)){
        tags[tag] = 0;
        
        note_ids=Tags[tag]
        for (index in note_ids)
          if (document.getElementById(note_ids[index]).style.display != 'none')
            tags[tag]++
      }

    var notesCount = $(".note:visible").length;
    for (tag in Tags)
      if (!Filter.isTagChosen(tag) && tags[tag] > 0) {
          
        var _size = tags[tag] / notesCount;
        if (_size > 0.05)
          _size = 1;
        else if (_size > 0.01)
          _size = 2;
        else
          _size = 3;
        
        this.addTag(tag, _size);
      }
  }

}();

/* --- Filter --------------------------------------------------------------- */

var Filter = new function(){

  this.chosenTags = new Array();
  
  this.isEmpty = function(){
    return this.chosenTags.length == 0;
  }

  this.addTag = function(tag){
    this.chosenTags.push(tag);
  
    $("#chosen_tags").show();
    $("#chosen_tags").append("<a href='' class='chosen_tag'>" + tag + "</a> ");
    tag_setClickHandler($("#chosen_tags .chosen_tag").slice(-1));
      // "#chosen_tags .chosen_tag :last" does not work
    
    Notes.updateForSelectedTag(tag);
    Cloud.recalculate();
  }
  
  this.removeTag = function(tag){

    var jqueryTag = $("#chosen_tags .chosen_tag").select(
      function(){
        return $(this).text() == tag;
      },
      function(){
        $(this).remove();
        return false; // break (select only one)
      }
    );
        
    array_remove(this.chosenTags, tag);
    if (this.chosenTags.length == 0){
      $("#chosen_tags").hide();
    }
    
    Notes.updateForDeselectedTag(tag);
    Cloud.recalculate();
  }
  
  this.isTagChosen = function(tag){
    return this.chosenTags.indexOf(tag) != -1;
  }

}();

/* --- Notes ---------------------------------------------------------------- */

var Notes = new function(){

  this.updateForSelectedTag = function(tag){
  
    $(".note:visible").each(function(){
      if (! $(this).find(".note_tag").existsText(tag)){
        $(this).hide();
      }
    });
    
    $(".note .note_tag").select(
      function(){
        return $(this).text() == tag; 
      },
      function(){
        $(this).addClass("chosen_tag");
      }
    );
  }

  this.updateForDeselectedTag = function(tag){

    $(".note:hidden").each(function(){
      var jqueryTags = $(this).find(".note_tag");
      for (var i = 0; i < Filter.chosenTags.length; i++){
        if (! jqueryTags.existsText(Filter.chosenTags[i])){
          return;
        }
      }
      $(this).show();
    });
    
    $(".note .note_tag").select(
      function(){
        return $(this).text() == tag; 
      },
      function(){
        $(this).removeClass("chosen_tag");
      }
    );
  }

  this.update = function(){

    $(".note").each(function(){
      var jqueryTags = $(this).find(".note_tag");
      for (var i = 0; i < Filter.chosenTags.length; i++){
        if (! jqueryTags.existsText(Filter.chosenTags[i])){
          $(this).hide();
          return;
        }
      }
      $(this).show();
    });
    
    $(".note .note_tag").each(function(){
      if (Filter.isTagChosen($(this).text())){
        $(this).addClass("chosen_tag"); 
      }
      else{
        $(this).removeClass("chosen_tag");
      }
    });
  }

}();

/* --- Tag utils ------------------------------------------------------------ */

function tag_setClickHandler(jqueryTags){
  jqueryTags.unbind("click").click(function(){
    if ($(this).hasClass("chosen_tag")){
      Filter.removeTag($(this).text()); 
    }
    else{
      Filter.addTag($(this).text());  
    }
    return false;
  });
}

/* --- Startup -------------------------------------------------------------- */

$(document).ready(function(){
  
  tag_setClickHandler($(".note_tag"));
    
  Cloud.recalculate();
  
  $("#toggle_tags").click(function(){
    if (!$(this).hasClass("active_link")){
    
      $("#toggle_popular_tags").removeClass("active_link");
      $("#toggle_all_tags").removeClass("active_link");
      $(this).addClass("active_link");
      
      $("#all_tags").hide();
      $("#popular_tags").hide();
    }
    return false;
  });
  
  $("#toggle_popular_tags").click(function(){
    if (!$(this).hasClass("active_link")){
    
      $("#toggle_tags").removeClass("active_link");
      $("#toggle_all_tags").removeClass("active_link");
      $(this).addClass("active_link");
      
      $("#all_tags").hide();
      $("#popular_tags").show();
    }
    return false;
  });
  
  $("#toggle_all_tags").click(function(){
    if (!$(this).hasClass("active_link")){
    
      $("#toggle_tags").removeClass("active_link");
      $("#toggle_popular_tags").removeClass("active_link");
      $(this).addClass("active_link");
      
      $("#popular_tags").hide();
      $("#all_tags").show();
    }
    return false;
  });
});