/**

 * Javascript auto-completion for form fields.

 */

var af_current = false;

function AutofillUsername(parent, event, allowanon)

{

  // if this is IE, use the old code

  if ( IE )

  {

    ajaxUserNameComplete(parent);

    return false;

  }

  if ( parent.afobj )

  {

    parent.afobj.go();

    return true;

  }

  parent.autocomplete = 'off';

  parent.setAttribute('autocomplete', 'off');

  this.repeat = false;

  this.event = event;

  this.box_id = false;

  this.boxes = new Array();

  this.state = false;

  this.allowanon = ( allowanon ) ? true : false;

  if ( !parent.id )

    parent.id = 'afuser_' + Math.floor(Math.random() * 1000000);

  this.field_id = parent.id;

  // constants

  this.KEY_UP    = 38;

  this.KEY_DOWN  = 40;

  this.KEY_ESC   = 27;

  this.KEY_TAB   = 9;

  this.KEY_ENTER = 13;

  // response cache

  this.responses = new Object();

  // ajax placeholder

  this.process_dataset = function(resp_json)

  {

    // window.console.info('Processing the following dataset.');

    // window.console.debug(resp_json);

    var autofill = this;

    if ( typeof(autofill.event) == 'object' )

    {

      if ( autofill.event.keyCode )

      {

        if ( autofill.event.keyCode == autofill.KEY_ENTER && autofill.boxes.length < 1 && !autofill.box_id )

        {

          // user hit enter after accepting a suggestion - submit the form

          var frm = findParentForm($(autofill.field_id).object);

          frm._af_acting = false;

          frm.submit();

          // window.console.info('Submitting form');

          return false;

        }

        if ( autofill.event.keyCode == autofill.KEY_UP || autofill.event.keyCode == autofill.KEY_DOWN || autofill.event.keyCode == autofill.KEY_ESC || autofill.event.keyCode == autofill.KEY_TAB || autofill.event.keyCode == autofill.KEY_ENTER )

        {

          autofill.keyhandler();

          // window.console.info('Control key detected, called keyhandler and exiting');

          return true;

        }

      }

    }

    if ( this.box_id )

    {

      this.destroy();

      // window.console.info('already have a box open - destroying and exiting');

      //return false;

    }

    var users = new Array();

    for ( var i = 0; i < resp_json.users_real.length; i++ )

    {

      try

      {

        var user = resp_json.users_real[i].toLowerCase();

        var inp  = $(autofill.field_id).object.value;

        inp = inp.toLowerCase();

        if ( user.indexOf(inp) > -1 )

        {

          users.push(resp_json.users_real[i]);

        }

      }

      catch(e)

      {

        users.push(resp_json.users_real[i]);

      }

    }

    // This was used ONLY for debugging the DOM and list logic    

    // resp_json.users = resp_json.users_real;

    // construct table

    var div = document.createElement('div');

    div.className = 'tblholder';

    div.style.clip = 'rect(0px,auto,auto,0px)';

    div.style.maxHeight = '200px';

    div.style.overflow = 'auto';

    div.style.zIndex = '9999';

    var table = document.createElement('table');

    table.border = '0';

    table.cellSpacing = '1';

    table.cellPadding = '3';

    var tr = document.createElement('tr');

    var th = document.createElement('th');

    th.appendChild(document.createTextNode('Username suggestions'));

    tr.appendChild(th);

    table.appendChild(tr);

    if ( users.length < 1 )

    {

      var tr = document.createElement('tr');

      var td = document.createElement('td');

      td.className = 'row1';

      td.appendChild(document.createTextNode('No suggestions'));

      td.afobj = autofill;

      tr.appendChild(td);

      table.appendChild(tr);

    }

    else

      for ( var i = 0; i < users.length; i++ )

      {

        var user = users[i];

        var tr = document.createElement('tr');

        var td = document.createElement('td');

        td.className = ( i == 0 ) ? 'row2' : 'row1';

        td.appendChild(document.createTextNode(user));

        td.afobj = autofill;

        td.style.cursor = 'pointer';

        td.onclick = function()

        {

          this.afobj.set(this.firstChild.nodeValue);

        }

        tr.appendChild(td);

        table.appendChild(tr);

      }

    // Finalize div

    var tb_top    = $(autofill.field_id).Top();

    var tb_height = $(autofill.field_id).Height();

    var af_top    = tb_top + tb_height - 9;

    var tb_left   = $(autofill.field_id).Left();

    var af_left   = tb_left;

    div.style.position = 'absolute';

    div.style.left = af_left + 'px';

    div.style.top  = af_top  + 'px';

    div.style.width = '200px';

    div.style.fontSize = '7pt';

    div.style.fontFamily = 'Trebuchet MS, arial, helvetica, sans-serif';

    div.id = 'afuserdrop_' + Math.floor(Math.random() * 1000000);

    div.appendChild(table);

    autofill.boxes.push(div.id);

    autofill.box_id = div.id;

    if ( users.length > 0 )

      autofill.state = users[0];

    var body = document.getElementsByTagName('body')[0];

    body.appendChild(div);

    autofill.repeat = true;

  }

  // perform ajax call

  this.fetch_and_process = function()

  {

    af_current = this;

    var processResponse = function()

    {

      if ( ajax.readyState == 4 )

      {

        var afobj = af_current;

        af_current = false;

        // parse the JSON response

        var response = String(ajax.responseText) + ' ';

        if ( response.substr(0,1) != '{' )

        {

          new messagebox(MB_OK|MB_ICONSTOP, 'Invalid response', 'Invalid or unexpected JSON response from server:<pre>' + ajax.responseText + '</pre>');

          return false;

        }

        if ( $(afobj.field_id).object.value.length < 3 )

          return false;

        var resp_json = parseJSON(response);

        var resp_code = $(afobj.field_id).object.value.toLowerCase().substr(0, 3);

        afobj.responses[resp_code] = resp_json;

        afobj.process_dataset(resp_json);

      }

    }

    var usernamefragment = ajaxEscape($(this.field_id).object.value);

    ajaxGet(stdAjaxPrefix + '&_mode=fillusername&name=' + usernamefragment + '&allowanon=' + ( this.allowanon ? '1' : '0' ), processResponse);

  }

  this.go = function()

  {

    if ( document.getElementById(this.field_id).value.length < 3 )

    {

      this.destroy();

      return false;

    }

    if ( af_current )

      return false;

    var resp_code = $(this.field_id).object.value.toLowerCase().substr(0, 3);

    if ( this.responses.length < 1 || ! this.responses[ resp_code ] )

    {

      // window.console.info('Cannot find dataset ' + resp_code + ' in cache, sending AJAX request');

      this.fetch_and_process();

    }

    else

    {

      // window.console.info('Using cached dataset: ' + resp_code);

      var resp_json = this.responses[ resp_code ];

      this.process_dataset(resp_json);

    }

    document.getElementById(this.field_id).onkeyup = function(event)

    {

      this.afobj.event = event;

      this.afobj.go();

    }

    document.getElementById(this.field_id).onkeydown = function(event)

    {

      var form = findParentForm(this);

      if ( typeof(event) != 'object' )

        var event = window.event;

      if ( typeof(event) == 'object' )

      {

        if ( event.keyCode == this.afobj.KEY_ENTER && this.afobj.boxes.length < 1 && !this.afobj.box_id )

        {

          // user hit enter after accepting a suggestion - submit the form

          form._af_acting = false;

          return true;

        }

      }

      form._af_acting = true;

    }

  }

  this.keyhandler = function()

  {

    var key = this.event.keyCode;

    if ( key == this.KEY_ENTER && !this.repeat )

    {

      var form = findParentForm($(this.field_id).object);

        form._af_acting = false;

      return true;

    }

    switch(key)

    {

      case this.KEY_UP:

        this.focus_up();

        break;

      case this.KEY_DOWN:

        this.focus_down();

        break;

      case this.KEY_ESC:

        this.destroy();

        break;

      case this.KEY_TAB:

        this.destroy();

        break;

      case this.KEY_ENTER:

        this.set();

        break;

    }

    var form = findParentForm($(this.field_id).object);

      form._af_acting = false;

  }

  this.get_state_td = function()

  {

    var div = document.getElementById(this.box_id);

    if ( !div )

      return false;

    if ( !this.state )

      return false;

    var table = div.firstChild;

    for ( var i = 1; i < table.childNodes.length; i++ )

    {

      // the table is DOM-constructed so no cruddy HTML hacks :-)

      var child = table.childNodes[i];

      var tn = child.firstChild.firstChild;

      if ( tn.nodeValue == this.state )

        return child.firstChild;

    }

    return false;

  }

  this.focus_down = function()

  {

    var state_td = this.get_state_td();

    if ( !state_td )

      return false;

    if ( state_td.parentNode.nextSibling )

    {

      // Ooh boy, DOM stuff can be so complicated...

      // <tr>  -->  <tr>

      // <td>       <td>

      // user       user

      var newstate = state_td.parentNode.nextSibling.firstChild.firstChild.nodeValue;

      if ( !newstate )

        return false;

      this.state = newstate;

      state_td.className = 'row1';

      state_td.parentNode.nextSibling.firstChild.className = 'row2';

      // Exception - automatically scroll around if the item is off-screen

      var height = $(this.box_id).Height();

      var top = $(this.box_id).object.scrollTop;

      var scroll_bottom = height + top;

      var td_top = $(state_td.parentNode.nextSibling.firstChild).Top() - $(this.box_id).Top();

      var td_height = $(state_td.parentNode.nextSibling.firstChild).Height();

      var td_bottom = td_top + td_height;

      if ( td_bottom > scroll_bottom )

      {

        var scrollY = td_top - height + 2*td_height - 7;

        // window.console.debug(scrollY);

        $(this.box_id).object.scrollTop = scrollY;

        /*

        var newtd = state_td.parentNode.nextSibling.firstChild;

        var a = document.createElement('a');

        var id = 'autofill' + Math.floor(Math.random() * 100000);

        a.name = id;

        a.id = id;

        newtd.appendChild(a);

        window.location.hash = '#' + id;

        */

        // In firefox, scrolling like that makes the field get unfocused

        $(this.field_id).object.focus();

      }

    }

    else

    {

      return false;

    }

  }

  this.focus_up = function()

  {

    var state_td = this.get_state_td();

    if ( !state_td )

      return false;

    if ( state_td.parentNode.previousSibling && state_td.parentNode.previousSibling.firstChild.tagName != 'TH' )

    {

      // Ooh boy, DOM stuff can be so complicated...

      // <tr>  <--  <tr>

      // <td>       <td>

      // user       user

      var newstate = state_td.parentNode.previousSibling.firstChild.firstChild.nodeValue;

      if ( !newstate )

      {

        return false;

      }

      this.state = newstate;

      state_td.className = 'row1';

      state_td.parentNode.previousSibling.firstChild.className = 'row2';

      // Exception - automatically scroll around if the item is off-screen

      var top = $(this.box_id).object.scrollTop;

      var td_top = $(state_td.parentNode.previousSibling.firstChild).Top() - $(this.box_id).Top();

      if ( td_top < top )

      {

        $(this.box_id).object.scrollTop = td_top - 10;

        /*

        var newtd = state_td.parentNode.previousSibling.firstChild;

        var a = document.createElement('a');

        var id = 'autofill' + Math.floor(Math.random() * 100000);

        a.name = id;

        a.id = id;

        newtd.appendChild(a);

        window.location.hash = '#' + id;

        */

        // In firefox, scrolling like that makes the field get unfocused

        $(this.field_id).object.focus();

      }

    }

    else

    {

      $(this.box_id).object.scrollTop = 0;

      return false;

    }

  }

  this.destroy = function()

  {

    this.repeat = false;

    var body = document.getElementsByTagName('body')[0];

    var div = document.getElementById(this.box_id);

    if ( !div )

      return false;

    setTimeout('var body = document.getElementsByTagName("body")[0]; body.removeChild(document.getElementById("'+div.id+'"));', 20);

    // hackish workaround for divs that stick around past their welcoming period

    for ( var i = 0; i < this.boxes.length; i++ )

    {

      var div = document.getElementById(this.boxes[i]);

      if ( div )

        setTimeout('var body = document.getElementsByTagName("body")[0]; var div = document.getElementById("'+div.id+'"); if ( div ) body.removeChild(div);', 20);

      delete(this.boxes[i]);

    }

    this.box_id = false;

    this.state = false;

  }

  this.set = function(val)

  {

    var ta = document.getElementById(this.field_id);

    if ( val )

      ta.value = val;

    else if ( this.state )

      ta.value = this.state;

    this.destroy();

  }

  this.sleep = function()

  {

    if ( this.box_id )

    {

      var div = document.getElementById(this.box_id);

      div.style.display = 'none';

    }

    var el = $(this.field_id).object;

    var fr = findParentForm(el);

    el._af_acting = false;

  }

  this.wake = function()

  {

    if ( this.box_id )

    {

      var div = document.getElementById(this.box_id);

      div.style.display = 'block';

    }

  }

  parent.onblur = function()

  {

    af_current = this.afobj;

    window.setTimeout('if ( af_current ) af_current.sleep(); af_current = false;', 50);

  }

  parent.onfocus = function()

  {

    af_current = this.afobj;

    window.setTimeout('if ( af_current ) af_current.wake(); af_current = false;', 50);

  }

  parent.afobj = this;

  var frm = findParentForm(parent);

  if ( frm.onsubmit )

  {

    frm.orig_onsubmit = frm.onsubmit;

    frm.onsubmit = function(e)

    {

      if ( this._af_acting )

        return false;

      this.orig_onsubmit(e);

    }

  }

  else

  {

    frm.onsubmit = function()

    {

      if ( this._af_acting )

        return false;

    }

  }

  if ( parent.value.length < 3 )

  {

    this.destroy();

    return false;

  }

}

function findParentForm(o)

{

  if ( o.tagName == 'FORM' )

    return o;

  while(true)

  {

    o = o.parentNode;

    if ( !o )

      return false;

    if ( o.tagName == 'FORM' )

      return o;

  }

  return false;

}