/* ************************************************************************

   qooxdoo - the new era of web development

   http://qooxdoo.org

   Copyright:
     2004-2006 by 1&1 Internet AG, Germany, http://www.1and1.org

   License:
     LGPL 2.1: http://www.gnu.org/licenses/lgpl.html

   Authors:
     * Sebastian Werner (wpbasti)
     * Andreas Ecker (ecker)

************************************************************************ */

/* ************************************************************************


************************************************************************ */

/*!
  A class to generate a widget hierarchy from XML

  qx.client.Builder is not thread safe by design
    - state information is stored at the instance level
    - only use it from a single thread
*/
qx.OO.defineClass("qx.client.Builder", qx.core.Target,
function(flags)
{
  qx.core.Target.call(this);

  // map<className, map<propertyName, function>>
  this._propertyEditors = {};

  this._registerDefaultPropertyEditors();

  this._flags = flags || {};

  // ensure the default flags are setup
  if (this._flags.strict == null) {
    // strick mode throws exceptions when
    //  * widget setters don't exist
    this._flags.strict = true;
  }

});

/*
------------------------------------------------------------------------------------
  BUILD
------------------------------------------------------------------------------------
*/

/*!
  Asynchronous method - fetches XML data from the URL then delegates to build to process the xml
  Dispatches a qx.event.type.Event("done") after the hierarchy is built
*/
qx.Proto.buildFromUrl = function(parent, url) {
  var req = new qx.io.remote.Request(url, "GET", "application/xml");
  var self = this;
  req.addEventListener("completed", function(e) {
    self.build(parent, e.getData().getContent());
    qx.ui.core.Widget.flushGlobalQueues();
  });
  req.send();
}

/*!
  parse the children of the xml and appending all widgets to the parent widget
  @param parent can either be the application instance, or a widget to append the xml toplevel widgets to
  @param node can be either a xml string, or a xml dom document or fragment
*/
qx.Proto.build = function(parent, node) {
    // support embedding of an XML string within a textarea
    if (typeof node == "object" && node.nodeName == 'TEXTAREA') {
      node = node.value;
    }

    // parse strings in to XML DOM
    if (typeof node == "string") {
      var parser = new DOMParser();
      node = parser.parseFromString(node, "text/xml");
      // TODO handle parse errors
    }
    this._buildNodes(parent, node.childNodes);
}

qx.Proto._buildNodes = function(parent, nodes) {
    var x = 0;
    for (var i = 0; i < nodes.length; i++) {
      var n = nodes[i];
      // 1 = ELEMENT_NODE
      if (n.nodeType == 1) {
          this._buildWidgetFromNode(parent, n);
      }
    }
}

qx.Proto._buildEventListener = function(widget, args, text) {
  if (qx.util.Validation.isInvalidString(args.type)) {
    throw this._newError('eventListener requires a string type attribute');
  }

  var self = this;

  // are we delegating ?
  if (qx.util.Validation.isValidString(args.delegate)) {

    if (args.delegate.indexOf('.') > -1) {
      // delegation to a global method
      var p = args.delegate.split('.');
      var o = p[0];
      var m = p[1];
      widget.addEventListener(args.type, function(e) {

          if (!window[o]) {
            throw self._newError('delegate not found', {delegate:args.delegate});
          }

          if (!window[o][m]) {
            throw self._newError('delegate not found', {delegate:args.delegate});
          }

          window[o][m].apply(window[o], [e]);
      });
    }
    else {

      // delegation to a global method
      widget.addEventListener(args.type, function(e) {

        if (!window[args.delegate]) {
          throw self._newError('delegate not found', {delegate:args.delegate});
        }

        window[args.delegate].apply(null, [e]);
      });
    }
  }
  else {

    // build a function object using text as the function body
    //
    // the args attribute indicates the name of the event argument
    // if not provided - use 'event' as the name
    if (!args.args) {
      args.args = "event";
    }

    var f = new Function(args.args, text);
    widget.addEventListener(args.type, f);
  }
}


/*
  a node builder that will be used if no node builder is declared for a nodeName
*/
qx.Proto._buildWidgetFromNode = function(parent, node) {

  var className = this._extractClassName(node);

  if (!className) {
    throw this._newError("unrecognised node", {nodeName:node.nodeName});
  }

  if (className == "qx.client.builder.Container") {
    // generic container node to allow xml to contain multiple toplevel nodes
    this._buildNodes(parent, node.childNodes);
    return;
  }

  if (className == "qx.client.builder.Script") {
    var e = document.createElement("script");
    var attribs = this._mapXmlAttribToObject(node);
    if (attribs.type) {
      e.type = attribs.type;
    }
    else {
      e.type='text/javascript';
    }

    // e.innerHTML = node.firstChild.nodeValue;

    // fix for Internet Explorer by Cristian Bica
    if (qx.sys.Client.getInstance().isMshtml())
    {
      e.innerHTML = eval(node.firstChild.nodeValue);
    }
    else
    {
      e.innerHTML = node.firstChild.nodeValue;
    }

    document.body.appendChild(e);
    return;
  }

  if (className == "qx.client.builder.EventListener") {
    var attribs = this._mapXmlAttribToObject(node);
    var text;
    if (node.firstChild) {
      text = node.firstChild.nodeValue;
    }
    this._buildEventListener(parent, attribs, text);
    return;
  }


  var classConstructor = qx.OO.classes[className];
  if (!classConstructor) {
    throw this._newError("constructor not found", {className:className});
  }

  // construct the widget instance - using the default constructor
  var widget = new classConstructor();
  var attribs = this._mapXmlAttribToObject(node, widget);
  delete attribs['qxtype'];

  var dummyWidget = attribs.id && attribs.id.indexOf("_") == 0;

  if (attribs.id) {
    // register a global refrence for this widget
    window[attribs.id] = widget;
    delete attribs.id;
  }

  // convert any on??  attribs into event listeners
  for (var a in attribs) {

    if (a.toLowerCase().indexOf('on') == 0 && a.length > 2) {

      // there may be issues here for XHTML based attributes - due to their case
      var type = a.substring(2);
      type = type.charAt(0) + type.substring(1);

      this._buildEventListener(widget, {type:type,args:'event'}, attribs[a]);

      delete attribs[a];
    }
  }

  for (var n in attribs) {
    this._setWidgetProperty(widget, n, attribs[n]);
  }

  if(!dummyWidget) {
    parent.add(widget);
  }

  // recurse to all of the nodes children, using the newly created widget as the parent
  this._buildNodes(widget, node.childNodes);
}

/*
------------------------------------------------------------------------------------
  WIDGET PROPERTIES
------------------------------------------------------------------------------------
*/


/*!
  Set a widget's property using a propertyEditor
*/
qx.Proto._setWidgetProperty = function(widget, name, value) {
  var editor = this._findPropertyEditor(widget.classname, name);
  if (!editor) {
    editor = this._coercePropertyEditor;
  }
  editor.set(widget, name, value);
}

qx.Proto._findPropertyEditor = function(className, propertyName) {
  // get all defined propertyEditors for this widget's prototype
  var m = this._propertyEditors[className];
  // lookup the converter for this property name
  if (m && m[propertyName]) {
    return m[propertyName];
  }

  // try the widget's superclass
  var w = qx.OO.classes[className];
  if (w && w.superclass && w.superclass.prototype.classname) {
    return this._findPropertyEditor(w.superclass.prototype.classname, propertyName);
  }

  return null;
}

qx.Proto.registerPropertyEditor = function(className, propertyName, editor) {
  if (!this._propertyEditors[className]) this._propertyEditors[className] = {};
  this._propertyEditors[className][propertyName] = editor;
}

qx.Proto._registerDefaultPropertyEditors = function() {
  var self = this;

  // a property editor that splits the values on a comma and coerces each one into a suitable type
  var commaDelimitedPropertyEditor = {};
  commaDelimitedPropertyEditor.set = function(widget, name, value) {
      if (value == null || value == "") {
        self._setProperty(widget, name, null);
        return;
      }

      var s = value.split(",");
      var v = [];
      for (var i = 0; i < s.length; i++) {
        v[i] = self._coerce(s[i]);
      }

      self._setProperties(widget, name, v);
  }

  var evalPropertyEditor = {};
  evalPropertyEditor.set = function(widget, name, value) {
      if (value == null || value == "") {
        self._setProperty(widget, name, null);
        return;
      }

      self._setProperty(widget, name, eval(value));
  }

  var referencePropertyEditor = {};
  referencePropertyEditor.set = function(widget, name, value) {
    self._setProperty(widget, name, window[value]);
  }

  this.registerPropertyEditor('qx.ui.core.Widget', 'location', commaDelimitedPropertyEditor);
  this.registerPropertyEditor('qx.ui.core.Widget', 'dimension', commaDelimitedPropertyEditor);

  this.registerPropertyEditor('qx.ui.core.Widget', 'space', commaDelimitedPropertyEditor);
  this.registerPropertyEditor('qx.ui.core.Widget', 'edge', commaDelimitedPropertyEditor);

  this.registerPropertyEditor('qx.ui.core.Widget', 'padding', commaDelimitedPropertyEditor);
  this.registerPropertyEditor('qx.ui.core.Widget', 'margin', commaDelimitedPropertyEditor);

  this.registerPropertyEditor('qx.ui.core.Widget', 'heights', commaDelimitedPropertyEditor);
  this.registerPropertyEditor('qx.ui.core.Widget', 'widths', commaDelimitedPropertyEditor);

  this.registerPropertyEditor('qx.ui.core.Widget', 'align', commaDelimitedPropertyEditor);
  this.registerPropertyEditor('qx.ui.core.Widget', 'stretch', commaDelimitedPropertyEditor);

  this.registerPropertyEditor('qx.ui.core.Widget', 'clipLocation', commaDelimitedPropertyEditor);
  this.registerPropertyEditor('qx.ui.core.Widget', 'clipDimension', commaDelimitedPropertyEditor);
  this.registerPropertyEditor('qx.ui.core.Widget', 'clip', commaDelimitedPropertyEditor);

  this.registerPropertyEditor('qx.ui.core.Widget', 'backgroundColor', evalPropertyEditor);
  this.registerPropertyEditor('qx.ui.core.Widget', 'color', evalPropertyEditor);
  this.registerPropertyEditor('qx.ui.core.Widget', 'border', evalPropertyEditor);


  this.registerPropertyEditor('qx.ui.menu.Button', 'menu', referencePropertyEditor);
  this.registerPropertyEditor('qx.ui.form.RadioButton', 'manager', referencePropertyEditor);
  this.registerPropertyEditor('qx.ui.menu.RadioButton', 'group', referencePropertyEditor);


  // a property editor that just tries to coerce the string value into a suitable type
  this._coercePropertyEditor = {};
  this._coercePropertyEditor.set = function(widget, name, value) {
      self._setProperty(widget, name, self._coerce(value));
  }

}


qx.Proto._coerce = function(value) {

  // don't really care if its null
  if (value == null) return value;

  // is it alreay a javascript type
  if (typeof value == 'object') return value;
  if (typeof value == 'function') return value;
  if (typeof value == 'number') return value;
  if (typeof value == 'boolean') return value;
  if (typeof value == 'date') return value;
  if (typeof value == 'array') return value;

  // is it a number ?
  var n = new Number(value);
  if (!isNaN(n)) return n.valueOf();

  // is it a boolean ?
  if (value == "true") return true;
  if (value == "false") return false;

  // is it a date ?
  var d = Date.parse(value);
  if (d != null && !isNaN(d)) return d;

  // leave it as a string
  if (typeof value == 'string') {
    // convert empty string into null
    if (value == "") return null;
  }

  return value;
}

qx.Proto._setProperty = function(widget, name, value) {
  this._setProperties(widget, name, [value]);
}

qx.Proto._setProperties = function(widget, name, value) {

  // TODO : find a cheaper way to find the setter
  // NOTE : the name is LOWERCASE - hence we iterate all properties of the widget
  //         to try and find a matching one
  var n = "set" + name;
  for (var a in widget) {
    if (n == a.toLowerCase()) {
      var setter = widget[a];
      break;
    }
  }
  if (!setter && this._flags.strict) throw this._newError('no setter defined on widget instance', {widget:widget, property:name});
  setter.apply(widget, value);
}


/*
------------------------------------------------------------------------------------
  UTILS
------------------------------------------------------------------------------------
*/

/*
2 format
1. <qx.ui.basic.Atom/>
3. <div qxtype="qx.ui.basic.Atom"/>
*/
qx.Proto._extractClassName = function(node) {
  if (node.nodeName.toLowerCase() == "div") {
    if (!node.attributes['qxtype'])
      return null;
    return node.attributes['qxtype'].value;
  } else {
    return node.nodeName;
  }
}

qx.Proto._mapXmlAttribToObject = function(node) {
  var r = {};
  var c = node.attributes;
  for (var i=0; i<c.length; i++) {
    r[c[i].name.toLowerCase()] = c[i].value;
  }
  return r;
}

/*
------------------------------------------------------------------------------------
  EXCEPTION HANDLING / DEBUGGING
------------------------------------------------------------------------------------
*/

qx.Proto._newError = function(message, data, exception) {
  var m = message;
  var joiner = "";
  var d = "";
  if (data) {
    for (var p in data) {
      d += joiner + p + "=" + data[p] + '';
      joiner = " ";
    }
    m += " " + d + " ";
  }
  if (exception) {
    m+= " error: " + exception + " ";
  }
  return new Error(m);
}