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

   qooxdoo - the new era of web development

   http://qooxdoo.org

   Copyright:
     2006 by STZ-IDA, Germany, http://www.stz-ida.de

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

   Authors:
     * Til Schneider (til132)

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

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

#module(log)

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

/**
 * An appender that writes all messages to a div element.
 *
 * This class does not depend on qooxdoo widgets, so it also works when there
 * are problems with widgets or when the widgets are not yet initialized.
 *
 * @param divId {string ? "qx_log"} the ID of the div element to write the
 *        messages to.
 */
qx.OO.defineClass("qx.dev.log.DivAppender", qx.dev.log.Appender,
function(divId) {
  qx.dev.log.Appender.call(this);

  this._divId = divId ? divId : "qx_log";
});


/**
 * The maximum number of messages to show. If null the number of messages is not
 * limited.
 */
qx.OO.addProperty({ name:"maxMessages", type:"number", defaultValue:500 });

// overridden
qx.OO.changeProperty({ name:"useLongFormat", type:"boolean", defaultValue:false, allowNull:false });

/** The CSS class name for the head div {containing the clear button}. */
qx.OO.addProperty({ name:"headClassName", type:"string", defaultValue:"log-head" });

/** The CSS class name for the body div {containing the log messages}. */
qx.OO.addProperty({ name:"bodyClassName", type:"string", defaultValue:"log-body" });

/** The CSS class name for a div showing the name of the current group. */
qx.OO.addProperty({ name:"groupClassName", type:"string", defaultValue:"log-group" });

/** The CSS class name for a div showing a debug message. */
qx.OO.addProperty({ name:"debugClassName", type:"string", defaultValue:"log-debug" });

/** The CSS class name for a div showing a info message. */
qx.OO.addProperty({ name:"infoClassName", type:"string", defaultValue:"log-info" });

/** The CSS class name for a div showing a warn message. */
qx.OO.addProperty({ name:"warnClassName", type:"string", defaultValue:"log-warn" });

/** The CSS class name for a div showing a error message. */
qx.OO.addProperty({ name:"errorClassName", type:"string", defaultValue:"log-error" });


/**
 * Creates an onclick handler that clears a div element. This method is used to
 * create a minimum closure.
 *
 * @param logElem {Element} the element to clear when the handler is called.
 * @return {Function} the handler.
 */
qx.Proto._createClearButtonHandler = function(logElem) {
  return function(evt) {
    logElem.innerHTML = "";
  }
}


// overridden
qx.Proto.appendLogEvent = function(evt) {
  var Logger = qx.dev.log.Logger;

  // Initialize the log element if nessesary
  if (this._logElem == null) {
    var divElem = document.getElementById(this._divId);
    if (divElem == null) {
      throw new Error("Logging div with ID " + this._divId + " not found");
    }
    divElem.innerHTML = '<div class="' + this.getHeadClassName() + '"><button>Clear</button></div>'
      + '<div class="' + this.getBodyClassName() + '"></div>';

    this._clearBt = divElem.firstChild.firstChild;
    this._logElem = divElem.lastChild;

    this._clearBt.onclick = this._createClearButtonHandler(this._logElem);
  }

  // Append the group when needed
  var group = evt.logger.getName();
  if (evt.instanceId != null) {
    group += "[" + evt.instanceId + "]";
  }

  if (group != this._lastGroup) {
    var elem = document.createElement("div");
    elem.className = this.getGroupClassName();
    elem.innerHTML = group;

    this._logElem.appendChild(elem);
    this._lastGroup = group;
  }

  // Append the message
  var elem = document.createElement("div");
  switch (evt.level) {
    case Logger.LEVEL_DEBUG: elem.className = this.getDebugClassName(); break;
    case Logger.LEVEL_INFO:  elem.className = this.getInfoClassName();  break;
    case Logger.LEVEL_WARN:  elem.className = this.getWarnClassName();  break;
    case Logger.LEVEL_ERROR: elem.className = this.getErrorClassName(); break;
  }
  elem.innerHTML = this.formatLogEvent(evt).replace(/&/g, "&amp;")
    .replace(/</g, "&lt;").replace(/  /g, " &#160;").replace(/[\n]/g, "<br>");
  this._logElem.appendChild(elem);

  // Remove superflous messages
  while (this._logElem.childNodes.length > this.getMaxMessages()) {
    this._logElem.removeChild(this._logElem.firstChild);

    if (this._removedMessageCount == null) {
      this._removedMessageCount = 1;
    } else {
      this._removedMessageCount++;
    }
  }

  if (this._removedMessageCount != null) {
    this._logElem.firstChild.className = "";
    this._logElem.firstChild.innerHTML = "(" + this._removedMessageCount
      + " messages removed)";
  }
}


// overridden
qx.Proto.dispose = function() {
  if (this.getDisposed()) {
      return true;
  }

  if (this._clearBt) {
    this._clearBt.onclick = null;
    this._clearBt = null;
  }
  this._logElem = null;

  return qx.dev.log.Appender.prototype.dispose.call(this);
}