// Copyright 2007 Google Inc.

// All Rights Reserved.

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

// 

//     http://www.apache.org/licenses/LICENSE-2.0

// 

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

/**

 * @fileoverview Defines the code for the application logging console.

 */

/**

 * The namespace we're using for all javascript classes and functions related

 * to the logging console.

 */

var AH = {};

/**

 * A collection of utility functions for reading and writing cookies.

 * @constructor

 */

AH.CookieUtil = function() {};

/**

 * Creates and adds a cookie with the specified expiration.

 * @param {String} name  The name of the desired cookie.

 * @param {String} value  The value of the desired cookie.

 * @param {Number} opt_days  If non-negative, the expiration time in days of the

 *     desired cookie. If not provided, the default value is 1.

 */

AH.CookieUtil.prototype.setCookie = function(name, value, opt_days) {

  if (opt_days == null) {

    opt_days = 1;

  }

  var expires = '';

  if (opt_days < 0) {

    var date = new Date;

    date.setTime(date.getTime() + (opt_days * 24 * 60 * 60 * 1000));

    expires = '; expires=' + date.toGMTString();

  }

  document.cookie = name + '=' + value + expires + '; path=/';

};

/**

 * Returns the value of the requested cookie if it is available, and otherwise

 * returns a default value.

 * @param {String} name  The name of the requested cookie.

 * @param {String} defaultValue  The value to return if the requested cookie

 *     cannot be found.

 * @return {String} The requested cookie's value, or the default value.

 */

AH.CookieUtil.prototype.getCookie = function(name, defaultValue) {

  var nameEQ = name + '=';

  var cookiePieces = document.cookie.split(';');

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

    var c = cookiePieces[i];

    c = c.replace(/^\s+/, '');

    if (c.indexOf(nameEQ) == 0) {

      return c.substring(nameEQ.length, c.length);

    }

  }

  return defaultValue;

};

/**

 * Deletes the specified cookie.

 * @param {String} name  The name of the specified cookie.

 */

AH.CookieUtil.prototype.removeCookie = function(name) {

  this.setCookie(name, '', -100);

};

/**

 * The logging console is a div that displays log statements generated by the

 * application during it's execution. It can be moved around, and the verbosity

 * can be adjusted.

 * @constructor

 */

AH.LoggingConsole = function() {

  this.baseDiv = document.getElementById('_ah_base');

  this.logSeverityLevels = ['debug', 'info', 'warning', 'error', 'critical'];

  this.cookieUtil = new AH.CookieUtil;

};

/**

 * Creates and positions the logging console based on preferences available from

 * the cookies '_ah_severity' and '_ah_position'.

 */

AH.LoggingConsole.prototype.initConsole = function() {

  // Define the font colors for the different log severity levels.

  this.addCssRule('._ah_logline_debug_prefix', 'color:#110000');

  this.addCssRule('._ah_logline_info_prefix', 'color:#440000');

  this.addCssRule('._ah_logline_warning_prefix', 'color:#880000');

  this.addCssRule('._ah_logline_error_prefix', 'color:#CC0000');

  this.addCssRule('._ah_logline_critical_prefix', 'color:#FF0000');

  // Change to the severity level stored in the cookie, defaulting to the lowest

  // severity level.

  this.changeLogSeverity(this.cookieUtil.getCookie('_ah_severity', 'debug'));

  // Move the console to position stored in the cookie, defaulting to the

  // bottom right position.

  this.moveBaseDiv(this.cookieUtil.getCookie('_ah_position', 'down_right'));

};

/**

 * Add CSS rules to the document to modify the presentation for elements of the

 * specified class name. This works for IE and Firefox, but does not work for

 * Safari.

 * @param {String} selector  A selector for the style class rule to modify.

 * @param {String} styleRules  The rules to add to the specified style class.

 */

AH.LoggingConsole.prototype.addCssRule = function(selector, styleRules) {

  // If no sheet exists for the document, create one.

  var sheet;

  if (document.createStyleSheet) {

    // For IE:

    sheet = document.createStyleSheet();

  } else {

    // For Firefox:

    var styleElement = document.createElement('style');

    document.getElementsByTagName('head')[0].appendChild(styleElement);

    sheet = (styleElement.styleSheet ?

             styleElement.styleSheet :

             styleElement.sheet);

  }

  // Add the new style rules to the style sheet.

  if (sheet.addRule) {

    // For IE:

    sheet.addRule(selector, styleRules);

  } else if (sheet.insertRule) {

    // For Firefox:

    sheet.insertRule(selector + ' { ' + styleRules + ' }',

                     sheet.cssRules.length);

  }

};

/**

 * Change the log severity level, and persist the change to the '_ah_severity'

 * cookie.

 * @param {String} newSeverity  The desired log severity level.

 */

AH.LoggingConsole.prototype.changeLogSeverity = function(newSeverity) {

  // First, find the numeric level for the provided severity.

  var severityLevel = -1;

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

    if (newSeverity == this.logSeverityLevels[i]) {

      severityLevel = i;

    }

  }

  // An unknown logging severity was provided, so ignore the call.

  if (severityLevel == -1) {

    return;

  }

  // Display log lines if they have severity greater than or equal to the

  // desired severity.

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

    var selector =

        '._ah_logline_' + this.logSeverityLevels[i];

    if (i < severityLevel) {

      this.addCssRule(selector, 'display:none');

    } else {

      this.addCssRule(selector, 'display:block');

    }

  }

  // Update the link text colors for the severity controls, and blur the links.

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

    var linkToUpdate = document.getElementById(

        '_ah_show_' + this.logSeverityLevels[i]);

    if (i == severityLevel) {

      linkToUpdate.style.color = 'red';

    } else {

      linkToUpdate.style.color = 'blue';

    }

    linkToUpdate.blur();

  }

  // Save the new severity level to a cookie.

  this.cookieUtil.setCookie('_ah_severity', newSeverity);

};

/**

 * Set the colors for the whole navigation table to white.

 */

AH.LoggingConsole.prototype.clearNavigationTable = function() {

  document.getElementById('_ah_up_left').style.backgroundColor = 'white';

  document.getElementById('_ah_up_right').style.backgroundColor = 'white';

  document.getElementById('_ah_down_left').style.backgroundColor = 'white';

  document.getElementById('_ah_down_right').style.backgroundColor = 'white';

};

/**

 * Moves the logging console to the desired position.

 * @param {String} newPosition  The desired position, which must be one of

 *     'up_left', 'up_right', 'down_left', or 'down_right'.

 */

AH.LoggingConsole.prototype.moveBaseDiv = function(newPosition) {

  // Move the logging console to the desired position on the page.

  var newPositionPieces = newPosition.split('_');

  var newVerticalPosition = newPositionPieces[0];

  var newHorizontalPosition = newPositionPieces[1];

  if (newVerticalPosition == 'up') {

    this.baseDiv.style.top = '10px';

    this.baseDiv.style.bottom = '';

  } else {

    this.baseDiv.style.top = '';

    this.baseDiv.style.bottom = '10px';

  }

  if (newHorizontalPosition == 'left') {

    this.baseDiv.style.left = '10px';

    this.baseDiv.style.right = '';

  } else {

    this.baseDiv.style.left = '';

    this.baseDiv.style.right = '10px';

  }

  // Update the navigation table cell colors to reflect the new position.

  this.clearNavigationTable();

  document.getElementById('_ah_' + newPosition).style.backgroundColor = 'red';

  // Save the new position to a cookie.

  this.cookieUtil.setCookie('_ah_position', newPosition);

};

/**

 * Disable the logging console, and delete all cookies which were storing

 * logging console preferences.

 */

AH.LoggingConsole.prototype.closeEverything = function() {

  this.cookieUtil.removeCookie('_ah_severity');

  this.cookieUtil.removeCookie('_ah_position');

  this.baseDiv.style.display = 'none';

};