/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */

// Author: Kelvin Tan  (kelvint at apache.org)
// JavaScript Lucene Query Validator
// Version: $Id: validator.js,v 1.2 2008/06/02 15:29:48 pferrari Exp $
// Tested: IE 6.0.2800 and Mozilla Firebird 0.7

// Special characters are + - && || ! ( ) { } [ ] ^ " ~ * ? : \
// Special words are (case-sensitive) AND NOT OR

// Makes wildcard queries case-insensitive if true.
// Refer to http://www.mail-archive.com/lucene-user@jakarta.apache.org/msg00646.html
var wildcardCaseInsensitive = true;

//Regular expressions validatores, includes special characters support: ãõáéíóúäëïöüàèìòùâêîôûçñ and ÃÕÁÉÍÓÚÄËÏÖÜÀÈÌÒÙÂÊÎÔÛÇÑ
var EXPRESSION_ALLOWD_CHARACTERES 		= /[^a-zA-ZãõáéíóúäëïöüàèìòùâêîôûçñÃÕÁÉÍÓÚÄËÏÖÜÀÈÌÒÙÂÊÎÔÛÇÑ0-9_+\-:.()\"*?&|!{}\[\]\^~\\@#\/$%'= ]/;
var EXPRESSION_CHECK_CARET				= /[^\\]\^([^\s]*[^0-9.]+)|[^\\]\^$/;
var EXPRESSION_CHECK_ASTERISK			= /^[\*]*$|[\s]\*|^\*[^\s]/;
var EXPRESSION_CHECK_AMPERSANDS			= /^([a-zA-ZãõáéíóúäëïöüàèìòùâêîôûçñÃÕÁÉÍÓÚÄËÏÖÜÀÈÌÒÙÂÊÎÔÛÇÑ0-9_+\-:.()\"*?&|!{}\[\]\^~\\@#\/$%'=]+( && )?[a-zA-ZãõáéíóúäëïöüàèìòùâêîôûçñÃÕÁÉÍÓÚÄËÏÖÜÀÈÌÒÙÂÊÎÔÛÇÑ0-9_+\-:.()\"*?|!{}\[\]\^~\\@#\/$%'=]+[ ]*)+$/
var EXPRESSION_CHECK_SQUIGGLE			= /[^\\]~[^\s]*[^0-9\s]+/;
var EXPRESSION_CHECK_EXCLAMATION_MARK	= /^[^!]*$|^([a-zA-ZãõáéíóúäëïöüàèìòùâêîôûçñÃÕÁÉÍÓÚÄËÏÖÜÀÈÌÒÙÂÊÎÔÛÇÑ0-9_+\-:.()\"*?&|!{}\[\]\^~\\@#\/$%'=]+( ! )?[a-zA-ZãõáéíóúäëïöüàèìòùâêîôûçñÃÕÁÉÍÓÚÄËÏÖÜÀÈÌÒÙÂÊÎÔÛÇÑ0-9_+\-:.()\"*?&|!{}\[\]\^~\\@#\/$%'=]+[ ]*)+$/;
var EXPRESSION_CHECK_QUESTION_MARK		= /^(\?)|([^a-zA-ZãõáéíóúäëïöüàèìòùâêîôûçñÃÕÁÉÍÓÚÄËÏÖÜÀÈÌÒÙÂÊÎÔÛÇÑ0-9_+\-:.()\"*?&|!{}\[\]\^~\\@#\/$%'=]\?+)/;
var EXPRESSION_CHECK_PLUS_MINUS			= /^[^\n+\-]*$|^([+-]?[a-zA-ZãõáéíóúäëïöüàèìòùâêîôûçñÃÕÁÉÍÓÚÄËÏÖÜÀÈÌÒÙÂÊÎÔÛÇÑ0-9_:.()\"*?&|!{}\[\]\^~\\@#\/$%'=]+[ ]?)+$/;
var EXPRESSION_CHECK_AND_OR_NOT			= /^([a-zA-ZãõáéíóúäëïöüàèìòùâêîôûçñÃÕÁÉÍÓÚÄËÏÖÜÀÈÌÒÙÂÊÎÔÛÇÑ0-9_+\-:.()\"*?&|!{}\[\]\^~\\@\/#$%'=]+\s*((AND )|(OR )|(AND NOT )|(NOT ))?[a-zA-ZãõáéíóúäëïöüàèìòùâêîôûçñÃÕÁÉÍÓÚÄËÏÖÜÀÈÌÒÙÂÊÎÔÛÇÑ0-9_+\-:.()\"*?&|!{}\[\]\^~\\@\/#$%'=]+[ ]*)+$/;


// Mutator method for wildcardCaseInsensitive.
// @param Should wildcard queries be case-insensitive?
function setWildcardCaseInsensitive(bool) {
  wildcardCaseInsensitive = bool;
}

// Should the user be prompted with an alert box if validation fails?
var alertUser = true;

function setAlertUser(bool) {
  alertUser = bool;
}

// validates a lucene query.
// @param Form field that contains the query
function doCheckLuceneQuery(queryField) {
  return doCheckLuceneQueryValue(queryField.value)
}

// validates a lucene query.
// @param query string
function doCheckLuceneQueryValue(query) {
  if(query != null && query.length > 0) {
    query = removeEscapes(query);

    // check for allowed characters
    if(!checkAllowedCharacters(query)) return false;
    
    // check * is used properly
    if(!checkAsterisk(query)) return false;
    
    // check for && usage
    if(!checkAmpersands(query)) return false;
    
    // check ^ is used properly 
    if(!checkCaret(query)) return false;
    
    // check ~ is used properly
    if(!checkSquiggle(query)) return false;
    
    // check ! is used properly 
    if(!checkExclamationMark(query)) return false;
    
    // check question marks are used properly
    if(!checkQuestionMark(query)) return false;
    
    // check parentheses are used properly
    if(!checkParentheses(query)) return false;
    
    // check '+' and '-' are used properly      
    if(!checkPlusMinus(query)) return false;
    
    // check AND, OR and NOT are used properly
    if(!checkANDORNOT(query)) return false;    
    
    // check that quote marks are closed
    if(!checkQuotes(query)) return false;
    
    // check ':' is used properly
    if(!checkColon(query)) return false;
    
    if(wildcardCaseInsensitive) {
      if(query.indexOf("*") != -1) {
        var i = query.indexOf(':');
        if(i == -1) {
          query.value = query.toLowerCase();
        } else { // found a wildcard field search
          query.value = query.substring(0, i) + query.substring(i).toLowerCase();
        }
      }
    }
    return true;
  }
}

// remove the escape character and the character immediately following it
function removeEscapes(query) {
  return query.replace(/\\./g, "");
}

function checkAllowedCharacters(query) {
  matches = query.match(EXPRESSION_ALLOWD_CHARACTERES);
  if(matches != null && matches.length > 0) {
    if(alertUser) alert(ALE_VAL_LUCENE_1)
    return false;
  }
  return true;
}

function checkAsterisk(query) {
  matches = query.match(EXPRESSION_CHECK_ASTERISK);
  if(matches != null) {
    if(alertUser) alert(ALE_VAL_LUCENE_2)
    return false;
  }
  return true;
}

function checkAmpersands(query) {
  // NB: doesn't handle term1 && term2 && term3 in Firebird 0.7
  matches = query.match(/[&]{2}/);
  if(matches != null && matches.length > 0) {
    matches = query.match(EXPRESSION_CHECK_AMPERSANDS); // note missing & in pattern
    if(matches == null) {
      if(alertUser) alert(ALE_VAL_LUCENE_3)
      return false;
    }
  }
  return true;
}

function checkCaret(query) {
  //matches = query.match(/^[^\^]*$|^([a-zA-Z0-9_+\-:.()\"*?&|!{}\[\]\~\\@#\/]+(\^[\d]+)?[ ]*)+$/); // note missing ^ in pattern
  matches = query.match(EXPRESSION_CHECK_CARET);
  if(matches != null) {
    if(alertUser) alert(ALE_VAL_LUCENE_4)
    return false;
  }
  return true;
}

function checkSquiggle(query) {
  //matches = query.match(/^[^~]*$|^([a-zA-Z0-9_+\-:.()\"*?&|!{}\[\]\^\\@#\/]+(~[\d.]+|[^\\]\\~)?[ ]*)+$/); // note missing ~ in pattern
  matches = query.match(EXPRESSION_CHECK_SQUIGGLE);
  if(matches != null) {
    if(alertUser) alert(ALE_VAL_LUCENE_5)
    return false;
  }    
  return true;
}

function checkExclamationMark(query) {
  // foo! is not a query, but !foo is. hmmmm...
  // NB: doesn't handle term1 ! term2 ! term3 or term1 !term2
  matches = query.match(EXPRESSION_CHECK_EXCLAMATION_MARK);
  if(matches == null || matches.length == 0) {
    if(alertUser) alert(ALE_VAL_LUCENE_6)
    return false;
  }
  
  return true;
}

function checkQuestionMark(query) {
  matches = query.match(EXPRESSION_CHECK_QUESTION_MARK);
  if(matches != null && matches.length > 0) {
    if(alertUser) alert(ALE_VAL_LUCENE_7)
    return false;
  }
  return true;
}

function checkParentheses(query) {
  var hasLeft = false;
  var hasRight = false;
  matchLeft = query.match(/[(]/g);
  if(matchLeft != null) hasLeft = true
  matchRight = query.match(/[)]/g);
  if(matchRight != null) hasRight = true;
  
  if(hasLeft || hasRight) {
    if(hasLeft && !hasRight || hasRight && !hasLeft) {
      if(alertUser) alert(ALE_VAL_LUCENE_8)
      return false;
    } else {
      var number = matchLeft.length + matchRight.length;
      if((number % 2) > 0 || matchLeft.length != matchRight.length) {
        if(alertUser) alert(ALE_VAL_LUCENE_8)
        return false;
      }    
    }
    matches = query.match(/\(\)/);
    if(matches != null) {
      if(alertUser) alert(ALE_VAL_LUCENE_9)
      return false;    
    }
  }  
  return true;    
}

function checkPlusMinus(query) {
  matches = query.match(EXPRESSION_CHECK_PLUS_MINUS);
  if(matches == null || matches.length == 0) {
    if(alertUser) alert(ALE_VAL_LUCENE_10)
    return false;
  }
  return true;
}

function checkANDORNOT(query) {
  matches = query.match(/AND|OR|NOT/);
  if(matches != null && matches.length > 0) {
    matches = query.match(EXPRESSION_CHECK_AND_OR_NOT);       
    if(matches == null || matches.length == 0) {
      if(alertUser) alert(ALE_VAL_LUCENE_11)
      return false;
    }
    
    // its difficult to distinguish AND/OR/... from the usual [a-zA-Z] because they're...words!
    matches = query.match(/^((AND )|(OR )|(AND NOT )|(NOT ))|((AND)|(OR)|(AND NOT )|(NOT))[ ]*$/)
    if(matches != null && matches.length > 0) {
      if(alertUser) alert(ALE_VAL_LUCENE_12)
      return false;
    }
  }
  return true;
}

function checkQuotes(query) {
  matches = query.match(/\"/g);
  if(matches != null && matches.length > 0) {
    var number = matches.length;
    if((number % 2) > 0) {
      if(alertUser) alert(ALE_VAL_LUCENE_13);
      return false;
    }
    matches = query.match(/""/);
    if(matches != null) {
      if(alertUser) alert(ALE_VAL_LUCENE_14)
      return false;    
    }    
  }
  return true;
}

function checkColon(query) {
  matches = query.match(/[^\\\s]:[\s]|[^\\\s]:$|[\s][^\\]?:|^[^\\\s]?:/);
  if(matches != null) {
    if(alertUser) alert(ALE_VAL_LUCENE_15)
    return false;
  }
  return true;
}