/*
 * Indicia custom functions
 */
function writeQuerySyntaxLink() {
	document.writeln("<a href=\"http://www.bam.nl/componenten/zoeken/query_syntax/index.jsp\">[?]</a>")
}

/*
 * 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: $Id$
// 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;

// 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, emptyString)
{
  return doCheckLuceneQueryValue(queryField.value, emptyString)
}

// validates a lucene query.
// @param query string
function doCheckLuceneQueryValue(query, emptyString)
{
  if (typeof(emptyString)!="undefined" && query == emptyString) query = "";

  if(query != null && query.length > 0)
  {
    query = removeEscapes(query);
    
    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();
        }
      }
    }

    // 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;
    
    return true;
  } else {
  	if(alertUser) displayAlert("Vul alstublieft tenminste een zoekterm in.");
	return false;
  }
}

function displayAlert(str)
{
	alert("Ongeldige zoekvraag! " + str + " Probeer het nogmaals.");
}

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

function checkAllowedCharacters(query)
{
  matches = query.match(/[^a-zA-Z0-9_+\-:.()\"*?&|!{}\[\]\^~\\@#\/$%'= ]/);
  if(matches != null && matches.length > 0)
  {
    if(alertUser) displayAlert("Niet alle gebruikte karakters zijn toegestaan.")
    return false;
  }
  return true;
}

function checkAsterisk(query)
{
  matches = query.match(/^[\*]*$|[\s]\*|^\*[^\s]/);
  if(matches != null)
  {
    if(alertUser) displayAlert("De wildcard (*) moet worden voorafgegaan door tenminste een letter of cijfer.")
    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(/^([a-zA-Z0-9_+\-:.()\"*?&|!{}\[\]\^~\\@#\/$%'=]+( && )?[a-zA-Z0-9_+\-:.()\"*?|!{}\[\]\^~\\@#\/$%'=]+[ ]*)+$/); // note missing & in pattern
    if(matches == null)
    {
      if(alertUser) displayAlert("Zoekvragen die de speciale karakters && bevatten dienen van de volgende vorm te zijn: term1 && term2.")
      return false;
    }
  }
  return true;
}

function checkCaret(query)
{
  //matches = query.match(/^[^\^]*$|^([a-zA-Z0-9_+\-:.()\"*?&|!{}\[\]\~\\@#\/]+(\^[\d]+)?[ ]*)+$/); // note missing ^ in pattern
  matches = query.match(/[^\\]\^([^\s]*[^0-9.]+)|[^\\]\^$/);
  if(matches != null)
  {
    if(alertUser) displayAlert("De circumflex (^) moet worden voorafgegaan door alfanumerieke karakters en worden gevolgd door cijfers.")
    return false;
  }
  return true;
}

function checkSquiggle(query)
{
  //matches = query.match(/^[^~]*$|^([a-zA-Z0-9_+\-:.()\"*?&|!{}\[\]\^\\@#\/]+(~[\d.]+|[^\\]\\~)?[ ]*)+$/); // note missing ~ in pattern
  matches = query.match(/[^\\]~[^\s]*[^0-9\s]+/);
  if(matches != null)
  {
    if(alertUser) displayAlert("De tilde (~)  moet worden voorafgegaan door alfanumerieke karakters en worden gevolgd door cijfers.")
    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(/^[^!]*$|^([a-zA-Z0-9_+\-:.()\"*?&|!{}\[\]\^~\\@#\/$%'=]+( ! )?[a-zA-Z0-9_+\-:.()\"*?&|!{}\[\]\^~\\@#\/$%'=]+[ ]*)+$/);
  if(matches == null || matches.length == 0)
  {
    if(alertUser) displayAlert("Zoekvragen die het speciale karakter ! bevatten dienen van de volgende vorm te zijn: term1 ! term2.")
    return false;
  }
  
  
  return true;
}

function checkQuestionMark(query)
{
  matches = query.match(/^(\?)|([^a-zA-Z0-9_+\-:.()\"*?&|!{}\[\]\^~\\@#\/$%'=]\?+)/);
  if(matches != null && matches.length > 0)
  {
      if(alertUser) displayAlert("Het vraagteken (?) moet worden voorafgegaan door tenminste een letter of cijfer.")
    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) displayAlert("Haakjes moeten gesloten worden.")
        return false;
    }
    else
    {
      var number = matchLeft.length + matchRight.length;
      if((number % 2) > 0 || matchLeft.length != matchRight.length)
      {
        if(alertUser) displayAlert("Haakjes moeten gesloten worden.")
        return false;
      }    
    }
    matches = query.match(/\(\)/);
    if(matches != null)
    {
      if(alertUser) displayAlert("Haakjes moeten tenminste een karakter bevatten.")
      return false;    
    }
  }  
  return true;    
}

function checkPlusMinus(query)
{
  matches = query.match(/^[^\n+\-]*$|^([+-]?[a-zA-Z0-9_:.()\"*?&|!{}\[\]\^~\\@#\/$%'=]+[ ]?)+$/);
  if(matches == null || matches.length == 0)
  {
    if(alertUser) displayAlert("'+' en '-' modifiers moeten gevolgd worden door tenminste een letter of cijfer.")
    return false;
  }
  return true;
}

function checkANDORNOT(query)
{
  matches = query.match(/AND|OR|NOT/);
  if(matches != null && matches.length > 0)
  {
    matches = query.match(/^([a-zA-Z0-9_+\-:.()\"*?&|!{}\[\]\^~\\@\/#$%'=]+\s*((AND )|(OR )|(AND NOT )|(NOT ))?[a-zA-Z0-9_+\-:.()\"*?&|!{}\[\]\^~\\@\/#$%'=]+[ ]*)+$/);       
    if(matches == null || matches.length == 0)
    {
      if(alertUser) displayAlert("Zoekvragen die AND/OR/NOT bevatten dienen van de volgende vorm te zijn: term1 AND|OR|NOT|AND NOT term2.")
      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) displayAlert("Zoekvragen die AND/OR/NOT bevatten dienen van de volgende vorm te zijn: term1 AND|OR|NOT|AND NOT term2.")
      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) displayAlert("Sluit alstublieft alle aanhalingstekens.");
      return false;
    }
    matches = query.match(/""/);
    if(matches != null)
    {
      if(alertUser) displayAlert("Aanhalingstekens moeten tenminste een karakter bevatten.")
      return false;    
    }    
  }
  return true;
}

function checkColon(query)
{
  matches = query.match(/[^\\\s]:[\s]|[^\\\s]:$|[\s][^\\]?:|^[^\\\s]?:/);
  if(matches != null)
  {
    if(alertUser) displayAlert("Velddeclaraties (:) moeten worden voorafgegaan door tenminste een letter of cijfer en worden gevolgd door tenminste een letter of cijfer.")
    return false;
  }
  return true;
}