// Author: Kelvin Tan  (kelvint at apache.org)
// JavaScript Lucene Query Validator
// Version: $Id: form_validation.js,v 1.5 2005/11/07 13:57:11 aleksey 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;

// 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 square brackets are used properly
    if(!checkSquareBrackets(query)) return false;
    
    // check '+' and '-' are used properly      
    /* if(!checkPlusMinus(query)) return false; //commented to work w/c++ etc.  */
    
    // 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(/[^a-zA-Z0-9_+\-:.,()\"*?&|!{}\[\]\^~\\@#\/$%'= ]/);
  if(matches != null && matches.length > 0) {
//    if(alertUser) alert("Invalid search query! The allowed characters are a-z A-Z 0-9.  _ + - : () \" & * ? | ! {} [ ] ^ ~ \\ @ = # % $ ' /. Please try again.")
    setTimeout("", 1);
    throw new Error('The allowed characters are a-z A-Z 0-9. _ + - : , () " & * ? | ! {} [ ] ^ ~ \\ @ = # % $ \' / and space');
    return false;
  }
  return true;
}

function checkAsterisk(query) {
  matches = query.match(/^[\*]*$|[\s]\*|^\*[^\s]/);
  if(matches != null) {
//    if(alertUser) alert("Invalid search query! The wildcard (*) character must be preceded by at least one alphabet or number. Please try again.")
    setTimeout("", 1);
    throw new Error('The wildcard (*) character must be preceded by at least one alphanumeric character');
    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) alert("Invalid search query! Queries containing the special characters && must be in the form: term1 && term2. Please try again.")
        setTimeout("", 1);
        throw new Error('Queries containing the special characters && must be in the form: term1 && term2');
      return false;
    }
  }
  return true;
}

function checkCaret(query) {
  //matches = query.match(/^[^\^]*$|^([a-zA-Z0-9_+\-:.()\"*?&|!{}\[\]\~\\@#\/]+(\^[\d]+)?[ ]*)+$/); // note missing ^ in pattern
  //matches = query.match(/[^\\]\^([^\s]*[^0-9.]+)|[^\\]\^$/);
  matches = query.match(/[^\\]*\w+\^[^\d]+/);
  if(matches != null) {
//    if(alertUser) alert("Invalid search query! The caret (^) character must be preceded by alphanumeric characters and followed by numbers. Please try again.")
        setTimeout("", 1);
        throw new Error('The caret (^) character must be preceded by alphanumeric characters and followed by numbers');
    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) alert("Invalid search query! The tilde (~) character must be preceded by alphanumeric characters and followed by numbers. Please try again.")
        setTimeout("", 1);
        throw new Error('The tilde (~) character must be preceded by alphanumeric characters and followed by numbers');
    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) alert("Invalid search query! Queries containing the special character ! must be in the form: term1 ! term2. Please try again.")
        setTimeout("", 1);
        throw new Error('Queries containing the special character ! must be in the form: term1 ! term2');
    return false;
  }
  
  
  return true;
}

function checkQuestionMark(query) {
  matches = query.match(/^(\?)|([^a-zA-Z0-9_+\-:.()\"*?&|!{}\[\]\^~\\@#\/$%'=]\?+)/);
  if(matches != null && matches.length > 0) {
//      if(alertUser) alert("Invalid search query! The question mark (?) character must be preceded by at least one alphabet or number. Please try again.")
        setTimeout("", 1);
        throw new Error('The question mark (?) character must be preceded by at least one alphanumeric character');
    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("Invalid search query! Parentheses must be closed. Please try again.")
            setTimeout("", 1);
            throw new Error('Parentheses must be closed');
        return false;
    } else {
      var number = matchLeft.length + matchRight.length;
      if((number % 2) > 0 || matchLeft.length != matchRight.length) {
//        if(alertUser) alert("Invalid search query! Parentheses must be closed. Please try again.")
            setTimeout("", 1);
            throw new Error('Parentheses must be closed');
        return false;
      }    
    }
    matches = query.match(/\(\)/);
    if(matches != null) {
//      if(alertUser) alert("Invalid search query! Parentheses must contain at least one character. Please try again.")
        setTimeout("", 1);
        throw new Error('Parentheses must contain at least one character');
      return false;    
    }
  }  
  return true;    
}

function checkSquareBrackets(query) {
  var hasLeft = false;
  var hasRight = false;
  var datish = 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("Invalid search query! Square brackets must be closed. Please try again.")
            setTimeout("", 1);
            throw new Error('Square brackets must be closed');
        return false;
    } else {
      var number = matchLeft.length + matchRight.length;
      if((number % 2) > 0 || matchLeft.length != matchRight.length) {
//        if(alertUser) alert("Invalid search query! Square brackets must be closed. Please try again.")
            setTimeout("", 1);
            throw new Error('Square brackets must be closed');
        return false;
      }    
    }
    matches = query.match(/\[\]/);
    if(matches != null) {
//      if(alertUser) alert("Invalid search query! Parentheses must contain at least one character. Please try again.")
        setTimeout("", 1);
        throw new Error('Square brackets must contain at least one character');
      return false;    
    }
    datish = query.match(/^date:\[\d{4}-\d{2}-\d{2} TO \d{4}-\d{2}-\d{2}\]$/);
    if(datish == null) {
//      if(alertUser) alert("Invalid search query! Parentheses must contain at least one character. Please try again.")
        setTimeout("", 1);
        throw new Error('\nSquare brackets query must look like this:\ndate:[YYYY-MM-DD TO YYYY-MM-DD]');
      return false;    
    }
  }  
  return true;    
}

function checkPlusMinus(query) {
  matches = query.match(/^[^\n+\-]*$|^([+-]?[a-zA-Z0-9_:.()\"*?&|!{}\[\]\^~\\@#\/$%'=]+[ ]?)+$/);
  if(matches == null || matches.length == 0) {
//    if(alertUser) alert("Invalid search query! '+' and '-' modifiers must be followed by at least one alphabet or number. Please try again.")
        setTimeout("", 1);
        throw new Error("'+' and '-' modifiers must be followed by at least one alphanumeric character");
    return false;
  }
  return true;
}

function checkANDORNOT(query) {
  matches = query.match(/\b(AND|OR|NOT)\b/);
  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) alert("Invalid search query! Queries containing AND/OR/NOT must be in the form: term1 AND|OR|NOT|AND NOT term2 Please try again.")
        setTimeout("", 1);
        throw new Error('Queries containing AND/OR/NOT must be in the form: 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) alert("Invalid search query! Queries containing AND/OR/NOT must be in the form: term1 AND|OR|NOT|AND NOT term2 Please try again.")
        setTimeout("", 1);
        throw new Error('Queries containing AND/OR/NOT must be in the form: 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) alert("Invalid search query! Please close all quote (\") marks.");
        setTimeout("", 1);
        throw new Error('Please close all quote (") marks');
      return false;
    }
    matches = query.match(/""/);
    if(matches != null) {
//      if(alertUser) alert("Invalid search query! Quotes must contain at least one character. Please try again.")
        setTimeout("", 1);
        throw new Error('Quotes must contain at least one character');
      return false;    
    }    
  }
  return true;
}

function checkColon(query) {
  matches = query.match(/[^\\\s]:[\s]|[^\\\s]:$|[\s][^\\]?:|^[^\\\s]?:/);
  if(matches != null) {
//    if(alertUser) alert("Invalid search query! Field declarations (:) must be preceded by at least one alphabet or number and followed by at least one alphabet or number. Please try again.")
        setTimeout("", 1);
        throw new Error('Field declarations (:) must be preceded by at least one alphanumeric character and followed\n   by at least one alphanumeric character too');
    return false;
  }
  return true;
}