Auto-numbering with Custom Prefix

(function executeRule(current, previous /*null when async*/) {

  // Configuration: Define number prefixes based on category
  var prefixMap = {
    'hardware': 'HW',
    'software': 'SW',
    'network': 'NET',
    'database': 'DB',
    'inquiry': 'INQ',
    'default': 'INC'  // Default prefix if category not found
  };

  try {
    // Get category to determine prefix
    var category = current.getValue('category') || 'default';
    var prefix = prefixMap[category] || prefixMap['default'];

    // Alternative: Use different field for prefix determination
    // var type = current.getValue('u_type');
    // var prefix = prefixMap[type] || prefixMap['default'];

    // Get current year for prefix (optional)
    var year = new GlideDateTime().getYear().toString().substring(2);  // Last 2 digits
    prefix = prefix + year;  // e.g., HW24

    // Query for the highest number with this prefix
    var ga = new GlideAggregate('incident');
    ga.addQuery('number', 'STARTSWITH', prefix);
    ga.addAggregate('MAX', 'number');
    ga.query();

    var nextNumber = 1;

    if (ga.next()) {
      var maxNumber = ga.getAggregate('MAX', 'number');

      if (maxNumber) {
        // Extract numeric part from the number
        // Assumes format: PREFIX-NNNN (e.g., HW24-0001)
        var parts = maxNumber.split('-');
        if (parts.length > 1) {
          var numericPart = parseInt(parts[1], 10);
          if (!isNaN(numericPart)) {
            nextNumber = numericPart + 1;
          }
        }
      }
    }

    // Format number with leading zeros (e.g., 0001, 0042, 1234)
    var paddedNumber = String(nextNumber).padStart(4, '0');

    // Construct final number
    var customNumber = prefix + '-' + paddedNumber;

    // Set the number
    current.setValue('number', customNumber);

    gs.info('Auto-numbering: Generated number ' + customNumber + 
            ' for category: ' + category);

    // Optional: Set a display number field if you want to keep standard number
    // current.setValue('u_custom_number', customNumber);

  } catch (e) {
    gs.error('Auto-numbering BR error: ' + e.message);

    // Fallback to default numbering
    // Let ServiceNow handle the number generation
  }

  // Alternative approach: Use number maintenance records
  /*
  function getNextNumber(prefix) {
    // Create/use a custom table to track number sequences
    var grCounter = new GlideRecord('u_number_counter');
    grCounter.addQuery('prefix', prefix);
    grCounter.query();

    var nextNum = 1;

    if (grCounter.next()) {
      nextNum = parseInt(grCounter.current_number) + 1;
      grCounter.current_number = nextNum;
      grCounter.update();
    } else {
      // Create new counter record
      grCounter.initialize();
      grCounter.prefix = prefix;
      grCounter.current_number = nextNum;
      grCounter.insert();
    }

    return nextNum;
  }

  var nextNum = getNextNumber(prefix);
  var paddedNumber = String(nextNum).padStart(4, '0');
  current.setValue('number', prefix + '-' + paddedNumber);
  */

})(current, previous);