pick static method

String? pick(Param param, String parameterName)

Shows an interactive menu to select an enum value for the given parameter. Returns the selected value or null if cancelled.

Implementation

static String? pick(Param param, String parameterName) {
  if (!param.isEnum || param.values == null || param.values!.isEmpty) {
    return null;
  }

  final values = param.values!;
  int selectedIndex = 0; // Currently selected option (0-based)

  // Calculate max value length for alignment
  int maxValueLength = 0;
  for (final value in values) {
    if (value.length > maxValueLength) {
      maxValueLength = value.length;
    }
  }

  // Helper function to display the menu
  void displayMenu() {
    print('');
    print('Select value for ${colors.blue}$parameterName${colors.reset}:');
    if (param.description != null && param.description!.isNotEmpty) {
      print('${colors.gray}${param.description}${colors.reset}');
    }
    print('');

    for (var i = 0; i < values.length; i++) {
      final value = values[i];
      final number = i + 1;
      final isSelected = i == selectedIndex;
      final checkMark = isSelected ? ' ✓' : '  '; // Always 2 chars width

      // Pad value to align everything
      final paddedValue = value.padRight(maxValueLength);

      // Build display string
      String display = isSelected
          ? '    ${colors.green}$number. $paddedValue$checkMark${colors.reset}'
          : '    $number. $paddedValue$checkMark';

      print(display);
    }

    print('');
    print('${colors.gray}Press number (1-${values.length}) or press Esc to cancel:${colors.reset}');
  }

  // Display initial menu
  displayMenu();

  // Enable raw mode to detect arrow keys and ESC
  stdin.echoMode = false;
  stdin.lineMode = false;

  while (true) {
    final charCode = stdin.readByteSync();

    // ESC key (27) - check if it's part of arrow key sequence
    if (charCode == 27) {
      // Sleep briefly to see if more bytes are coming (for arrow keys)
      sleep(Duration(milliseconds: 10));

      // Check if there's more input (arrow keys send ESC[A/B/C/D)
      if (stdin.hasTerminal) {
        try {
          // Try to read next byte without blocking
          final bytesAvailable = stdin.readByteSync();

          if (bytesAvailable == 91) {
            // '[' character - this is an arrow key sequence
            final arrowChar = stdin.readByteSync();

            // Arrow Up (65 = 'A')
            if (arrowChar == 65) {
              selectedIndex = (selectedIndex - 1 + values.length) % values.length;
              // Clear screen and redraw
              _clearScreen(values.length + 5);
              displayMenu();
              continue;
            }

            // Arrow Down (66 = 'B')
            if (arrowChar == 66) {
              selectedIndex = (selectedIndex + 1) % values.length;
              // Clear screen and redraw
              _clearScreen(values.length + 5);
              displayMenu();
              continue;
            }
          }
        } catch (e) {
          // No more bytes available - it's just ESC key
        }
      }

      // Just ESC key - cancel
      stdin.echoMode = true;
      stdin.lineMode = true;
      print('\n${colors.yellow}Cancelled${colors.reset}');
      return null;
    }

    // Enter key (10 or 13) - execute selected option
    if (charCode == 10 || charCode == 13) {
      stdin.echoMode = true;
      stdin.lineMode = true;
      print('');
      return values[selectedIndex];
    }

    // Number keys (49-57 correspond to '1'-'9')
    if (charCode >= 49 && charCode <= 57) {
      final number = charCode - 48; // Convert to 1-9
      if (number >= 1 && number <= values.length) {
        stdin.echoMode = true;
        stdin.lineMode = true;
        print('');
        return values[number - 1];
      }
    }
  }
}