#Class: ChatSendBeforeEventSignal experimental

import { world, DimensionLocation } from '@minecraft/server';

function customCommand(targetLocation: DimensionLocation) {
  const chatCallback = world.beforeEvents.chatSend.subscribe(eventData => {
    if (eventData.message.includes('cancel')) {
      // Cancel event if the message contains "cancel"
      eventData.cancel = true;
    } else {
      const args = eventData.message.split(' ');

      if (args.length > 0) {
        switch (args[0].toLowerCase()) {
          case 'echo':
            // Send a modified version of chat message
            world.sendMessage(`Echo '${eventData.message.substring(4).trim()}'`);
            break;
          case 'help':
            world.sendMessage(`Available commands: echo <message>`);
            break;
        }
      }
    }
  });
}