Minecraft-protocol-1.20.4-kick-msg-parser/kick.js

const lang = require("./en_us.json"); // translate message
const nbt = require('prismarine-nbt');

function uuidFromIntArray (arr) {
  const buf = Buffer.alloc(16)
  arr.forEach((num, index) => { buf.writeInt32BE(num, index * 4) })
  return buf.toString('hex')
}

function processNbtMessage (msg) {
  try {
    if (!msg || msg.type === 'end') return null;
    if (typeof msg === 'string') return msg

    const simplified = simplify(msg); // Ensure nbt is defined elsewhere
    const json = JSON.stringify(simplified, (key, val) => {
      if (key === 'id' && Array.isArray(val)) return uuidFromIntArray(val);
      return val;
    });

    return json;
  } catch (e) {
    return e;
  }
}

const msg = {
  reason: '{"translate":"multiplayer.disconnect.unverified_username"}'
}

const msg2 = {
  "reason": {
    "type": "compound",
    "value": {
      "with": {
        "type": "list",
        "value": {
          "type": "string",
          "value": [ "Internal Exception: io.netty.handler.codec.EncoderException: java.io.UTFDataFormatException: encoded string (t§k腻腻腻腻腻...腻腻腻腻§rno) too long: 97869 bytes" ]
        }
      },
      "translate": {
        "type": "string",
        "value": "disconnect.genericReason"
      }
    }
  }
}

console.log(kickparser(msg.reason));
console.log(kickparser(msg2.reason));

// lazy to make it color
function kickparser(component) {
	if (component === undefined) return;
	if (typeof component === "string") return component;
	
    function kickparserText(comp) {
        let text = '';
        
		if (comp.text && typeof comp.text === 'string' || typeof comp.text === 'number') {
		  text += comp.text;
		}
		if (comp[""] && typeof comp[""] === 'string' || typeof comp[""] === 'number') {
		  text += comp[""];
		}
		if (comp && typeof comp === 'string' || typeof comp === 'number') {
		  return comp;
		}
		
		if (comp.extra) {
			if (!Array.isArray(comp.extra)) comp.extra = [comp.extra]
			comp.extra.forEach(subComp => {
				text += extractText(subComp);
			});
		}
	
		if (comp.translate) {
			let translateString = lang[comp.translate] || comp.translate;
			let DefaultTranslateString = lang[comp.translate] || comp.translate;
			let DefaultMsg = false;

			if (comp.with) {
				const withArgs = comp.with.map(arg => extractText(arg));
				let usedReplacements = 0;

				translateString = translateString.replace(/thing__placeholder__/g, 'default_thing__placeholder__');
				translateString = translateString.replace(/%s/g, (match, offset, string) => {
					if (offset > 0 && string[offset - 1] === '%') {
						return 's';
					}

					if (usedReplacements < withArgs.length) {
						if (translateString.length + withArgs[usedReplacements].length > 2048) return 'Translate Crash';  // Prevent translate crash
						return `thing__placeholder__${usedReplacements++}`;
					}

					DefaultMsg = true;
					return "%s";
				});

				translateString = translateString.replace(/%(-?\d+)\$s/g, (match, index, stringindex, string) => {
					const argIndex = parseInt(index, 10) - 1;
					
					if (argIndex < 0 || argIndex >= withArgs.length) {
						DefaultMsg = true;
						return match;
					}

					if (stringindex > 0 && string[stringindex - 1] === '%') {
						return match;
					}

					if (translateString.length + withArgs[argIndex].length > 2048) return 'Translate Crash';  // Prevent translate crash
					return `thing__placeholder__${argIndex}`;
				});

				for (let i = 0; i < withArgs.length; i++) {
					if (translateString.length + withArgs[i].length > 2048) return 'Translate Crash';  // Prevent translate crash
					translateString = translateString.replace(new RegExp(`thing__placeholder__${i}`, 'g'), (match) => {
						const formattedArg = withArgs[i];
						return formattedArg;
					});
				}
				translateString = translateString.replace(/default_thing__placeholder__/g, 'thing__placeholder__');
			}
			
			if (DefaultMsg) {
				text += DefaultTranslateString;
			} else {
				text += translateString;
			}
		}
            
        

        return text;
    }
	// console.log(simplify(component));
    return kickparserText(simplify(component));
}