bufferStuff/writers/WriterBE.ts

// Copyright (c) Holly Stubbs (tgpholly) - Licensed under MIT
// Check LICENSE in repository root for more information.

import { IWriter } from "./IWriter";
import { WriterBase } from "../base/WriterBase";
import { getBufferClass } from "../base/BufferShim";

export class WriterBE extends WriterBase implements IWriter {
	public writeShort(value:number) {
		if (this.resizable) {
			const buffer = getBufferClass().alloc(2);
			buffer.writeInt16BE(value);
			this.writeBuffer(buffer);
		} else {
			this.buffer.writeInt16BE(value, this.offset);
			this.offset += 2;
		}

		return this;
	}

	public writeUShort(value:number) {
		if (this.resizable) {
			const buffer = getBufferClass().alloc(2);
			buffer.writeUInt16BE(value);
			this.writeBuffer(buffer);
		} else {
			this.buffer.writeUInt16BE(value, this.offset);
			this.offset += 2;
		}

		return this;
	}

	public writeInt(value:number) {
		if (this.resizable) {
			const buffer = getBufferClass().alloc(4);
			buffer.writeInt32BE(value);
			this.writeBuffer(buffer);
		} else {
			this.buffer.writeInt32BE(value, this.offset);
			this.offset += 4;
		}

		return this;
	}

	public writeUInt(value:number) {
		if (this.resizable) {
			const buffer = getBufferClass().alloc(4);
			buffer.writeUInt32BE(value);
			this.writeBuffer(buffer);
		} else {
			this.buffer.writeUInt32BE(value, this.offset);
			this.offset += 4;
		}

		return this;
	}

	public writeLong(value:number|bigint) {
		if (typeof(value) !== "bigint") {
			value = BigInt(value);
		}

		if (this.resizable) {
			const buffer = getBufferClass().alloc(8);
			buffer.writeBigInt64BE(value);
			this.writeBuffer(buffer);
		} else {
			this.buffer.writeBigInt64BE(value, this.offset);
			this.offset += 8;
		}

		return this;
	}

	public writeULong(value:number|bigint) {
		if (typeof(value) !== "bigint") {
			value = BigInt(value);
		}

		if (this.resizable) {
			const buffer = getBufferClass().alloc(8);
			buffer.writeBigUint64BE(value);
			this.writeBuffer(buffer);
		} else {
			this.buffer.writeBigUInt64BE(value, this.offset);
			this.offset += 8;
		}

		return this;
	}

	public writeFloat(value:number) {
		if (this.resizable) {
			const buffer = getBufferClass().alloc(4);
			buffer.writeFloatBE(value);
			this.writeBuffer(buffer);
		} else {
			this.buffer.writeFloatBE(value, this.offset);
			this.offset += 4;
		}

		return this;
	}

	public writeDouble(value:number) {
		if (this.resizable) {
			const buffer = getBufferClass().alloc(8);
			buffer.writeDoubleBE(value);
			this.writeBuffer(buffer);
		} else {
			this.buffer.writeDoubleBE(value, this.offset);
			this.offset += 8;
		}

		return this;
	}

	public writeUString(text:string) {
		this.writeUShort(text.length);

		for (let i = 0; i < text.length; i++) {
			this.writeUByte(text.charCodeAt(i));
		}

		return this;
	}

	public writeString(text:string) {
		this.writeShort(text.length);

		for (let i = 0; i < text.length; i++) {
			this.writeByte(text.charCodeAt(i));
		}

		return this;
	}

	public writeUString16(text:string) {
		this.writeUShort(text.length);

		for (let i = 0; i < text.length; i++) {
			this.writeUShort(text.charCodeAt(i));
		}

		return this;
	}

	public writeString16(text:string) {
		this.writeShort(text.length);

		for (let i = 0; i < text.length; i++) {
			this.writeShort(text.charCodeAt(i));
		}

		return this;
	}

	public writeStringAsShorts(text:string) {
		let buffer:Buffer;
		if (this.resizable) {
			buffer = getBufferClass().alloc(text.length * 2);
		} else {
			buffer = this.buffer;
		}

		for (let i = 0; i < text.length; i++) {
			buffer.writeUInt16BE(text.charCodeAt(i), i);
		}

		return this;
	}

	// ! TODO: Implement this properly. This was a quick, hacky implementation for mc-beta-server
	// !       as it is used in one single place in the whole game's protocol.
	public writeJavaUTF(text: string) {
		const dataWriter = new WriterBE();

		for (let i = 0; i < text.length; i++) {
			const val = text.charCodeAt(i);
			if (val === 0) {
				dataWriter.writeByte(0xC0);
				dataWriter.writeByte(0X80);
			} else {
				dataWriter.writeByte(val);
			}
		}

		this.writeUShort(text.length);
		this.writeBuffer(dataWriter.toBuffer());

		return this;
	}
}