ClientScript.java

package net.scapeemulator.cache.def;

import java.nio.ByteBuffer;
import java.util.HashMap;
import java.util.Map;

import net.scapeemulator.cache.util.ByteBufferUtils;

public final class ClientScript {

	@SuppressWarnings("unchecked")
	public static ClientScript decode(ByteBuffer buffer) {
		ClientScript script = new ClientScript();

		buffer.position(buffer.limit() - 2);
		int trailerLength = buffer.getShort() & 0xFFFF;
		int trailerPosition = buffer.limit() - 14 - trailerLength;

		buffer.position(trailerPosition);
		int ops = buffer.getInt();
		script.intArgsCount = buffer.getShort() & 0xFFFF;
		script.strArgsCount = buffer.getShort() & 0xFFFF;
		script.intStackDepth = buffer.getShort() & 0xFFFF;
		script.strStackDepth = buffer.getShort() & 0xFFFF;

		int switches = buffer.get() & 0xFF;
		script.switchTables = new HashMap[switches];
		for (int i = 0; i < switches; i++) {
			script.switchTables[i] = new HashMap<>();

			int size = buffer.getShort() & 0xFFFF;
			while (size-- > 0) {
				int index = buffer.getInt();
				int value = buffer.getInt();
				script.switchTables[i].put(index, value);
			}
		}

		buffer.position(0);
		script.name = ByteBufferUtils.getString(buffer);
		script.opcodes = new int[ops];
		script.intOperands = new int[ops];
		script.strOperands = new String[ops];

		int op = 0;
		while (buffer.position() < trailerPosition) {
			int opcode = buffer.getShort() & 0xFFFF;
			if (opcode == 3) {
				script.strOperands[op] = ByteBufferUtils.getString(buffer);
			} else if (opcode >= 100 || opcode == 21 || opcode == 38 || opcode == 39) {
				script.intOperands[op] = buffer.get();
			} else {
				script.intOperands[op] = buffer.getInt();
			}

			script.opcodes[op++] = opcode;
		}

		return script;
	}

	private String name;
	private int intArgsCount, strArgsCount, intStackDepth, strStackDepth;
	private Map<Integer, Integer>[] switchTables;
	private int[] opcodes, intOperands;
	private String[] strOperands;

	public String getName() {
		return name;
	}

	public int getIntArgsCount() {
		return intArgsCount;
	}

	public int getStrArgsCount() {
		return strArgsCount;
	}

	public int getIntStackDepth() {
		return intStackDepth;
	}

	public int getStrStackDepth() {
		return strStackDepth;
	}

	public int getLength() {
		return opcodes.length;
	}

	public int getOpcode(int index) {
		return opcodes[index];
	}

	public int getIntOperand(int index) {
		return intOperands[index];
	}

	public String getStrOperand(int index) {
		return strOperands[index];
	}

	// TODO nicer interface for accessing this structure?
	public Map<Integer, Integer>[] getSwitchTables() {
		return switchTables;
	}

}