package launchserver.auth.handler;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.Arrays;
import java.util.UUID;

import launcher.helper.IOHelper;
import launcher.helper.LogHelper;
import launcher.helper.VerifyHelper;
import launcher.serialize.config.entry.BlockConfigEntry;

public final class MemoryAuthHandler extends CachedAuthHandler {
	public MemoryAuthHandler(BlockConfigEntry block) {
		super(block);
		LogHelper.warning("Usage of MemoryAuthHandler isn't recommended!");
	}

	@Override
	public void flush() throws IOException {
		// Do nothing
	}

	@Override
	protected Entry fetchEntry(UUID uuid) throws IOException {
		return new Entry(uuid, toUsername(uuid), null, null);
	}

	@Override
	protected Entry fetchEntry(String username) throws IOException {
		return new Entry(toUUID(username), username, null, null);
	}

	@Override
	protected boolean updateAuth(UUID uuid, String username, String accessToken) throws IOException {
		return true; // Do nothing
	}

	@Override
	protected boolean updateServerID(UUID uuid, String serverID) throws IOException {
		return true; // Do nothing
	}

	private static UUID toUUID(String username) {
		ByteBuffer buffer = ByteBuffer.wrap(Arrays.copyOf(IOHelper.encodeASCII(username), 16));
		return new UUID(buffer.getLong(), buffer.getLong()); // MOST, LEAST
	}

	private static String toUsername(UUID uuid) {
		byte[] bytes = ByteBuffer.allocate(16).
			putLong(uuid.getMostSignificantBits()).
			putLong(uuid.getLeastSignificantBits()).array();

		// Find username end
		int length = 0;
		while (length < bytes.length && bytes[length] != 0) {
			length++;
		}

		// Decode and verify
		return VerifyHelper.verifyUsername(new String(bytes, 0, length, IOHelper.ASCII_CHARSET));
	}
}