package launcher.hasher;

import java.io.IOException;
import java.nio.file.Path;
import java.util.Arrays;

import launcher.LauncherAPI;
import launcher.helper.IOHelper;
import launcher.helper.SecurityHelper;
import launcher.helper.VerifyHelper;
import launcher.serialize.HInput;
import launcher.serialize.HOutput;

public final class HashedFile extends HashedEntry {
	private static final byte[] DUMMY_HASH = new byte[0];

	// Instance
	@LauncherAPI public final long size;
	private final byte[] digest;

	@LauncherAPI
	public HashedFile(long size, byte[] digest) {
		this.size = VerifyHelper.verifyLong(size,
			VerifyHelper.L_NOT_NEGATIVE, "Illegal size: " + size);
		this.digest = Arrays.copyOf(digest, digest.length);
	}

	@LauncherAPI
	public HashedFile(Path file, long size, boolean hash) throws IOException {
		this(size, hash ? SecurityHelper.digest(SecurityHelper.DigestAlgorithm.MD5, file) : DUMMY_HASH);
	}

	@LauncherAPI
	public HashedFile(HInput input) throws IOException {
		this(input.readVarLong(), input.readByteArray(SecurityHelper.CRYPTO_MAX_LENGTH));
	}

	@Override
	public Type getType() {
		return Type.FILE;
	}

	@Override
	public long size() {
		return size;
	}

	@Override
	public void write(HOutput output) throws IOException {
		output.writeVarLong(size);
		output.writeByteArray(digest, SecurityHelper.CRYPTO_MAX_LENGTH);
	}

	@LauncherAPI
	public boolean isSame(HashedFile o) {
		return size == o.size && Arrays.equals(digest, o.digest);
	}

	@LauncherAPI
	public boolean isSame(Path file) throws IOException {
		return isSame(new HashedFile(file, IOHelper.readAttributes(file).size(), true));
	}

	@LauncherAPI
	public boolean isSameDigest(byte[] digest) {
		return Arrays.equals(this.digest, digest);
	}
}