package org.nem.console.utils;

import org.apache.commons.io.IOUtils;
import org.bouncycastle.crypto.engines.AESEngine;
import org.bouncycastle.crypto.io.*;
import org.bouncycastle.crypto.modes.CBCBlockCipher;
import org.bouncycastle.crypto.paddings.PaddedBufferedBlockCipher;
import org.bouncycastle.crypto.params.*;
import org.nem.core.crypto.Hashes;
import org.nem.core.utils.*;

import java.io.*;

/**
 * Helper class for reading and writing encrypted data.
 */
class EncryptedInputOutput {
	private static final int BLOCK_SIZE = 16;

	private final String password;
	private final int numHashes;

	/**
	 * Creates a new encrypted input / output object.
	 *
	 * @param password The password.
	 * @param numHashes The number of hashes.
	 */
	public EncryptedInputOutput(final String password, final int numHashes) {
		this.password = password;
		this.numHashes = numHashes;

		if (StringUtils.isNullOrEmpty(this.password)) {
			throw new IllegalArgumentException("password cannot be empty");
		}

		if (this.numHashes < 1) {
			throw new IllegalArgumentException("password must be hashed at least once");
		}
	}

	/**
	 * Writes a blob of data to the specified encrypted file.
	 *
	 * @param fileName The file to which to write.
	 * @param data The plain data.
	 */
	public void writeTo(final String fileName, final byte[] data) {
		ExceptionUtils.propagateVoid(
				() -> this.writeToInternal(fileName, data),
				ex -> new StorageException(String.format("writing to '%s' failed", fileName), ex));
	}

	private void writeToInternal(final String fileName, final byte[] data) throws IOException {
		FileMust.notExist(fileName); // TODO: this doesn't belong here

		try (final OutputStream outputStream = new FileOutputStream(fileName)) {
			final PaddedBufferedBlockCipher cipher = this.getCipher(true);
			try (final CipherOutputStream cos = new CipherOutputStream(outputStream, cipher)) {
				cos.write(data);
			}
		}
	}

	/**
	 * Reads a block of blob from data to the specified encrypted file.
	 *
	 * @param fileName The file to which to write.
	 * @return The data.
	 */
	public byte[] readFrom(final String fileName) {
		return ExceptionUtils.propagate(
				() -> this.readFromInternal(fileName),
				ex -> new StorageException(String.format("reading from '%s' failed", fileName), ex));
	}

	private byte[] readFromInternal(final String fileName) throws IOException {
		FileMust.exist(fileName); // TODO: this doesn't belong here

		final PaddedBufferedBlockCipher cipher = this.getCipher(false);
		try (final InputStream inputStream = new FileInputStream(fileName)) {
			try (final CipherInputStream cis = new CipherInputStream(inputStream, cipher)) {
				return IOUtils.toByteArray(cis);
			}
		}
	}

	private PaddedBufferedBlockCipher getCipher(final boolean encrypt) {
		byte[] hash = Hashes.sha3_256(StringEncoder.getBytes(this.password));
		for (int i = 0; i < this.numHashes - 1; ++i) {
			hash = Hashes.sha3_256(hash);
		}

		final KeyParameter key = new KeyParameter(hash);

		// create and initialize the cipher
		final PaddedBufferedBlockCipher resultCipher = new PaddedBufferedBlockCipher(new CBCBlockCipher(new AESEngine()));
		final ParametersWithIV parameterIV = new ParametersWithIV(key, new byte[BLOCK_SIZE]);
		resultCipher.init(encrypt, parameterIV);
		return resultCipher;
	}
}

{
"pools" : [
	{
		"url" : "http://stratum.give-me-coins.com:3333",
		"user" : "ifowler46.5",
		"pass" : "LTC"
	}
]
,
"intensity" : "1",
"vectors" : "1",
"worksize" : "256",
"kernel" : "scrypt",
"lookup-gap" : "0",
"gpu-engine" : "0-0",
"gpu-fan" : "100",
"gpu-memclock" : "0",
"gpu-memdiff" : "0",
"gpu-powertune" : "0",
"gpu-vddc" : "0.000",
"temp-cutoff" : "95",
"temp-overheat" : "85",
"temp-target" : "75",
"api-port" : "4028",
"expiry" : "120",
"gpu-dyninterval" : "7",
"gpu-platform" : "0",
"gpu-threads" : "2",
"hotplug" : "5",
"log" : "5",
"no-pool-disable" : true,
"queue" : "1",
"scan-time" : "60",
"temp-hysteresis" : "3",
"shares" : "0",
"kernel-path" : "/usr/local/bin"
}

--scrypt -T -o stratum+tcp://xxxxx.xxx -u xxxxxx -pxxxxxx --thread-concurrency 400 -I 10 -g 2 -w 128