using System;
using System.IO;
using Org.BouncyCastle.Crypto.Engines;
using Org.BouncyCastle.Utilities;

namespace Org.BouncyCastle.Crypto;

public class BufferedIesCipher : BufferedCipherBase
{
	private readonly IesEngine engine;

	private bool forEncryption;

	private MemoryStream buffer = new MemoryStream();

	public override string AlgorithmName => "IES";

	public BufferedIesCipher(IesEngine engine)
	{
		if (engine == null)
		{
			throw new ArgumentNullException("engine");
		}
		this.engine = engine;
	}

	public override void Init(bool forEncryption, ICipherParameters parameters)
	{
		this.forEncryption = forEncryption;
		throw Platform.CreateNotImplementedException("IES");
	}

	public override int GetBlockSize()
	{
		return 0;
	}

	public override int GetOutputSize(int inputLen)
	{
		if (engine == null)
		{
			throw new InvalidOperationException("cipher not initialised");
		}
		int num = inputLen + (int)buffer.Length;
		if (!forEncryption)
		{
			return num - 20;
		}
		return num + 20;
	}

	public override int GetUpdateOutputSize(int inputLen)
	{
		return 0;
	}

	public override byte[] ProcessByte(byte input)
	{
		buffer.WriteByte(input);
		return null;
	}

	public override byte[] ProcessBytes(byte[] input, int inOff, int length)
	{
		if (input == null)
		{
			throw new ArgumentNullException("input");
		}
		if (inOff < 0)
		{
			throw new ArgumentException("inOff");
		}
		if (length < 0)
		{
			throw new ArgumentException("length");
		}
		if (inOff + length > input.Length)
		{
			throw new ArgumentException("invalid offset/length specified for input array");
		}
		buffer.Write(input, inOff, length);
		return null;
	}

	public override byte[] DoFinal()
	{
		byte[] array = buffer.ToArray();
		Reset();
		return engine.ProcessBlock(array, 0, array.Length);
	}

	public override byte[] DoFinal(byte[] input, int inOff, int length)
	{
		ProcessBytes(input, inOff, length);
		return DoFinal();
	}

	public override void Reset()
	{
		buffer.SetLength(0L);
	}
}