// Copyright (C) 2003-2008 Dolphin Project.

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 2.0.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License 2.0 for more details.

// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/

// Official SVN repository and contact information can be found at
// http://code.google.com/p/dolphin-emu/

#include "stdafx.h"

#include "VolumeWiiCrypted.h"
#include "StringUtil.h"

namespace DiscIO
{
CVolumeWiiCrypted::CVolumeWiiCrypted(IBlobReader* _pReader, u64 _VolumeOffset, const unsigned char* _pVolumeKey)
	: m_pReader(_pReader),
	m_pBuffer(0),
	m_VolumeOffset(_VolumeOffset),
	m_LastDecryptedBlockOffset(-1)
{
	AES_set_decrypt_key(_pVolumeKey, 128, &m_AES_KEY);
	m_pBuffer = new u8[0x8000];
}


CVolumeWiiCrypted::~CVolumeWiiCrypted()
{
	delete m_pReader; // is this really our responsibility?
	delete[] m_pBuffer;
}


bool
CVolumeWiiCrypted::Read(u64 _ReadOffset, u64 _Length, u8* _pBuffer) const
{
	if (m_pReader == NULL)
	{
		return(false);
	}

	while (_Length > 0)
	{
		static unsigned char IV[16];

		// math block offset
		u64 Block  = _ReadOffset / 0x7C00;
		u64 Offset = _ReadOffset % 0x7C00;

		// read current block
		if (!m_pReader->Read(m_VolumeOffset + Block * 0x8000, 0x8000, m_pBuffer))
		{
			return(false);
		}

		if (m_LastDecryptedBlockOffset != Block)
		{
			memcpy(IV, m_pBuffer + 0x3d0, 16);
			AES_cbc_encrypt(m_pBuffer + 0x400, m_LastDecryptedBlock, 0x7C00, &m_AES_KEY, IV, AES_DECRYPT);

			m_LastDecryptedBlockOffset = Block;
		}

		// copy the encrypted data
		u64 MaxSizeToCopy = 0x7C00 - Offset;
		u64 CopySize = (_Length > MaxSizeToCopy) ? MaxSizeToCopy : _Length;
		memcpy(_pBuffer, &m_LastDecryptedBlock[Offset], (size_t)CopySize);

		// increase buffers
		_Length -= CopySize;
		_pBuffer    += CopySize;
		_ReadOffset += CopySize;
	}

	return(true);
}


std::string
CVolumeWiiCrypted::GetName() const
{
	if (m_pReader == NULL)
	{
		return(false);
	}

	char Name[0xFF];

	if (!Read(0x20, 0x60, (u8*)&Name))
	{
		return(false);
	}

	return(Name);
}


std::string
CVolumeWiiCrypted::GetUniqueID() const
{
	if (m_pReader == NULL)
	{
		return(false);
	}

	char ID[7];

	if (!Read(0, 6, (u8*)ID))
	{
		return(false);
	}

	ID[6] = 0;

	return(ID);
}


IVolume::ECountry
CVolumeWiiCrypted::GetCountry() const
{
	if (!m_pReader)
	{
		return(COUNTRY_UNKNOWN);
	}

	u8 CountryCode;
	m_pReader->Read(3, 1, &CountryCode);

	ECountry country = COUNTRY_UNKNOWN;

	switch (CountryCode)
	{
	    case 'S':
		    country = COUNTRY_EUROPE;
		    break; // PAL // <- that is shitty :) zelda demo disc

	    case 'P':
		    country = COUNTRY_EUROPE;
		    break; // PAL

	    case 'D':
		    country = COUNTRY_EUROPE;
		    break; // PAL

	    case 'F':
		    country = COUNTRY_FRANCE;
		    break; // PAL

	    case 'X':
		    country = COUNTRY_EUROPE;
		    break; // XIII <- uses X but is PAL rip

	    case 'E':
		    country = COUNTRY_USA;
		    break; // USA

	    case 'J':
		    country = COUNTRY_JAP;
		    break; // JAP

	    case 'O':
		    country = COUNTRY_UNKNOWN;
		    break; // SDK

	    default:
		    PanicAlert(StringFromFormat("Unknown Country Code!").c_str());
		    break;
	}

	return(country);
}


u64
CVolumeWiiCrypted::GetSize() const
{
	if (m_pReader)
	{
		return(m_pReader->GetDataSize());
	}
	else
	{
		return(0);
	}
}
} // namespace