// Copyright (c) 2012- PPSSPP 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 or later versions.

// 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 git repository and contact information can be found at
// https://github.com/hrydgard/ppsspp and http://www.ppsspp.org/.

#include <cstdio>
#include <cstring>
#include <algorithm>

#include "Common/Data/Text/I18n.h"
#include "Common/File/FileUtil.h"
#include "Common/System/OSD.h"
#include "Common/Log.h"
#include "Common/Swap.h"
#include "Core/Loaders.h"
#include "Core/FileSystems/BlockDevices.h"

extern "C"
{
#include "zlib.h"
#include "ext/libkirk/amctrl.h"
#include "ext/libkirk/kirk_engine.h"
};

std::mutex NPDRMDemoBlockDevice::mutex_;

BlockDevice *constructBlockDevice(FileLoader *fileLoader) {
	// Check for CISO
	if (!fileLoader->Exists())
		return nullptr;
	char buffer[4]{};
	size_t size = fileLoader->ReadAt(0, 1, 4, buffer);
	if (size == 4 && !memcmp(buffer, "CISO", 4))
		return new CISOFileBlockDevice(fileLoader);
	if (size == 4 && !memcmp(buffer, "\x00PBP", 4)) {
		uint32_t psarOffset = 0;
		size = fileLoader->ReadAt(0x24, 1, 4, &psarOffset);
		if (size == 4 && psarOffset < fileLoader->FileSize())
			return new NPDRMDemoBlockDevice(fileLoader);
	}
	return new FileBlockDevice(fileLoader);
}

u32 BlockDevice::CalculateCRC(volatile bool *cancel) {
	u32 crc = crc32(0, Z_NULL, 0);

	u8 block[2048];
	for (u32 i = 0; i < GetNumBlocks(); ++i) {
		if (cancel && *cancel)
			return 0;
		if (!ReadBlock(i, block, true)) {
			ERROR_LOG(FILESYS, "Failed to read block for CRC");
			return 0;
		}
		crc = crc32(crc, block, 2048);
	}

	return crc;
}

void BlockDevice::NotifyReadError() {
	auto err = GetI18NCategory(I18NCat::ERRORS);
	if (!reportedError_) {
		g_OSD.Show(OSDType::MESSAGE_WARNING, err->T("Game disc read error - ISO corrupt"), fileLoader_->GetPath().ToVisualString(), 6.0f);
		reportedError_ = true;
	}
}

FileBlockDevice::FileBlockDevice(FileLoader *fileLoader)
	: BlockDevice(fileLoader) {
	filesize_ = fileLoader->FileSize();
}

FileBlockDevice::~FileBlockDevice() {
}

bool FileBlockDevice::ReadBlock(int blockNumber, u8 *outPtr, bool uncached) {
	FileLoader::Flags flags = uncached ? FileLoader::Flags::HINT_UNCACHED : FileLoader::Flags::NONE;
	size_t retval = fileLoader_->ReadAt((u64)blockNumber * (u64)GetBlockSize(), 1, 2048, outPtr, flags);
	if (retval != 2048) {
		DEBUG_LOG(FILESYS, "Could not read 2048 byte block, at block offset %d. Only got %d bytes", blockNumber, (int)retval);
		return false;
	}

	return true;
}

bool FileBlockDevice::ReadBlocks(u32 minBlock, int count, u8 *outPtr) {
	size_t retval = fileLoader_->ReadAt((u64)minBlock * (u64)GetBlockSize(), 2048, count, outPtr);
	if (retval != (size_t)count) {
		ERROR_LOG(FILESYS, "Could not read %d blocks, at block offset %d. Only got %d blocks", count, minBlock, (int)retval);
		return false;
	}
	return true;
}

// .CSO format

// compressed ISO(9660) header format
typedef struct ciso_header
{
	unsigned char magic[4];         // +00 : 'C','I','S','O'
	u32_le header_size;             // +04 : header size (==0x18)
	u64_le total_bytes;             // +08 : number of original data size
	u32_le block_size;              // +10 : number of compressed block size
	unsigned char ver;              // +14 : version 01
	unsigned char align;            // +15 : align of index value
	unsigned char rsv_06[2];        // +16 : reserved
#if 0
	// INDEX BLOCK
	unsigned int index[0];          // +18 : block[0] index
	unsigned int index[1];          // +1C : block[1] index
	:
	:
	unsigned int index[last];       // +?? : block[last]
	unsigned int index[last+1];     // +?? : end of last data point
	// DATA BLOCK
	unsigned char data[];           // +?? : compressed or plain sector data
#endif
} CISO_H;


// TODO: Need much better error handling.

static const u32 CSO_READ_BUFFER_SIZE = 256 * 1024;

CISOFileBlockDevice::CISOFileBlockDevice(FileLoader *fileLoader)
	: BlockDevice(fileLoader)
{
	// CISO format is fairly simple, but most tools do not write the header_size.

	CISO_H hdr;
	size_t readSize = fileLoader->ReadAt(0, sizeof(CISO_H), 1, &hdr);
	if (readSize != 1 || memcmp(hdr.magic, "CISO", 4) != 0) {
		WARN_LOG(LOADER, "Invalid CSO!");
	}
	if (hdr.ver > 1) {
		WARN_LOG(LOADER, "CSO version too high!");
	}

	frameSize = hdr.block_size;
	if ((frameSize & (frameSize - 1)) != 0)
		ERROR_LOG(LOADER, "CSO block size %i unsupported, must be a power of two", frameSize);
	else if (frameSize < 0x800)
		ERROR_LOG(LOADER, "CSO block size %i unsupported, must be at least one sector", frameSize);

	// Determine the translation from block to frame.
	blockShift = 0;
	for (u32 i = frameSize; i > 0x800; i >>= 1)
		++blockShift;

	indexShift = hdr.align;
	const u64 totalSize = hdr.total_bytes;
	numFrames = (u32)((totalSize + frameSize - 1) / frameSize);
	numBlocks = (u32)(totalSize / GetBlockSize());
	VERBOSE_LOG(LOADER, "CSO numBlocks=%i numFrames=%i align=%i", numBlocks, numFrames, indexShift);

	// We might read a bit of alignment too, so be prepared.
	if (frameSize + (1 << indexShift) < CSO_READ_BUFFER_SIZE)
		readBuffer = new u8[CSO_READ_BUFFER_SIZE];
	else
		readBuffer = new u8[frameSize + (1 << indexShift)];
	zlibBuffer = new u8[frameSize + (1 << indexShift)];
	zlibBufferFrame = numFrames;

	const u32 indexSize = numFrames + 1;
	const size_t headerEnd = hdr.ver > 1 ? (size_t)hdr.header_size : sizeof(hdr);

#if COMMON_LITTLE_ENDIAN
	index = new u32[indexSize];
	if (fileLoader->ReadAt(headerEnd, sizeof(u32), indexSize, index) != indexSize) {
		NotifyReadError();
		memset(index, 0, indexSize * sizeof(u32));
	}
#else
	index = new u32[indexSize];
	u32_le *indexTemp = new u32_le[indexSize];

	if (fileLoader->ReadAt(headerEnd, sizeof(u32), indexSize, indexTemp) != indexSize) {
		NotifyReadError();
		memset(indexTemp, 0, indexSize * sizeof(u32_le));
	}

	for (u32 i = 0; i < indexSize; i++)
		index[i] = indexTemp[i];

	delete[] indexTemp;
#endif

	ver_ = hdr.ver;

	// Double check that the CSO is not truncated.  In most cases, this will be the exact size.
	u64 fileSize = fileLoader->FileSize();
	u64 lastIndexPos = index[indexSize - 1] & 0x7FFFFFFF;
	u64 expectedFileSize = lastIndexPos << indexShift;
	if (expectedFileSize > fileSize) {
		ERROR_LOG(LOADER, "Expected CSO to at least be %lld bytes, but file is %lld bytes. File: '%s'",
			expectedFileSize, fileSize, fileLoader->GetPath().c_str());
		NotifyReadError();
	}
}

CISOFileBlockDevice::~CISOFileBlockDevice()
{
	delete [] index;
	delete [] readBuffer;
	delete [] zlibBuffer;
}

bool CISOFileBlockDevice::ReadBlock(int blockNumber, u8 *outPtr, bool uncached)
{
	FileLoader::Flags flags = uncached ? FileLoader::Flags::HINT_UNCACHED : FileLoader::Flags::NONE;
	if ((u32)blockNumber >= numBlocks) {
		memset(outPtr, 0, GetBlockSize());
		return false;
	}

	const u32 frameNumber = blockNumber >> blockShift;
	const u32 idx = index[frameNumber];
	const u32 indexPos = idx & 0x7FFFFFFF;
	const u32 nextIndexPos = index[frameNumber + 1] & 0x7FFFFFFF;
	z_stream z{};

	const u64 compressedReadPos = (u64)indexPos << indexShift;
	const u64 compressedReadEnd = (u64)nextIndexPos << indexShift;
	const size_t compressedReadSize = (size_t)(compressedReadEnd - compressedReadPos);
	const u32 compressedOffset = (blockNumber & ((1 << blockShift) - 1)) * GetBlockSize();

	bool plain = (idx & 0x80000000) != 0;
	if (ver_ >= 2) {
		// CSO v2+ requires blocks be uncompressed if large enough to be.  High bit means other things.
		plain = compressedReadSize >= frameSize;
	}
	if (plain) {
		int readSize = (u32)fileLoader_->ReadAt(compressedReadPos + compressedOffset, 1, GetBlockSize(), outPtr, flags);
		if (readSize < GetBlockSize())
			memset(outPtr + readSize, 0, GetBlockSize() - readSize);
	} else if (zlibBufferFrame == frameNumber) {
		// We already have it.  Just apply the offset and copy.
		memcpy(outPtr, zlibBuffer + compressedOffset, GetBlockSize());
	} else {
		const u32 readSize = (u32)fileLoader_->ReadAt(compressedReadPos, 1, compressedReadSize, readBuffer, flags);

		z.zalloc = Z_NULL;
		z.zfree = Z_NULL;
		z.opaque = Z_NULL;
		if (inflateInit2(&z, -15) != Z_OK) {
			ERROR_LOG(LOADER, "GetBlockSize() ERROR: %s\n", (z.msg) ? z.msg : "?");
			NotifyReadError();
			return false;
		}
		z.avail_in = readSize;
		z.next_out = frameSize == (u32)GetBlockSize() ? outPtr : zlibBuffer;
		z.avail_out = frameSize;
		z.next_in = readBuffer;

		int status = inflate(&z, Z_FINISH);
		if (status != Z_STREAM_END) {
			ERROR_LOG(LOADER, "block %d: inflate : %s[%d]\n", blockNumber, (z.msg) ? z.msg : "error", status);
			NotifyReadError();
			inflateEnd(&z);
			memset(outPtr, 0, GetBlockSize());
			return false;
		}
		if (z.total_out != frameSize) {
			ERROR_LOG(LOADER, "block %d: block size error %d != %d\n", blockNumber, (u32)z.total_out, frameSize);
			NotifyReadError();
			inflateEnd(&z);
			memset(outPtr, 0, GetBlockSize());
			return false;
		}
		inflateEnd(&z);

		if (frameSize != (u32)GetBlockSize()) {
			zlibBufferFrame = frameNumber;
			memcpy(outPtr, zlibBuffer + compressedOffset, GetBlockSize());
		}
	}
	return true;
}

bool CISOFileBlockDevice::ReadBlocks(u32 minBlock, int count, u8 *outPtr) {
	if (count == 1) {
		return ReadBlock(minBlock, outPtr);
	}
	if (minBlock >= numBlocks) {
		memset(outPtr, 0, GetBlockSize() * count);
		return false;
	}

	const u32 lastBlock = std::min(minBlock + count, numBlocks) - 1;
	const u32 missingBlocks = (lastBlock + 1 - minBlock) - count;
	if (lastBlock < minBlock + count) {
		memset(outPtr + GetBlockSize() * (count - missingBlocks), 0, GetBlockSize() * missingBlocks);
	}

	const u32 minFrameNumber = minBlock >> blockShift;
	const u32 lastFrameNumber = lastBlock >> blockShift;
	const u32 afterLastIndexPos = index[lastFrameNumber + 1] & 0x7FFFFFFF;
	const u64 totalReadEnd = (u64)afterLastIndexPos << indexShift;

	z_stream z{};
	if (inflateInit2(&z, -15) != Z_OK) {
		ERROR_LOG(LOADER, "Unable to initialize inflate: %s\n", (z.msg) ? z.msg : "?");
		return false;
	}

	u64 readBufferStart = 0;
	u64 readBufferEnd = 0;
	u32 block = minBlock;
	const u32 blocksPerFrame = 1 << blockShift;
	for (u32 frame = minFrameNumber; frame <= lastFrameNumber; ++frame) {
		const u32 idx = index[frame];
		const u32 indexPos = idx & 0x7FFFFFFF;
		const u32 nextIndexPos = index[frame + 1] & 0x7FFFFFFF;

		const u64 frameReadPos = (u64)indexPos << indexShift;
		const u64 frameReadEnd = (u64)nextIndexPos << indexShift;
		const u32 frameReadSize = (u32)(frameReadEnd - frameReadPos);
		const u32 frameBlockOffset = block & ((1 << blockShift) - 1);
		const u32 frameBlocks = std::min(lastBlock - block + 1, blocksPerFrame - frameBlockOffset);

		if (frameReadEnd > readBufferEnd) {
			const s64 maxNeeded = totalReadEnd - frameReadPos;
			const size_t chunkSize = (size_t)std::min(maxNeeded, (s64)std::max(frameReadSize, CSO_READ_BUFFER_SIZE));

			const u32 readSize = (u32)fileLoader_->ReadAt(frameReadPos, 1, chunkSize, readBuffer);
			if (readSize < chunkSize) {
				memset(readBuffer + readSize, 0, chunkSize - readSize);
			}

			readBufferStart = frameReadPos;
			readBufferEnd = frameReadPos + readSize;
		}

		u8 *rawBuffer = &readBuffer[frameReadPos - readBufferStart];
		const int plain = idx & 0x80000000;
		if (plain) {
			memcpy(outPtr, rawBuffer + frameBlockOffset * GetBlockSize(), frameBlocks * GetBlockSize());
		} else {
			z.avail_in = frameReadSize;
			z.next_out = frameBlocks == blocksPerFrame ? outPtr : zlibBuffer;
			z.avail_out = frameSize;
			z.next_in = rawBuffer;

			int status = inflate(&z, Z_FINISH);
			if (status != Z_STREAM_END) {
				ERROR_LOG(LOADER, "Inflate frame %d: failed - %s[%d]\n", frame, (z.msg) ? z.msg : "error", status);
				NotifyReadError();
				memset(outPtr, 0, frameBlocks * GetBlockSize());
			} else if (z.total_out != frameSize) {
				ERROR_LOG(LOADER, "Inflate frame %d: block size error %d != %d\n", frame, (u32)z.total_out, frameSize);
				NotifyReadError();
				memset(outPtr, 0, frameBlocks * GetBlockSize());
			} else if (frameBlocks != blocksPerFrame) {
				memcpy(outPtr, zlibBuffer + frameBlockOffset * GetBlockSize(), frameBlocks * GetBlockSize());
				// In case we end up reusing it in a single read later.
				zlibBufferFrame = frame;
			}

			inflateReset(&z);
		}

		block += frameBlocks;
		outPtr += frameBlocks * GetBlockSize();
	}

	inflateEnd(&z);
	return true;
}

NPDRMDemoBlockDevice::NPDRMDemoBlockDevice(FileLoader *fileLoader)
	: BlockDevice(fileLoader)
{
	std::lock_guard<std::mutex> guard(mutex_);
	MAC_KEY mkey;
	CIPHER_KEY ckey;
	u8 np_header[256];
	u32 tableOffset, tableSize;
	u32 lbaStart, lbaEnd;

	fileLoader_->ReadAt(0x24, 1, 4, &psarOffset);
	size_t readSize = fileLoader_->ReadAt(psarOffset, 1, 256, &np_header);
	if(readSize!=256){
		ERROR_LOG(LOADER, "Invalid NPUMDIMG header!");
	}

	kirk_init();

	// getkey
	sceDrmBBMacInit(&mkey, 3);
	sceDrmBBMacUpdate(&mkey, np_header, 0xc0);
	bbmac_getkey(&mkey, np_header+0xc0, vkey);

	// decrypt NP header
	memcpy(hkey, np_header+0xa0, 0x10);
	sceDrmBBCipherInit(&ckey, 1, 2, hkey, vkey, 0);
	sceDrmBBCipherUpdate(&ckey, np_header+0x40, 0x60);
	sceDrmBBCipherFinal(&ckey);

	lbaStart = *(u32*)(np_header+0x54); // LBA start
	lbaEnd   = *(u32*)(np_header+0x64); // LBA end
	lbaSize  = (lbaEnd-lbaStart+1);     // LBA size of ISO
	blockLBAs = *(u32*)(np_header+0x0c); // block size in LBA
	blockSize = blockLBAs*2048;
	numBlocks = (lbaSize+blockLBAs-1)/blockLBAs; // total blocks;

	blockBuf = new u8[blockSize];
	tempBuf  = new u8[blockSize];

	tableOffset = *(u32*)(np_header+0x6c); // table offset

	tableSize = numBlocks*32;
	table = new table_info[numBlocks];

	readSize = fileLoader_->ReadAt(psarOffset + tableOffset, 1, tableSize, table);
	if(readSize!=tableSize){
		ERROR_LOG(LOADER, "Invalid NPUMDIMG table!");
	}

	u32 *p = (u32*)table;
	u32 i, k0, k1, k2, k3;
	for(i=0; i<numBlocks; i++){
		k0 = p[0]^p[1];
		k1 = p[1]^p[2];
		k2 = p[0]^p[3];
		k3 = p[2]^p[3];
		p[4] ^= k3;
		p[5] ^= k1;
		p[6] ^= k2;
		p[7] ^= k0;
		p += 8;
	}

	currentBlock = -1;

}

NPDRMDemoBlockDevice::~NPDRMDemoBlockDevice()
{
	std::lock_guard<std::mutex> guard(mutex_);
	delete [] table;
	delete [] tempBuf;
	delete [] blockBuf;
}

int lzrc_decompress(void *out, int out_len, void *in, int in_len);

bool NPDRMDemoBlockDevice::ReadBlock(int blockNumber, u8 *outPtr, bool uncached)
{
	FileLoader::Flags flags = uncached ? FileLoader::Flags::HINT_UNCACHED : FileLoader::Flags::NONE;
	std::lock_guard<std::mutex> guard(mutex_);
	CIPHER_KEY ckey;
	int block, lba, lzsize;
	size_t readSize;
	u8 *readBuf;

	lba = blockNumber-currentBlock;
	if(lba>=0 && lba<blockLBAs){
		memcpy(outPtr, blockBuf+lba*2048, 2048);
		return true;
	}

	block = blockNumber/blockLBAs;
	lba = blockNumber%blockLBAs;
	currentBlock = block*blockLBAs;

	if(table[block].unk_1c!=0){
		if((u32)block==(numBlocks-1))
			return true; // demos make by fake_np
		else
			return false;
	}

	if(table[block].size<blockSize)
		readBuf = tempBuf;
	else
		readBuf = blockBuf;

	readSize = fileLoader_->ReadAt(psarOffset+table[block].offset, 1, table[block].size, readBuf, flags);
	if(readSize != (size_t)table[block].size){
		if((u32)block==(numBlocks-1))
			return true;
		else
			return false;
	}

	if((table[block].flag&1)==0){
		// skip mac check
	}

	if((table[block].flag&4)==0){
		sceDrmBBCipherInit(&ckey, 1, 2, hkey, vkey, table[block].offset>>4);
		sceDrmBBCipherUpdate(&ckey, readBuf, table[block].size);
		sceDrmBBCipherFinal(&ckey);
	}

	if(table[block].size<blockSize){
		lzsize = lzrc_decompress(blockBuf, 0x00100000, readBuf, table[block].size);
		if(lzsize!=blockSize){
			ERROR_LOG(LOADER, "LZRC decompress error! lzsize=%d\n", lzsize);
			NotifyReadError();
			return false;
		}
	}

	memcpy(outPtr, blockBuf+lba*2048, 2048);

	return true;
}
