/*
Copyright (C) 2006 StrmnNrmn

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; either version 2
of the License, or (at your option) any later version.

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 for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/

#include "BuildOptions.h"
#include "Base/Types.h"

#include "Core/ROMBuffer.h"
#include "Core/ROM.h"
#include "Core/DMA.h"
#include "Debug/DBGConsole.h"
#include "Base/MathUtil.h"
#include "Interface/Preferences.h"
#include "RomFile/RomFile.h"
#include "RomFile/RomFileCache.h"
#include "RomFile/RomFileMemory.h"
#include "Utility/Stream.h"
#include "System/IO.h"


#ifdef DAEDALUS_PSP
#include "Graphics/GraphicsContext.h"
#include "intraFont.h"
extern bool PSP_IS_SLIM;
#endif

namespace
{
	bool			sRomLoaded	= false;
	u8 *			spRomData	= nullptr;
	u32				sRomSize	= 0;
	bool			sRomFixed	= false;
	bool			sRomWritten	= false;
	u32				sRomValue	= 0;
	ROMFileCache *	spRomFileCache	= nullptr;

#ifdef DAEDALUS_COMPRESSED_ROM_SUPPORT
	static bool		DECOMPRESS_ROMS	= true;
#endif
	// Maximum read length is 8 bytes (i.e. double, u64)
	const u32		SCRATCH_BUFFER_LENGTH = 16;
	u8				sScratchBuffer[ SCRATCH_BUFFER_LENGTH ];

	bool		ShouldLoadAsFixed( u32 rom_size )
	{
#ifdef DAEDALUS_PSP
		if (PSP_IS_SLIM && !gGlobalPreferences.LargeROMBuffer)
			return rom_size <= 32 * 1024 * 1024;
		else
			return rom_size <= 2 * 1024 * 1024;
#else
		return true;
#endif
	}

#ifdef DAEDALUS_COMPRESSED_ROM_SUPPORT
	std::unique_ptr<ROMFile> DecompressRom( std::unique_ptr<ROMFile> p_rom_file, const char * temp_filename, COutputStream & messages )
	{
		auto p_new_file = nullptr;
		FILE *		fh( fopen( temp_filename, "wb" ) );

		if( fh == nullptr )
		{
			messages << "Unable to create temporary rom '" << temp_filename << "' for decompression\n";
		}
		else
		{
			bool			failed = false;
			const u32		TEMP_BUFFER_SIZE = 32 * 1024;
			u8 *			p_temp_buffer( new u8[ TEMP_BUFFER_SIZE ] );

#ifdef DAEDALUS_DEBUG_CONSOLE
			CDebugConsole::Get().MsgOverwriteStart();
#endif

			u32				offset( 0 );
			u32				total_length( p_rom_file->GetRomSize() );
			u32				length_remaining( total_length );

			while( length_remaining > 0 )
			{
#ifdef DAEDALUS_DEBUG_CONSOLE
				if ((offset % 0x8000) == 0)
				{
					CDebugConsole::Get().MsgOverwrite(0, "Converted [M%d / %d] KB", offset /1024, total_length / 1024 );
				}
#endif
				u32			length_to_process( std::min( length_remaining, TEMP_BUFFER_SIZE ) );

				if( !p_rom_file->ReadChunk( offset, p_temp_buffer, length_to_process ) )
				{
					failed = true;
					break;
				}

				if( fwrite( p_temp_buffer, 1, length_to_process, fh ) != length_to_process )
				{
					failed = true;
					break;
				}

				offset += length_to_process;
				length_remaining -= length_to_process;
			}
#ifdef DAEDALUS_DEBUG_CONSOLE
			CDebugConsole::Get().MsgOverwrite(0, "Converted [M%d / %d] KB", offset /1024, total_length / 1024 );
			CDebugConsole::Get().MsgOverwriteEnd();
#endif

			fclose( fh );
			delete [] p_temp_buffer;

			if( failed )
			{
				messages << "Failed to decompress rom to '" << temp_filename << "' - out of disk space?\n";
			}
			else
			{
				//
				//	Open the newly created file
				//
				p_new_file = ROMFile::Create( temp_filename );
				if( p_new_file == nullptr )
				{
					messages << "Failed to open temporary rom '" << temp_filename << "' we just created\n";
				}
				else
				{
					if( !p_new_file->Open( messages ) )
					{
						messages << "Failed to open temporary rom '" << temp_filename << "' we just created\n";
						delete p_new_file;
						p_new_file = nullptr;
					}
				}
			}
		}

		return p_new_file;
	}
#endif
}

//*****************************************************************************
//
//*****************************************************************************
bool RomBuffer::Create()
{
	// Create memory heap used for either ROM Cache or ROM buffer
	// We do this to avoid memory fragmentation
	CROMFileMemory::Create();
	return true;
}

//*****************************************************************************
//
//*****************************************************************************
void RomBuffer::Destroy()
{

}

//*****************************************************************************
//
//*****************************************************************************
bool RomBuffer::Open()
{
	CNullOutputStream messages;
	const std::filesystem::path filename   = g_ROM.mFileName;
	auto p_rom_file = ROMFile::Create( filename.c_str() );
	if(p_rom_file == nullptr)
	{
		DBGConsole_Msg(0, "Failed to create [C%s]\n", filename.c_str());
		return false;
	}

	if( !p_rom_file->Open( messages ) )
	{

		DBGConsole_Msg(0, "Failed to open [C%s]\n", filename.c_str());
		return false;
	}

	sRomSize = p_rom_file->GetRomSize();

	if( ShouldLoadAsFixed( sRomSize ) )
	{
		// Now, allocate memory for rom - round up to a 4 byte boundry
		u32		size_aligned( AlignPow2( sRomSize, 4 ) );
		u8 *	p_bytes( (u8*)CROMFileMemory::Get().Alloc( size_aligned ) );

#ifndef DAEDALUS_PSP
		if( !p_rom_file->LoadData( sRomSize, p_bytes, messages ) )
		{
			#ifdef DAEDALUS_DEBUG_CONSOLE
			DBGConsole_Msg(0, "Failed to load [C%s]\n", filename.c_str());
			#endif
			CROMFileMemory::Get().Free( p_bytes );
			return false;
		}
#else
		u32 offset( 0 );
		u32 length_remaining( sRomSize );
		const u32 TEMP_BUFFER_SIZE = 128 * 1024;

		intraFont* ltn8  = intraFontLoad( "flash0:/font/ltn8.pgf", INTRAFONT_CACHE_ASCII);
		intraFontSetStyle( ltn8, 1.5f, 0xFFFFFFFF, 0, 0.f, INTRAFONT_ALIGN_CENTER );

		while( offset < sRomSize )
		{
			u32 length_to_process( std::min( length_remaining, TEMP_BUFFER_SIZE ) );

			if( !p_rom_file->ReadChunk( offset, p_bytes + offset, length_to_process ) )
			{
				break;
			}

			offset += length_to_process;
			length_remaining -= length_to_process;

			CGraphicsContext::Get().BeginFrame();
			CGraphicsContext::Get().ClearToBlack();
			intraFontPrintf( ltn8, 480/2, (272>>1), "Buffering ROM %d%%...", offset * 100 / sRomSize );
			CGraphicsContext::Get().EndFrame();
			CGraphicsContext::Get().UpdateFrame( false );
		}

		intraFontUnload( ltn8 );
#endif
		spRomData = p_bytes;
		sRomFixed = true;

	}
	else
	{
#ifdef DAEDALUS_COMPRESSED_ROM_SUPPORT
		if(DECOMPRESS_ROMS)
		{
			bool	compressed( p_rom_file->IsCompressed() );
			bool	byteswapped( p_rom_file->RequiresSwapping() );
			if(compressed)// || byteswapped)
			{
				const char * temp_filename( "daedrom.tmp" );

				#ifdef DAEDALUS_DEBUG_CONSOLE
				if(compressed && byteswapped)
				{
					DBGConsole_Msg( 0, "Rom is [Mcompressed] and [Mbyteswapped]" );
				}
				else if(compressed)
				{
					DBGConsole_Msg( 0, "Rom is [Mcompressed]" );
				}
				else
				{
					DBGConsole_Msg( 0, "Rom is [Mbyteswapped]" );
				}
				DBGConsole_Msg( 0, "Decompressing rom to [C%s] (this may take some time)", temp_filename );
				#endif
				CNullOutputStream		local_messages;

				auto p_new_file = DecompressRom( p_rom_file, temp_filename, local_messages );
				#ifdef DAEDALUS_DEBUG_CONSOLE
				DBGConsole_Msg( 0, "messages:\n%s", local_messages.c_str() );
				#endif
				messages << local_messages;

				if(p_new_file != nullptr)
				{
					#ifdef DAEDALUS_DEBUG_CONSOLE
					DBGConsole_Msg( 0, "Decompression [gsuccessful]. Booting using decompressed rom" );
					#endif
					delete p_rom_file;
					p_rom_file = p_new_file;
				}
				#ifdef DAEDALUS_DEBUG_CONSOLE
				else
				{
					DBGConsole_Msg( 0, "Decompression [rfailed]. Booting using original rom" );
				}
				#endif
			}
		}
#endif
		spRomFileCache = new ROMFileCache();
		spRomFileCache->Open( std::move(p_rom_file) );
		sRomFixed = false;
	}

	DBGConsole_Msg(0, "Opened [C%s]\n", filename.c_str());
	sRomLoaded = true;
	return true;
}

//*****************************************************************************
//
//*****************************************************************************
void	RomBuffer::Close()
{
	if (spRomData)
	{
		CROMFileMemory::Get().Free( spRomData );
		spRomData = nullptr;
	}

	if (spRomFileCache)
	{
		spRomFileCache->Close();
		delete spRomFileCache;
		spRomFileCache = nullptr;
	}

	sRomSize   = 0;
	sRomLoaded = false;
	sRomFixed  = false;
	sRomWritten = false;
	sRomValue	= 0;
}

bool	RomBuffer::IsRomLoaded() { return sRomLoaded; }
u32		RomBuffer::GetRomSize() { return sRomSize; }

namespace
{
	void	CopyBytesRaw( ROMFileCache * p_cache, u8 * p_dst, u32 rom_offset, u32 length )
	{
		// Read the cached bytes into our scratch buffer, and return that
		u32		dst_offset( 0 );
		u32		src_offset( rom_offset );

		// Similar algorithm to below - we don't care about byte swapping though
		while(length > 0)
		{
			u8 *	p_chunk_base = 0;
			u32		chunk_offset = 0;
			u32		chunk_size = 0;

			if( !p_cache->GetChunk( src_offset, &p_chunk_base, &chunk_offset, &chunk_size ) )
			{
				// Out of range
				break;
			}

			// Calculate how many bytes we can transfer this pass
			u32		offset_into_chunk( src_offset - chunk_offset );
			u32		bytes_remaining_in_chunk( chunk_size - offset_into_chunk );
			u32		bytes_this_pass( std::min( length, bytes_remaining_in_chunk ) );

			DAEDALUS_ASSERT( s32( bytes_this_pass ) > 0, "How come we're trying to copy <= 0 bytes across?" );
		
			// Copy this chunk across
			memcpy( p_dst + dst_offset, p_chunk_base + offset_into_chunk, bytes_this_pass );

			// Update the src/dst pointers and reduce length by the number of copied bytes
			dst_offset += bytes_this_pass;
			src_offset += bytes_this_pass;
			length -= bytes_this_pass;
		}
	}
}

//*****************************************************************************
//
//*****************************************************************************
void	RomBuffer::GetRomBytesRaw( void * p_dst, u32 rom_start, u32 length )
{
	if( sRomFixed )
	{
		memcpy(p_dst, (const u8*)spRomData + rom_start, length );
	}
	else
	{
		DAEDALUS_ASSERT( spRomFileCache != nullptr, "How come we have no file cache?" );

		CopyBytesRaw( spRomFileCache, reinterpret_cast< u8 * >( p_dst ), rom_start, length );
	}
}

//*****************************************************************************
//
//*****************************************************************************
void	RomBuffer::SaveRomValue( u32 value )
{
	sRomWritten = true;
	sRomValue	= value;
}

//*****************************************************************************
//
//*****************************************************************************
void	RomBuffer::PutRomBytesRaw( u32 rom_start, const void * p_src, u32 length )
{
	DAEDALUS_ASSERT( sRomFixed, "Cannot put rom bytes when the data isn't fixed" );
	memcpy( (u8*)spRomData + rom_start, p_src, length );
}

//*****************************************************************************
//
//*****************************************************************************
void * RomBuffer::GetAddressRaw( u32 rom_start )
{
	if (sRomWritten)
	{
		sRomWritten = false;

		return (u8 *)&sRomValue;
	}

	if( rom_start < sRomSize )
	{
		if( sRomFixed )
		{
			return (u8 *)spRomData + rom_start;
		}
		else
		{
			// Read the cached bytes into our scratch buffer, and return that
			DAEDALUS_ASSERT( spRomFileCache != nullptr, "How come we have no file cache?" );
			CopyBytesRaw( spRomFileCache, sScratchBuffer, rom_start, SCRATCH_BUFFER_LENGTH );

			return sScratchBuffer;
		}
	}

	return nullptr;
}

//*****************************************************************************
//
//*****************************************************************************
bool RomBuffer::CopyToRam( u8 * p_dst, u32 dst_offset, u32 dst_size, u32 src_offset, u32 length )
{
	if( sRomFixed )
	{
		const u8* p_src = (const u8 *)spRomData ;
		u32	src_size = sRomSize;

		return DMA_HandleTransfer( p_dst, dst_offset, dst_size, p_src, src_offset, src_size, length );
	}
	else
	{
		while(length > 0)
		{
			u8 *	p_chunk_base = 0;
			u32		chunk_offset = 0;
			u32		chunk_size = 0;

			if( !spRomFileCache->GetChunk( src_offset, &p_chunk_base, &chunk_offset, &chunk_size ) )
			{
				// Out of range
				break;
			}

			// Calculate how many bytes we can transfer this pass
			u32		offset_into_chunk( src_offset - chunk_offset );
			u32		bytes_remaining_in_chunk( chunk_size - offset_into_chunk );
			u32		bytes_this_pass( std::min( length, bytes_remaining_in_chunk ) );

			DAEDALUS_ASSERT( s32( bytes_this_pass ) > 0, "How come we're trying to copy <= 0 bytes across?" );

			// Copy this chunk across
			if( !DMA_HandleTransfer( p_dst, dst_offset, dst_size, p_chunk_base, offset_into_chunk, chunk_size, bytes_this_pass  ) )
			{
				break;
			}

			// Update the src/dst pointers and reduce length by the number of copied bytes
			dst_offset += bytes_this_pass;
			src_offset += bytes_this_pass;
			length -= bytes_this_pass;
		}
		return length == 0;
	}
}

//*****************************************************************************
//
//*****************************************************************************
bool RomBuffer::CopyFromRam( u32 dst_offset, const u8 * p_src, u32 src_offset, u32 src_size, u32 length )
{
	if( sRomFixed )
	{
		u8 * p_dst = (u8 *)spRomData;
		u32	dst_size = sRomSize;

		return DMA_HandleTransfer( p_dst, dst_offset, dst_size, p_src, src_offset, src_size, length );
	}
	else
	{
		DAEDALUS_ERROR( "Cannot put rom bytes when the data isn't fixed" );
		return false;
	}
}

//*****************************************************************************
//
//*****************************************************************************
bool RomBuffer::IsRomAddressFixed()
{
	return sRomFixed;
}

//*****************************************************************************
//
//*****************************************************************************
const void * RomBuffer::GetFixedRomBaseAddress()
{
	DAEDALUS_ASSERT( sRomLoaded, "The rom isn't loaded" );
	DAEDALUS_ASSERT( sRomFixed, "Trying to access the rom base address when it's not fixed" );

	return spRomData;
}