/* Cygne
*
* Copyright notice for this file:
*  Copyright (C) 2002 Dox dox@space.pl
*
* 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 "system.h"
#include <cstring>
#include <cstdlib>
#include <cstdio>
#include <cstdarg>

#define EXPORT extern "C" __declspec(dllexport)

namespace MDFN_IEN_WSWAN
{

	// maybe change?
	int Debug::puts ( const char * str )
	{
		return std::puts(str);
	}
	int Debug::printf ( const char * format, ... )
	{
		va_list args;
		va_start(args, format);
		int ret = vprintf(format, args);
		va_end(args);
		return ret;
	}

#include "start.inc"

	void System::Reset()
	{
		cpu.reset();
		memory.Reset();
		gfx.Reset();
		sound.Reset();
		interrupt.Reset();
		//rtc.Reset(); // at the moment, RTC changes no state on hard reset
		eeprom.Reset();

		for(int u0=0;u0<0xc9;u0++)
		{
			if(u0 != 0xC4 && u0 != 0xC5 && u0 != 0xBA && u0 != 0xBB)
				memory.writeport(u0,startio[u0]);
		}

		cpu.set_reg(NEC_SS,0);
		cpu.set_reg(NEC_SP,0x2000);
	}

	bool System::Advance(uint32 buttons, bool novideo, uint32 *surface, int16 *soundbuff, int &soundbuffsize)
	{
		// we hijack the top bit of the buttons input and use it as a positive edge sensitive toggle to the rotate input
		rotate ^= (buttons & 0x80000000) > (oldbuttons & 0x80000000);
		oldbuttons = buttons;

		memory.WSButtonStatus = rotate ? buttons >> 16 : buttons;
		memory.WSButtonStatus &= 0x7ff; // mask out "rotate" bit and other unused bits
		memory.Lagged = true;
		while (!gfx.ExecuteLine(surface, novideo))
		{
		}

		soundbuffsize = sound.Flush(soundbuff, soundbuffsize);

		// cycles elapsed in the frame can be read here
		// how is this OK to reset?  it's only used by the sound code, so once the sound for the frame has
		// been collected, it's OK to zero.  indeed, it should be done as there's no rollover protection
		cpu.timestamp = 0;
		return memory.Lagged;
	}

	// Source: http://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2
	// Rounds up to the nearest power of 2.
	static inline uint32 round_up_pow2(uint32 v)
	{
		v--;
		v |= v >> 1;
		v |= v >> 2;
		v |= v >> 4;
		v |= v >> 8;
		v |= v >> 16;
		v++;

		v += (v == 0);

		return(v);
	}

	bool System::Load(const uint8 *data, int length, const SyncSettings &settings)
	{
		uint32 real_rom_size;

		if(length < 65536)
		{
			Debug::puts("Rom image is too small (<64K)");
			return false;
		}

		if(!memcmp(data + length - 0x20, "WSRF", 4))
		{
			Debug::puts("WSRF files not supported");
			return false;
		}

		real_rom_size = (length + 0xFFFF) & ~0xFFFF;
		memory.rom_size = round_up_pow2(real_rom_size);

		memory.wsCartROM = (uint8 *)std::calloc(1, memory.rom_size);


		if(real_rom_size < memory.rom_size)
			memset(memory.wsCartROM, 0xFF, memory.rom_size - real_rom_size);

		memcpy(memory.wsCartROM + (memory.rom_size - real_rom_size), data, length);


		uint8 header[10];
		memcpy(header, memory.wsCartROM + memory.rom_size - 10, 10);

		{
			const char *developer_name = "???";
			for(unsigned int x = 0; x < sizeof(Developers) / sizeof(DLEntry); x++)
			{
				if(Developers[x].id == header[0])
				{
					developer_name = Developers[x].name;
					break;
				}
			}
			Debug::printf("Developer: %s (0x%02x)\n", developer_name, header[0]);
		}

		memory.sram_size = 0;
		eeprom.eeprom_size = 0;

		switch(header[5])
		{
		case 0x01: memory.sram_size = 8 * 1024; break;
		case 0x02: memory.sram_size = 32 * 1024; break;
		case 0x03: memory.sram_size = 128 * 1024; break; // Taikyoku Igo.  Maybe it should only be 65536 bytes?
		case 0x04: memory.sram_size = 256 * 1024; break; // Dicing Knight, Judgement Silversword
		case 0x05: memory.sram_size = 512 * 1024; break; // Wonder Gate

		case 0x10: eeprom.eeprom_size = 128; break;
		case 0x20: eeprom.eeprom_size = 2*1024; break;
		case 0x50: eeprom.eeprom_size = 1024; break;
		}

		//printf("%02x\n", header[5]);

		if(eeprom.eeprom_size)
			Debug::printf("EEPROM:  %d bytes\n", eeprom.eeprom_size);

		if(memory.sram_size)
			Debug::printf("Battery-backed RAM:  %d bytes\n", memory.sram_size);

		Debug::printf("Recorded Checksum:  0x%04x\n", header[8] | (header[9] << 8));
		{
			uint16 real_crc = 0;
			for(unsigned int i = 0; i < memory.rom_size - 2; i++)
				real_crc += memory.wsCartROM[i];
			Debug::printf("Real Checksum:      0x%04x\n", real_crc);
		}

		if((header[8] | (header[9] << 8)) == 0x8de1 && (header[0]==0x01)&&(header[2]==0x27)) /* Detective Conan */
		{
			Debug::printf("Activating Detective Conan Hack\n");
			/* WS cpu is using cache/pipeline or there's protected ROM bank where pointing CS */
			memory.wsCartROM[0xfffe8]=0xea;
			memory.wsCartROM[0xfffe9]=0x00;
			memory.wsCartROM[0xfffea]=0x00;
			memory.wsCartROM[0xfffeb]=0x00;
			memory.wsCartROM[0xfffec]=0x20;
		}

		rotate = header[6] & 1;

		memory.Init(settings);
		gfx.Init(settings.color);
		rtc.Init(settings.initialtime, settings.userealtime);

		gfx.MakeTiles();

		Reset();

		return true;
	}

	// this is more than just being defensive; these classes do
	// in some cases rely on zero filled constuct state
	void *System::operator new(std::size_t size)
	{
		void *p = ::operator new(size);
		std::memset(p, 0, size);
		return p;
	}

	System::System()
	{
		gfx.sys = this;
		memory.sys = this;
		eeprom.sys = this;
		rtc.sys = this;
		sound.sys = this;
		cpu.sys = this;
		interrupt.sys = this;
	}

	System::~System()
	{
	}

	int System::SaveRamSize() const
	{
		return eeprom.ieeprom_size + eeprom.eeprom_size + memory.sram_size;
	}

	bool System::SaveRamLoad(const uint8 *data, int size)
	{
		if (size != SaveRamSize())
			return false;

		#define LOAD(sz,ptr) { if (sz) { std::memcpy((ptr), data, (sz)); data += (sz); } }

		LOAD(eeprom.ieeprom_size, eeprom.iEEPROM);
		LOAD(eeprom.eeprom_size, eeprom.wsEEPROM);
		LOAD(memory.sram_size, memory.wsSRAM);

		#undef LOAD

		return true;
	}

	bool System::SaveRamSave(uint8 *dest, int maxsize) const
	{
		if (maxsize != SaveRamSize())
			return false;

		#define SAVE(sz,ptr) { if (sz) { std::memcpy(dest, (ptr), (sz)); dest += (sz); } }

		SAVE(eeprom.ieeprom_size, eeprom.iEEPROM);
		SAVE(eeprom.eeprom_size, eeprom.wsEEPROM);
		SAVE(memory.sram_size, memory.wsSRAM);

		#undef SAVE

		return true;
	}

	void System::PutSettings(const Settings &s)
	{
		gfx.SetLayerEnableMask(s.LayerMask);
		gfx.SetBWPalette(s.BWPalette);
		gfx.SetColorPalette(s.ColorPalette);
	}

	uint32 System::GetNECReg(int which) const
	{
		return cpu.get_reg(which);
	}

	bool System::GetMemoryArea(int index, const char *&name, int &size, uint8 *&data)
	{
		bool ret = true;
		switch (index)
		{
		case 0: name = "RAM"; size = 65536; data = memory.wsRAM; break;
		case 1: name = "ROM"; size = memory.rom_size; data = memory.wsCartROM; break;
		case 2: name = "SRAM"; size = memory.sram_size; data = memory.wsSRAM; break;
		case 3: name = "iEEPROM"; size = eeprom.ieeprom_size; data = eeprom.iEEPROM; break;
		case 4: name = "EEPROM"; size = eeprom.eeprom_size; data = eeprom.wsEEPROM; break;
		default: ret = false; break;
		}
		return ret;
	}

	SYNCFUNC(System)
	{
		SSS(gfx);
		SSS(memory);
		SSS(eeprom);
		SSS(rtc);
		SSS(sound);
		SSS(cpu);
		SSS(interrupt);
	
		NSS(rotate);
		NSS(oldbuttons);
	}

	EXPORT System *bizswan_new()
	{
		return new System();
	}

	EXPORT void bizswan_delete(System *s)
	{
		delete s;
	}

	EXPORT void bizswan_reset(System *s)
	{
		s->Reset();
	}

	EXPORT int bizswan_advance(System *s, uint32 buttons, bool novideo, uint32 *surface, int16 *soundbuff, int *soundbuffsize, int *IsRotated)
	{
		int ret = s->Advance(buttons, novideo, surface, soundbuff, *soundbuffsize);
		*IsRotated = s->rotate;
		return ret;
	}

	EXPORT int bizswan_load(System *s, const uint8 *data, int length, const SyncSettings *settings, int *IsRotated)
	{
		bool ret = s->Load(data, length, *settings);
		*IsRotated = s->rotate;
		return ret;
	}

	EXPORT int bizswan_saveramsize(System *s)
	{
		return s->SaveRamSize();
	}

	EXPORT int bizswan_saveramload(System *s, const uint8 *data, int size)
	{
		return s->SaveRamLoad(data, size);
	}

	EXPORT int bizswan_saveramsave(System *s, uint8 *dest, int maxsize)
	{
		return s->SaveRamSave(dest, maxsize);
	}

	EXPORT void bizswan_putsettings(System *s, const Settings *settings)
	{
		s->PutSettings(*settings);
	}

	EXPORT uint32 bizswan_getnecreg(System *s, int which)
	{
		return s->GetNECReg(which);
	}

	EXPORT int bizswan_getmemoryarea(System *s, int index, const char **name, int *size, uint8 **data)
	{
		return s->GetMemoryArea(index, *name, *size, *data);
	}

	EXPORT int bizswan_binstatesize(System *s)
	{
		NewStateDummy dummy;
		s->SyncState<false>(&dummy);
		return dummy.GetLength();
	}

	EXPORT int bizswan_binstatesave(System *s, char *data, int length)
	{
		NewStateExternalBuffer saver(data, length);
		s->SyncState<false>(&saver);
		return !saver.Overflow() && saver.GetLength() == length;
	}
	
	EXPORT int bizswan_binstateload(System *s, const char *data, int length)
	{
		NewStateExternalBuffer loader(const_cast<char *>(data), length);
		s->SyncState<true>(&loader);
		return !loader.Overflow() && loader.GetLength() == length;
	}

	EXPORT void bizswan_txtstatesave(System *s, FPtrs *ff)
	{
		NewStateExternalFunctions saver(ff);
		s->SyncState<false>(&saver);
	}

	EXPORT void bizswan_txtstateload(System *s, FPtrs *ff)
	{
		NewStateExternalFunctions loader(ff);
		s->SyncState<true>(&loader);
	}

	EXPORT void bizswan_setmemorycallbacks(System *s, void (*rcb)(uint32), void (*ecb)(uint32), void (*wcb)(uint32))
	{
		s->cpu.ReadHook = rcb;
		s->cpu.WriteHook = wcb;
		s->cpu.ExecHook = ecb;
	}

	EXPORT void bizswan_setbuttoncallback(System *s, void (*bcb)())
	{
		s->memory.ButtonHook = bcb;
	}
}