/*
 * Project 64 - A Nintendo 64 emulator.
 *
 * (c) Copyright 2001 zilmar (zilmar@emulation64.com) and 
 * Jabo (jabo@emulation64.com).
 *
 * pj64 homepage: www.pj64.net
 *
 * Permission to use, copy, modify and distribute Project64 in both binary and
 * source form, for non-commercial purposes, is hereby granted without fee,
 * providing that this license information and copyright notice appear with
 * all copies and any derived work.
 *
 * This software is provided 'as-is', without any express or implied
 * warranty. In no event shall the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Project64 is freeware for PERSONAL USE only. Commercial users should
 * seek permission of the copyright holders first. Commercial use includes
 * charging money for Project64 or software derived from Project64.
 *
 * The copyright holders request that bug fixes and improvements to the code
 * should be forwarded to them so if they want them.
 *
 */

#include <windows.h>
#include <stdio.h>
#include "main.h"
#include "CPU.h"

static HANDLE hEepromFile = NULL;
BYTE EEPROM[0x800];

void CloseEeprom (void) {
	if (hEepromFile) {
		CloseHandle(hEepromFile);
		hEepromFile = NULL;
	}
}

void EepromCommand ( BYTE * Command) {
	if (SaveUsing == SaveChip_Auto) { SaveUsing = SaveChip_Eeprom_4K; }

	switch (Command[2]) {
	case 0: // check
		if (SaveUsing != SaveChip_Eeprom_4K &&  SaveUsing != SaveChip_Eeprom_16K) {
			Command[1] |= 0x80;
			break;
		}
		if (Command[1] != 3) { 
			Command[1] |= 0x40; 
			if ((Command[1] & 3) > 0) { Command[3] = 0x00; }
			if (SaveUsing == SaveChip_Eeprom_4K) {
				if ((Command[1] & 3) > 1) { Command[4] = 0x80; }
			} else {
				if ((Command[1] & 3) > 1) { Command[4] = 0xC0; }
			}
			if ((Command[1] & 3) > 2) { Command[5] = 0x00; }
		} else {
			Command[3] = 0x00;
			Command[4] = SaveUsing == SaveChip_Eeprom_4K?0x80:0xC0;
			Command[5] = 0x00;
		}
		break;
	case 4: // Read from Eeprom
#ifndef EXTERNAL_RELEASE
		if (Command[0] != 2) { DisplayError("What am I meant to do with this Eeprom Command"); }
		if (Command[1] != 8) { DisplayError("What am I meant to do with this Eeprom Command"); }
#endif
		ReadFromEeprom(&Command[4],Command[3]);
		break;
	case 5:
#ifndef EXTERNAL_RELEASE
		if (Command[0] != 10) { DisplayError("What am I meant to do with this Eeprom Command"); }
		if (Command[1] != 1) { DisplayError("What am I meant to do with this Eeprom Command"); }
#endif
		WriteToEeprom(&Command[4],Command[3]);
		break;
	default:
		if (ShowPifRamErrors) { DisplayError("Unkown EepromCommand %d",Command[2]); }
	}
}


void LoadEeprom (void) {
	char File[255], Directory[255];
	DWORD dwRead;

	GetAutoSaveDir(Directory);
	sprintf(File,"%s%s.eep",Directory,RomName);
	
	hEepromFile = CreateFile(File,GENERIC_WRITE | GENERIC_READ, FILE_SHARE_READ,NULL,OPEN_ALWAYS,
		FILE_ATTRIBUTE_NORMAL | FILE_FLAG_RANDOM_ACCESS, NULL);
	if (hEepromFile == INVALID_HANDLE_VALUE) {
		switch (GetLastError()) {
		case ERROR_PATH_NOT_FOUND:
			CreateDirectory(Directory,NULL);
			hEepromFile = CreateFile(File,GENERIC_WRITE | GENERIC_READ, FILE_SHARE_READ,
				NULL,OPEN_ALWAYS,FILE_ATTRIBUTE_NORMAL | FILE_FLAG_RANDOM_ACCESS, NULL);
			if (hEepromFile == INVALID_HANDLE_VALUE) {
				DisplayError(GS(MSG_FAIL_OPEN_EEPROM));
			}
			return;
			break;
		default:
			DisplayError(GS(MSG_FAIL_OPEN_EEPROM));
			return;
		}
	}
	memset(EEPROM,0,sizeof(EEPROM));
	SetFilePointer(hEepromFile,0,NULL,FILE_BEGIN);	
	ReadFile(hEepromFile,EEPROM,sizeof(EEPROM),&dwRead,NULL);
}

void ReadFromEeprom(BYTE * Buffer, int line) {
	int i;
	
	if (hEepromFile == NULL) {
		LoadEeprom();
	}
	for(i=0;i<8;i++) { Buffer[i]=EEPROM[line*8+i]; }
}

void WriteToEeprom(BYTE * Buffer, int line) {
	DWORD dwWritten;
	int i;

	if (hEepromFile == NULL) {
		LoadEeprom();
	}
	for(i=0;i<8;i++) { EEPROM[line*8+i]=Buffer[i]; }
	SetFilePointer(hEepromFile,line*8,NULL,FILE_BEGIN);	
	WriteFile( hEepromFile,Buffer,8,&dwWritten,NULL );
}