/****************************************************************************
 *  Genesis Plus 1.2a
 *
 *  Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003  Charles Mac Donald
 *
 *  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 "shared.h"
#include "dvd.h"
#include "font.h"
#include "rominfo.h"
#include "saveicon.h"	/*** Nice little icon - thanks brakken! ***/

/* Support for MemCards  */
/**
 * libOGC System Work Area
 */
static u8 SysArea[CARD_WORKAREA] ATTRIBUTE_ALIGN (32);

/**
 * DMA Transfer Area.
 * Must be 32-byte aligned.
 * 64k SRAM + 2k Icon
 */
unsigned char savebuffer[0x24000] ATTRIBUTE_ALIGN (32);

card_dir CardDir;
card_file CardFile;
card_stat CardStatus;
extern int CARDSLOT;
extern int use_SDCARD;

int ManageSRAM (int direction);
int ManageState (int direction);

/****************************************************************************
 * SRAM autoload
 *
 * the detection order is the following:
 *		MCARD (SLOTA) > MCARD (SLOTB) > SDCARD (SLOTA) > SDCARD (SLOTB)
 *
 *****************************************************************************/
extern u8 SILENT;

void sram_autoload()
{
	int ret = 0;
	int i = 0;
	int old_cardslot = CARDSLOT;
	int old_sdcard = use_SDCARD;

	SILENT = 1; /* this should be transparent to the user */
	while ((i < 4) && (!ret))
	{
		use_SDCARD = (i&2) ? 1 : 0;
		CARDSLOT   = (i&1) ? CARD_SLOTB : CARD_SLOTA;
		ret = ManageSRAM(1);
		i++;
	}
	if (!ret)
	{
		/* restore old settings if not found */
		CARDSLOT = old_cardslot; 
		use_SDCARD = old_sdcard;
	}
	SILENT = 0;
}

/****************************************************************************
 * SDCARD Access functions
 *
 * We use the same buffer as for Memory Card manager
 * Function returns TRUE on success.
 *****************************************************************************/
int SD_ManageFile(char *filename, int direction, int filetype)
{
    char name[1024];
	sd_file *handle;
    int len = 0;
    int offset = 0;
	int filesize;
	unsigned long inbytes,outbytes;
	
	/* build complete SDCARD filename */
	sprintf (name, "dev%d:\\genplus\\saves\\%s", CARDSLOT, filename);

	/* open file */
	handle = direction ? SDCARD_OpenFile (name, "rb") :
						 SDCARD_OpenFile (name, "wb");

	if (handle == NULL)
	{
		sprintf (filename, "Error opening %s", name);
		WaitPrompt(filename);
		return 0;
	}
	
	switch (direction)
	{
		case 0: /* SAVING */

			if (filetype) /* SRAM */
			{
				inbytes = 0x10000;
				outbytes = 0x12000;
				compress2 ((char *) &savebuffer[sizeof(outbytes)], &outbytes, (char *) &sram.sram, inbytes, 9);
				memcpy(&savebuffer[0], &outbytes, sizeof(outbytes));
				filesize = outbytes + sizeof(outbytes);
			}
			else filesize = state_save(&savebuffer[0]); /* STATE */

			len = SDCARD_WriteFile (handle, savebuffer, filesize);
			SDCARD_CloseFile (handle);

			if (len != filesize)
			{
				sprintf (filename, "Error writing %s", name);
				WaitPrompt (filename);
				return 0;
			}
			
			sprintf (filename, "Saved %d bytes successfully", filesize);
			WaitPrompt (filename);
			return 1;
		
		case 1: /* LOADING */
		
			while ((len = SDCARD_ReadFile (handle, &savebuffer[offset], 2048)) > 0) offset += len;
			if (filetype) /* SRAM */
			{
				memcpy(&inbytes,&savebuffer[0],sizeof(inbytes));
				outbytes = 0x10000;
				uncompress ((char *) &sram.sram, &outbytes, (char *) &savebuffer[sizeof(inbytes)], inbytes);
				sram.crc = crc32 (0, &sram.sram[0], outbytes);
				system_reset ();
			}
			else state_load(&savebuffer[0]); /* STATE */
            SDCARD_CloseFile (handle);

			sprintf (filename, "Loaded %d bytes successfully", offset);
			WaitPrompt (filename);
			return 1;
	}
	
	return 0; 
}

/****************************************************************************
 * MountTheCard
 *
 * libOGC provides the CARD_Mount function, and it should be all you need.
 * However, experience with previous emulators has taught me that you are
 * better off doing a little bit more than that!
 *
 * Function returns TRUE on success.
 *****************************************************************************/
int MountTheCard ()
{
	int tries = 0;
	int CardError;
	while (tries < 10)
	{
		*(unsigned long *) (0xcc006800) |= 1 << 13; /*** Disable Encryption ***/
		uselessinquiry ();
		VIDEO_WaitVSync ();
		CardError = CARD_Mount (CARDSLOT, SysArea, NULL); /*** Don't need or want a callback ***/
		if (CardError == 0) return 1;
		else EXI_ProbeReset ();
		tries++;
	}
	return 0;
}

/****************************************************************************
 * CardFileExists
 *
 * Wrapper to search through the files on the card.
 * Returns TRUE if found.
 ****************************************************************************/
int CardFileExists (char *filename)
{
	int CardError = CARD_FindFirst (CARDSLOT, &CardDir, TRUE);
	while (CardError != CARD_ERROR_NOFILE)
	{
		CardError = CARD_FindNext (&CardDir);
		if (strcmp ((char *) CardDir.filename, filename) == 0) return 1;
	}
	return 0;
}

/****************************************************************************
 * ManageSRAM
 *
 * Here is the main SRAM Management stuff.
 * The output file contains an icon (2K), 64 bytes comment and the SRAM (64k).
 * As memcards are allocated in blocks of 8k or more, you have a around
 * 6k bytes to save/load any other data you wish without altering any of the
 * main save / load code.
 *
 * direction == 0 save, 1 load.
 ****************************************************************************/
int ManageSRAM (int direction)
{
	char filename[128];
	char action[80];
	int CardError;
	unsigned int SectorSize;
	int blocks;
	char comment[2][32] = { {"Genesis Plus 1.2a"}, {"SRAM Save"} };
    int outbytes = 0;
	int sbo;
	int i;
	unsigned long inzipped,outzipped;

	if (!genromsize) return 0;

	if (direction) ShowAction ("Loading SRAM ...");
	else ShowAction ("Saving SRAM ...");

	/* First, build a filename based on the information retrieved for this ROM */
	if (strlen (rominfo.domestic)) strcpy (filename, rominfo.domestic);
	else strcpy (filename, rominfo.international);

	/* As these names tend to be bulked with spaces, let's strip them */
	/* Name should be in 16 character blocks, so take first 16        */
	filename[16] = 0;
	for (i = strlen (filename) - 1; i > 0; i--)
		if (filename[i] != 32) break;
	filename[i + 1] = 0;

	/* Now add the 16bit checksum, to ensure it's the same ROM */
	sprintf (filename, "%s%02X.srm", filename, rominfo.checksum);
	strcpy (comment[1], filename);

	/* device is SDCARD, let's go */
	if (use_SDCARD) return SD_ManageFile(filename,direction,1);

	/* device is MCARD, we continue */
	if (direction == 0) /*** Saving ***/
	{
		/*** Build the output buffer ***/
		memcpy (&savebuffer, &icon, 2048);
		memcpy (&savebuffer[2048], &comment[0], 64);

		inzipped = 0x10000;
		outzipped = 0x12000;
		compress2 ((char *) &savebuffer[2112+sizeof(outzipped)], &outzipped, (char *) &sram.sram, inzipped, 9);
		memcpy(&savebuffer[2112], &outzipped, sizeof(outzipped));
	}
	
	outbytes = 2048 + 64 + outzipped + sizeof(outzipped);

	/*** Initialise the CARD system ***/
	memset (&SysArea, 0, CARD_WORKAREA);
	CARD_Init ("GENP", "00");

	/*** Attempt to mount the card ***/
	CardError = MountTheCard ();

	if (CardError)
	{
		/*** Retrieve the sector size ***/
		CardError = CARD_GetSectorSize (CARDSLOT, &SectorSize);

		switch (direction)
		{
			case 0: /*** Saving ***/
				/*** Determine number of blocks on this card ***/
				blocks = (outbytes / SectorSize) * SectorSize;
				if (outbytes % SectorSize)  blocks += SectorSize;

				/*** Check if a previous save exists ***/
				if (CardFileExists (filename))
				{
					CardError = CARD_Open (CARDSLOT, filename, &CardFile);
					if (CardError)
					{
						sprintf (action, "Error Open : %d", CardError);
						WaitPrompt (action);
						CARD_Unmount (CARDSLOT);
						return 0;
					}

					int size = CardFile.len;
					CARD_Close (&CardFile);

					if (size < blocks)
					{
						/* new size is bigger: check if there is enough space left */
					    CardError = CARD_Create (CARDSLOT, "TEMP", blocks-size, &CardFile);
						if (CardError)
						{
							sprintf (action, "Error Update : %d", CardError);
							WaitPrompt (action);
							CARD_Unmount (CARDSLOT);
							return 0;
						}
						CARD_Close (&CardFile);
						CARD_Delete(CARDSLOT, "TEMP");
					}

					/* always delete existing slot */
					CARD_Delete(CARDSLOT, filename);
				}                    
				
				/*** Create a new slot ***/
				CardError = CARD_Create (CARDSLOT, filename, blocks, &CardFile);
				if (CardError)
				{
					sprintf (action, "Error create : %d %d", CardError, CARDSLOT);
					WaitPrompt (action);
					CARD_Unmount (CARDSLOT);
					return 0;
				}

				/*** Continue and save ***/
				CARD_GetStatus (CARDSLOT, CardFile.filenum, &CardStatus);
				CardStatus.icon_addr = 0x0;
				CardStatus.icon_fmt = 2;
				CardStatus.icon_speed = 1;
				CardStatus.comment_addr = 2048;
				CARD_SetStatus (CARDSLOT, CardFile.filenum, &CardStatus);

				/*** And write the blocks out ***/
				sbo = 0;
				while (outbytes > 0)
				{
					CardError = CARD_Write (&CardFile, &savebuffer[sbo], SectorSize, sbo);
					outbytes -= SectorSize;
					sbo += SectorSize;
				}

				CARD_Close (&CardFile);
				CARD_Unmount (CARDSLOT);
				sram.crc = crc32 (0, &sram.sram[0], 0x10000);
				sprintf (action, "Saved %d bytes successfully", blocks);
				WaitPrompt (action);
				return 1;

			default: /*** Loading ***/
				if (!CardFileExists (filename))
				{
					WaitPrompt ("No SRAM File Found");
					CARD_Unmount (CARDSLOT);
					return 0;
				}

				memset (&CardFile, 0, sizeof (CardFile));
				CardError = CARD_Open (CARDSLOT, filename, &CardFile);
				if (CardError)
				{
					sprintf (action, "Error Open : %d", CardError);
					WaitPrompt (action);
					CARD_Unmount (CARDSLOT);
					return 0;
				}

				blocks = CardFile.len;
				if (blocks < SectorSize) blocks = SectorSize;
				if (blocks % SectorSize) blocks++;

				/*** Just read the file back in ***/
				sbo = 0;
				int size = blocks;
				while (blocks > 0)
				{
					CARD_Read (&CardFile, &savebuffer[sbo], SectorSize, sbo);
					sbo += SectorSize;
					blocks -= SectorSize;
				}
				CARD_Close (&CardFile);
				CARD_Unmount (CARDSLOT);

				/* Copy to SRAM */
				memcpy(&inzipped,&savebuffer[2112],sizeof(inzipped));
				outzipped = 0x10000;
				uncompress ((char *) &sram.sram, &outzipped, (char *) &savebuffer[2112+sizeof(inzipped)], inzipped);
				sram.crc = crc32 (0, &sram.sram[0], 0x10000);
				system_reset ();

				/*** Inform user ***/
				sprintf (action, "Loaded %d bytes successfully", size);
				WaitPrompt (action);
				return 1;
		}
	}
	else WaitPrompt ("Unable to mount memory card");
	return 0; /*** Signal failure ***/
}

/****************************************************************************
 * ManageSTATE
 *
 * Here is the main Freeze File Management stuff.
 * The output file contains an icon (2K), 64 bytes comment and the STATE (~128k)
 *
 * direction == 0 save, 1 load.
 ****************************************************************************/
int ManageState (int direction)
{
	char filename[128];
	char action[80];
	int CardError;
	unsigned int SectorSize;
	int blocks;
	char comment[2][32] = { {"Genesis Plus 1.2a [FRZ]"}, {"Freeze State"} };
	int outbytes;
	int sbo;
	int i;
	int state_size = 0;

	if (!genromsize) return 0;

	if (direction) ShowAction ("Loading State ...");
	else ShowAction ("Saving State ...");

	/* First, build a filename based on the information retrieved for this ROM */
	if (strlen (rominfo.domestic)) strcpy (filename, rominfo.domestic);
	else strcpy (filename, rominfo.international);

	/* As these names tend to be bulked with spaces, let's strip them */
	/* Name should be in 16 character blocks, so take first 16        */
	filename[16] = 0;
	for (i = strlen (filename) - 1; i > 0; i--) if (filename[i] != 32) break;
	filename[i + 1] = 0;

	/* Now add the 16bit checksum, to ensure it's the same ROM */
	sprintf (filename, "%s%02X.gpz", filename, rominfo.checksum);
	strcpy (comment[1], filename);

	/* device is SDCARD, let's go */
	if (use_SDCARD) return SD_ManageFile(filename,direction,0);

	/* device is MCARD, we continue */
	if (direction == 0) /* Saving */
	{
		/* Build the output buffer */
		memcpy (&savebuffer, &icon, 2048);
		memcpy (&savebuffer[2048], &comment[0], 64);
		state_size = state_save(&savebuffer[2112]);
	}

	outbytes = 2048 + 64 + state_size;

	/*** Initialise the CARD system ***/
	memset (&SysArea, 0, CARD_WORKAREA);
	CARD_Init ("GENP", "00");

	/*** Attempt to mount the card ***/
	CardError = MountTheCard ();

	if (CardError)
	{
		/*** Retrieve the sector size ***/
		CardError = CARD_GetSectorSize (CARDSLOT, &SectorSize);

		switch (direction)
		{
			case 0: /*** Saving ***/
				/*** Determine number of blocks on this card ***/
				blocks = (outbytes / SectorSize) * SectorSize;
				if (outbytes % SectorSize) blocks += SectorSize;

				/*** Check if a previous save exists ***/
				if (CardFileExists (filename))
				{
					CardError = CARD_Open (CARDSLOT, filename, &CardFile);
					if (CardError)
					{
						sprintf (action, "Error Open : %d", CardError);
						WaitPrompt (action);
						CARD_Unmount (CARDSLOT);
						return 0;
					}

					int size = CardFile.len;
					CARD_Close (&CardFile);

					if (size < blocks)
					{
						/* new size is bigger: check if there is enough space left */
					    CardError = CARD_Create (CARDSLOT, "TEMP", blocks-size, &CardFile);
						if (CardError)
						{
							sprintf (action, "Error Update : %d", CardError);
							WaitPrompt (action);
							CARD_Unmount (CARDSLOT);
							return 0;
						}
						CARD_Close (&CardFile);
						CARD_Delete(CARDSLOT, "TEMP");
					}

					/* always delete existing slot */
					CARD_Delete(CARDSLOT, filename);
				}                    

				/*** Create a new slot ***/
				CardError = CARD_Create (CARDSLOT, filename, blocks, &CardFile);
				if (CardError)
				{
					sprintf (action, "Error create : %d %d", CardError, CARDSLOT);
					WaitPrompt (action);
					CARD_Unmount (CARDSLOT);
					return 0;
				}
				
				/*** Continue and save ***/
				CARD_GetStatus (CARDSLOT, CardFile.filenum, &CardStatus);
				CardStatus.icon_addr = 0x0;
				CardStatus.icon_fmt = 2;
				CardStatus.icon_speed = 1;
				CardStatus.comment_addr = 2048;
				CARD_SetStatus (CARDSLOT, CardFile.filenum, &CardStatus);

				/*** And write the blocks out ***/
				sbo = 0;
				while (outbytes > 0)
				{
					CardError = CARD_Write (&CardFile, &savebuffer[sbo], SectorSize, sbo);
					outbytes -= SectorSize;
					sbo += SectorSize;
				}

				CARD_Close (&CardFile);
				CARD_Unmount (CARDSLOT);
				sprintf (action, "Saved %d bytes successfully", blocks);
				WaitPrompt (action);
				return 1;

			default: /*** Loading ***/
				if (!CardFileExists (filename))
				{
					WaitPrompt ("No Savestate Found");
					CARD_Unmount (CARDSLOT);
					return 0;
				}

				memset (&CardFile, 0, sizeof (CardFile));
				CardError = CARD_Open (CARDSLOT, filename, &CardFile);
				if (CardError)
				{
					sprintf (action, "Error Open : %d", CardError);
					WaitPrompt (action);
					CARD_Unmount (CARDSLOT);
					return 0;
				}

				blocks = CardFile.len;
				if (blocks < SectorSize) blocks = SectorSize;
				if (blocks % SectorSize) blocks++;

				/*** Just read the file back in ***/
				sbo = 0;
				int size = blocks;
				while (blocks > 0)
				{
					CARD_Read (&CardFile, &savebuffer[sbo], SectorSize, sbo);
					sbo += SectorSize;
					blocks -= SectorSize;
				}
				CARD_Close (&CardFile);
				CARD_Unmount (CARDSLOT);

				state_load(&savebuffer[2112]);

				/*** Inform user ***/
				sprintf (action, "Loaded %d bytes successfully", size);
				WaitPrompt (action);
				return 1;
		}
	}
	else WaitPrompt ("Unable to mount memory card");
	return 0; /*** Signal failure ***/
}