/* FCE Ultra - NES/Famicom Emulator
*
* Copyright notice for this file:
*  Copyright (C) 2002 Xodnizel
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*/


#include "types.h"
#include "x6502.h"
#include "cheat.h"
#include "fceu.h"
#include "file.h"
#include "cart.h"
#include "driver.h"
#include "utils/memory.h"

#include <string>
#include <cstdlib>
#include <cstring>
#include <cstdio>
#include <cctype>

using namespace std;

static uint8 *CheatRPtrs[64];

vector<uint16> FrozenAddresses;			//List of addresses that are currently frozen
unsigned int FrozenAddressCount = 0;		//Keeps up with the Frozen address count, necessary for using in other dialogs (such as hex editor)

void FCEU_CheatResetRAM(void)
{
	int x;

	for(x=0;x<64;x++)
		CheatRPtrs[x]=0;
}

void FCEU_CheatAddRAM(int s, uint32 A, uint8 *p)
{
	uint32 AB=A>>10;
	int x;

	for(x=s-1;x>=0;x--)
		CheatRPtrs[AB+x]=p-A;
}


CHEATF_SUBFAST SubCheats[256] = { 0 };
uint32 numsubcheats = 0;
int globalCheatDisabled = 0;
int disableAutoLSCheats = 0;
bool disableShowGG = 0;
static _8BYTECHEATMAP* cheatMap = NULL;
struct CHEATF *cheats = 0, *cheatsl = 0;


#define CHEATC_NONE     0x8000
#define CHEATC_EXCLUDED 0x4000
#define CHEATC_NOSHOW   0xC000

static uint16 *CheatComp = 0;
int savecheats = 0;

static DECLFR(SubCheatsRead)
{
	CHEATF_SUBFAST *s = SubCheats;
	int x=numsubcheats;

	do
	{
		if(s->addr==A)
		{
			if(s->compare>=0)
			{
				uint8 pv=s->PrevRead(A);

				if(pv==s->compare)
					return(s->val);
				else return(pv);
			}
			else return(s->val);
		}
		s++;
	} while(--x);
	return(0);	/* We should never get here. */
}

void RebuildSubCheats(void)
{
	uint32 x;
	struct CHEATF *c = cheats;
	for (x = 0; x < numsubcheats; x++)
	{
		SetReadHandler(SubCheats[x].addr, SubCheats[x].addr, SubCheats[x].PrevRead);
		if (cheatMap)
			FCEUI_SetCheatMapByte(SubCheats[x].addr, false);
	}

	numsubcheats = 0;

	if (!globalCheatDisabled)
	{
		while(c)
		{
			if(c->type == 1 && c->status && GetReadHandler(c->addr) != SubCheatsRead)
			{
				SubCheats[numsubcheats].PrevRead = GetReadHandler(c->addr);
				SubCheats[numsubcheats].addr = c->addr;
				SubCheats[numsubcheats].val = c->val;
				SubCheats[numsubcheats].compare = c->compare;
				SetReadHandler(c->addr, c->addr, SubCheatsRead);
				if (cheatMap)
					FCEUI_SetCheatMapByte(SubCheats[numsubcheats].addr, true);
				numsubcheats++;
			}
			c = c->next;
		}
	}
	FrozenAddressCount = numsubcheats;		//Update the frozen address list

}

void FCEU_PowerCheats()
{
	numsubcheats = 0;	/* Quick hack to prevent setting of ancient read addresses. */
	if (cheatMap)
		FCEUI_RefreshCheatMap();
	RebuildSubCheats();
}

int FCEU_CalcCheatAffectedBytes(uint32 address, uint32 size) {

	uint32 count = 0;
	if (cheatMap)
		for (uint32 i = 0; i < size; ++i)
			if (FCEUI_FindCheatMapByte(address + i))
				++count;
	return count;
}

static void CheatMemErr(void)
{
	FCEUD_PrintError("Error allocating memory for cheat data.");
}

int AddCheatEntry(const char *name, uint32 addr, uint8 val, int compare, int status, int type)
{
	struct CHEATF *temp;
	if(!(temp = (struct CHEATF *)FCEU_dmalloc(sizeof(struct CHEATF))))
	{
		CheatMemErr();
		return(0);
	}

	temp->name = strcpy((char*) FCEU_dmalloc(strlen(name) + 1), name);
	temp->addr = addr;
	temp->val = val;
	temp->status = status;
	temp->compare = compare;
	temp->type = type;
	temp->next = 0;

	if(cheats)
	{
		cheatsl->next = temp;
		cheatsl = temp;
	}
	else
		cheats = cheatsl = temp;

	return (1);
}

/* The "override_existing" parameter is used only in cheat dialog import.
   Since the default behaviour will reset numsubcheats to 0 everytime,
   In game loading, this is absolutely right, but when importing in cheat window,
   resetting numsubcheats to 0 will override existed cheat items to make them
   invalid.
*/
void FCEU_LoadGameCheats(FILE *override, int override_existing)
{
	FILE *fp;
	unsigned int addr;
	unsigned int val;
	unsigned int status;
	unsigned int type;
	unsigned int compare;
	int x;

	char linebuf[2048] = { 0 };
	char namebuf[128] = { 0 };
	int tc = 0;
	char *fn;

	if (override_existing)
	{
		numsubcheats = 0;
		if (cheatMap)
			FCEUI_RefreshCheatMap();
	}

	if(override)
		fp = override;
	else
	{
		fn = strdup(FCEU_MakeFName(FCEUMKF_CHEAT, 0, 0).c_str());
		fp = FCEUD_UTF8fopen(fn, "rb");
		free(fn);
		if (!fp) {
			return;
		}
	}

	while(fgets(linebuf, 2048, fp) != nullptr)
	{
		char *tbuf = linebuf;
		int doc = 0;

		addr = val = compare = status = type = 0;

		if(tbuf[0] == 'S')
		{
			tbuf++;
			type = 1;
		}
		else
			type = 0;

		if(tbuf[0] == 'C')
		{
			tbuf++;
			doc = 1;
		}

		if(tbuf[0] == ':')
		{
			tbuf++;
			status = 0;
		}
		else status = 1;

		if(doc)
		{
			char *neo = &tbuf[4+2+2+1+1+1];
			if(sscanf(tbuf, "%04x%*[:]%02x%*[:]%02x", &addr, &val, &compare) != 3)
				continue;
			strcpy(namebuf, neo);
		}
		else
		{
			char *neo = &tbuf[4+2+1+1];
			if(sscanf(tbuf, "%04x%*[:]%02x", &addr, &val) != 2)
				continue;
			strcpy(namebuf, neo);
		}

		for(x = 0; x < (int)strlen(namebuf); x++)
		{
			if(namebuf[x] == 10 || namebuf[x] == 13)
			{
				namebuf[x] = 0;
				break;
			}
			else if(namebuf[x] > 0x00 && namebuf[x] < 0x20)
				namebuf[x] = 0x20;
		}

		AddCheatEntry(namebuf, addr, val, doc ? compare : -1, status, type);
		tc++;
	}

	RebuildSubCheats();

	FCEU_DispMessage("Cheats file loaded.", 0); //Tells user a cheats file was loaded.

	if(!override)
		fclose(fp);
}

void FCEU_SaveGameCheats(FILE* fp, int release)
{
	struct CHEATF *next = cheats;
	while (next)
	{
		if (next->type)
			fputc('S', fp);
		if (next->compare >= 0)
			fputc('C', fp);

		if (!next->status)
			fputc(':', fp);

		if (next->compare >= 0)
			fprintf(fp, "%04x:%02x:%02x:%s\n", next->addr, next->val, next->compare, next->name);
		else
			fprintf(fp, "%04x:%02x:%s\n", next->addr, next->val, next->name);

		if (release) free(next->name);
		struct CHEATF *t = next;
		next = next->next;
		if (release) free(t);
	}
}

void FCEU_FlushGameCheats(FILE *override, int nosave)
{
	if(CheatComp)
	{
		free(CheatComp);
		CheatComp=0;
	}
	if((!savecheats || nosave) && !override)	/* Always save cheats if we're being overridden. */
	{
		if(cheats)
		{
			struct CHEATF *next=cheats;
			for(;;)
			{
				struct CHEATF *last=next;
				next=next->next;
				free(last->name);
				free(last);
				if(!next) break;
			}
			cheats=cheatsl=0;
		}
	}
	else
	{
		char *fn = 0;

		if(!override)
			fn = strdup(FCEU_MakeFName(FCEUMKF_CHEAT,0,0).c_str());

		if(cheats)
		{
			FILE *fp;

			if(override)
				fp = override;
			else
				fp=FCEUD_UTF8fopen(fn,"wb");

			if(fp)
			{
				FCEU_SaveGameCheats(fp, 1);
				if(!override)
					fclose(fp);
			}
			else
				FCEUD_PrintError("Error saving cheats.");
			cheats=cheatsl=0;
		}
		else if(!override)
			remove(fn);
		if(!override)
			free(fn);
	}

	RebuildSubCheats();  /* Remove memory handlers. */

}


int FCEUI_AddCheat(const char *name, uint32 addr, uint8 val, int compare, int type)
{

	if(!AddCheatEntry(name, addr, val, compare, 1, type))
		return 0;
	savecheats = 1;
	RebuildSubCheats();

	return 1;
}

int FCEUI_DelCheat(uint32 which)
{
	struct CHEATF *prev;
	struct CHEATF *cur;
	uint32 x=0;

	for(prev=0,cur=cheats;;)
	{
		if(x==which)          // Remove this cheat.
		{
			if(prev)             // Update pointer to this cheat.
			{
				if(cur->next)       // More cheats.
					prev->next=cur->next;
				else                // No more.
				{
					prev->next=0;
					cheatsl=prev;      // Set the previous cheat as the last cheat.
				}
			}
			else                 // This is the first cheat.
			{
				if(cur->next)       // More cheats
					cheats=cur->next;
				else
					cheats=cheatsl=0;  // No (more) cheats.
			}
			free(cur->name);     // Now that all references to this cheat are removed,
			free(cur);           // free the memory.
			break;
		}                     // *END REMOVE THIS CHEAT*


		if(!cur->next)        // No more cheats to go through(this shouldn't ever happen...)
			return(0);
		prev=cur;
		cur=prev->next;
		x++;
	}

	savecheats=1;
	RebuildSubCheats();
	return(1);
}

void FCEU_ApplyPeriodicCheats(void)
{
	struct CHEATF *cur=cheats;
	if(!cur) return;

	for(;;)
	{
		if(cur->status && !(cur->type))
			if(CheatRPtrs[cur->addr>>10])
				CheatRPtrs[cur->addr>>10][cur->addr]=cur->val;
		if(cur->next)
			cur=cur->next;
		else
			break;
	}
}


void FCEUI_ListCheats(int (*callb)(char *name, uint32 a, uint8 v, int compare, int s, int type, void *data), void *data)
{
	struct CHEATF *next=cheats;

	while(next)
	{
		if(!callb(next->name,next->addr,next->val,next->compare,next->status,next->type,data)) break;
		next=next->next;
	}
}

int FCEUI_GetCheat(uint32 which, char **name, uint32 *a, uint8 *v, int *compare, int *s, int *type)
{
	struct CHEATF *next=cheats;
	uint32 x=0;

	while(next)
	{
		if(x==which)
		{
			if(name)
				*name=next->name;
			if(a)
				*a=next->addr;
			if(v)
				*v=next->val;
			if(s)
				*s=next->status;
			if(compare)
				*compare=next->compare;
			if(type)
				*type=next->type;
			return(1);
		}
		next=next->next;
		x++;
	}
	return(0);
}

static int GGtobin(char c)
{
	static char lets[16]={'A','P','Z','L','G','I','T','Y','E','O','X','U','K','S','V','N'};
	int x;

	for(x=0;x<16;x++)
		if(lets[x] == toupper(c)) return(x);
	return(0);
}

/* Returns 1 on success, 0 on failure. Sets *a,*v,*c. */
int FCEUI_DecodeGG(const char *str, int *a, int *v, int *c)
{
	uint16 A;
	uint8 V,C;
	uint8 t;
	int s;

	A=0x8000;
	V=0;
	C=0;

	s=strlen(str);
	if(s!=6 && s!=8) return(0);

	t=GGtobin(*str++);
	V|=(t&0x07);
	V|=(t&0x08)<<4;

	t=GGtobin(*str++);
	V|=(t&0x07)<<4;
	A|=(t&0x08)<<4;

	t=GGtobin(*str++);
	A|=(t&0x07)<<4;
	//if(t&0x08) return(0);	/* 8-character code?! */

	t=GGtobin(*str++);
	A|=(t&0x07)<<12;
	A|=(t&0x08);

	t=GGtobin(*str++);
	A|=(t&0x07);
	A|=(t&0x08)<<8;

	if(s==6)
	{
		t=GGtobin(*str++);
		A|=(t&0x07)<<8;
		V|=(t&0x08);

		*a=A;
		*v=V;
		*c=-1;
		return(1);
	}
	else
	{
		t=GGtobin(*str++);
		A|=(t&0x07)<<8;
		C|=(t&0x08);

		t=GGtobin(*str++);
		C|=(t&0x07);
		C|=(t&0x08)<<4;

		t=GGtobin(*str++);
		C|=(t&0x07)<<4;
		V|=(t&0x08);
		*a=A;
		*v=V;
		*c=C;
		return(1);
	}
	return(0);
}

int FCEUI_DecodePAR(const char *str, int *a, int *v, int *c, int *type)
{
	unsigned int boo[4];
	if(strlen(str)!=8) return(0);

	sscanf(str,"%02x%02x%02x%02x",boo,boo+1,boo+2,boo+3);

	*c=-1;

	if(1)
	{
		*a=(boo[3]<<8)|(boo[2]+0x7F);
		*v=0;
	}
	else
	{
		*v=boo[3];
		*a=boo[2]|(boo[1]<<8);
	}
	/* Zero-page addressing modes don't go through the normal read/write handlers in FCEU, so
	we must do the old hacky method of RAM cheats.
	*/
	if(*a<0x0100)
		*type=0;
	else
		*type=1;
	return(1);
}

/* name can be NULL if the name isn't going to be changed. */
/* same goes for a, v, and s(except the values of each one must be <0) */

int FCEUI_SetCheat(uint32 which, const char *name, int32 a, int32 v, int c, int s, int type)
{
	struct CHEATF *next = cheats;
	uint32 x = 0;

	while(next)
	{
		if(x == which)
		{
			if(name)
			{
				char *t;
				if((t = (char *)realloc(next->name, strlen(name) + 1)))
					strcpy(next->name = t, name);
				else
					return 0;
			}
			if(a >= 0)
				next->addr = a;
			if(v >= 0)
				next->val = v;
			if(s >= 0)
				next->status = s;
			if(c >= -1)
				next->compare = c;
			next->type = type;

			savecheats = 1;
			RebuildSubCheats();

			return 1;
		}
		next = next->next;
		x++;
	}
	return 0;
}

/* Convenience function. */
int FCEUI_ToggleCheat(uint32 which)
{
	struct CHEATF *next=cheats;
	uint32 x=0;

	while(next)
	{
		if(x==which)
		{
			next->status=!next->status;
			savecheats=1;
			RebuildSubCheats();
			return(next->status);
		}
		next=next->next;
		x++;
	}

	return(-1);
}

int FCEUI_GlobalToggleCheat(int global_enabled)
{
	int _numsubcheats = numsubcheats;
	globalCheatDisabled = !global_enabled;
	RebuildSubCheats();
	return _numsubcheats != numsubcheats;
}

static int InitCheatComp(void)
{
	uint32 x;

	CheatComp=(uint16*)FCEU_dmalloc(65536*sizeof(uint16));
	if(!CheatComp)
	{
		CheatMemErr();
		return(0);
	}
	for(x=0;x<65536;x++)
		CheatComp[x]=CHEATC_NONE;

	return(1);
}

void FCEUI_CheatSearchSetCurrentAsOriginal(void)
{
	uint32 x;

	if(!CheatComp)
	{
		if(InitCheatComp())
		{
			CheatMemErr();
			return;
		}
	}
	for(x=0x000;x<0x10000;x++)
		if(!(CheatComp[x]&CHEATC_NOSHOW))
		{
			if(CheatRPtrs[x>>10])
				CheatComp[x]=CheatRPtrs[x>>10][x];
			else
				CheatComp[x]|=CHEATC_NONE;
		}
}

void FCEUI_CheatSearchShowExcluded(void)
{
	uint32 x;

	for(x=0x000;x<0x10000;x++)
		CheatComp[x]&=~CHEATC_EXCLUDED;
}


int32 FCEUI_CheatSearchGetCount(void)
{
	uint32 x,c=0;

	if(CheatComp)
	{
		for(x=0x0000;x<0x10000;x++)
			if(!(CheatComp[x]&CHEATC_NOSHOW) && CheatRPtrs[x>>10])
				c++;
	}

	return c;
}
/* This function will give the initial value of the search and the current value at a location. */

void FCEUI_CheatSearchGet(int (*callb)(uint32 a, uint8 last, uint8 current, void *data),void *data)
{
	uint32 x;

	if(!CheatComp)
	{
		if(!InitCheatComp())
			CheatMemErr();
		return;
	}

	for(x=0;x<0x10000;x++)
		if(!(CheatComp[x]&CHEATC_NOSHOW) && CheatRPtrs[x>>10])
			if(!callb(x,CheatComp[x],CheatRPtrs[x>>10][x],data))
				break;
}

void FCEUI_CheatSearchGetRange(uint32 first, uint32 last, int (*callb)(uint32 a, uint8 last, uint8 current))
{
	uint32 x;
	uint32 in = 0;

	if(!CheatComp)
	{
		if(!InitCheatComp())
			CheatMemErr();
		return;
	}

	for(x = 0; x < 0x10000; x++)
		if(!(CheatComp[x] & CHEATC_NOSHOW) && CheatRPtrs[x >> 10])
		{
			if(in >= first)
				if(!callb(x, CheatComp[x], CheatRPtrs[x >> 10][x]))
					break;
			in++;
			if(in > last)
				return;
		}
}

void FCEUI_CheatSearchBegin(void)
{
	uint32 x;

	if(!CheatComp)
	{
		if(!InitCheatComp())
		{
			CheatMemErr();
			return;
		}
	}
	for(x=0;x<0x10000;x++)
	{
		if(CheatRPtrs[x>>10])
			CheatComp[x]=CheatRPtrs[x>>10][x];
		else
			CheatComp[x]=CHEATC_NONE;
	}
}


static int INLINE CAbs(int x)
{
	if(x<0)
		return(0-x);
	return x;
}

void FCEUI_CheatSearchEnd(int type, uint8 v1, uint8 v2)
{
	uint32 x;

	if(!CheatComp)
	{
		if(!InitCheatComp())
		{
			CheatMemErr();
			return;
		}
	}

	switch (type)
	{
		default:
		case FCEU_SEARCH_SPECIFIC_CHANGE: // Change to a specific value
			for (x = 0; x < 0x10000; ++x)
				if (!(CheatComp[x] & CHEATC_NOSHOW) && (CheatComp[x] != v1 || CheatRPtrs[x >> 10][x] != v2))
					CheatComp[x] |= CHEATC_EXCLUDED;
			break;
		case FCEU_SEARCH_RELATIVE_CHANGE: // Search for relative change (between values).
			for (x = 0; x < 0x10000; x++)
				if (!(CheatComp[x] & CHEATC_NOSHOW) && (CheatComp[x] != v1 || CAbs(CheatComp[x] - CheatRPtrs[x >> 10][x]) != v2))
					CheatComp[x] |= CHEATC_EXCLUDED;
			break;
		case FCEU_SEARCH_PUERLY_RELATIVE_CHANGE: // Purely relative change.
			for (x = 0x000; x<0x10000; x++)
				if (!(CheatComp[x] & CHEATC_NOSHOW) && CAbs(CheatComp[x] - CheatRPtrs[x >> 10][x]) != v2)
					CheatComp[x] |= CHEATC_EXCLUDED;
			break;
		case FCEU_SEARCH_ANY_CHANGE: // Any change.
			for (x = 0x000; x < 0x10000; x++)
				if (!(CheatComp[x] & CHEATC_NOSHOW) && CheatComp[x] == CheatRPtrs[x >> 10][x])
					CheatComp[x] |= CHEATC_EXCLUDED;
			break;
		case FCEU_SEARCH_NEWVAL_KNOWN: // new value = known
			for (x = 0x000; x < 0x10000; x++)
				if (!(CheatComp[x] & CHEATC_NOSHOW) && CheatRPtrs[x >> 10][x] != v1)
					CheatComp[x] |= CHEATC_EXCLUDED;
			break;
		case FCEU_SEARCH_NEWVAL_GT: // new value greater than
			for (x = 0x000; x < 0x10000; x++)
				if (!(CheatComp[x] & CHEATC_NOSHOW) && CheatComp[x] >= CheatRPtrs[x >> 10][x])
					CheatComp[x] |= CHEATC_EXCLUDED;
			break;
		case FCEU_SEARCH_NEWVAL_LT: // new value less than
			for (x = 0x000; x < 0x10000; x++)
				if (!(CheatComp[x] & CHEATC_NOSHOW) && CheatComp[x] <= CheatRPtrs[x >> 10][x])
					CheatComp[x] |= CHEATC_EXCLUDED;
			break;
		case FCEU_SEARCH_NEWVAL_GT_KNOWN: // new value greater than by known value
			for (x = 0x000; x < 0x10000; x++)
				if (!(CheatComp[x] & CHEATC_NOSHOW) && CheatRPtrs[x >> 10][x] - CheatComp[x] != v2)
					CheatComp[x] |= CHEATC_EXCLUDED;
			break;
		case FCEU_SEARCH_NEWVAL_LT_KNOWN: // new value less than by known value
			for (x = 0x000; x < 0x10000; x++)
				if (!(CheatComp[x] & CHEATC_NOSHOW) && (CheatComp[x] - CheatRPtrs[x >> 10][x]) != v2)
					CheatComp[x] |= CHEATC_EXCLUDED;
			break;
	}

}

int FCEU_CheatGetByte(uint32 A)
{
	if(A < 0x10000) {
		uint32 ret;
		fceuindbg=1;
		ret = ARead[A](A);
		fceuindbg=0;
		return ret;
	} else
		return 0;
}

void FCEU_CheatSetByte(uint32 A, uint8 V)
{
   if(CheatRPtrs[A>>10])
    CheatRPtrs[A>>10][A]=V;
   else if(A < 0x10000)
    BWrite[A](A, V);
}

// disable all cheats
int FCEU_DisableAllCheats(void)
{
	int count = 0;
	struct CHEATF *next = cheats;
	while(next)
	{
		if(next->status){
			count++;
		}
		next->status = 0;
		next = next->next;
	}
	savecheats = 1;
	RebuildSubCheats();
	return count;
}

// delete all cheats
int FCEU_DeleteAllCheats(void)
{
	struct CHEATF *cur = cheats;
	struct CHEATF *next = NULL;
	while (cur)
	{
		next = cur->next;
		if ( cur->name )
		{
			free(cur->name);
		}
		free(cur);
		cur = next;
	}
	cheats = cheatsl = 0;
	savecheats = 1;
	RebuildSubCheats();

	return 0;
}

int FCEUI_FindCheatMapByte(uint16 address)
{
	return cheatMap[address / 8] >> (address % 8) & 1;
}

void FCEUI_SetCheatMapByte(uint16 address, bool cheat)
{
	cheat ? cheatMap[address / 8] |= (1 << address % 8) : cheatMap[address / 8] ^= (1 << address % 8);
}

void FCEUI_CreateCheatMap(void)
{
	if (!cheatMap)
		cheatMap = (unsigned char*)malloc(CHEATMAP_SIZE);
	FCEUI_RefreshCheatMap();
}

void FCEUI_RefreshCheatMap(void)
{
	memset(cheatMap, 0, CHEATMAP_SIZE);
	for (uint32 i = 0; i < numsubcheats; ++i)
		FCEUI_SetCheatMapByte(SubCheats[i].addr, true);
}

void FCEUI_ReleaseCheatMap(void)
{
	if (cheatMap)
	{
		free(cheatMap);
		cheatMap = NULL;
	}
}