/*

    GEMMA - Z80 testbed

    Copyright (C) 2006  Ian Cowburn (ianc@noddybox.demon.co.uk)

    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

    -------------------------------------------------------------------------

*/
static const char id[]="$Id$";

#include <stdlib.h>
#include <stdio.h>
#include <signal.h>
#include <string.h>
#include <ctype.h>

#include "gemma.h"
#include "expr.h"
#include "gtkutil.h"
#include "support.h"

#define HI(w)   (((w)&0xff00)>>8)
#define LO(w)   ((w)&0xff)
#define MK(h,l) (((Z80Word)(h)<<8)|(l))

/* ---------------------------------------- GLOBALS
*/
static Z80		*z80;
static Z80Byte		mem[0x10000];
static int		memctl[256];

static sig_atomic_t	stop=FALSE;

static Z80Label		*label=NULL;

static GtkWidget	*run_button;
static GtkWidget	*step_button;
static GtkWidget	*step_over_button;
static GtkWidget	*stop_button;
static GtkWidget	*run_until_button;

static GtkWidget	*breakpoint_text;

static GtkWidget	*top_window;
static GtkWidget	*regview;
static GtkWidget	*memview;
static GtkWidget	*viewreg;
static GtkWidget	*logview;
static GtkWidget	*assemview;

static GtkWidget	*memview_combo;
static GtkWidget	*memview_check;

#define RUNNING(t)	gtk_widget_set_sensitive(run_button,!t); \
			gtk_widget_set_sensitive(step_button,!t); \
			gtk_widget_set_sensitive(step_over_button,!t); \
			gtk_widget_set_sensitive(run_until_button,!t); \
			gtk_widget_set_sensitive(stop_button,t);


/* ---------------------------------------- PROTOS
*/
static void		Log(const char *format, ...);
static Z80Word		Address(const char *p);
static void		*Malloc(size_t len);
static void		*Realloc(void *p, size_t len);


/* ---------------------------------------- PC BUFFER
*/
#define PC_BUFFER	100
static Z80Word		pc_buffer[PC_BUFFER]={0};
static int		pc_head=0;

static Z80Word Get_PC(int back)
{
    return pc_buffer[(pc_head+back+1)%PC_BUFFER];
}

static void Step(void)
{
    pc_buffer[pc_head]=Z80GetPC(z80);

    if (pc_head)
    	pc_head--;
    else
    	pc_head=PC_BUFFER-1;

    Z80SingleStep(z80);
}

/* ---------------------------------------- DYNAMIC STRINGS
*/

typedef struct
{
    size_t	len;
    char	*text;
} *DString;


#define BLOCKSIZE	512


DString DSInit(void)
{
    DString ds;

    ds=Malloc(sizeof *ds);

    ds->len=0;
    ds->text=Malloc(BLOCKSIZE);
    ds->text[0]=0;

    return ds;
}


void DSFree(DString ds)
{
    if (ds)
    {
	free(ds->text);
	free(ds);
    }
}


DString DSAddChar(DString to, char c)
{
    if (((to->len+2)%BLOCKSIZE)==0)
    {
    	to->text=Realloc(to->text,(((to->len+2)/BLOCKSIZE)+1)*BLOCKSIZE);
    }

    to->text[to->len++]=c;
    to->text[to->len]=0;

    return to;
}


DString DSAdd(DString to, const char *from)
{
    to->len+=strlen(from);
    to->text=Realloc(to->text,(((to->len+1)/BLOCKSIZE)+1)*BLOCKSIZE);

    strcat(to->text,from);

    return to;
}


/* ---------------------------------------- PRIVATE FUNCTIONS
*/
static void Log(const char *format, ...)
{
    static char buff[4096];
    va_list va;

    va_start(va,format);
    vsprintf(buff,format,va);
    va_end(va);

    AppendText(logview,buff);
}


static int StrEq(const char *a, const char *b)
{
    while(*a && *b && tolower(*a)==tolower(*b))
    {
    	a++;
	b++;
    }

    if (*a || *b)
	return FALSE;
    else
	return TRUE;
}


static int Expand(void *client, const char *p, long *res)
{
    Z80State s;
    int ok=TRUE;

    Z80GetState(z80,&s);

    if (StrEq(p,"AF"))
    	*res=s.AF;
    else if (StrEq(p,"BC"))
    	*res=s.BC;
    else if (StrEq(p,"DE"))
    	*res=s.DE;
    else if (StrEq(p,"HL"))
    	*res=s.HL;
    else if (StrEq(p,"IX"))
    	*res=s.IX;
    else if (StrEq(p,"IY"))
    	*res=s.IY;
    else if (StrEq(p,"SP"))
    	*res=s.SP;
    else if (StrEq(p,"PC"))
    	*res=s.PC;
    else if (StrEq(p,"A"))
    	*res=HI(s.AF);
    else if (StrEq(p,"F"))
    	*res=LO(s.AF);
    else if (StrEq(p,"B"))
    	*res=HI(s.BC);
    else if (StrEq(p,"C"))
    	*res=LO(s.BC);
    else if (StrEq(p,"D"))
    	*res=HI(s.DE);
    else if (StrEq(p,"E"))
    	*res=LO(s.DE);
    else if (StrEq(p,"H"))
    	*res=HI(s.HL);
    else if (StrEq(p,"L"))
    	*res=LO(s.HL);
    else if (StrEq(p,"AF_"))
    	*res=s.AF_;
    else if (StrEq(p,"BC_"))
    	*res=s.BC_;
    else if (StrEq(p,"DE_"))
    	*res=s.DE_;
    else if (StrEq(p,"HL_"))
    	*res=s.HL_;
    else if (StrEq(p,"A_"))
    	*res=HI(s.AF_);
    else if (StrEq(p,"F_"))
    	*res=LO(s.AF_);
    else if (StrEq(p,"B_"))
    	*res=HI(s.BC_);
    else if (StrEq(p,"C_"))
    	*res=LO(s.BC_);
    else if (StrEq(p,"D_"))
    	*res=HI(s.DE_);
    else if (StrEq(p,"E_"))
    	*res=LO(s.DE_);
    else if (StrEq(p,"H_"))
    	*res=HI(s.HL_);
    else if (StrEq(p,"L_"))
	*res=LO(s.HL_);
    else if (StrEq(p,"IM"))
	*res=s.IM;
    else if (StrEq(p,"R"))
	*res=s.R;
    else if (StrEq(p,"IFF1"))
	*res=s.IFF1;
    else if (StrEq(p,"IFF2"))
	*res=s.IFF2;
    else if (p[0]=='@')
    {
	Z80Word n;

	n=Address(p+1);
	*res=mem[n];
    }
    else if (p[0]=='#')
    {
	Z80Word n;

	n=Address(p+1);
	*res=MK(mem[n+1],mem[n]);
    }
    else        /* Check for labels */
    {
        int f;

        ok=FALSE;

        for(f=0;label && label[f].label;f++)
        {
            if (StrEq(p,label[f].label))
            {
                *res=label[f].address;
                ok=TRUE;
                break;
            }
        }
    }

    return ok;
}


static Z80Word Address(const char *p)
{
    long e=0;

    if (!ExprEval(p,&e,Expand,z80))
	Log("%s\n",ExprError());

    return (Z80Word)e;
}


static void *Malloc(size_t len)
{
    void *n;

    n=malloc(len);

    if (!n)
    {
    	fprintf(stderr,"malloc failed\n");
	exit(EXIT_FAILURE);
    }

    return n;
}

static void *Realloc(void *p, size_t len)
{
    void *n;

    n=realloc(p,len);

    if (!n)
    {
    	fprintf(stderr,"realloc failed\n");
	exit(EXIT_FAILURE);
    }

    return n;
}

static char *StrCopy(const char *p)
{
    return strcpy(Malloc(strlen(p)+1),p);
}

static const int ToHex(char c)
{
    c=toupper(c);

    if (c>='0' && c<='9')
    	return c-'0';

    if (c>='A' && c<='F')
    	return c-'A'+10;

    return 0;
}

static void FlagString(DString s, Z80Byte flag, Z80Byte last)
{
    static char *c[]={"S","Z","5","H","3","P","N","C"};
    int f;

    DSAdd(s,"Flags: ");

    for(f=0;f<8;f++)
    {
	int b=1<<(7-f);

	if ((last&b)!=(flag&b))
	{
	    DSAdd(s,"<span foreground=\"white\" background=\"black\">");
	}

	if (flag&b)
	{
	    DSAdd(s,c[f]);
	}
	else
	{
	    DSAdd(s,"-");
	}

	if ((last&b)!=(flag&b))
	{
	    DSAdd(s,"</span>");
	}
    }
}


static void DisplayState(DString s, const char *label,
			 int width, Z80Val val, Z80Val last)
{
    static char buff[128];

    sprintf(buff,"%s: %s%*.*lX</span>",
		    label,
		    (last==val) ?
		    	"<span>" :
			"<span foreground=\"white\" background=\"black\">",
		    width,width,
		    val);

    DSAdd(s,buff);
}


/* ---------------------------------------- MEMORY
*/
static Z80Byte ReadPort(Z80 *z80, Z80Word addr)
{
    Z80Byte b=0xff;
    Z80Word ptr;
    Z80State s;
    char expr[1024];
    char *p;

    Z80GetState(z80,&s);

    switch(addr&0xff)
    {
    	case 0x80:
	    ptr=MK(mem[1],mem[0]);

	    p=expr;

	    while(mem[ptr])
	    	*p++=mem[ptr++];

	    *p=0;

	    b=(Z80Byte)Address(expr);

	    /* Log("%s -> %u\n",expr,b); */

	    break;

    	case 0x81:
	    ptr=s.DE;

	    p=expr;

	    while(mem[ptr])
	    	*p++=mem[ptr++];

	    *p=0;

	    b=(Z80Byte)Address(expr);

	    break;

	default:
	    Log("Read from port 0x%4.4x\n",(int)addr);
	    break;
    }

    return b;
}


static void WritePort(Z80 *z80, Z80Word addr, Z80Byte val)
{
    Z80State s;
    DString ds;

    ds=DSInit();
    Z80GetState(z80,&s);

    switch(addr&0xff)
    {
    	case 0x80:
	    DSAddChar(ds,val);
	    break;

	case 0x81:
	    DSAdd(ds,"Stop requested via OUT(0x81)\n");
	    stop=TRUE;
	    break;

    	case 0x82:
	    while(mem[s.DE]!='$')
	    {
		if (isspace(mem[s.DE]) || isprint(mem[s.DE]))
		{
		    DSAddChar(ds,mem[s.DE]);
		}

		s.DE++;
	    }
	    break;

    	case 0x83:
	    while(mem[s.DE])
	    {
		DSAddChar(ds,mem[s.DE]);
		s.DE++;
	    }
	    break;

	default:
	    Log("Wrote 0x%2.2x to port 0x%4.4x\n",(int)val,(int)addr);
	    return;
    }

    Log(ds->text);
    DSFree(ds);
}


static int Halt(Z80 *z80, Z80Val v)
{

    Log("**** Processor halted\n");
    DialogOK("Processor halted\n");
    stop=TRUE;
    return FALSE;
}


/* ---------------------------------------- EXPORTED FUNCTIONS
*/
void GEMMA_UpdateDisplay(GEMMA_View view)
{
    Z80State reg;

    Z80GetState(z80,&reg);

    if (view&UPDATE_ASSEM_VIEW)
    {
	Z80Word pc;
	DString ds;
	char buff[10];
	int f;

	ds=DSInit();
	DSAdd(ds,"<tt><small>");

	for(f=10;f>=0;f--)
	{
	    pc=Get_PC(f);

	    sprintf(buff,"%4.4X: ",pc);
	    DSAdd(ds,buff);
	    DSAdd(ds,Z80Disassemble(z80,&pc));
	    DSAddChar(ds,'\n');
	}

	pc=Z80GetPC(z80);

	for(f=0;f<12;f++)
	{
	    if (f==0)
	    {
	    	DSAdd(ds,"<span foreground=\"white\" background=\"black\">");
	    }

	    sprintf(buff,"%4.4X: ",pc);
	    DSAdd(ds,buff);

	    DSAdd(ds,Z80Disassemble(z80,&pc));

	    if (f==0)
	    {
	    	DSAdd(ds,"</span>");
	    }

	    DSAddChar(ds,'\n');
	}

	DSAdd(ds,"</small></tt>");
	gtk_label_set_markup(GTK_LABEL(assemview),ds->text);

	DSFree(ds);
    }

    if (view&UPDATE_REG_VIEW)
    {
	static int reg_once=FALSE;
	static Z80State last_reg;
	DString ds;

	ds=DSInit();

	if (!reg_once)
	{
	    last_reg=reg;
	    reg_once=TRUE;
	}

	DSAdd(ds,"<tt>");

	DisplayState(ds,"A  ",2,HI(reg.AF),HI(last_reg.AF));
	DSAdd(ds,"    ");
	FlagString(ds,LO(reg.AF),LO(last_reg.AF));
	DSAdd(ds,"\n");

	DisplayState(ds,"BC ",4,reg.BC,last_reg.BC);
	DSAdd(ds,"    ");
	DisplayState(ds,"DE ",4,reg.DE,last_reg.DE);
	DSAdd(ds,"    ");
	DisplayState(ds,"HL ",4,reg.HL,last_reg.HL);
	DSAdd(ds,"\n");

	DisplayState(ds,"SP ",4,reg.SP,last_reg.SP);
	DSAdd(ds,"    ");
	DisplayState(ds,"IX ",4,reg.IX,last_reg.IX);
	DSAdd(ds,"    ");
	DisplayState(ds,"IY ",4,reg.IY,last_reg.IY);
	DSAdd(ds,"\n\n");

	DisplayState(ds,"A' ",2,HI(reg.AF_),HI(last_reg.AF_));
	DSAdd(ds,"    ");
	FlagString(ds,LO(reg.AF_),LO(last_reg.AF_));
	DSAdd(ds,"\n");

	DisplayState(ds,"BC'",4,reg.BC_,last_reg.BC_);
	DSAdd(ds,"    ");
	DisplayState(ds,"DE'",4,reg.DE_,last_reg.DE_);
	DSAdd(ds,"    ");
	DisplayState(ds,"HL'",4,reg.HL_,last_reg.HL_);
	DSAdd(ds,"\n\n");

	DisplayState(ds,"PC ",4,reg.PC,last_reg.PC);
	DSAdd(ds,"  ");
	DisplayState(ds,"CYCLE",8,reg.cycle,last_reg.cycle);
	DSAdd(ds,"\n\n");

	DisplayState(ds,"R  ",2,reg.R,last_reg.R);
	DSAdd(ds,"     ");
	DisplayState(ds,"IFF1",1,reg.IFF1,last_reg.IFF1);
	DSAdd(ds,"      ");
	DisplayState(ds,"IFF2",1,reg.IFF2,last_reg.IFF2);
	DSAdd(ds,"\n");

	DisplayState(ds,"IM ",1,reg.IM,last_reg.IM);
	DSAdd(ds,"         ");
	DisplayState(ds,"I",1,reg.I,last_reg.I);
	DSAdd(ds,"\n");

	DSAdd(ds,"</tt>");

	gtk_label_set_markup(GTK_LABEL(regview),ds->text);

	DSFree(ds);

	last_reg=reg;
    }

    if (view&UPDATE_MEM_VIEW)
    {
	Z80Word addr;
	Z80Word orig;
	DString ds;
	int f;
	gboolean as_words;

	ds=DSInit();

	as_words=gtk_toggle_button_get_active(GTK_TOGGLE_BUTTON(memview_check));

	switch(gtk_combo_box_get_active(GTK_COMBO_BOX(memview_combo)))
	{
	    case 0:
		addr=reg.HL;
	    	break;
	    case 1:
		addr=reg.SP;
		as_words=TRUE;
	    	break;
	    case 2:
		addr=reg.IX;
	    	break;
	    case 3:
		addr=reg.IY;
	    	break;
	    case 4:
		addr=reg.BC;
	    	break;
	    case 5:
		addr=reg.DE;
	    	break;
	    default:
		addr=reg.PC;
	    	break;
	}

	DSAdd(ds,"<tt><small>");

	orig=addr;
	addr-=6*8;

	for(f=0;f<13;f++)
	{
	    DString asc;
	    char buff[10];
	    Z80Word off;

	    asc=DSInit();

	    sprintf(buff,"%4.4X:   ",addr);
	    DSAdd(ds,buff);

	    for(off=0;off<8;off++)
	    {
		gchar *p;
		p=g_markup_printf_escaped
		    ("%c",isprint(mem[addr+off]) ? mem[addr+off] : '.');
		DSAdd(asc,p);
		g_free(p);
	    }

	    for(off=0;off<8;off+=(as_words ? 2:1))
	    {
		Z80Word a;

		a=addr+off;

	    	if (a==orig)
		{
		    DSAdd(ds,"<span foreground=\"white\" "
		    		"background=\"black\">");
		}

		if (as_words)
		{
		    sprintf(buff,"%4.4X  ",MK(mem[a+1],mem[a]));
		}
		else
		{
		    sprintf(buff,"%2.2X ",mem[a]);
		}

		DSAdd(ds,buff);

	    	if (a==orig)
		{
		    DSAdd(ds,"</span>");
		}
	    }

	    DSAdd(ds,"     ");
	    DSAdd(ds,asc->text);
	    DSAdd(ds,"\n");

	    DSFree(asc);

	    addr+=8;
	}

	DSAdd(ds,"</small></tt>");

	gtk_label_set_markup(GTK_LABEL(memview),ds->text);

	DSFree(ds);
    }
}


void GEMMA_LoadHEX(const char *path)
{
    FILE *fp;
    char buff[1024];
    int done=FALSE;

    if (!(fp=fopen(path,"r")))
    {
    	Log("Failed to open %s\n",path);
	return;
    }

    while(!done)
    {
    	if (!fgets(buff,sizeof buff,fp))
	{
	    Log("Missing EOF record\n");
	    done=TRUE;
	}

	if (!done && buff[0]!=':')
	{
	    Log("Invalid Intel HEX file\n");
	    done=TRUE;
	}

	if (!done && buff[8]=='1')
	{
	    Log("<EOF>\n");
	    done=TRUE;
	}

	if (!done)
	{
	    Z80Word addr;
	    int len;
	    int f;

	    len=ToHex(buff[1])<<4|ToHex(buff[2]);

	    addr=ToHex(buff[3])<<12|ToHex(buff[4])<<8|
		 ToHex(buff[5])<<4|ToHex(buff[6]);

	    Log("Segment of 0x%2.2x bytes at address 0x%4.4x\n",len,addr);

	    for(f=0;f<len;f++)
	    {
	    	Z80Byte b;

		b=ToHex(buff[f*2+9])<<4|ToHex(buff[f*2+10]);
		mem[addr++]=b;
	    }
	}
    }

    fclose(fp);

    GEMMA_UpdateDisplay(UPDATE_ALL_VIEWS);
}


void GEMMA_LoadLabels(const char *path)
{
    FILE *fp;
    int f;
    char buff[512];

    if (!(fp=fopen(path,"r")))
    {
    	Log("Failed to open %s\n",path);
	return;
    }

    for(f=0;label && label[f].label;f++)
    	free((void *)label[f].label);

    free(label);
    label=NULL;
    f=0;

    while(fgets(buff,sizeof buff,fp))
    {
    	char *name=NULL;
	char *addr=NULL;

	if (strlen(buff) && buff[strlen(buff)-1]=='\n')
	    buff[strlen(buff)-1]=0;

	name=strtok(buff," \t");

	if (name)
	    addr=strtok(NULL," \t");

	if (name && addr)
	{
	    label=Realloc(label,sizeof(*label)*(f+2));

	    label[f].label=StrCopy(name);
	    label[f].address=Address(addr);

	    f++;
	}
    }

    if (label)
    	label[f].label=NULL;

    Z80SetLabels(label);

    fclose(fp);
}


void GEMMA_Step(void)
{
    Step();
    GEMMA_UpdateDisplay(UPDATE_ALL_VIEWS);
}


void GEMMA_StepOver(void)
{
    Z80Word next;
    Z80State reg;

    stop=FALSE;

    Z80GetState(z80,&reg);
    next=reg.PC;
    Z80Disassemble(z80,&next);

    RUNNING(TRUE);

    while(reg.PC!=next && !stop)
    {
	Step();
	Z80GetState(z80,&reg);
	gtk_main_iteration_do(FALSE);
    }

    GEMMA_UpdateDisplay(UPDATE_ALL_VIEWS);

    RUNNING(FALSE);
}


void GEMMA_Run(void)
{
    stop=FALSE;

    RUNNING(TRUE);

    while(!stop)
    {
    	GEMMA_Step();
	gtk_main_iteration_do(FALSE);
    }

    RUNNING(FALSE);
}


void GEMMA_RunUntil(void)
{
    char *expr;

    expr=StrCopy(gtk_entry_get_text(GTK_ENTRY(breakpoint_text)));

    stop=FALSE;

    RUNNING(TRUE);

    while(!stop)
    {
	long e;

	if (!ExprEval(expr,&e,Expand,z80))
	{
	    DialogOK("Error evaluating express:\n%s",ExprError());
	    stop=TRUE;
	    continue;
	}

	if (e)
	{
	    DialogOK("%s TRUE",expr);
	    stop=TRUE;
	    continue;
	}

    	GEMMA_Step();
	gtk_main_iteration_do(FALSE);
    }

    free(expr);

    RUNNING(FALSE);
}


void GEMMA_Stop(void)
{
    stop=TRUE;
}


void GEMMA_Init(GtkWidget *top)
{
    int f;

    for(f=0;f<256;f++) memctl[f]=1;

    z80=Z80Init(mem,memctl,WritePort,ReadPort);
    Z80SetPC(z80,0x100);

    if (!z80)
    {
    	fprintf(stderr,"Failed to initialise Z80\n");
	exit(EXIT_FAILURE);
    }

    Z80LodgeCallback(z80,eZ80_Halt,Halt);

    top_window=top;
    regview=lookup_widget(top_window,"register_view");
    memview=lookup_widget(top_window,"memory_view");
    viewreg=lookup_widget(top_window,"memory_view_choice");
    logview=lookup_widget(top_window,"log_view");
    assemview=lookup_widget(top_window,"assem_view");

    memview_combo=lookup_widget(top_window,"memory_view_choice");
    memview_check=lookup_widget(top_window,"viewmode_check");

    breakpoint_text=lookup_widget(top_window,"breakpoint_text");

    run_button=lookup_widget(top_window,"run_button");
    step_button=lookup_widget(top_window,"step_button");
    step_over_button=lookup_widget(top_window,"step_over_button");
    stop_button=lookup_widget(top_window,"stop_button");
    run_until_button=lookup_widget(top_window,"run_until_button");

    gtk_combo_box_set_active(GTK_COMBO_BOX(memview_combo),0);
}


void GEMMA_Interrupt(int nmi)
{
    if (nmi)
    {
	Z80NMI(z80);
    }
    else
    {
    	Z80Interrupt(z80,0);
    }
}


/* END OF FILE */