#include <curses.h>
#include <stdio.h>
#include <stdlib.h>
 
struct data
{
struct data* plast;
struct data* pnext;
char vals[16];
unsigned long zeile;
char len;
};

WINDOW *stdscr,*woffs,*whex, *wascii, *wtop, *wbot;
const char *topline= " Offset    Hex                                                ASCII          ";
char xoffs[]  = "12345678",*soffs;
char xhex[]   = " 14 15 16 32 32 34 20 54 61 67 65 73 61 6D 74 0D  ",*shex;
char xascii[] = "1234567890123456",*sascii;
int result;
char *ptv="12345678";
FILE *fp;
int ipoint;
data daten,*pdaten,*pfirst, *phelp;

void initvar()
{
 pfirst=&daten;
 (*pfirst).plast=NULL;
 (*pfirst).pnext=NULL;
 (*pfirst).zeile=0;
 (*pfirst).len=0;
 soffs=xoffs;
 shex=xhex;
 sascii=xascii;
}

void miniinit()
{
xoffs  = "        ";
xhex   = "                                                  ";
xascii = "                ";
}

int screeninit()
{
 int retval=0;

 stdscr= initscr();
 if(start_color()) retval=1;
 nonl();
 intrflush(stdscr, FALSE);
 keypad(stdscr, TRUE);

// Zwei Fenster
 woffs =newwin(18,10,3 ,0 );
 whex  =newwin(18,52,3 ,10);
 wascii=newwin(18,18,3 ,62);
 wtop  =newwin(3 ,80,0 ,0 );
 wbot  =newwin(4 ,80,21,0 );

// Scrollen erlauben
 scrollok(woffs,1);
 scrollok(whex,1);
 scrollok(wascii,1);

// Tastatureingabe erlauben
 keypad(stdscr,1);
 keypad(whex,1);
 keypad(wascii,1);

// Color-Pairs anlegen (Farbkombinationen)
 if(init_pair(1,COLOR_BLUE,COLOR_BLACK)) retval=1;
 if(init_pair(2,COLOR_CYAN,COLOR_BLACK)) retval=1;

 wattrset(woffs,COLOR_PAIR(1));
 wattrset(whex,COLOR_PAIR(1));
 wattrset(wascii,COLOR_PAIR(1));
 wattrset(wbot,COLOR_PAIR(1));
 wattrset(wtop,COLOR_PAIR(1));

 box(woffs,0,0); 
 box(whex,0,0); 
 box(wascii,0,0); 
 box(wtop,0,0); 
 box(wbot,0,0); 
 
 wattrset(woffs,COLOR_PAIR(2));
 wattrset(whex,COLOR_PAIR(2));
 wattrset(wascii,COLOR_PAIR(2));
 wattrset(wtop,COLOR_PAIR(2)); 
 wattrset(wbot,COLOR_PAIR(2));

 return(retval);
}

char* tonumsysx(int base10,int newbase)
{
 int erg;
 int rest=0;
 int pos=0;
 int i;
 static char swap[9];
 char c[9];
 
 swap="********";
 c[pos]='0'+rest;
 while (base10 > 0)
  {
    erg=base10/newbase;
    rest=base10%newbase;
    if (rest <= 9)
      c[pos]='0'+rest;
    else
      c[pos]='A'+(rest-10);

    base10=erg;
    pos++;
    c[pos]='\0';
  }
 while(pos < 8)
  {
   c[pos]='0';
   pos++;
  }
 pos--;
 for (i=0;i<=pos;i++)
  {
    swap[i]=c[pos-i];
  }

return(swap);


}

int loadcontents()
{
 int retval=0;
 int x;
 char ch;
 int k=0;
 unsigned long zeile=0;


 pdaten=pfirst;

 ch=fgetc(fp);
 printf("Printing hashmark for every 8 Kbytes.\n");
 while (!(feof(fp)))
 {
 for(x=0;x<16;x++)
   {
    ((*pdaten).vals[x])=ch;
    if (feof(fp)) //(*pdaten).vals[x]==EOF) 
    {
     (*pdaten).vals[x]=0;
     break;     
    }
    (*pdaten).len=x+1;
    ch=fgetc(fp);
   }
 (*pdaten).zeile=zeile++;
 if(!(feof(fp)))
 {
  phelp=pdaten;
  if (!(zeile%500)) {fprintf(stderr,"%c",'#');}
  pdaten=((*pdaten).pnext)=(malloc(sizeof(daten)));
// BUG: Check for Memory-Full does not work.
  if(!pdaten) {abort();}
  (*pdaten).plast=phelp;
  (*pdaten).pnext=NULL;
 }

 }
/* D E B U G   O N L Y
getchar();

 pdaten=pfirst;

printf("%d\n",zeile);

while (zeile--)
 {
 for(x=0;x<16;x++)
   {
    printf("%c-",(*pdaten).vals[x]);
   }
   pdaten=(*pdaten).pnext;
 } 
getchar();
  --- END DEBUG ---*/
 return (retval);
}

void endscr()
{
 delwin(woffs);
 delwin(whex);
 delwin(wascii);
 delwin(wtop);
 delwin(wbot);
 endwin();
}

void unallocmem()
{
int zv;
pdaten=pfirst;
for(;(*pdaten).pnext;pdaten=(*pdaten).pnext)
 ;
while((*pdaten).plast)
{
phelp=(*pdaten).plast;
free(pdaten);
pdaten=phelp;
}
}


void scrrefresh()
{
 wattrset(woffs,COLOR_PAIR(1));
 wattrset(whex,COLOR_PAIR(1));
 wattrset(wascii,COLOR_PAIR(1));
 wattrset(wbot,COLOR_PAIR(1));
 wattrset(wtop,COLOR_PAIR(1));

 box(woffs,0,0); 
 box(whex,0,0); 
 box(wascii,0,0); 
 box(wtop,0,0); 
 box(wbot,0,0); 
 
 wattrset(woffs,COLOR_PAIR(2));
 wattrset(whex,COLOR_PAIR(2));
 wattrset(wascii,COLOR_PAIR(2));
 wattrset(wtop,COLOR_PAIR(2)); 
 wattrset(wbot,COLOR_PAIR(2));

 wrefresh(woffs);
 wrefresh(whex);
 wrefresh(wascii);
 wrefresh(wtop);
 wrefresh(wbot);
}

void lineout(unsigned long zeile)
{
 int z;

 miniinit();

 ptv = tonumsysx((*pdaten).zeile*16,16);
 for(z=0;z<9;z++)
 {  
  xoffs[z] = *(ptv+z);
 }
 mvwaddstr(woffs,zeile,1,soffs);
 for (z=0;z<(*pdaten).len;z++)
 {
  ptv = tonumsysx((*pdaten).vals[z],16);
  xhex[z*3+1] = *(ptv+6);
  xhex[z*3+2] = *(ptv+7);
 }
 mvwaddstr(whex,zeile,1,shex);
 for (z=0;z<(*pdaten).len;z++)
 {
  xascii[z] = (((*pdaten).vals[z]) > 31)?((*pdaten).vals[z]):254;
 }
 mvwaddstr(wascii,zeile,1,sascii);
}

void initout()
{
//Initiale Ausgabe (Alle)
int i;
bool schalter=false;
unsigned long zeile=1;
pdaten=pfirst;
 
if ((*pdaten).pnext == NULL) schalter=true;
for(i=0;i<16;i++)
 {
  lineout(i+1);
  if (schalter) break;
  pdaten=(*pdaten).pnext;
  if ((*pdaten).pnext == NULL) schalter=true;
 }
 scrrefresh();

if(i>15) pdaten=(*pdaten).plast;
}

void scrolld()
{
 wscrl(woffs,1);
 wscrl(whex,1);
 wscrl(wascii,1);

 int z;

 miniinit();

 lineout(16);
}

void scrollu()
{
 wscrl(woffs,-1);
 wscrl(whex,-1);
 wscrl(wascii,-1);

 miniinit();

 lineout(1);
}


int main(int argc, char *argv[])
{
//Variablen
 unsigned int i,z;
 unsigned long zeile=0,pos=0;
 bool schalter;
 int inpch;

 printf("GHEX Version 0.5\n");

//Vorbereitung
 //Parameter angegeben?
 if(argc < 2)
 {
  fprintf(stderr,"GHEX-MESSAGE:\n\nUSAGE: %s <filename> \n",argv[0]); 
  exit(1);
 }
 //Datei öffnen
 fp=fopen(argv[1],"r");
 if (fp == NULL)
 {
  fprintf(stderr,"GHEX-MESSAGE:\n\nERROR opening file: %s \n",argv[1]); 
  exit(2);
 }
 // pointer setzen
 initvar();
 //Datei -> Speicher
 if(loadcontents())
 {
  fprintf(stderr,"GHEX-MESSAGE:\n\nERROR reading %s (too less RAM?)\n",argv[1]); 
  exit(3);
 }
 // Terminal initialisieren
 if(screeninit()) 
 {
  endscr(); 
  fprintf(stderr,"!!!Terminal not supported!!! -> Abort \n"); 
  exit(5);
 }
 mvwaddstr(wtop,1,1,topline);
 mvwaddstr(wbot,1,1,argv[1]);


//Hauptprogramm

initout();

//Eventschleife
 while(inpch!=KEY_F(10))
 {
 inpch=wgetch(whex);
  switch(inpch)
  {
   case KEY_DOWN: 
		  if ((*pdaten).pnext != NULL)
                  { pdaten=(*pdaten).pnext;
                  scrolld(); 
                  }
                  break;
   case KEY_UP: 
                  z=0;
		  while(((*pdaten).plast != NULL)&&(z < 16))
                  { 
                   pdaten=(*pdaten).plast;
                   z++; 
                  }
                  if(z>15)
                  {
                   z--;
                   scrollu();
                  }
                  while(z--)
                  { 
		   if ((*pdaten).pnext != NULL)
                   { 
                    pdaten=(*pdaten).pnext;
                   }
                  }
                  break;
   case KEY_NPAGE: 
                  for(i=0;i<16;i++)
                  {
       		   if ((*pdaten).pnext != NULL)
                   { pdaten=(*pdaten).pnext;
                   scrolld(); 
                   }
                  }
                  break;
   case KEY_PPAGE:
                  for(i=0;i<16;i++)
                  { 
                   z=0;
		   while(((*pdaten).plast != NULL)&&(z < 16))
                   { 
                    pdaten=(*pdaten).plast;
                    z++; 
                   }
                   if(z>15)
                   {
                    z--;
                    scrollu();
                   }
                   while(z--)
                   { 
		    if ((*pdaten).pnext != NULL)
                    { 
                     pdaten=(*pdaten).pnext;
                    }
                   }
                  }
                  break;
   case KEY_HOME:
                  initout();
                  break;
   case KEY_END: 
                  while((*pdaten).pnext)
                  {
       		   if ((*pdaten).pnext != NULL)
                   { pdaten=(*pdaten).pnext;
                   scrolld(); 
                   }
                  }
                  break;
  
  };
 scrrefresh();
 } 
 sleep(1);
 endscr();
 unallocmem();
 return (fclose(fp));
}