/* Original source is from the VED editor provided with the  */
/* Aztec C compiler from Manx Systems                        */
/* It has been heavily modified for CP/M and VT100 terminals */
/* JWD 10/15/2024                                            */

#include "vi.h"

int errflag=0;
int errline, errcol;
char errmsg[90];

int main(argc, argv)
int argc;
char **argv;
{
   register int c, l, i;
   register char *t;

   scr_init();
   init();
   End_buf = Mem_buf;
   Cur_ptr = Cur_lp = Mem_buf;
   *Fil_nam = 0;

   while (--argc)
   {
      Tabwidth = 4; /* set default tab width to 4 */

      if (*(*++argv) == '-')

      {

         switch ((*argv)[1])
         {
            case 't':
               Tabwidth = atoi(*argv+2);
               break;
         }
      }

      else
      {
         strcpy(Fil_nam, argv[0]);
      }
   }

   if (*Fil_nam == 0 || read_fil(Fil_nam) < 0)
      t_insert(Cur_ptr, 0, "\r", 1);

   Modflg = 0;  /* File modified flag */
   redraw(Mem_buf, 1, SCR_TOP);  /* Display first page of buffer */
   stats();  /* Display file stats */

   for (;;)
   {
      set_param(Cur_lp);  /* Set the Lin_siz variable */
      mv_curs(Cur_x, Cur_y);  /* Set cursor position */

      /* Use "getkey" assembly key mapper for ANSI keyboard strings. */
      /* getchar() is too slow for polled I/O */

#ifdef ANSIKEY
      c = getkey();  /* Get character from console with VT100 cursor keys */
#else
      c = getchar();  /* Read one character from stdin */
#endif

      if (c != '0')  /* Check for number and set repeat */
      {
         c = get_num(c);  /* Returns with character if not a number */
      }

      switch (c)
      {
         case 'y':  /* Yank buffer command (vi) */
            c = getchar();  /* Read one character from stdin */

            if (c == 'y' || c == 'd')
               yank();

            if (c == 'd')
               lin_del();
            break;

         case 'p':  /* Put lines from yank buffer (vi) */
            put();
            break;

         case 'n':  /* Find next matching string (vi) */
            while (Num--)
              search(1);
            break;

         case '/':  /* String search (vi) */
            search(0);
            break;

         case 0xc:  /* Redraw screen (vi) */
            redraw(Cur_lp, Cur_lin, SCR_BOT/2);
            break;

         case 'r':  /* Replace character (vi) */
            if (*Cur_ptr == '\r' || (c = getchar()) == '\r')
            {
               beep();
               break;
            }

            l = Lin_siz;
            *Cur_ptr = c;
            Modflg = 1;
            set_param(Cur_lp);

            if (l != Lin_siz)
               draw(Cur_lp, Cur_lin, Cur_y);
            else
               draw_lin(Cur_ptr, Cur_x, Cur_y);
            break;

         case 'k':  /* Cursor up (vi) */
            while (Num-- && Cur_lp != Mem_buf)
            {
               l=Cur_ptr-Cur_lp;
               t=Cur_lp;

               Cur_ptr = Cur_lp = get_prev(Cur_lp);

               if (c==0xb)
                  Cur_ptr += (l<(i=t-Cur_lp-1)?l:i);

               set_param(Cur_lp);
               Cur_y -= Lin_siz;
               Cur_lin--;

               if (Cur_lin < Top_lin)
                  scrl_dn();
            }
            break;

         case '\r':  /* Carriage return (vi) */
         case 'j':   /* Cursor down (vi) */
            while (Num-- && get_next(Cur_ptr) != End_buf)
            {
               l=Cur_ptr-Cur_lp;

               Cur_ptr = Cur_lp = get_next(Cur_ptr);

               if (c==0xa)
                  Cur_ptr += (l<(i=get_next(Cur_lp)-Cur_lp-1)?l:i);

               Cur_lin++;
               Cur_y += Lin_siz;

               if (Cur_lin == Bot_lin)
                  scrl_up();
            }
            break;

         case 'h':  /* Cursor left (vi) */
            while (Num-- && Cur_ptr > Cur_lp)
               Cur_ptr--;
            break;

         case 'l':  /* Cursor right (vi) */
            while (Num-- && *Cur_ptr != '\r')
               Cur_ptr++;
            break;

         case 0x2:  /* Page Up (vi) */
            Num = Cur_lin - 23 + Cur_x;

            if (Num < 1)
               Num = 1;

            Cur_lp = Mem_buf;
            Cur_lin = 1;

            while (--Num && (t = get_next(Cur_lp)) != End_buf)
            {
               Cur_lp = t;
               Cur_lin++;
            }

            Cur_ptr = Cur_lp;
            redraw(Cur_lp, Cur_lin, SCR_BOT/2);
            break;

         case 0x6:  /* Page Down (vi) */
            Num = Cur_lin + 23 + Cur_x;
            Cur_lp = Mem_buf;
            Cur_lin = 1;

            while (--Num && (t = get_next(Cur_lp)) != End_buf)
            {
               Cur_lp = t;
               Cur_lin++;
            }

            Cur_ptr = Cur_lp;
            redraw(Cur_lp, Cur_lin, SCR_BOT/2);
            break;

         case '0':  /* Beginning of line */
            Cur_ptr = Cur_lp;
            break;

         case '$':  /* End of line */
            Cur_ptr = get_next(Cur_ptr) - 1;
            break;

         case 'H':  /* Move to top line of screen (vi) */
            Cur_lp = Cur_ptr = Top_lp;
            Cur_y = Top_y;
            Cur_lin = Top_lin;
            break;

         case 'M':  /* Move to middle of screen */
            Cur_lp = Cur_ptr = Top_lp;
            Cur_y = Top_y;
            Cur_lin = Top_lin;
            Num = (SCR_BOT/2) - 1;

            while (Num-- && get_next(Cur_ptr) != End_buf)
            {
               l=Cur_ptr-Cur_lp;

               Cur_ptr = Cur_lp = get_next(Cur_ptr);

               if (c==0xa)
                  Cur_ptr += (l<(i=get_next(Cur_lp)-Cur_lp-1)?l:i);

               Cur_lin++;
               Cur_y += Lin_siz;
            }
            break;

         case 'L':  /* Move cursor to bottom of screen (vi) */
            Cur_lp = Cur_ptr = get_prev(Bot_lp);
            set_param(Cur_lp);
            Cur_y = Bot_y - Lin_siz;
            Cur_lin = Bot_lin - 1;
            break;

         case 'G':  /* Goto nG line or end of file (vi) */
            if (Val == 0)   /* If no number prefix, set up for 65535 reps. */
               Num = -1;    /* Bottom of file */

            Cur_lp = Mem_buf;
            Cur_lin = 1;

            while (--Num && (t = get_next(Cur_lp)) != End_buf)
            {
               Cur_lp = t;
               Cur_lin++;
            }

            Cur_ptr = Cur_lp;
            redraw(Cur_lp, Cur_lin, SCR_BOT/2);
            break;

         case ':':  /* vi command */
            colon();
            break;

         case 'x':  /* Delete n characters under cursor (vi) */
            delete();
            break;

         case 'd':  /* Double d for delete n lines (vi) */
            if (getchar() == 'd')
               lin_del();
            break;

         case 'o':  /* Open new line (vi) */
            if (End_buf > Mem_buf+1)
            {
               set_param(Cur_lp);
               Cur_lp = Cur_ptr = get_next(Cur_ptr);
               Cur_y += Lin_siz;
               t_insert(Cur_lp, 0, "\r", 1);

               if (Cur_y >= SCR_BOT)
                  scrl_up();
               else
                  ++Cur_lin;
                  draw(Cur_lp, Cur_lin, Cur_y);
            }
            insert();
            break;

         case 'i':  /* Insert characters on line (vi) */
            insert();
            break;

         case 'Z':  /* Start of save command */
            if (getchar() == 'Z' && Modflg)
               if (writ_fil(Fil_nam) != 0)
                  break;
            quit();
            break;
      }
      if (Val == 1)
         clr_statline();
   }
}