#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include "libtmt/tmt.h"

void hackvr_draw_character(int c,int r,const TMTCHAR *ch) {
 int i;
 FILE *fp;
 char str[16];
 char line[256];//whatever
 if(ch->c < 128) {
  snprintf(str,sizeof(str)-1,"%02lx",ch->c);
 } else {
  snprintf(str,sizeof(str)-1,"%08lx",ch->c);
 }
 if((fp=fopen("font","r")) == NULL ) {
  printf("# fail to open font\n");
  return;
 }
 printf("term_%02d_%02d addshape %d 4  -1 -3 0  5 -3 0  5 7 0  -1 7 0\n",c,r,ch->a.bg+15);
 for(i=0;fgets(line,sizeof(line)-1,fp) != 0;i++) {
  if(!strncmp(str,line,2)) {
   printf("term_%02d_%02d addshape %d %s",c,r,ch->a.fg==-1?2:ch->a.fg+15,line+strlen("XX addshape X "));
  }
 }
 if(i) printf("term_%02d_%02d move %d %d 0\n",c,r,c*6,-r*10);
 fclose(fp);
}

void callback(tmt_msg_t m,TMT *vt, const void *a,void *vt_old) {
 static int cr_old=0;
 static int cc_old=0;
 const TMTSCREEN *s_old=tmt_screen(vt_old);
 const TMTSCREEN *s=tmt_screen(vt);
 const TMTPOINT *c=tmt_cursor(vt);
 const TMTCHAR *ch;
 switch(m) {
  case TMT_MSG_BELL:
   printf("term set global.beep\n");
   break;
  case TMT_MSG_UPDATE:
   for (size_t r = 0; r < s->nline; r++){
    if (s->lines[r]->dirty){
     for (size_t c = 0; c < s->ncol; c++){
      if(memcmp(&(s->lines[r]->chars[c]),&(s_old->lines[r]->chars[c]),sizeof(TMTCHAR))) {
       ch=&(s->lines[r]->chars[c]);
       printf("term_%02d_%02d deletegroup term_%02d_%02d\n",c,r,c,r);
       hackvr_draw_character(c,r,ch);
       memcpy(&(s_old->lines[r]->chars[c]),&(s->lines[r]->chars[c]),sizeof(TMTCHAR));
      }
     }
    }
   }
   break;
  case TMT_MSG_ANSWER://what does this do?
   fprintf(stderr,"ANSWER: %s\n",(const char *)a);
   break;
  case TMT_MSG_MOVED:
   printf("cursor move %d %d 0\n", (c->c - cc_old) * 5, - (c->r - cr_old) * 9);//calculate relative movement needed based on previous and current positions.
   cr_old=c->r;
   cc_old=c->c;
   break;
  case TMT_MSG_CURSOR:
   if(!strcmp(a,"t")) {
    printf("cursor deletegroup cursor\n");//just delete it and redraw the cursor.
    printf("cursor addshape 2 4  0 -2 0  4 -2 0  4 6 0  0 6 0\n");//let's pretend this is how cursors should be.
    printf("cursor move %d %d 0\n",c->c * 5,-c->r * 9);
   }
   if(!strcmp(a,"f")) {
    printf("cursor deletegroup cursor\n");
    cr_old=0;
    cc_old=0;
   }
   break;
  default:
   fprintf(stderr,"unhandled message type: %d\n",m);
 }
 return;
}

int main(int argc,char *argv[]) {
 char in[16];
 if(argc < 3) return fprintf(stderr,"usage: ./hackvr_term rows cols\n"),1;
 int r=atoi(argv[2]);
 int ret=0;
 int c=atoi(argv[1]);
 setbuf(stdin,0);
 setbuf(stdout,0);
 TMT *vt_old = tmt_open(r,c,NULL,NULL,NULL);
 if(!vt_old) return fprintf(stderr,"failed to open tmt's virtual terminal for storage"),1;
 TMT *vt = tmt_open(r,c,callback,vt_old,NULL);
 if(!vt) return fprintf(stderr,"failed to open tmt's virtual terminal"),1;
 //read from stdin and write to terminal.
 while((ret=read(0,in,16)) != 0) {//16 bytes at a time work?
  if(ret == -1) {
   if(errno == EAGAIN) continue;
   break;
  }
  tmt_write(vt,in,ret);
 }
 tmt_close(vt);
 return 0;
}