#include <unistd.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <assert.h>
#include <string.h>
#include <stdio.h>
#include "myc_mem.h"
#include "sys_select.h"

#define ESC_TMO 1000
#define REF_TMO 100
#define HISTORY_LINES 256

#define L_ARROW '\200'
#define R_ARROW '\201'
#define U_ARROW '\202'
#define D_ARROW '\203'
#define EVT_CHAR '\0'
#define DEL_CHAR '\b'
#define RET_CHAR '\n'

static char esc_key='\0';

static fd_set regMask;
static int lastFd=-1;

void term_reg_socket(int fd) {
  FD_SET(fd, &regMask);
}

void term_unr_socket(int fd) {
  FD_CLR(fd, &regMask);
}

int term_raw_key(char *key, int msecTmo) {
  fd_set mask;

  mask=regMask;
  return(sys_select_or_key(&mask, msecTmo, key));
}

int term_wait_fd(int fd, int msecTmo) {
  fd_set mask;
  struct timeval tmo;

  FD_ZERO(&mask);
  FD_SET(fd, &mask);
  tmo.tv_sec=msecTmo / 1000;
  tmo.tv_usec=(msecTmo % 1000) * 1000+1;
  return(select(FD_SETSIZE, &mask, NULL, NULL, &tmo));
}

int term_get_key(char *key, int msecTmo) {
  int iret;
  char k;

  if (esc_key==0) {
    iret=term_raw_key(&k, msecTmo);
  } else {
    k=esc_key;
  }
  while (k==27) { /* esc */
    iret=term_raw_key(&k, ESC_TMO);
    switch (k) {
    case 'O': k='\217'; break; /* ss3 */
    case '[': k='\233'; break; /* csi */
    default: break;
    }
  }      
  if (iret!=STDIN_FILENO) {
    esc_key=k;
    *key='\0';
    return(iret);
  }
  switch (k) {
  case '\233': /* csi */
    iret=term_raw_key(&k, ESC_TMO);
    while (k>='0' && k <='9') {
      iret=term_raw_key(&k, ESC_TMO);
    }
    if (iret!=STDIN_FILENO) {
      esc_key=k;
      *key='\0';
      return(iret);
    }
    switch (k) { /* L,R,U,D arrows */
    case 'D': k=L_ARROW; break;
    case 'C': k=R_ARROW; break;
    case 'A': k=U_ARROW; break;
    case 'B': k=D_ARROW; break;
    default: k='?';
    }
    break;
  case '\217': /* ss3 */
    iret=term_raw_key(&k, ESC_TMO);
    if (iret!=STDIN_FILENO) {
      esc_key=k;
      *key='\0';
      return(iret);
    }
    if (k=='M') { /* enter */
      k=RET_CHAR;
    } else if (k >= 'l' && k <= 'y') {
      k=k-64;
    } else {
      k='?';
    }
    break;
  case '\177': /* del */
  case '\b': /* bs */
    k=DEL_CHAR;
    break;
  case '\r': /* cr */
  case '\n': /* lf */
    k=RET_CHAR;
    break;
  case EVT_CHAR: /* time out*/
    break;
  default:
    if (k<' ' || k>'\176') k='?';
  }
  *key=k;
  esc_key='\0';
  return (STDIN_FILENO);
}

static char *history[HISTORY_LINES]={NULL};
/* history array: it's a cyclic buffer, when it is full, the oldest values
   are overwritten.
*/

static int hist_pos=0; /* position when scrolling through the history */
static int hist_end=0; /* end of history. Always history[hist_end]==NULL */

int term_get_line(char *buf, int size, int *pos, char *prompt, fd_set *mask) {
  char key, *lin;
  int i,j,l,iret,buflen;
  char tmp[512];

  buf[size-1]='\0'; /* make sure buf is null terminated */
  l=strlen(buf);
  if (*pos>l) {
    *pos=l;
  } else if (*pos<0) {
    *pos=0;
  }
  iret=term_get_key(&key, 0);
  while (1) {
    if (iret==-1 || key == RET_CHAR || key==EVT_CHAR) { /* refresh after a short timeout */
      assert(l*2+20+strlen(prompt)<sizeof(tmp));
      tmp[0]='\r';
      tmp[1]='\0';
      strcat(tmp, prompt);
      strcat(tmp, buf);
      strcat(tmp,"\033[K");
      j=strlen(tmp);
      for (i=l; i>*pos; i--) {
        tmp[j]='\b'; j++;
      }
      tmp[j]='\0';
      fputs(tmp, stdout);
      if (iret==-1) {
        iret=term_get_key(&key, -1); /* no timeout */
      }
    }
    switch (key) {
    case EVT_CHAR:
      fputs("\r\033[K", stdout);
      return(iret);

      /* interrupted EXIT */

    case RET_CHAR:
      /* fputs("\r\033[K", stdout); */
      i=hist_end-1; if (i<0) i=HISTORY_LINES-1;
      if ((history[i]==NULL || 0!=strcmp(history[i], buf)) && buf[0]!='\0') { /* do not save equal and empty lines */
        buflen=strlen(buf)+1;
	lin=MALLOC(buflen);
        strncpy(lin, buf, buflen);
        history[hist_end]=lin;
        hist_end++; if (hist_end>=HISTORY_LINES) hist_end=0;
        if (history[hist_end]!=NULL) {
          FREE(history[hist_end]); /* clear line at end of history */
        }
        history[hist_end]==NULL;
      }
      hist_pos=hist_end;
      return(STDIN_FILENO);

      /* normal EXIT */

    case DEL_CHAR:
      if (*pos>0) {
        for (i=*pos; buf[i]!='\0'; i++) {
          buf[i-1] = buf [i];
        }
        buf[i-1]='\0';
        (*pos)--;
        l--;
      }
      break;
    case L_ARROW:
      if (*pos>0) (*pos)--;
      break;
    case R_ARROW:
      if (buf[*pos]!='\0') (*pos)++;
      break;
    case U_ARROW:
    case D_ARROW:
      if (key==U_ARROW) {
        i=hist_pos-1; if (i<0) i=HISTORY_LINES-1;
      } else {
        i=hist_pos+1; if (i>=HISTORY_LINES) i=0;
      }
      if (history[i]!=NULL) {
        strncpy(buf, history[i], size-1);
        buf[size-1]='\0';
        hist_pos=i;
        l=strlen(buf);
        *pos=l;
      }
      break;
    default:
      if (l<size-1) {
        for (i=l; i>*pos; i--) {
          buf[i]=buf[i-1];
        }
        (*pos)++; l++;
        buf[i]=key;
        buf[l]='\0';
      }
      break;
    }
    iret=term_get_key(&key, REF_TMO);
  }
}