/*
 *                  _ c o n r e a d _ c
 *
 *  This routine is called from the 'read' call.  It handles
 *  input from the console/screen device.
 *
 *  The idea of vectoring the call into this routine is that
 *  this makes it possible to replace this routine with a
 *  full terminal emulator if so desired.    This can be done
 *  in a way that is transparent to user-level programs.
 *
 *
 *  RETURN VALUES:
 *          0/+ve   This many bytes (from the start of the data
 *                  buffer passed) have been read
 *                  any translation.
 *          -1      Error occurred.
 *
 *
 *  AMENDMENT HISTORY
 *  ~~~~~~~~~~~~~~~~~
 *  18 Sep 92   DJW   - Original version
 *                      an upgrade to support a CURSES library.
 *
 *  11 Jul 93   DJW   - Removed assumption that io_fbyte() sets _oserr.
 *                    - Removed assumption that sd_curs() sets _oserr.
 *
 *   4 Apr 94   DJW  - When CTRL-D pressed, must return 0 (was returning -1).
 *                    - Also, was not necessarily returning -1 on error.
 *
 *   8 Apr 94   EAJ   - Added sd_donl() call to force any pending newlines
 *                      to be done (needed on QXL).
 *
 *  13 Apr 94   EAJ   - vectored the call to io_fbyte. See readmove_c.
 *
 *  12 Nov 95   DJW   - Now get timeout via support routine to allow for
 *                      the setting of the UFB_ND and UFB_NB flags.
 */

#define __LIBRARY__

#include <qdos.h>
#include <fcntl.h>
#include <errno.h>

static
int     default_conread _LIB_F3_(struct UFB *,       uptr,  \
                                 unsigned char *,   buf,    \
                                 unsigned int,     len)
{
    int     reply;
    unsigned char  *ptr;
    unsigned char  *bufend;
    chanid_t    chanid;
    timeout_t   timeout;

    /*
     *  See if we are in EOF state
     */
    if (uptr->ufbst & UFB_EOF) {
        uptr->ufbst &= (char)~UFB_EOF;    /* Clear EOF flag */
        _oserr = ERR_EF;
        errno = EOSERR;
        return 0;
    }
    chanid  = uptr->ufbfh;
    timeout = _GetTimeout(uptr);
    /*
     *  First do any pending newlines, explicitly, for QXL,
     *  since QXL doesn't do it when enabling the cursor
     */
    (void) sd_donl( chanid, timeout);

    /*
     *  Ensure that a cursor is enabled
     */
    (void) sd_cure( chanid, timeout);

    /*
     *  Now start reading data from the keyboard.
     *  Certain characters are treated as having
     *  special meaning.
     */
    for ( ptr=buf, bufend=buf+len ; ptr < bufend ; ptr++) {
        if ((reply=(*_readkbd)( chanid, timeout, (char *)ptr)) != 0) {
            _oserr = (short)reply;
            errno = EOSERR;
            (void) sd_curs( chanid, timeout);
            return (-1);
        }
        /*
         *  If in RAW mode, there are no special
         *  characters, and no echoing done.
         */
        if (uptr->ufbflg & UFB_NT) {
            continue;
        }
        /*
         *  Handle those characters which need special treatment
         */
        switch (*ptr) {
        case 4 :         /* CTRL_D == EOF */
                _oserr = ERR_EF;                    /* Set QDOS EOF code */
                uptr->ufbst |= (char) UFB_EOF;      /* ... and set flag in UFB */
                goto DO_EXIT;                       /* Ignore this character, by not incrementing ptr */

        case 192:       /* LEFT == Delete */
        case 194:       /* CTRL-LEFT == Delete */
                if (ptr != buf) {
                    (void) sd_pcol  (chanid, timeout);
                    (void) io_sbyte (chanid, timeout, ' ');
                    (void) sd_pcol  (chanid, timeout);
                    ptr--;          /* Ignore character just deleted */
                }
                /* FALLTHRU */
        case 200:       /* RIGHT */
        case 202:       /* CTRL-RIGHT */
                ptr--;              /* Ignore character just read */
                continue;

        case 208:       /* UP */
        case 216:       /* DOWN */
        case '\n':      /* Newline */
                (void) io_sbyte (chanid, timeout, '\n');
                ptr++;
                goto DO_EXIT;
        default:
                (void) io_sbyte (chanid, timeout, *ptr);
                break;
        }   /* End of switch */
    }   /* End of for loop */
    /*
     *  Suppress cursor when finished
     */
DO_EXIT:
    (void) sd_curs( chanid, timeout);
    return ((int)(ptr - buf));
}

/*===================================================================
 *      Default vector points to this routine
 *------------------------------------------------------------------*/
#if __STDC__
int     (*_conread)(UFB_t *, void *, unsigned int) = (int (*)(UFB_t *, void *, unsigned int)) default_conread;
#else
int     (*_conread)() = default_conread;
#endif