/*
Copyright (C) Magna Carta Software, Inc. 1990.  All Rights Reserved
C COMMUNICATIONS TOOLKIT
CWAITS.C -- Basic serial I/O functions (no data translation)
*/

#define CCT_DEVELOPMENT
#if (defined(CCTW) || defined(_WINDOWS))
    #include <windows.h>
#endif
#include <dos.h>
#include <string.h>
#include <comm.h>


#define MAX_STRING_LEN      80      /* max. length of search strings */


/*
C_WAITS -- Wait for the specified time to receive the specified string
from the specified port.  Incorrect characters received during the wait time
are ignored.
Arguments:
    COMM_PORT *p -- a pointer to the port;
    char      *p_str  -- a pointer to the desired string;
    WORD     duration -- the maximum time to wait for the whole string;
Return value:
    0               -- success -- correct string returned;
    EOF             -- whole string not returned in time;
    USER_CANCELLED  -- abort key entered;
*/
short c_waits(COMM_PORT *p, char *p_str, WORD duration)
{
    short ch, ret = 0;
    WORD now;
    unsigned long t=0;
    char buf[MAX_STRING_LEN], *ps, *pb, *savepb;
    pb = buf;
    ps = p_str;

    memset(buf, 0X0, MAX_STRING_LEN);
    now = peek(0, LOW_TIME);
    while (*ps != '\0' && !ret) {
        if (now != (WORD) peek(0, LOW_TIME)) {
            t += 55;
            now = peek(0, LOW_TIME);
            if (t >= (unsigned long) duration) ret = EOF;
        }
        if (!ret) {
            if (pb > &buf[MAX_STRING_LEN-1]) pb = buf; /* return to start of buffer */
            if (is_key(p->abort_key)) return(USER_CANCELLED);
            ch =  c_inchar(p);
            if (ch == EOF) continue;
        if (isrxecholocal(p) && ch >= 0) (*p->con_out)(p, ch);
            if ((char) ch == *ps) {
                ps++;     /* success -- advance string ptr. */
                *pb++ = (char) ch;
            }
            else {                          /* failure -- return to start */
                savepb = pb;
                pb = buf+1;
                ps = p_str;
                /*
                This loop is necessary to catch the start of a correct string
                that occurs after the first character in "buf".
                E.g. waiting for "abracadabra" we may receive "abrabracadabra".
                */
                while (pb < savepb) {
                    if (*pb++ != *ps) ps = p_str;
                    else ps++;
                }
                if ((char) ch == *ps) {
                    ps++;     /* success -- advance string ptr. */
                    *pb++ = (char) ch;
                }
            }
        }
    }
    if (p->rx_tbdelay) mspause(p->rx_tbdelay);

    return (ret);
}