/*
 * Copyright 2000, International Business Machines Corporation and others.
 * All Rights Reserved.
 * 
 * This software has been released under the terms of the IBM Public
 * License.  For details, see the LICENSE file in the top-level source
 * directory or online at http://www.openafs.org/dl/license10.html
 */

/*
 * LWP_WaitForKeystroke - wait indefinitely or for a specified number of
 * seconds for keyboard input.
 *
 * If seconds < 0, LWP_WaitForKeystroke will wait indefinitely. 
 * If seconds == 0, LWP_WaitForKeystroke will just determine if data is now
 *	present.
 * Otherwise, wait "seconds" for data.
 *
 * Return 1 if data available.
 */

#include <afsconfig.h>
#include <afs/param.h>

RCSID
    ("$Header: /cvs/openafs/src/lwp/waitkey.c,v 1.13 2003/11/29 22:08:14 jaltman Exp $");

#include <stdio.h>
#include <sys/types.h>
#ifdef AFS_NT40_ENV
#include <time.h>
#include <conio.h>
#include <assert.h>
#else
#include <sys/time.h>
#include <unistd.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#else
#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif
#endif
#include "lwp.h"

#define LWP_KEYSTROKE_DELAY   250	/* 250ms. Must be < 1000 */
#define LWP_MAXLINELEN  256

#ifdef AFS_NT40_ENV
/* LWP_WaitForKeystroke : Wait until a key has been struck or time (secconds)
 * runs out and return to caller. The NT version of this function will return
 * immediately after a key has been pressed (doesn't wait for cr).
 * Input:
 *   seconds: wait for <seconds> seconds before returning. If seconds < 0,
 *            wait infinitely.
 * Return Value:
 *    1:  Keyboard input available
 *    0:  seconds elapsed. Timeout.
 */
int
LWP_WaitForKeystroke(int seconds)
{
    time_t startTime, nowTime;
    double timeleft = 1;
    struct timeval twait;

    time(&startTime);

    twait.tv_sec = 0;
    twait.tv_usec = LWP_KEYSTROKE_DELAY;

    if (seconds >= 0)
	timeleft = seconds;

    do {
	/* check if we have a keystroke */
	if (_kbhit())
	    return 1;

	if (timeleft == 0)
	    break;

	/* sleep for  LWP_KEYSTROKE_DELAY ms and let other
	 * process run some*/
	IOMGR_Select(0, 0, 0, 0, &twait);

	if (seconds > 0) {	/* we only worry about elapsed time if 
				 * not looping forever (seconds < 0) */
	    /* now check elapsed time */
	    time(&nowTime);
	    timeleft = seconds - difftime(nowTime, startTime);
	}
    }
    while (timeleft > 0);

    return 0;
}

/* LWP_GetLine() - Waits indefinitely until a newline has been typed
 * and then returns the line typed.
 * 
 * This is trivial in unix, but requires some processing on NT.
 *   we basically read all chars into a buffer until we hit a newline and
 *   then return it to the user.
 * Return Value:
 *   n - a whole line has been read.(has n chars)
 *   0 - buf not big enough.
 *   -1 - line with only EOF
 */

int
LWP_GetLine(char *linebuf, int len)
{
    int cnt = 0;
    int ch = 0;

    fflush(stdin);
    /* loop until a new line has been entered */
    while (ch != '\r' && cnt < len - 1) {
	LWP_WaitForKeystroke(-1);
	ch = getch();

	if ((ch == EOF) && (cnt == 0))
	    return -1;

	if (ch == '\b') {	/* print and throw away a backspace */
	    if (!cnt)		/* if we are at the start of the line don't bspace */
		continue;
	    /* print a space to delete char and move cursor back */
	    printf("\b \b");
	    cnt--;
	} else {
	    putchar(ch);
	    linebuf[cnt++] = ch;
	}
    }

    if (ch == '\r') {		/* got a cr. translate to nl */
	linebuf[cnt - 1] = '\n';
	linebuf[cnt] = '\0';
	putchar('\n');
	return cnt;
    } else {			/* buffer too small */
	linebuf[cnt] = '\0';
	return 0;
    }

}
#else
/* LWP_WaitForKeystroke(Unix) :Wait until a key has been struck or time (secconds)
 * runs out and return to caller. The Unix version will actually wait until
 * a <cr> has been entered before returning. 
 * Input:
 *   seconds: wait for <seconds> seconds before returning. If seconds < 0,
 *            wait infinitely.
 * Return Value:
 *    1:  Keyboard input available
 *    0:  seconds elapsed. Timeout.
 */
int
LWP_WaitForKeystroke(int seconds)
{
    fd_set rdfds;
    int code;
    struct timeval twait;
    struct timeval *tp = NULL;

#ifndef AFS_DJGPP_ENV
#ifdef AFS_LINUX20_ENV
    if (stdin->_IO_read_ptr < stdin->_IO_read_end)
	return 1;
#else
#if defined(AFS_DARWIN_ENV) || defined(AFS_XBSD_ENV)
    if (stdin->_bf._size > 0)
	return 1;
#else
    if (stdin->_cnt > 0)
	return 1;
#endif
#endif
#else /* DJGPP */
    if (stdin->_cnt > 0)
	return 1;
#endif /* DJGPP */

    FD_ZERO(&rdfds);
    FD_SET(fileno(stdin), &rdfds);

    if (seconds >= 0) {
	twait.tv_sec = seconds;
	twait.tv_usec = 0;
	tp = &twait;
    }

    code = IOMGR_Select(1 + fileno(stdin), &rdfds, NULL, NULL, tp);

    return (code == 1) ? 1 : 0;
}

/* LWP_GetLine() - Waits indefinitely until a newline has been typed
 * and then returns the line typed.
 * 
 * This is trivial in unix, but requires some processing on NT.
 *   we basically read all chars into a buffer until we hit a newline and
 *   then return it to the user.
 * Return Value:
 *   n - a whole line has been read.(has n chars)
 *   0 - buf not big enough.
 *   -1 - line with only EOF
 */

int
LWP_GetLine(char *linebuf, int len)
{
    int linelen;
    char *s;

    LWP_WaitForKeystroke(-1);

    s = fgets(linebuf, len, stdin);
    if (s == NULL)
	return -1;

    linelen = strlen(linebuf);
    if (linebuf[linelen - 1] != '\n')	/* buffer too small */
	return 0;
    else
	return linelen;
}

#endif /* else NT40 */

/* LWP_GetResponseKey() - Waits for a specified period of time and
 * returns a char when one has been typed by the user.
 * Input:
 *    seconds - how long to wait for a key press.
 *    *key    - char entered by user
 * Return Values: 
 *    0 - Time ran out before the user typed a key.
 *    1 - Valid char is being returned.
 */

int
LWP_GetResponseKey(int seconds, char *key)
{
    int rc;

    if (key == NULL)
	return 0;		/* need space to store char */


    fflush(stdin);		/* flush all existing data and start anew */


    rc = LWP_WaitForKeystroke(seconds);
    if (rc == 0) {		/* time ran out */
	*key = 0;
	return rc;
    }

    /* now read the char. */
#ifdef AFS_NT40_ENV
    *key = getche();		/* get char and echo it to screen */
#else
    *key = (char)getchar();
#endif

    return rc;
}
