/*      $OpenBSD: test___freading.c,v 1.2 2025/06/12 07:39:26 yasuoka Exp $     */

/*
 * Copyright (c) 2025 YASUOKA Masahiko <yasuoka@yasuoka.net>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <assert.h>
#include <stdio.h>
#include <stdio_ext.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

/* we use assert() */
#undef  NDEBUG

#define TMPFILENAME     "test___freading.tmp"

void setup(void);

void test___freading0(void);
void test___freading1(void);
void test___freading2(void);

void
setup(void)
{
        FILE    *fp;

        /* common setup */
        unlink(TMPFILENAME);
        fp = fopen(TMPFILENAME, "w+");
        assert(fp != NULL);
        fputs("Hello world\n", fp);
        fclose(fp);
}

void
test___freading0(void)
{
        FILE    *fp;
        int      r;
        char     buf[80];

        fp = popen("echo Hello world", "r");
        assert(fp != NULL);
        assert(__freading(fp) != 0);
        assert(fgets(buf, sizeof(buf), fp) != NULL);
        assert(strcmp(buf, "Hello world\n") == 0);
        r = pclose(fp);
        assert(r == 0);
}

void
test___freading1(void)
{
        FILE    *fp;
        int      r;

        /* when the last operaiton is read, __freading() returns true */
        fp = fopen(TMPFILENAME, "w+");
        assert(fp != NULL);
        assert(__freading(fp) == 0);
        r = fputs("Hello world\n", fp);
        assert(r >= 0);
        assert(__freading(fp) == 0);
        rewind(fp);
        assert(fgetc(fp) == 'H');
        assert(__freading(fp) != 0);
        /* write */
        fseek(fp, 0, SEEK_END);
        r = fputs("\n", fp);
        assert(__freading(fp) == 0);
        /* ungetc */
        rewind(fp);
        assert(ungetc('X', fp) != 0);
        assert(__freading(fp) != 0);    /* reading */

        r = fclose(fp);
        assert(r == 0);
}

void
test___freading2(void)
{
        int      r;
        FILE    *fp;

        /*
         * until v1.10 of fpurge.c mistakenly enables the writing buffer
         * without _SRD flag set.
         */
        fp = fopen(TMPFILENAME, "r+");
        assert(fp != NULL);
        assert(fgetc(fp) == 'H');
        fpurge(fp);
        fseek(fp, 0, SEEK_CUR);
        assert(fputc('X', fp) == 'X');
        assert(__freading(fp) == 0);

        r = fclose(fp);
        assert(r == 0);
}

int
main(int argc, char *argv[])
{
        test___freading0();
        test___freading1();
        test___freading2();

        exit(0);
}