/*      $OpenBSD: test_ungetwc.c,v 1.1 2025/05/25 05:32:45 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 <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <locale.h>
#include <wchar.h>

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

#define TMPFILENAME     "test_ungetwc.tmp"

void setupw(void);
void test_fflush_ungetwc0(void);

void
setupw(void)
{
        FILE    *fp;

        /* common setup */
        unlink(TMPFILENAME);
        fp = fopen(TMPFILENAME, "w+");
        assert(fp != NULL);
        /* Konnitiwa Sekai(in Kanji) */
        fputws(L"\u3053\u3093\u306b\u3061\u308f \u4e16\u754c\n", fp);
        fclose(fp);
}

/* fflush work with reading file and seekable + ungetwc */
void
test_fflush_ungetwc0(void)
{
        int      r;
        wchar_t  buf[80];
        FILE    *fp;

        setupw();

        fp = fopen(TMPFILENAME, "r");

        assert(fp != NULL);
        assert(fgetwc(fp) == L'\u3053');        /* Ko */
        assert(fgetwc(fp) == L'\u3093');        /* N  */
        assert(fgetwc(fp) == L'\u306b');        /* Ni */
        assert(fgetwc(fp) == L'\u3061');        /* Ti */
        assert(fgetwc(fp) == L'\u308f');        /* Wa */

        /* push 263A(smile) back */
        assert(ungetwc(L'\u263a', fp));

        /* we support 1 push back wchar_t */
        assert(fgetwc(fp) == L'\u263a');

        /* can read reset of that */
        fgetws(buf, sizeof(buf), fp);
        assert(wcscmp(buf, L" \u4e16\u754c\n") == 0);

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

int
main(int argc, char *argv[])
{
        setlocale(LC_ALL, "C.UTF-8");

        test_fflush_ungetwc0();

        exit(0);
}