/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8                               :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2021 Justine Alexandra Roberts Tunney                              │
│                                                                              │
│ Permission to use, copy, modify, and/or 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 "libc/calls/calls.h"
#include "libc/nexgen32e/crc32.h"
#include "libc/runtime/runtime.h"
#include "libc/stdio/rand.h"
#include "libc/stdio/stdio.h"
#include "libc/str/str.h"
#include "libc/testlib/hyperion.h"
#include "libc/testlib/testlib.h"

FILE *f;
char buf[512];

void SetUpOnce(void) {
  testlib_enable_tmp_setup_teardown();
}

TEST(ungetc, testGetChar_canBeUndoneWithinReason) {
  ASSERT_NE(NULL, (f = fopen("hog", "wb")));
  EXPECT_EQ(12, fputs("hello world\n", f));
  EXPECT_NE(-1, fputs(kHyperion, f));
  EXPECT_EQ(0, fclose(f));
  ASSERT_NE(NULL, (f = fopen("hog", "r")));
  EXPECT_EQ('h', fgetc(f));
  EXPECT_EQ('e', fgetc(f));
  EXPECT_EQ('e', ungetc('e', f));
  EXPECT_EQ('h', ungetc('h', f));
  EXPECT_EQ(5, fread(buf, 1, 5, f));
  EXPECT_BINEQ(u"hello", buf);
  EXPECT_EQ(0, fclose(f));
}

TEST(ungetc, testRead_canBeUndoneWithinReason) {
  ASSERT_NE(NULL, (f = fopen("hog", "wb")));
  EXPECT_EQ(12, fputs("hello world\n", f));
  EXPECT_EQ(0, fclose(f));
  ASSERT_NE(NULL, (f = fopen("hog", "r")));
  EXPECT_EQ(3, fread(buf, 1, 3, f));
  EXPECT_BINEQ(u"hel", buf);
  EXPECT_EQ('l', ungetc(buf[2], f));
  EXPECT_EQ('e', ungetc(buf[1], f));
  EXPECT_EQ(4, fread(buf, 1, 4, f));
  EXPECT_BINEQ(u"ello", buf);
  EXPECT_EQ(0, fclose(f));
}

TEST(ungetwc, testGetWideChar_canBeUndoneWithinReason) {
  memset(buf, 0, sizeof(buf));
  ASSERT_NE(NULL, (f = fopen("hog", "wb")));
  EXPECT_NE(-1, fputs("𐌰𐌱\n", f));
  EXPECT_EQ(0, fclose(f));
  ASSERT_NE(NULL, (f = fopen("hog", "r")));
  EXPECT_EQ(L'𐌰', fgetwc(f));
  EXPECT_EQ(L'𐌱', fgetwc(f));
  EXPECT_EQ(L'𐌱', ungetwc(L'𐌱', f));
  EXPECT_EQ(L'𐌰', ungetwc(L'𐌰', f));
  EXPECT_NE(0, fread(buf, 1, sizeof(buf), f));
  EXPECT_STREQ("𐌰𐌱\n", buf);
  EXPECT_EQ(0, fclose(f));
}

TEST(ungetc, io) {
  static char b1[BUFSIZ * 2];
  static char b2[BUFSIZ * 2];
  for (int i = 0; i < sizeof(b1); ++i) {
    b1[i] = rand();
  }
  FILE *f = tmpfile();
  fwrite(b1, 1, sizeof(b1), f);
  rewind(f);
  for (int i = 0; i < sizeof(b1); ++i) {
    int c;
    ASSERT_NE(EOF, (c = fgetc(f)));
    ASSERT_EQ(c, ungetc(c, f));
    ASSERT_EQ(c, fgetc(f));
    b2[i] = c;
    if (rand() % 10 == 0) {
      ASSERT_NE(EOF, fflush(f));
      ASSERT_NE(i, lseek(fileno(f), 0, SEEK_CUR));
    }
  }
  ASSERT_EQ(EOF, fgetc(f));
  fclose(f);
  ASSERT_EQ(crc32c(0, b1, sizeof(b1)), crc32c(0, b2, sizeof(b2)));
}