// Copyright 2020 The Wuffs Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// ----------------

/*
This test program is typically run indirectly, by the "wuffs test" or "wuffs
bench" commands. These commands take an optional "-mimic" flag to check that
Wuffs' output mimics (i.e. exactly matches) other libraries' output, such as
giflib for GIF, libpng for PNG, etc.

To manually run this test:

for CC in clang gcc; do
  $CC -std=c99 -Wall -Werror json.c && ./a.out
  rm -f a.out
done

Each edition should print "PASS", amongst other information, and exit(0).

Add the "wuffs mimic cflags" (everything after the colon below) to the C
compiler flags (after the .c file) to run the mimic tests.

To manually run the benchmarks, replace "-Wall -Werror" with "-O3" and replace
the first "./a.out" with "./a.out -bench". Combine these changes with the
"wuffs mimic cflags" to run the mimic benchmarks.
*/

// !! wuffs mimic cflags: -DWUFFS_MIMIC

// Wuffs ships as a "single file C library" or "header file library" as per
// https://github.com/nothings/stb/blob/master/docs/stb_howto.txt
//
// To use that single file as a "foo.c"-like implementation, instead of a
// "foo.h"-like header, #define WUFFS_IMPLEMENTATION before #include'ing or
// compiling it.
#define WUFFS_IMPLEMENTATION

// Defining the WUFFS_CONFIG__MODULE* macros are optional, but it lets users of
// release/c/etc.c whitelist which parts of Wuffs to build. That file contains
// the entire Wuffs standard library, implementing a variety of codecs and file
// formats. Without this macro definition, an optimizing compiler or linker may
// very well discard Wuffs code for unused codecs, but listing the Wuffs
// modules we use makes that process explicit. Preprocessing means that such
// code simply isn't compiled.
#define WUFFS_CONFIG__MODULES
#define WUFFS_CONFIG__MODULE__BASE
#define WUFFS_CONFIG__MODULE__JSON

// If building this program in an environment that doesn't easily accommodate
// relative includes, you can use the script/inline-c-relative-includes.go
// program to generate a stand-alone C file.
#include "../../../release/c/wuffs-unsupported-snapshot.c"
#include "../testlib/testlib.c"
#ifdef WUFFS_MIMIC
// No mimic library.
#endif

// ---------------- String Conversions Tests

const char*  //
test_strconv_parse_number_i64() {
  CHECK_FOCUS(__func__);

  const int64_t fail = 0xDEADBEEF;

  struct {
    int64_t want;
    const char* str;
  } test_cases[] = {
      {.want = +0x0000000000000000, .str = "+0"},
      {.want = +0x0000000000000000, .str = "-0"},
      {.want = +0x0000000000000000, .str = "0"},
      {.want = +0x000000000000012C, .str = "+300"},
      {.want = +0x7FFFFFFFFFFFFFFF, .str = "+9223372036854775807"},
      {.want = +0x7FFFFFFFFFFFFFFF, .str = "9223372036854775807"},
      {.want = -0x0000000000000002, .str = "-2"},
      {.want = -0x00000000000000AB, .str = "_-_0x_AB"},
      {.want = -0x7FFFFFFFFFFFFFFF, .str = "-9223372036854775807"},
      {.want = -0x8000000000000000, .str = "-9223372036854775808"},

      {.want = fail, .str = "+ 1"},
      {.want = fail, .str = "++1"},
      {.want = fail, .str = "+-1"},
      {.want = fail, .str = "+9223372036854775808"},  // 1 << 63.
      {.want = fail, .str = "-"},
      {.want = fail, .str = "-+1"},
      {.want = fail, .str = "-0x8000000000000001"},   // -((1 << 63) + 1).
      {.want = fail, .str = "-9223372036854775809"},  // -((1 << 63) + 1).
      {.want = fail, .str = "0x8000000000000000"},    // 1 << 63.
      {.want = fail, .str = "1-"},
      {.want = fail, .str = "9223372036854775808"},  // 1 << 63.
  };

  int tc;
  for (tc = 0; tc < WUFFS_TESTLIB_ARRAY_SIZE(test_cases); tc++) {
    wuffs_base__result_i64 r =
        wuffs_base__parse_number_i64(wuffs_base__make_slice_u8(
            (void*)test_cases[tc].str, strlen(test_cases[tc].str)));
    int64_t have = (r.status.repr == NULL) ? r.value : fail;
    if (have != test_cases[tc].want) {
      RETURN_FAIL("\"%s\": have 0x%" PRIX64 ", want 0x%" PRIX64,
                  test_cases[tc].str, have, test_cases[tc].want);
    }
  }

  return NULL;
}

const char*  //
test_strconv_parse_number_u64() {
  CHECK_FOCUS(__func__);

  const uint64_t fail = 0xDEADBEEF;

  struct {
    uint64_t want;
    const char* str;
  } test_cases[] = {
      {.want = 0x0000000000000000, .str = "0"},
      {.want = 0x0000000000000000, .str = "0_"},
      {.want = 0x0000000000000000, .str = "0d0"},
      {.want = 0x0000000000000000, .str = "0x000"},
      {.want = 0x0000000000000000, .str = "_0"},
      {.want = 0x0000000000000000, .str = "__0__"},
      {.want = 0x000000000000004A, .str = "0x4A"},
      {.want = 0x000000000000004B, .str = "0x__4_B_"},
      {.want = 0x000000000000007B, .str = "123"},
      {.want = 0x000000000000007C, .str = "12_4"},
      {.want = 0x000000000000007D, .str = "_1__2________5_"},
      {.want = 0x00000000000001F4, .str = "0d500"},
      {.want = 0x00000000000001F5, .str = "0D___5_01__"},
      {.want = 0x00000000FFFFFFFF, .str = "4294967295"},
      {.want = 0x0000000100000000, .str = "4294967296"},
      {.want = 0x0123456789ABCDEF, .str = "0x0123456789ABCDEF"},
      {.want = 0x0123456789ABCDEF, .str = "0x0123456789abcdef"},
      {.want = 0xFFFFFFFFFFFFFFF9, .str = "18446744073709551609"},
      {.want = 0xFFFFFFFFFFFFFFFA, .str = "18446744073709551610"},
      {.want = 0xFFFFFFFFFFFFFFFE, .str = "0xFFFFffffFFFFfffe"},
      {.want = 0xFFFFFFFFFFFFFFFE, .str = "18446744073709551614"},
      {.want = 0xFFFFFFFFFFFFFFFF, .str = "0xFFFF_FFFF_FFFF_FFFF"},
      {.want = 0xFFFFFFFFFFFFFFFF, .str = "18446744073709551615"},

      {.want = fail, .str = " "},
      {.want = fail, .str = " 0"},
      {.want = fail, .str = " 12 "},
      {.want = fail, .str = ""},
      {.want = fail, .str = "+0"},
      {.want = fail, .str = "+1"},
      {.want = fail, .str = "-0"},
      {.want = fail, .str = "-1"},
      {.want = fail, .str = "0 "},
      {.want = fail, .str = "00"},
      {.want = fail, .str = "000000x"},
      {.want = fail, .str = "000000x0"},
      {.want = fail, .str = "007"},
      {.want = fail, .str = "0644"},
      {.want = fail, .str = "0_0"},
      {.want = fail, .str = "0_x1"},
      {.want = fail, .str = "0d___"},
      {.want = fail, .str = "0x"},
      {.want = fail, .str = "0x10000000000000000"},      // 1 << 64.
      {.want = fail, .str = "0x1_0000_0000_0000_0000"},  // 1 << 64.
      {.want = fail, .str = "1 23"},
      {.want = fail, .str = "1,23"},
      {.want = fail, .str = "1.23"},
      {.want = fail, .str = "123 "},
      {.want = fail, .str = "123456789012345678901234"},
      {.want = fail, .str = "12a3"},
      {.want = fail, .str = "18446744073709551616"},  // UINT64_MAX.
      {.want = fail, .str = "18446744073709551617"},
      {.want = fail, .str = "18446744073709551618"},
      {.want = fail, .str = "18446744073709551619"},
      {.want = fail, .str = "18446744073709551620"},
      {.want = fail, .str = "18446744073709551621"},
      {.want = fail, .str = "_"},
      {.want = fail, .str = "d"},
      {.want = fail, .str = "x"},
  };

  int tc;
  for (tc = 0; tc < WUFFS_TESTLIB_ARRAY_SIZE(test_cases); tc++) {
    wuffs_base__result_u64 r =
        wuffs_base__parse_number_u64(wuffs_base__make_slice_u8(
            (void*)test_cases[tc].str, strlen(test_cases[tc].str)));
    uint64_t have = (r.status.repr == NULL) ? r.value : fail;
    if (have != test_cases[tc].want) {
      RETURN_FAIL("\"%s\": have 0x%" PRIX64 ", want 0x%" PRIX64,
                  test_cases[tc].str, have, test_cases[tc].want);
    }
  }

  return NULL;
}

const char*  //
test_strconv_utf_8_next() {
  CHECK_FOCUS(__func__);

  // Special case the "\x00" string, which is valid UTF-8 but its strlen is
  // zero, not one.
  uint8_t the_nul_byte[1];
  the_nul_byte[0] = '\x00';

  struct {
    uint32_t want_cp;
    uint32_t want_bl;
    const char* str;
  } test_cases[] = {
      {.want_cp = 0x00000000, .want_bl = 0, .str = ""},
      {.want_cp = 0x00000000, .want_bl = 1, .str = "The <NUL> byte"},
      {.want_cp = 0x00000009, .want_bl = 1, .str = "\t"},
      {.want_cp = 0x00000041, .want_bl = 1, .str = "A"},
      {.want_cp = 0x00000061, .want_bl = 1, .str = "abdefghij"},
      {.want_cp = 0x0000007F, .want_bl = 1, .str = "\x7F"},
      {.want_cp = 0x00000080, .want_bl = 2, .str = "\xC2\x80"},
      {.want_cp = 0x000007FF, .want_bl = 2, .str = "\xDF\xBF"},
      {.want_cp = 0x00000800, .want_bl = 3, .str = "\xE0\xA0\x80"},
      {.want_cp = 0x0000FFFD, .want_bl = 3, .str = "\xEF\xBF\xBD"},
      {.want_cp = 0x0000FFFF, .want_bl = 3, .str = "\xEF\xBF\xBF"},
      {.want_cp = 0x00010000, .want_bl = 4, .str = "\xF0\x90\x80\x80"},
      {.want_cp = 0x0010FFFF, .want_bl = 4, .str = "\xF4\x8F\xBF\xBF"},

      // U+00000394 GREEK CAPITAL LETTER DELTA.
      {.want_cp = 0x00000394, .want_bl = 2, .str = "\xCE\x94"},
      {.want_cp = 0x00000394, .want_bl = 2, .str = "\xCE\x94+"},
      {.want_cp = 0x00000394, .want_bl = 2, .str = "\xCE\x94++"},
      {.want_cp = 0x00000394, .want_bl = 2, .str = "\xCE\x94+++"},
      {.want_cp = 0x00000394, .want_bl = 2, .str = "\xCE\x94++++"},
      {.want_cp = 0x00000394, .want_bl = 2, .str = "\xCE\x94\x80"},
      {.want_cp = 0x00000394, .want_bl = 2, .str = "\xCE\x94\x80\x80"},
      {.want_cp = 0x00000394, .want_bl = 2, .str = "\xCE\x94\x80\x80\x80"},
      {.want_cp = 0x00000394, .want_bl = 2, .str = "\xCE\x94\x80\x80\x80\x80"},

      // U+00002603 SNOWMAN.
      {.want_cp = 0x00002603, .want_bl = 3, .str = "\xE2\x98\x83"},
      {.want_cp = 0x00002603, .want_bl = 3, .str = "\xE2\x98\x83+"},
      {.want_cp = 0x00002603, .want_bl = 3, .str = "\xE2\x98\x83++"},
      {.want_cp = 0x00002603, .want_bl = 3, .str = "\xE2\x98\x83+++"},
      {.want_cp = 0x00002603, .want_bl = 3, .str = "\xE2\x98\x83++++"},
      {.want_cp = 0x00002603, .want_bl = 3, .str = "\xE2\x98\x83\xFF"},

      // U+0001F4A9 PILE OF POO.
      {.want_cp = 0x0001F4A9, .want_bl = 4, .str = "\xF0\x9F\x92\xA9"},
      {.want_cp = 0x0001F4A9, .want_bl = 4, .str = "\xF0\x9F\x92\xA9+"},
      {.want_cp = 0x0001F4A9, .want_bl = 4, .str = "\xF0\x9F\x92\xA9++"},
      {.want_cp = 0x0001F4A9, .want_bl = 4, .str = "\xF0\x9F\x92\xA9+++"},
      {.want_cp = 0x0001F4A9, .want_bl = 4, .str = "\xF0\x9F\x92\xA9++++"},
      {.want_cp = 0x0001F4A9, .want_bl = 4, .str = "\xF0\x9F\x92\xA9\xFF"},

      // Invalid.
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\x80"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xBF"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xC0\x80"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xC1\xBF"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xC2"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xC2\x7F"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xC2\xC0"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xC2\xFF"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xCE"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xDF\xC0"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xDF\xFF"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xE0\x80"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xE0\x80\x80"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xE0\x9F\xBF"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xE2"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xF0"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xF0\x80\x80"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xF0\x80\x80\x80"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xF0\x8F\xBF\xBF"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xF4\x90\x80\x80"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xF5"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xF6\x80"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xF7\x80\x80"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xFF\xFF\xFF\xFF"},

      // Invalid. UTF-8 cannot contain the surrogates U+D800 ..= U+DFFF.
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xED\xA0\x80"},
      {.want_cp = 0x0000FFFD, .want_bl = 1, .str = "\xED\xBF\xBF"},
  };

  int tc;
  for (tc = 0; tc < WUFFS_TESTLIB_ARRAY_SIZE(test_cases); tc++) {
    wuffs_base__slice_u8 s = wuffs_base__make_slice_u8(
        (void*)test_cases[tc].str, strlen(test_cases[tc].str));

    // Override "The <NUL> byte" with "\x00".
    if ((test_cases[tc].want_cp == 0) && (test_cases[tc].want_bl == 1)) {
      s = wuffs_base__make_slice_u8(&the_nul_byte[0], 1);
    }

    wuffs_base__utf_8__next__output have = wuffs_base__utf_8__next(s);
    if ((have.code_point != test_cases[tc].want_cp) ||
        (have.byte_length != test_cases[tc].want_bl)) {
      RETURN_FAIL("\"%s\": have cp=0x%" PRIX32 " bl=%" PRIu32
                  ", want cp=0x%" PRIX32 " bl=%" PRIu32,
                  test_cases[tc].str, have.code_point, have.byte_length,
                  test_cases[tc].want_cp, test_cases[tc].want_bl);
    }
  }

  return NULL;
}

// ---------------- Golden Tests

golden_test json_australian_abc_gt = {
    .want_filename = "test/data/australian-abc-local-stations.tokens",  //
    .src_filename = "test/data/australian-abc-local-stations.json",     //
};

golden_test json_file_sizes_gt = {
    .src_filename = "test/data/file-sizes.json",  //
};

golden_test json_github_tags_gt = {
    .src_filename = "test/data/github-tags.json",  //
};

golden_test json_json_things_unformatted_gt = {
    .want_filename = "test/data/json-things.unformatted.tokens",  //
    .src_filename = "test/data/json-things.unformatted.json",     //
};

golden_test json_nobel_prizes_gt = {
    .src_filename = "test/data/nobel-prizes.json",  //
};

// ---------------- JSON Tests

const char*  //
test_wuffs_json_decode_interface() {
  CHECK_FOCUS(__func__);

  {
    wuffs_json__decoder dec;
    CHECK_STATUS("initialize",
                 wuffs_json__decoder__initialize(
                     &dec, sizeof dec, WUFFS_VERSION,
                     WUFFS_INITIALIZE__LEAVE_INTERNAL_BUFFERS_UNINITIALIZED));
    CHECK_STRING(do_test__wuffs_base__token_decoder(
        wuffs_json__decoder__upcast_as__wuffs_base__token_decoder(&dec),
        &json_json_things_unformatted_gt));
  }

  {
    wuffs_json__decoder dec;
    CHECK_STATUS("initialize",
                 wuffs_json__decoder__initialize(
                     &dec, sizeof dec, WUFFS_VERSION,
                     WUFFS_INITIALIZE__LEAVE_INTERNAL_BUFFERS_UNINITIALIZED));
    CHECK_STRING(do_test__wuffs_base__token_decoder(
        wuffs_json__decoder__upcast_as__wuffs_base__token_decoder(&dec),
        &json_australian_abc_gt));
  }

  return NULL;
}

const char*  //
wuffs_json_decode(wuffs_base__token_buffer* tok,
                  wuffs_base__io_buffer* src,
                  uint32_t wuffs_initialize_flags,
                  uint64_t wlimit,
                  uint64_t rlimit) {
  wuffs_json__decoder dec;
  CHECK_STATUS("initialize",
               wuffs_json__decoder__initialize(&dec, sizeof dec, WUFFS_VERSION,
                                               wuffs_initialize_flags));

  while (true) {
    wuffs_base__token_buffer limited_tok =
        make_limited_token_writer(*tok, wlimit);
    wuffs_base__io_buffer limited_src = make_limited_reader(*src, rlimit);

    wuffs_base__status status =
        wuffs_json__decoder__decode_tokens(&dec, &limited_tok, &limited_src);

    tok->meta.wi += limited_tok.meta.wi;
    src->meta.ri += limited_src.meta.ri;

    if (((wlimit < UINT64_MAX) &&
         (status.repr == wuffs_base__suspension__short_write)) ||
        ((rlimit < UINT64_MAX) &&
         (status.repr == wuffs_base__suspension__short_read))) {
      continue;
    }
    return status.repr;
  }
}

// test_wuffs_json_decode_prior_valid_utf_8 tests that when encountering
// invalid or incomplete UTF-8, or a backslash-escape, any prior valid UTF-8 is
// still output. The decoder batches output so that, ignoring the quotation
// marks, "abc\xCE\x94efg" can be a single 8-length token instead of multiple
// (e.g. 3+2+3) tokens. On the other hand, while "abc\xFF" ends with one byte
// of invalid UTF-8, the 3 good bytes before that should still be output.
const char*  //
test_wuffs_json_decode_prior_valid_utf_8() {
  CHECK_FOCUS(__func__);

  // The test cases contain combinations of valid, partial and invalid UTF-8:
  //  - "\xCE\x94"         is U+00000394 GREEK CAPITAL LETTER DELTA.
  //  - "\xE2\x98\x83"     is U+00002603 SNOWMAN.
  //  - "\xF0\x9F\x92\xA9" is U+0001F4A9 PILE OF POO.
  //
  // The code below can also add trailing 's' bytes, which change e.g. the
  // partial multi-byte UTF-8 "\xE2" to be the invalid UTF-8 "\xE2s".
  const char* test_cases[] = {
      "",
      "\\t",
      "\\u",
      "\\u1234",
      "\x1F",  // Valid UTF-8 but invalid in a JSON string.
      "\x20",
      "\xCE",
      "\xCE\x94",
      "\xE2",
      "\xE2\x98",
      "\xE2\x98\x83",
      "\xE2\x98\x83\xCE",
      "\xE2\x98\x83\xCE\x94",
      "\xF0",
      "\xF0\x9F",
      "\xF0\x9F\x92",
      "\xF0\x9F\x92\xA9",
      "\xF0\x9F\x92\xA9\xCE",
      "\xF0\x9F\x92\xA9\xCE\x94",
  };

  size_t prefixes[] = {
      0,
      1,
      15,
      WUFFS_BASE__TOKEN__LENGTH__MAX_INCL - 9,
      WUFFS_BASE__TOKEN__LENGTH__MAX_INCL - 8,
      WUFFS_BASE__TOKEN__LENGTH__MAX_INCL - 7,
      WUFFS_BASE__TOKEN__LENGTH__MAX_INCL - 6,
      WUFFS_BASE__TOKEN__LENGTH__MAX_INCL - 5,
      WUFFS_BASE__TOKEN__LENGTH__MAX_INCL - 4,
      WUFFS_BASE__TOKEN__LENGTH__MAX_INCL - 3,
      WUFFS_BASE__TOKEN__LENGTH__MAX_INCL - 2,
      WUFFS_BASE__TOKEN__LENGTH__MAX_INCL - 1,
      WUFFS_BASE__TOKEN__LENGTH__MAX_INCL + 0,
  };

  size_t suffixes[] = {0, 1, 17};

  wuffs_json__decoder dec;

  int tc;
  for (tc = 0; tc < WUFFS_TESTLIB_ARRAY_SIZE(test_cases); tc++) {
    size_t n = strlen(test_cases[tc]);
    size_t num_preceding = 0;
    while (num_preceding < n) {
      wuffs_base__utf_8__next__output x =
          wuffs_base__utf_8__next(wuffs_base__make_slice_u8(
              (void*)(test_cases[tc]) + num_preceding, n - num_preceding));
      if (!wuffs_base__utf_8__next__output__is_valid(&x) ||
          (x.code_point < 0x20) || (x.code_point == '\\')) {
        break;
      }
      num_preceding += x.byte_length;
      if (num_preceding > n) {
        RETURN_FAIL("tc=%d: utf_8__next overflow", tc);
      }
    }

    int pre;
    for (pre = 0; pre < WUFFS_TESTLIB_ARRAY_SIZE(prefixes); pre++) {
      size_t prefix = prefixes[pre];

      int suf;
      for (suf = 0; suf < WUFFS_TESTLIB_ARRAY_SIZE(suffixes); suf++) {
        size_t suffix = suffixes[suf];

        // Set src to "\"ppp...pppMIDDLEsss...sss", with a leading quotation
        // mark, where prefix and suffix are the number of 'p's and 's's and
        // test_cases[tc] is the "MIDDLE".
        wuffs_base__slice_u8 src_data = ((wuffs_base__slice_u8){
            .ptr = global_src_array,
            .len = 1 + prefix + n + suffix,
        });
        if (src_data.len > IO_BUFFER_SIZE) {
          RETURN_FAIL("total src length is too long");
        }
        src_data.ptr[0] = '\"';
        memset(&src_data.ptr[1], 'p', prefix);
        memcpy(&src_data.ptr[1 + prefix], test_cases[tc], n);
        memset(&src_data.ptr[1 + prefix + n], 's', suffix);

        int closed;
        for (closed = 0; closed < 2; closed++) {
          CHECK_STATUS(
              "initialize",
              wuffs_json__decoder__initialize(
                  &dec, sizeof dec, WUFFS_VERSION,
                  WUFFS_INITIALIZE__LEAVE_INTERNAL_BUFFERS_UNINITIALIZED));

          wuffs_base__token_buffer tok = ((wuffs_base__token_buffer){
              .data = global_have_token_slice,
          });

          wuffs_base__io_buffer src = ((wuffs_base__io_buffer){
              .data = src_data,
              .meta = wuffs_base__make_io_buffer_meta(src_data.len, 0, 0,
                                                      closed != 0),
          });

          wuffs_json__decoder__decode_tokens(&dec, &tok, &src);

          size_t have = 0;
          while (tok.meta.ri < tok.meta.wi) {
            wuffs_base__token* t = &tok.data.ptr[tok.meta.ri++];
            uint64_t vbc = wuffs_base__token__value_base_category(t);
            if (vbc == WUFFS_BASE__TOKEN__VBC__UNICODE_CODE_POINT) {
              break;
            } else if (vbc == WUFFS_BASE__TOKEN__VBC__STRING) {
              have += wuffs_base__token__length(t);
            } else {
              RETURN_FAIL(
                  "tc=%d, prefix=%zu, suffix=%zu, closed=%d: unexpected token",
                  tc, prefix, suffix, closed);
            }
          }
          size_t want = 1 + prefix + num_preceding;  // 1 for the leading '\"'.
          if (num_preceding == n) {
            want += suffix;
          }
          if (have != want) {
            RETURN_FAIL(
                "tc=%d, prefix=%zu, suffix=%zu, closed=%d: have %zu, want %zu",
                tc, prefix, suffix, closed, have, want);
          }
        }
      }
    }
  }

  return NULL;
}

const char*  //
test_wuffs_json_decode_unicode4_escapes() {
  CHECK_FOCUS(__func__);

  const uint32_t fail = 0xDEADBEEF;

  struct {
    uint32_t want;
    const char* str;
  } test_cases[] = {
      // Simple (non-surrogate) successes.
      {.want = 0x0000000A, .str = "\"\\u000a\""},
      {.want = 0x0000005C, .str = "\"\\\\u1234\""},  // U+005C is '\\'.
      {.want = 0x00001000, .str = "\"\\u10002345\""},
      {.want = 0x00001000, .str = "\"\\u1000234\""},
      {.want = 0x00001000, .str = "\"\\u100023\""},
      {.want = 0x00001000, .str = "\"\\u10002\""},
      {.want = 0x00001234, .str = "\"\\u1234\""},
      {.want = 0x0000D7FF, .str = "\"\\ud7ff\""},
      {.want = 0x0000E000, .str = "\"\\uE000\""},
      {.want = 0x0000FFFF, .str = "\"\\uFffF\""},

      // Unicode surrogate pair. U+0001F4A9 PILE OF POO is (U+D83D, U+DCA9),
      // because ((0x03D << 10) | 0x0A9) is 0xF4A9:
      //  - High surrogates are in the range U+D800 ..= U+DBFF.
      //  - Low  surrogates are in the range U+DC00 ..= U+DFFF.
      {.want = 0x0001F4A9, .str = "\"\\uD83D\\udca9\""},

      // More surrogate pairs.
      {.want = 0x00010000, .str = "\"\\uD800\\uDC00\""},
      {.want = 0x0010FFFF, .str = "\"\\uDBFF\\uDFFF\""},

      // Simple (non-surrogate) failures.
      {.want = fail, .str = "\"\\U1234\""},
      {.want = fail, .str = "\"\\u123"},
      {.want = fail, .str = "\"\\u123\""},
      {.want = fail, .str = "\"\\u123x\""},
      {.want = fail, .str = "\"u1234\""},

      // Invalid surrogate pairs.
      {.want = fail, .str = "\"\\uD800\""},         // High alone.
      {.want = fail, .str = "\"\\uD83D?udca9\""},   // High then not "\\u".
      {.want = fail, .str = "\"\\uD83D\\ud7ff\""},  // High then non-surrogate.
      {.want = fail, .str = "\"\\uD83D\\udbff\""},  // High then high.
      {.want = fail, .str = "\"\\uD83D\\ue000\""},  // High then non-surrogate.
      {.want = fail, .str = "\"\\uDC00\""},         // Low alone.
      {.want = fail, .str = "\"\\uDC00\\u0000\""},  // Low then non-surrogate.
      {.want = fail, .str = "\"\\uDC00\\ud800\""},  // Low then high.
      {.want = fail, .str = "\"\\uDC00\\udfff\""},  // Low then low.
      {.want = fail, .str = "\"\\uDFFF1234\""},     // Low alone.
  };

  wuffs_json__decoder dec;
  int tc;
  for (tc = 0; tc < WUFFS_TESTLIB_ARRAY_SIZE(test_cases); tc++) {
    CHECK_STATUS("initialize",
                 wuffs_json__decoder__initialize(
                     &dec, sizeof dec, WUFFS_VERSION,
                     WUFFS_INITIALIZE__LEAVE_INTERNAL_BUFFERS_UNINITIALIZED));

    wuffs_base__token_buffer tok = ((wuffs_base__token_buffer){
        .data = global_have_token_slice,
    });
    size_t n = strlen(test_cases[tc].str);
    wuffs_base__io_buffer src = ((wuffs_base__io_buffer){
        .data = wuffs_base__make_slice_u8((void*)(test_cases[tc].str), n),
        .meta = wuffs_base__make_io_buffer_meta(n, 0, 0, true),
    });

    wuffs_json__decoder__decode_tokens(&dec, &tok, &src);

    uint32_t have = fail;
    uint64_t total_length = 0;
    size_t i;
    for (i = tok.meta.ri; i < tok.meta.wi; i++) {
      wuffs_base__token* t = &tok.data.ptr[i];
      total_length =
          wuffs_base__u64__sat_add(total_length, wuffs_base__token__length(t));

      // Set have to the first Unicode code point token.
      if ((have == fail) && ((wuffs_base__token__value_base_category(t) ==
                              WUFFS_BASE__TOKEN__VBC__UNICODE_CODE_POINT))) {
        have = wuffs_base__token__value_base_detail(t);
        if (have > 0x10FFFF) {  // This also catches "have == fail".
          RETURN_FAIL("%s: invalid Unicode code point", test_cases[tc].str);
        }

        uint64_t have_length = wuffs_base__token__length(t);
        uint64_t want_length = (have == 0x5C) ? 2 : ((have <= 0xFFFF) ? 6 : 12);
        if (have_length != want_length) {
          RETURN_FAIL("%s: token length: have %" PRIu64 ", want %" PRIu64,
                      test_cases[tc].str, have_length, want_length);
        }
      }
    }

    if (have != test_cases[tc].want) {
      RETURN_FAIL("%s: have 0x%" PRIX32 ", want 0x%" PRIX32, test_cases[tc].str,
                  have, test_cases[tc].want);
    }

    if (total_length != src.meta.ri) {
      RETURN_FAIL("%s: total length: have %" PRIu64 ", want %" PRIu64,
                  test_cases[tc].str, total_length, src.meta.ri);
    }
  }

  return NULL;
}

const char*  //
test_wuffs_json_decode_string() {
  CHECK_FOCUS(__func__);

  const char* bad_bac = wuffs_json__error__bad_backslash_escape;
  const char* bad_ccc = wuffs_json__error__bad_c0_control_code;
  const char* bad_utf = wuffs_json__error__bad_utf_8;

  struct {
    const char* want_status_repr;
    const char* str;
  } test_cases[] = {
      {.want_status_repr = NULL, .str = "\"+++\\\"+\\/+\\\\+++\""},
      {.want_status_repr = NULL, .str = "\"+++\\b+\\f+\\n+\\r+\\t+++\""},
      {.want_status_repr = NULL, .str = "\"\x20\""},              // U+00000020.
      {.want_status_repr = NULL, .str = "\"\xC2\x80\""},          // U+00000080.
      {.want_status_repr = NULL, .str = "\"\xCE\x94\""},          // U+00000394.
      {.want_status_repr = NULL, .str = "\"\xDF\xBF\""},          // U+000007FF.
      {.want_status_repr = NULL, .str = "\"\xE0\xA0\x80\""},      // U+00000800.
      {.want_status_repr = NULL, .str = "\"\xE2\x98\x83\""},      // U+00002603.
      {.want_status_repr = NULL, .str = "\"\xED\x80\x80\""},      // U+0000D000.
      {.want_status_repr = NULL, .str = "\"\xED\x9F\xBF\""},      // U+0000D7FF.
      {.want_status_repr = NULL, .str = "\"\xEE\x80\x80\""},      // U+0000E000.
      {.want_status_repr = NULL, .str = "\"\xEF\xBF\xBD\""},      // U+0000FFFD.
      {.want_status_repr = NULL, .str = "\"\xEF\xBF\xBF\""},      // U+0000FFFF.
      {.want_status_repr = NULL, .str = "\"\xF0\x90\x80\x80\""},  // U+00010000.
      {.want_status_repr = NULL, .str = "\"\xF0\x9F\x92\xA9\""},  // U+0001F4A9.
      {.want_status_repr = NULL, .str = "\"\xF0\xB0\x80\x81\""},  // U+00030001.
      {.want_status_repr = NULL, .str = "\"\xF1\xB0\x80\x82\""},  // U+00070002.
      {.want_status_repr = NULL, .str = "\"\xF3\xB0\x80\x83\""},  // U+000F0003.
      {.want_status_repr = NULL, .str = "\"\xF4\x80\x80\x84\""},  // U+00100004.
      {.want_status_repr = NULL, .str = "\"\xF4\x8F\xBF\xBF\""},  // U+0010FFFF.
      {.want_status_repr = NULL, .str = "\"abc\""},
      {.want_status_repr = NULL, .str = "\"i\x6Ak\""},
      {.want_status_repr = NULL, .str = "\"space+\x20+space\""},
      {.want_status_repr = NULL, .str = "\"tab+\\t+tab\""},
      {.want_status_repr = NULL, .str = "\"tab+\\u0009+tab\""},

      {.want_status_repr = bad_bac, .str = "\"\\uIJKL\""},
      {.want_status_repr = bad_bac, .str = "\"space+\\x20+space\""},

      {.want_status_repr = bad_ccc, .str = "\"\x1F\""},
      {.want_status_repr = bad_ccc, .str = "\"tab+\t+tab\""},

      {.want_status_repr = bad_utf, .str = "\"\x80\""},
      {.want_status_repr = bad_utf, .str = "\"\xBF\""},
      {.want_status_repr = bad_utf, .str = "\"\xC1\x80\""},
      {.want_status_repr = bad_utf, .str = "\"\xC2\x7F\""},
      {.want_status_repr = bad_utf, .str = "\"\xDF\xC0\""},
      {.want_status_repr = bad_utf, .str = "\"\xDF\xFF\""},
      {.want_status_repr = bad_utf, .str = "\"\xE0\x9F\xBF\""},
      {.want_status_repr = bad_utf, .str = "\"\xED\xA0\x80\""},  // U+0000D800.
      {.want_status_repr = bad_utf, .str = "\"\xED\xAF\xBF\""},  // U+0000DBFF.
      {.want_status_repr = bad_utf, .str = "\"\xED\xB0\x80\""},  // U+0000DC00.
      {.want_status_repr = bad_utf, .str = "\"\xED\xBF\xBF\""},  // U+0000DFFF.
      {.want_status_repr = bad_utf, .str = "\"\xF0\x80\x80\""},
      {.want_status_repr = bad_utf, .str = "\"\xF0\x8F\xBF\xBF\""},
      {.want_status_repr = bad_utf, .str = "\"\xF2\x7F\x80\x80\""},
      {.want_status_repr = bad_utf, .str = "\"\xF2\x80\x7F\x80\""},
      {.want_status_repr = bad_utf, .str = "\"\xF2\x80\x80\x7F\""},
      {.want_status_repr = bad_utf, .str = "\"\xF4\x90\x80\x80\""},
      {.want_status_repr = bad_utf, .str = "\"\xF5\""},
      {.want_status_repr = bad_utf, .str = "\"\xFF\xFF\xFF\xFF\""},
  };

  wuffs_json__decoder dec;
  int tc;
  for (tc = 0; tc < WUFFS_TESTLIB_ARRAY_SIZE(test_cases); tc++) {
    CHECK_STATUS("initialize",
                 wuffs_json__decoder__initialize(
                     &dec, sizeof dec, WUFFS_VERSION,
                     WUFFS_INITIALIZE__LEAVE_INTERNAL_BUFFERS_UNINITIALIZED));

    wuffs_base__token_buffer tok = ((wuffs_base__token_buffer){
        .data = global_have_token_slice,
    });
    size_t n = strlen(test_cases[tc].str);
    wuffs_base__io_buffer src = ((wuffs_base__io_buffer){
        .data = wuffs_base__make_slice_u8((void*)(test_cases[tc].str), n),
        .meta = wuffs_base__make_io_buffer_meta(n, 0, 0, true),
    });

    wuffs_base__status have_status =
        wuffs_json__decoder__decode_tokens(&dec, &tok, &src);

    uint64_t total_length = 0;
    size_t i;
    for (i = tok.meta.ri; i < tok.meta.wi; i++) {
      wuffs_base__token* t = &tok.data.ptr[i];
      total_length =
          wuffs_base__u64__sat_add(total_length, wuffs_base__token__length(t));
    }

    if (have_status.repr != test_cases[tc].want_status_repr) {
      RETURN_FAIL("%s: have \"%s\", want \"%s\"", test_cases[tc].str,
                  have_status.repr, test_cases[tc].want_status_repr);
    }

    if (total_length != src.meta.ri) {
      RETURN_FAIL("%s: total length: have %" PRIu64 ", want %" PRIu64,
                  test_cases[tc].str, total_length, src.meta.ri);
    }
  }

  return NULL;
}

  // ---------------- Mimic Tests

#ifdef WUFFS_MIMIC

  // No mimic tests.

#endif  // WUFFS_MIMIC

// ---------------- JSON Benches

const char*  //
bench_wuffs_json_decode_1k() {
  CHECK_FOCUS(__func__);
  return do_bench_token_decoder(
      wuffs_json_decode, WUFFS_INITIALIZE__LEAVE_INTERNAL_BUFFERS_UNINITIALIZED,
      tcounter_src, &json_github_tags_gt, UINT64_MAX, UINT64_MAX, 10000);
}

const char*  //
bench_wuffs_json_decode_21k_formatted() {
  CHECK_FOCUS(__func__);
  return do_bench_token_decoder(
      wuffs_json_decode, WUFFS_INITIALIZE__LEAVE_INTERNAL_BUFFERS_UNINITIALIZED,
      tcounter_src, &json_file_sizes_gt, UINT64_MAX, UINT64_MAX, 300);
}

const char*  //
bench_wuffs_json_decode_26k_compact() {
  CHECK_FOCUS(__func__);
  return do_bench_token_decoder(
      wuffs_json_decode, WUFFS_INITIALIZE__LEAVE_INTERNAL_BUFFERS_UNINITIALIZED,
      tcounter_src, &json_australian_abc_gt, UINT64_MAX, UINT64_MAX, 250);
}

const char*  //
bench_wuffs_json_decode_217k_stringy() {
  CHECK_FOCUS(__func__);
  return do_bench_token_decoder(
      wuffs_json_decode, WUFFS_INITIALIZE__LEAVE_INTERNAL_BUFFERS_UNINITIALIZED,
      tcounter_src, &json_nobel_prizes_gt, UINT64_MAX, UINT64_MAX, 25);
}

  // ---------------- Mimic Benches

#ifdef WUFFS_MIMIC

  // No mimic benches.

#endif  // WUFFS_MIMIC

// ---------------- Manifest

// The empty comments forces clang-format to place one element per line.
proc tests[] = {

    // These strconv tests are really testing the Wuffs base library. They
    // aren't specific to the std/json code, but putting them here is as good
    // as any other place.
    test_strconv_parse_number_i64,  //
    test_strconv_parse_number_u64,  //
    test_strconv_utf_8_next,        //

    test_wuffs_json_decode_interface,          //
    test_wuffs_json_decode_prior_valid_utf_8,  //
    test_wuffs_json_decode_string,             //
    test_wuffs_json_decode_unicode4_escapes,   //

#ifdef WUFFS_MIMIC

// No mimic tests.

#endif  // WUFFS_MIMIC

    NULL,
};

// The empty comments forces clang-format to place one element per line.
proc benches[] = {

    bench_wuffs_json_decode_1k,             //
    bench_wuffs_json_decode_21k_formatted,  //
    bench_wuffs_json_decode_26k_compact,    //
    bench_wuffs_json_decode_217k_stringy,   //

#ifdef WUFFS_MIMIC

// No mimic benches.

#endif  // WUFFS_MIMIC

    NULL,
};

int  //
main(int argc, char** argv) {
  proc_package_name = "std/json";
  return test_main(argc, argv, tests, benches);
}