// Copyright 2020 The Abseil 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.

#include "absl/strings/internal/str_format/parser.h"

#include <string.h>
#include <algorithm>
#include <initializer_list>
#include <string>
#include <utility>

#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "absl/base/config.h"
#include "absl/base/macros.h"
#include "absl/strings/internal/str_format/constexpr_parser.h"
#include "absl/strings/internal/str_format/extension.h"
#include "absl/strings/string_view.h"

namespace absl {
ABSL_NAMESPACE_BEGIN
namespace str_format_internal {

namespace {

using testing::Pair;

TEST(LengthModTest, Names) {
  struct Expectation {
    int line;
    LengthMod mod;
    const char *name;
  };
  const Expectation kExpect[] = {
    {__LINE__, LengthMod::none, ""  },
    {__LINE__, LengthMod::h,    "h" },
    {__LINE__, LengthMod::hh,   "hh"},
    {__LINE__, LengthMod::l,    "l" },
    {__LINE__, LengthMod::ll,   "ll"},
    {__LINE__, LengthMod::L,    "L" },
    {__LINE__, LengthMod::j,    "j" },
    {__LINE__, LengthMod::z,    "z" },
    {__LINE__, LengthMod::t,    "t" },
    {__LINE__, LengthMod::q,    "q" },
  };
  EXPECT_EQ(ABSL_ARRAYSIZE(kExpect), 10);
  for (auto e : kExpect) {
    SCOPED_TRACE(e.line);
    EXPECT_EQ(e.name, LengthModToString(e.mod));
  }
}

TEST(ConversionCharTest, Names) {
  struct Expectation {
    FormatConversionChar id;
    char name;
  };
  // clang-format off
  const Expectation kExpect[] = {
#define X(c) {FormatConversionCharInternal::c, #c[0]}
    X(c), X(s),                                      // text
    X(d), X(i), X(o), X(u), X(x), X(X),              // int
    X(f), X(F), X(e), X(E), X(g), X(G), X(a), X(A),  // float
    X(n), X(p),                                      // misc
#undef X
    {FormatConversionCharInternal::kNone, '\0'},
  };
  // clang-format on
  for (auto e : kExpect) {
    SCOPED_TRACE(e.name);
    FormatConversionChar v = e.id;
    EXPECT_EQ(e.name, FormatConversionCharToChar(v));
  }
}

class ConsumeUnboundConversionTest : public ::testing::Test {
 public:
  std::pair<string_view, string_view> Consume(string_view src) {
    int next = 0;
    o = UnboundConversion();  // refresh
    const char* p = ConsumeUnboundConversion(
        src.data(), src.data() + src.size(), &o, &next);
    if (!p) return {{}, src};
    return {string_view(src.data(), p - src.data()),
            string_view(p, src.data() + src.size() - p)};
  }

  bool Run(const char *fmt, bool force_positional = false) {
    int next = force_positional ? -1 : 0;
    o = UnboundConversion();  // refresh
    return ConsumeUnboundConversion(fmt, fmt + strlen(fmt), &o, &next) ==
           fmt + strlen(fmt);
  }
  UnboundConversion o;
};

TEST_F(ConsumeUnboundConversionTest, ConsumeSpecification) {
  struct Expectation {
    int line;
    string_view src;
    string_view out;
    string_view src_post;
  };
  const Expectation kExpect[] = {
    {__LINE__, "",     "",     ""  },
    {__LINE__, "b",    "",     "b" },  // 'b' is invalid
    {__LINE__, "ba",   "",     "ba"},  // 'b' is invalid
    {__LINE__, "l",    "",     "l" },  // just length mod isn't okay
    {__LINE__, "d",    "d",    ""  },  // basic
    {__LINE__, "v",    "v",    ""  },  // basic
    {__LINE__, "d ",   "d",    " " },  // leave suffix
    {__LINE__, "dd",   "d",    "d" },  // don't be greedy
    {__LINE__, "d9",   "d",    "9" },  // leave non-space suffix
    {__LINE__, "dzz",  "d",    "zz"},  // length mod as suffix
    {__LINE__, "3v",   "",     "3v"},  // 'v' cannot have modifiers
    {__LINE__, "hv",   "",     "hv"},  // 'v' cannot have modifiers
    {__LINE__, "1$v",   "1$v",     ""},  // 'v' can have use posix syntax
    {__LINE__, "1$*2$d", "1$*2$d", ""  },  // arg indexing and * allowed.
    {__LINE__, "0-14.3hhd", "0-14.3hhd", ""},  // precision, width
    {__LINE__, " 0-+#14.3hhd", " 0-+#14.3hhd", ""},  // flags
  };
  for (const auto& e : kExpect) {
    SCOPED_TRACE(e.line);
    EXPECT_THAT(Consume(e.src), Pair(e.out, e.src_post));
  }
}

TEST_F(ConsumeUnboundConversionTest, BasicConversion) {
  EXPECT_FALSE(Run(""));
  EXPECT_FALSE(Run("z"));

  EXPECT_FALSE(Run("dd"));  // no excess allowed

  EXPECT_TRUE(Run("d"));
  EXPECT_EQ('d', FormatConversionCharToChar(o.conv));
  EXPECT_FALSE(o.width.is_from_arg());
  EXPECT_LT(o.width.value(), 0);
  EXPECT_FALSE(o.precision.is_from_arg());
  EXPECT_LT(o.precision.value(), 0);
  EXPECT_EQ(1, o.arg_position);
}

TEST_F(ConsumeUnboundConversionTest, ArgPosition) {
  EXPECT_TRUE(Run("d"));
  EXPECT_EQ(1, o.arg_position);
  EXPECT_TRUE(Run("3$d"));
  EXPECT_EQ(3, o.arg_position);
  EXPECT_TRUE(Run("1$d"));
  EXPECT_EQ(1, o.arg_position);
  EXPECT_TRUE(Run("1$d", true));
  EXPECT_EQ(1, o.arg_position);
  EXPECT_TRUE(Run("123$d"));
  EXPECT_EQ(123, o.arg_position);
  EXPECT_TRUE(Run("123$d", true));
  EXPECT_EQ(123, o.arg_position);
  EXPECT_TRUE(Run("10$d"));
  EXPECT_EQ(10, o.arg_position);
  EXPECT_TRUE(Run("10$d", true));
  EXPECT_EQ(10, o.arg_position);

  // Position can't be zero.
  EXPECT_FALSE(Run("0$d"));
  EXPECT_FALSE(Run("0$d", true));
  EXPECT_FALSE(Run("1$*0$d"));
  EXPECT_FALSE(Run("1$.*0$d"));

  // Position can't start with a zero digit at all. That is not a 'decimal'.
  EXPECT_FALSE(Run("01$p"));
  EXPECT_FALSE(Run("01$p", true));
  EXPECT_FALSE(Run("1$*01$p"));
  EXPECT_FALSE(Run("1$.*01$p"));
}

TEST_F(ConsumeUnboundConversionTest, WidthAndPrecision) {
  EXPECT_TRUE(Run("14d"));
  EXPECT_EQ('d', FormatConversionCharToChar(o.conv));
  EXPECT_FALSE(o.width.is_from_arg());
  EXPECT_EQ(14, o.width.value());
  EXPECT_FALSE(o.precision.is_from_arg());
  EXPECT_LT(o.precision.value(), 0);

  EXPECT_TRUE(Run("14.d"));
  EXPECT_FALSE(o.width.is_from_arg());
  EXPECT_FALSE(o.precision.is_from_arg());
  EXPECT_EQ(14, o.width.value());
  EXPECT_EQ(0, o.precision.value());

  EXPECT_TRUE(Run(".d"));
  EXPECT_FALSE(o.width.is_from_arg());
  EXPECT_LT(o.width.value(), 0);
  EXPECT_FALSE(o.precision.is_from_arg());
  EXPECT_EQ(0, o.precision.value());

  EXPECT_TRUE(Run(".5d"));
  EXPECT_FALSE(o.width.is_from_arg());
  EXPECT_LT(o.width.value(), 0);
  EXPECT_FALSE(o.precision.is_from_arg());
  EXPECT_EQ(5, o.precision.value());

  EXPECT_TRUE(Run(".0d"));
  EXPECT_FALSE(o.width.is_from_arg());
  EXPECT_LT(o.width.value(), 0);
  EXPECT_FALSE(o.precision.is_from_arg());
  EXPECT_EQ(0, o.precision.value());

  EXPECT_TRUE(Run("14.5d"));
  EXPECT_FALSE(o.width.is_from_arg());
  EXPECT_FALSE(o.precision.is_from_arg());
  EXPECT_EQ(14, o.width.value());
  EXPECT_EQ(5, o.precision.value());

  EXPECT_TRUE(Run("*.*d"));
  EXPECT_TRUE(o.width.is_from_arg());
  EXPECT_EQ(1, o.width.get_from_arg());
  EXPECT_TRUE(o.precision.is_from_arg());
  EXPECT_EQ(2, o.precision.get_from_arg());
  EXPECT_EQ(3, o.arg_position);

  EXPECT_TRUE(Run("*d"));
  EXPECT_TRUE(o.width.is_from_arg());
  EXPECT_EQ(1, o.width.get_from_arg());
  EXPECT_FALSE(o.precision.is_from_arg());
  EXPECT_LT(o.precision.value(), 0);
  EXPECT_EQ(2, o.arg_position);

  EXPECT_TRUE(Run(".*d"));
  EXPECT_FALSE(o.width.is_from_arg());
  EXPECT_LT(o.width.value(), 0);
  EXPECT_TRUE(o.precision.is_from_arg());
  EXPECT_EQ(1, o.precision.get_from_arg());
  EXPECT_EQ(2, o.arg_position);

  // mixed implicit and explicit: didn't specify arg position.
  EXPECT_FALSE(Run("*23$.*34$d"));

  EXPECT_TRUE(Run("12$*23$.*34$d"));
  EXPECT_EQ(12, o.arg_position);
  EXPECT_TRUE(o.width.is_from_arg());
  EXPECT_EQ(23, o.width.get_from_arg());
  EXPECT_TRUE(o.precision.is_from_arg());
  EXPECT_EQ(34, o.precision.get_from_arg());

  EXPECT_TRUE(Run("2$*5$.*9$d"));
  EXPECT_EQ(2, o.arg_position);
  EXPECT_TRUE(o.width.is_from_arg());
  EXPECT_EQ(5, o.width.get_from_arg());
  EXPECT_TRUE(o.precision.is_from_arg());
  EXPECT_EQ(9, o.precision.get_from_arg());

  EXPECT_FALSE(Run(".*0$d")) << "no arg 0";

  // Large values
  EXPECT_TRUE(Run("999999999.999999999d"));
  EXPECT_FALSE(o.width.is_from_arg());
  EXPECT_EQ(999999999, o.width.value());
  EXPECT_FALSE(o.precision.is_from_arg());
  EXPECT_EQ(999999999, o.precision.value());

  EXPECT_FALSE(Run("1000000000.999999999d"));
  EXPECT_FALSE(Run("999999999.1000000000d"));
  EXPECT_FALSE(Run("9999999999d"));
  EXPECT_FALSE(Run(".9999999999d"));
}

TEST_F(ConsumeUnboundConversionTest, Flags) {
  static const char kAllFlags[] = "-+ #0";
  static const int kNumFlags = ABSL_ARRAYSIZE(kAllFlags) - 1;
  for (int rev = 0; rev < 2; ++rev) {
    for (int i = 0; i < 1 << kNumFlags; ++i) {
      std::string fmt;
      for (int k = 0; k < kNumFlags; ++k)
        if ((i >> k) & 1) fmt += kAllFlags[k];
      // flag order shouldn't matter
      if (rev == 1) {
        std::reverse(fmt.begin(), fmt.end());
      }
      fmt += 'd';
      SCOPED_TRACE(fmt);
      EXPECT_TRUE(Run(fmt.c_str()));
      EXPECT_EQ(fmt.find('-') == std::string::npos,
                !FlagsContains(o.flags, Flags::kLeft));
      EXPECT_EQ(fmt.find('+') == std::string::npos,
                !FlagsContains(o.flags, Flags::kShowPos));
      EXPECT_EQ(fmt.find(' ') == std::string::npos,
                !FlagsContains(o.flags, Flags::kSignCol));
      EXPECT_EQ(fmt.find('#') == std::string::npos,
                !FlagsContains(o.flags, Flags::kAlt));
      EXPECT_EQ(fmt.find('0') == std::string::npos,
                !FlagsContains(o.flags, Flags::kZero));
    }
  }
}

TEST_F(ConsumeUnboundConversionTest, BasicFlag) {
  // Flag is on
  for (const char* fmt : {"d", "llx", "G", "1$X"}) {
    SCOPED_TRACE(fmt);
    EXPECT_TRUE(Run(fmt));
    EXPECT_EQ(o.flags, Flags::kBasic);
  }

  // Flag is off
  for (const char* fmt : {"3d", ".llx", "-G", "1$#X", "lc"}) {
    SCOPED_TRACE(fmt);
    EXPECT_TRUE(Run(fmt));
    EXPECT_NE(o.flags, Flags::kBasic);
  }
}

TEST_F(ConsumeUnboundConversionTest, LengthMod) {
  EXPECT_TRUE(Run("d"));
  EXPECT_EQ(LengthMod::none, o.length_mod);
  EXPECT_TRUE(Run("hd"));
  EXPECT_EQ(LengthMod::h, o.length_mod);
  EXPECT_TRUE(Run("hhd"));
  EXPECT_EQ(LengthMod::hh, o.length_mod);
  EXPECT_TRUE(Run("ld"));
  EXPECT_EQ(LengthMod::l, o.length_mod);
  EXPECT_TRUE(Run("lld"));
  EXPECT_EQ(LengthMod::ll, o.length_mod);
  EXPECT_TRUE(Run("Lf"));
  EXPECT_EQ(LengthMod::L, o.length_mod);
  EXPECT_TRUE(Run("qf"));
  EXPECT_EQ(LengthMod::q, o.length_mod);
  EXPECT_TRUE(Run("jd"));
  EXPECT_EQ(LengthMod::j, o.length_mod);
  EXPECT_TRUE(Run("zd"));
  EXPECT_EQ(LengthMod::z, o.length_mod);
  EXPECT_TRUE(Run("td"));
  EXPECT_EQ(LengthMod::t, o.length_mod);
}

struct SummarizeConsumer {
  std::string* out;
  explicit SummarizeConsumer(std::string* out) : out(out) {}

  bool Append(string_view s) {
    *out += "[" + std::string(s) + "]";
    return true;
  }

  bool ConvertOne(const UnboundConversion& conv, string_view s) {
    *out += "{";
    *out += std::string(s);
    *out += ":";
    *out += std::to_string(conv.arg_position) + "$";
    if (conv.width.is_from_arg()) {
      *out += std::to_string(conv.width.get_from_arg()) + "$*";
    }
    if (conv.precision.is_from_arg()) {
      *out += "." + std::to_string(conv.precision.get_from_arg()) + "$*";
    }
    *out += FormatConversionCharToChar(conv.conv);
    *out += "}";
    return true;
  }
};

std::string SummarizeParsedFormat(const ParsedFormatBase& pc) {
  std::string out;
  if (!pc.ProcessFormat(SummarizeConsumer(&out))) out += "!";
  return out;
}

class ParsedFormatTest : public testing::Test {};

TEST_F(ParsedFormatTest, ValueSemantics) {
  ParsedFormatBase p1({}, true, {});  // empty format
  EXPECT_EQ("", SummarizeParsedFormat(p1));

  ParsedFormatBase p2 = p1;  // copy construct (empty)
  EXPECT_EQ(SummarizeParsedFormat(p1), SummarizeParsedFormat(p2));

  p1 = ParsedFormatBase("hello%s", true,
                        {FormatConversionCharSetInternal::s});  // move assign
  EXPECT_EQ("[hello]{s:1$s}", SummarizeParsedFormat(p1));

  ParsedFormatBase p3 = p1;  // copy construct (nonempty)
  EXPECT_EQ(SummarizeParsedFormat(p1), SummarizeParsedFormat(p3));

  using std::swap;
  swap(p1, p2);
  EXPECT_EQ("", SummarizeParsedFormat(p1));
  EXPECT_EQ("[hello]{s:1$s}", SummarizeParsedFormat(p2));
  swap(p1, p2);  // undo

  p2 = p1;  // copy assign
  EXPECT_EQ(SummarizeParsedFormat(p1), SummarizeParsedFormat(p2));
}

struct ExpectParse {
  const char* in;
  std::initializer_list<FormatConversionCharSet> conv_set;
  const char* out;
};

TEST_F(ParsedFormatTest, Parsing) {
  // Parse should be equivalent to that obtained by ConversionParseIterator.
  // No need to retest the parsing edge cases here.
  const ExpectParse kExpect[] = {
      {"", {}, ""},
      {"ab", {}, "[ab]"},
      {"a%d", {FormatConversionCharSetInternal::d}, "[a]{d:1$d}"},
      {"a%+d", {FormatConversionCharSetInternal::d}, "[a]{+d:1$d}"},
      {"a% d", {FormatConversionCharSetInternal::d}, "[a]{ d:1$d}"},
      {"a%b %d", {}, "[a]!"},  // stop after error
  };
  for (const auto& e : kExpect) {
    SCOPED_TRACE(e.in);
    EXPECT_EQ(e.out,
              SummarizeParsedFormat(ParsedFormatBase(e.in, false, e.conv_set)));
  }
}

TEST_F(ParsedFormatTest, ParsingFlagOrder) {
  const ExpectParse kExpect[] = {
      {"a%+ 0d", {FormatConversionCharSetInternal::d}, "[a]{+ 0d:1$d}"},
      {"a%+0 d", {FormatConversionCharSetInternal::d}, "[a]{+0 d:1$d}"},
      {"a%0+ d", {FormatConversionCharSetInternal::d}, "[a]{0+ d:1$d}"},
      {"a% +0d", {FormatConversionCharSetInternal::d}, "[a]{ +0d:1$d}"},
      {"a%0 +d", {FormatConversionCharSetInternal::d}, "[a]{0 +d:1$d}"},
      {"a% 0+d", {FormatConversionCharSetInternal::d}, "[a]{ 0+d:1$d}"},
      {"a%+   0+d", {FormatConversionCharSetInternal::d}, "[a]{+   0+d:1$d}"},
  };
  for (const auto& e : kExpect) {
    SCOPED_TRACE(e.in);
    EXPECT_EQ(e.out,
              SummarizeParsedFormat(ParsedFormatBase(e.in, false, e.conv_set)));
  }
}

}  // namespace
}  // namespace str_format_internal
ABSL_NAMESPACE_END
}  // namespace absl