//
//  Copyright 2019 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 <sstream>

#include "gtest/gtest.h"
#include "absl/flags/flag.h"
#include "absl/flags/parse.h"
#include "absl/flags/internal/path_util.h"
#include "absl/flags/internal/program_name.h"
#include "absl/flags/internal/usage.h"
#include "absl/flags/usage_config.h"
#include "absl/memory/memory.h"
#include "absl/strings/match.h"

ABSL_FLAG(int, usage_reporting_test_flag_01, 101,
          "usage_reporting_test_flag_01 help message");
ABSL_FLAG(bool, usage_reporting_test_flag_02, false,
          "usage_reporting_test_flag_02 help message");
ABSL_FLAG(double, usage_reporting_test_flag_03, 1.03,
          "usage_reporting_test_flag_03 help message");
ABSL_FLAG(int64_t, usage_reporting_test_flag_04, 1000000000000004L,
          "usage_reporting_test_flag_04 help message");

struct UDT {
  UDT() = default;
  UDT(const UDT&) = default;
};
bool AbslParseFlag(absl::string_view, UDT*, std::string*) { return true; }
std::string AbslUnparseFlag(const UDT&) { return "UDT{}"; }

ABSL_FLAG(UDT, usage_reporting_test_flag_05, {},
          "usage_reporting_test_flag_05 help message");

namespace {

namespace flags = absl::flags_internal;

static std::string NormalizeFileName(absl::string_view fname) {
#ifdef _WIN32
  std::string normalized(fname);
  std::replace(normalized.begin(), normalized.end(), '\\', '/');
  fname = normalized;
#endif

  auto absl_pos = fname.find("/absl/");
  if (absl_pos != absl::string_view::npos) {
    fname = fname.substr(absl_pos + 1);
  }
  return std::string(fname);
}

class UsageReportingTest : public testing::Test {
 protected:
  UsageReportingTest() {
    // Install default config for the use on this unit test.
    // Binary may install a custom config before tests are run.
    absl::FlagsUsageConfig default_config;
    default_config.normalize_filename = &NormalizeFileName;
    absl::SetFlagsUsageConfig(default_config);
  }

 private:
  flags::FlagSaver flag_saver_;
};

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

using UsageReportingDeathTest = UsageReportingTest;

TEST_F(UsageReportingDeathTest, TestSetProgramUsageMessage) {
  EXPECT_EQ(flags::ProgramUsageMessage(), "Custom usage message");

#ifndef _WIN32
  // TODO(rogeeff): figure out why this does not work on Windows.
  EXPECT_DEATH(flags::SetProgramUsageMessage("custom usage message"),
               ".*SetProgramUsageMessage\\(\\) called twice.*");
#endif
}

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

TEST_F(UsageReportingTest, TestFlagHelpHRF_on_flag_01) {
  const auto* flag = flags::FindCommandLineFlag("usage_reporting_test_flag_01");
  std::stringstream test_buf;

  flags::FlagHelp(test_buf, *flag, flags::HelpFormat::kHumanReadable);
  EXPECT_EQ(
      test_buf.str(),
      R"(    -usage_reporting_test_flag_01 (usage_reporting_test_flag_01 help message);
      default: 101;
)");
}

TEST_F(UsageReportingTest, TestFlagHelpHRF_on_flag_02) {
  const auto* flag = flags::FindCommandLineFlag("usage_reporting_test_flag_02");
  std::stringstream test_buf;

  flags::FlagHelp(test_buf, *flag, flags::HelpFormat::kHumanReadable);
  EXPECT_EQ(
      test_buf.str(),
      R"(    -usage_reporting_test_flag_02 (usage_reporting_test_flag_02 help message);
      default: false;
)");
}

TEST_F(UsageReportingTest, TestFlagHelpHRF_on_flag_03) {
  const auto* flag = flags::FindCommandLineFlag("usage_reporting_test_flag_03");
  std::stringstream test_buf;

  flags::FlagHelp(test_buf, *flag, flags::HelpFormat::kHumanReadable);
  EXPECT_EQ(
      test_buf.str(),
      R"(    -usage_reporting_test_flag_03 (usage_reporting_test_flag_03 help message);
      default: 1.03;
)");
}

TEST_F(UsageReportingTest, TestFlagHelpHRF_on_flag_04) {
  const auto* flag = flags::FindCommandLineFlag("usage_reporting_test_flag_04");
  std::stringstream test_buf;

  flags::FlagHelp(test_buf, *flag, flags::HelpFormat::kHumanReadable);
  EXPECT_EQ(
      test_buf.str(),
      R"(    -usage_reporting_test_flag_04 (usage_reporting_test_flag_04 help message);
      default: 1000000000000004;
)");
}

TEST_F(UsageReportingTest, TestFlagHelpHRF_on_flag_05) {
  const auto* flag = flags::FindCommandLineFlag("usage_reporting_test_flag_05");
  std::stringstream test_buf;

  flags::FlagHelp(test_buf, *flag, flags::HelpFormat::kHumanReadable);
  EXPECT_EQ(
      test_buf.str(),
      R"(    -usage_reporting_test_flag_05 (usage_reporting_test_flag_05 help message);
      default: UDT{};
)");
}

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

TEST_F(UsageReportingTest, TestFlagsHelpHRF) {
  std::string usage_test_flags_out =
      R"(usage_test: Custom usage message

  Flags from absl/flags/internal/usage_test.cc:
    -usage_reporting_test_flag_01 (usage_reporting_test_flag_01 help message);
      default: 101;
    -usage_reporting_test_flag_02 (usage_reporting_test_flag_02 help message);
      default: false;
    -usage_reporting_test_flag_03 (usage_reporting_test_flag_03 help message);
      default: 1.03;
    -usage_reporting_test_flag_04 (usage_reporting_test_flag_04 help message);
      default: 1000000000000004;
    -usage_reporting_test_flag_05 (usage_reporting_test_flag_05 help message);
      default: UDT{};
)";

  std::stringstream test_buf_01;
  flags::FlagsHelp(test_buf_01, "usage_test.cc",
                   flags::HelpFormat::kHumanReadable);
  EXPECT_EQ(test_buf_01.str(), usage_test_flags_out);

  std::stringstream test_buf_02;
  flags::FlagsHelp(test_buf_02, "flags/internal/usage_test.cc",
                   flags::HelpFormat::kHumanReadable);
  EXPECT_EQ(test_buf_02.str(), usage_test_flags_out);

  std::stringstream test_buf_03;
  flags::FlagsHelp(test_buf_03, "usage_test",
                   flags::HelpFormat::kHumanReadable);
  EXPECT_EQ(test_buf_03.str(), usage_test_flags_out);

  std::stringstream test_buf_04;
  flags::FlagsHelp(test_buf_04, "flags/invalid_file_name.cc",
                   flags::HelpFormat::kHumanReadable);
  EXPECT_EQ(test_buf_04.str(),
            R"(usage_test: Custom usage message

  No modules matched: use -helpfull
)");

  std::stringstream test_buf_05;
  flags::FlagsHelp(test_buf_05, "", flags::HelpFormat::kHumanReadable);
  std::string test_out = test_buf_05.str();
  absl::string_view test_out_str(test_out);
  EXPECT_TRUE(
      absl::StartsWith(test_out_str, "usage_test: Custom usage message"));
  EXPECT_TRUE(absl::StrContains(
      test_out_str, "Flags from absl/flags/internal/usage_test.cc:"));
  EXPECT_TRUE(absl::StrContains(test_out_str,
                                "Flags from absl/flags/internal/usage.cc:"));
  EXPECT_TRUE(
      absl::StrContains(test_out_str, "-usage_reporting_test_flag_01 "));
  EXPECT_TRUE(absl::StrContains(test_out_str, "-help (show help"))
      << test_out_str;
}

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

TEST_F(UsageReportingTest, TestNoUsageFlags) {
  std::stringstream test_buf;
  EXPECT_EQ(flags::HandleUsageFlags(test_buf), -1);
}

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

TEST_F(UsageReportingTest, TestUsageFlag_helpshort) {
  absl::SetFlag(&FLAGS_helpshort, true);

  std::stringstream test_buf;
  EXPECT_EQ(flags::HandleUsageFlags(test_buf), 1);
  EXPECT_EQ(test_buf.str(),
            R"(usage_test: Custom usage message

  Flags from absl/flags/internal/usage_test.cc:
    -usage_reporting_test_flag_01 (usage_reporting_test_flag_01 help message);
      default: 101;
    -usage_reporting_test_flag_02 (usage_reporting_test_flag_02 help message);
      default: false;
    -usage_reporting_test_flag_03 (usage_reporting_test_flag_03 help message);
      default: 1.03;
    -usage_reporting_test_flag_04 (usage_reporting_test_flag_04 help message);
      default: 1000000000000004;
    -usage_reporting_test_flag_05 (usage_reporting_test_flag_05 help message);
      default: UDT{};
)");
}

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

TEST_F(UsageReportingTest, TestUsageFlag_help) {
  absl::SetFlag(&FLAGS_help, true);

  std::stringstream test_buf;
  EXPECT_EQ(flags::HandleUsageFlags(test_buf), 1);
  EXPECT_EQ(test_buf.str(),
            R"(usage_test: Custom usage message

  Flags from absl/flags/internal/usage_test.cc:
    -usage_reporting_test_flag_01 (usage_reporting_test_flag_01 help message);
      default: 101;
    -usage_reporting_test_flag_02 (usage_reporting_test_flag_02 help message);
      default: false;
    -usage_reporting_test_flag_03 (usage_reporting_test_flag_03 help message);
      default: 1.03;
    -usage_reporting_test_flag_04 (usage_reporting_test_flag_04 help message);
      default: 1000000000000004;
    -usage_reporting_test_flag_05 (usage_reporting_test_flag_05 help message);
      default: UDT{};

Try --helpfull to get a list of all flags.
)");
}

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

TEST_F(UsageReportingTest, TestUsageFlag_helppackage) {
  absl::SetFlag(&FLAGS_helppackage, true);

  std::stringstream test_buf;
  EXPECT_EQ(flags::HandleUsageFlags(test_buf), 1);
  EXPECT_EQ(test_buf.str(),
            R"(usage_test: Custom usage message

  Flags from absl/flags/internal/usage_test.cc:
    -usage_reporting_test_flag_01 (usage_reporting_test_flag_01 help message);
      default: 101;
    -usage_reporting_test_flag_02 (usage_reporting_test_flag_02 help message);
      default: false;
    -usage_reporting_test_flag_03 (usage_reporting_test_flag_03 help message);
      default: 1.03;
    -usage_reporting_test_flag_04 (usage_reporting_test_flag_04 help message);
      default: 1000000000000004;
    -usage_reporting_test_flag_05 (usage_reporting_test_flag_05 help message);
      default: UDT{};

Try --helpfull to get a list of all flags.
)");
}

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

TEST_F(UsageReportingTest, TestUsageFlag_version) {
  absl::SetFlag(&FLAGS_version, true);

  std::stringstream test_buf;
  EXPECT_EQ(flags::HandleUsageFlags(test_buf), 0);
#ifndef NDEBUG
  EXPECT_EQ(test_buf.str(),
            "usage_test\nDebug build (NDEBUG not #defined)\n");
#else
  EXPECT_EQ(test_buf.str(), "usage_test\n");
#endif
}

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

TEST_F(UsageReportingTest, TestUsageFlag_only_check_args) {
  absl::SetFlag(&FLAGS_only_check_args, true);

  std::stringstream test_buf;
  EXPECT_EQ(flags::HandleUsageFlags(test_buf), 0);
  EXPECT_EQ(test_buf.str(), "");
}

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

TEST_F(UsageReportingTest, TestUsageFlag_helpon) {
  absl::SetFlag(&FLAGS_helpon, "bla-bla");

  std::stringstream test_buf_01;
  EXPECT_EQ(flags::HandleUsageFlags(test_buf_01), 1);
  EXPECT_EQ(test_buf_01.str(),
            R"(usage_test: Custom usage message

  No modules matched: use -helpfull
)");

  absl::SetFlag(&FLAGS_helpon, "usage_test");

  std::stringstream test_buf_02;
  EXPECT_EQ(flags::HandleUsageFlags(test_buf_02), 1);
  EXPECT_EQ(test_buf_02.str(),
            R"(usage_test: Custom usage message

  Flags from absl/flags/internal/usage_test.cc:
    -usage_reporting_test_flag_01 (usage_reporting_test_flag_01 help message);
      default: 101;
    -usage_reporting_test_flag_02 (usage_reporting_test_flag_02 help message);
      default: false;
    -usage_reporting_test_flag_03 (usage_reporting_test_flag_03 help message);
      default: 1.03;
    -usage_reporting_test_flag_04 (usage_reporting_test_flag_04 help message);
      default: 1000000000000004;
    -usage_reporting_test_flag_05 (usage_reporting_test_flag_05 help message);
      default: UDT{};
)");
}

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

}  // namespace

int main(int argc, char* argv[]) {
  absl::GetFlag(FLAGS_undefok);  // Force linking of parse.cc
  flags::SetProgramInvocationName("usage_test");
  flags::SetProgramUsageMessage("Custom usage message");
  ::testing::InitGoogleTest(&argc, argv);

  return RUN_ALL_TESTS();
}
