//

//  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 "absl/flags/usage_config.h"

#include <functional>

#include <iostream>

#include <string>

#include "absl/base/attributes.h"

#include "absl/base/config.h"

#include "absl/base/const_init.h"

#include "absl/base/thread_annotations.h"

#include "absl/flags/internal/path_util.h"

#include "absl/flags/internal/program_name.h"

#include "absl/strings/match.h"

#include "absl/strings/string_view.h"

#include "absl/strings/strip.h"

#include "absl/synchronization/mutex.h"

extern "C" {

// Additional report of fatal usage error message before we std::exit. Error is

// fatal if is_fatal argument to ReportUsageError is true.

ABSL_ATTRIBUTE_WEAK void ABSL_INTERNAL_C_SYMBOL(

    AbslInternalReportFatalUsageError)(absl::string_view) {}

}  // extern "C"

namespace absl {

ABSL_NAMESPACE_BEGIN

namespace flags_internal {

namespace {

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

// Returns true if flags defined in the filename should be reported with

// -helpshort flag.

bool ContainsHelpshortFlags(absl::string_view filename) {

  // By default we only want flags in binary's main. We expect the main

  // routine to reside in <program>.cc or <program>-main.cc or

  // <program>_main.cc, where the <program> is the name of the binary

  // (without .exe on Windows).

  auto suffix = flags_internal::Basename(filename);

  auto program_name = flags_internal::ShortProgramInvocationName();

  absl::string_view program_name_ref = program_name;

#if defined(_WIN32)

  absl::ConsumeSuffix(&program_name_ref, ".exe");

#endif

  if (!absl::ConsumePrefix(&suffix, program_name_ref))

    return false;

  return absl::StartsWith(suffix, ".") || absl::StartsWith(suffix, "-main.") ||

         absl::StartsWith(suffix, "_main.");

}

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

// Returns true if flags defined in the filename should be reported with

// -helppackage flag.

bool ContainsHelppackageFlags(absl::string_view filename) {

  // TODO(rogeeff): implement properly when registry is available.

  return ContainsHelpshortFlags(filename);

}

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

// Generates program version information into supplied output.

std::string VersionString() {

  std::string version_str(flags_internal::ShortProgramInvocationName());

  version_str += "\n";

#if !defined(NDEBUG)

  version_str += "Debug build (NDEBUG not #defined)\n";

#endif

  return version_str;

}

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

// Normalizes the filename specific to the build system/filesystem used.

std::string NormalizeFilename(absl::string_view filename) {

  // Skip any leading slashes

  auto pos = filename.find_first_not_of("\\/");

  if (pos == absl::string_view::npos) return "";

  filename.remove_prefix(pos);

  return std::string(filename);

}

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

ABSL_CONST_INIT absl::Mutex custom_usage_config_guard(absl::kConstInit);

ABSL_CONST_INIT FlagsUsageConfig* custom_usage_config

    ABSL_GUARDED_BY(custom_usage_config_guard) = nullptr;

}  // namespace

FlagsUsageConfig GetUsageConfig() {

  absl::MutexLock l(&custom_usage_config_guard);

  if (custom_usage_config) return *custom_usage_config;

  FlagsUsageConfig default_config;

  default_config.contains_helpshort_flags = &ContainsHelpshortFlags;

  default_config.contains_help_flags = &ContainsHelppackageFlags;

  default_config.contains_helppackage_flags = &ContainsHelppackageFlags;

  default_config.version_string = &VersionString;

  default_config.normalize_filename = &NormalizeFilename;

  return default_config;

}

void ReportUsageError(absl::string_view msg, bool is_fatal) {

  std::cerr << "ERROR: " << msg << std::endl;

  if (is_fatal) {

    ABSL_INTERNAL_C_SYMBOL(AbslInternalReportFatalUsageError)(msg);

  }

}

}  // namespace flags_internal

void SetFlagsUsageConfig(FlagsUsageConfig usage_config) {

  absl::MutexLock l(&flags_internal::custom_usage_config_guard);

  if (!usage_config.contains_helpshort_flags)

    usage_config.contains_helpshort_flags =

        flags_internal::ContainsHelpshortFlags;

  if (!usage_config.contains_help_flags)

    usage_config.contains_help_flags = flags_internal::ContainsHelppackageFlags;

  if (!usage_config.contains_helppackage_flags)

    usage_config.contains_helppackage_flags =

        flags_internal::ContainsHelppackageFlags;

  if (!usage_config.version_string)

    usage_config.version_string = flags_internal::VersionString;

  if (!usage_config.normalize_filename)

    usage_config.normalize_filename = flags_internal::NormalizeFilename;

  if (flags_internal::custom_usage_config)

    *flags_internal::custom_usage_config = usage_config;

  else

    flags_internal::custom_usage_config = new FlagsUsageConfig(usage_config);

}

ABSL_NAMESPACE_END

}  // namespace absl