// Copyright 2018 The Cobalt Authors. All Rights Reserved.
//
// 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
//
//     http://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 "cobalt/browser/user_agent_string.h"

#include <vector>

#include "base/command_line.h"
#include "base/strings/string_util.h"
#include "base/strings/stringprintf.h"
#include "cobalt/browser/switches.h"
#if SB_IS(EVERGREEN)
#include "cobalt/extension/installation_manager.h"
#endif  // SB_IS(EVERGREEN)
#include "starboard/common/log.h"
#include "starboard/common/string.h"
#include "starboard/system.h"

namespace cobalt {
namespace browser {

namespace {

struct SanitizeReplacements {
  const char* replace_chars;
  const char* replace_with;
} kSanitizeReplacements[] = {
    {",", u8"\uFF0C"},  // fullwidth comma
    {"_", u8"\u2E0F"},  // paragraphos
    {"/", u8"\u2215"},  // division slash
    {"(", u8"\uFF08"},  // fullwidth left paren
    {")", u8"\uFF09"},  // fullwidth right paren
};

// Replace reserved characters with Unicode homoglyphs
std::string Sanitize(const std::string& str) {
  std::string clean(str);
  for (size_t i = 0; i < arraysize(kSanitizeReplacements); i++) {
    const SanitizeReplacements* replacement = kSanitizeReplacements + i;
    base::ReplaceChars(clean, replacement->replace_chars,
                       replacement->replace_with, &clean);
  }
  return clean;
}

}  // namespace

UserAgentPlatformInfo GetUserAgentPlatformInfoFromSystem() {
  UserAgentPlatformInfo platform_info;
  return platform_info;
}

// This function is expected to be deterministic and non-dependent on global
// variables and state.  If global state should be referenced, it should be done
// so during the creation of |platform_info| instead.
std::string CreateUserAgentString(const UserAgentPlatformInfo& platform_info) {
  // Cobalt's user agent contains the following sections:
  //   Mozilla/5.0 (ChromiumStylePlatform)
  //   Cobalt/Version.BuildNumber-BuildConfiguration (unlike Gecko)
  //   JavaScript Engine Name/Version
  //   Starboard/APIVersion,
  //   Device/FirmwareVersion (Brand, Model, ConnectionType)

  std::string os_name_and_version = platform_info.os_name_and_version();

#if defined(ENABLE_DEBUG_COMMAND_LINE_SWITCHES)
  // Because we add Cobalt's user agent string to Crashpad before we actually
  // start Cobalt, the command line won't be initialized when we first try to
  // get the user agent string.
  if (base::CommandLine::InitializedForCurrentProcess()) {
    base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
    if (command_line->HasSwitch(switches::kUserAgentOsNameVersion)) {
      os_name_and_version =
          command_line->GetSwitchValueASCII(switches::kUserAgentOsNameVersion);
    }
  }
#endif  // ENABLE_DEBUG_COMMAND_LINE_SWITCHES

  //   Mozilla/5.0 (ChromiumStylePlatform)
  std::string user_agent =
      base::StringPrintf("Mozilla/5.0 (%s)", os_name_and_version.c_str());

  //   Cobalt/Version.BuildNumber-BuildConfiguration (unlike Gecko)
  base::StringAppendF(&user_agent, " Cobalt/%s.%s-%s (unlike Gecko)",
                      platform_info.cobalt_version().c_str(),
                      platform_info.cobalt_build_version_number().c_str(),
                      platform_info.build_configuration().c_str());

  // JavaScript Engine Name/Version
  if (!platform_info.javascript_engine_version().empty()) {
    base::StringAppendF(&user_agent, " %s",
                        platform_info.javascript_engine_version().c_str());
  }

  // Rasterizer Type
  if (!platform_info.rasterizer_type().empty()) {
    base::StringAppendF(&user_agent, " %s",
                        platform_info.rasterizer_type().c_str());
  }

  // Evergreen version
  if (!platform_info.evergreen_version().empty()) {
    base::StringAppendF(&user_agent, " Evergreen/%s",
                        platform_info.evergreen_version().c_str());
#if SB_IS(EVERGREEN)
    if (!SbSystemGetExtension(kCobaltExtensionInstallationManagerName)) {
      // If the installation manager is not initialized, the "evergreen_lite"
      // command line parameter is specified and the system image is loaded.
      base::StringAppendF(&user_agent, " Evergreen-Lite");
    } else {
      base::StringAppendF(&user_agent, " Evergreen-Full");
    }
#endif  // SB_IS(EVERGREEN)
  }

  // Starboard/APIVersion,
  if (!platform_info.starboard_version().empty()) {
    base::StringAppendF(&user_agent, " %s",
                        platform_info.starboard_version().c_str());
  }

  // Device/FirmwareVersion (Brand, Model, ConnectionType)
  base::StringAppendF(
      &user_agent, ", %s_%s_%s_%s/%s (%s, %s, %s)",
      Sanitize(platform_info.original_design_manufacturer().value_or(""))
          .c_str(),
      platform_info.device_type_string().c_str(),
      Sanitize(platform_info.chipset_model_number().value_or("")).c_str(),
      Sanitize(platform_info.model_year().value_or("")).c_str(),
      Sanitize(platform_info.firmware_version().value_or("")).c_str(),
      Sanitize(platform_info.brand().value_or("")).c_str(),
      Sanitize(platform_info.model().value_or("")).c_str(),
      platform_info.connection_type_string().c_str());

  if (!platform_info.aux_field().empty()) {
    user_agent.append(" ");
    user_agent.append(platform_info.aux_field());
  }
  return user_agent;
}

}  // namespace browser
}  // namespace cobalt