// Copyright 2024 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/on_device_translation/component_manager.h"

#include "base/command_line.h"
#include "base/memory/raw_ptr.h"
#include "base/no_destructor.h"
#include "base/path_service.h"
#include "base/strings/string_split.h"
#include "base/strings/string_util.h"
#include "build/build_config.h"
#include "chrome/browser/browser_process.h"
#include "chrome/browser/component_updater/translate_kit_component_installer.h"
#include "chrome/browser/component_updater/translate_kit_language_pack_component_installer.h"
#include "chrome/browser/on_device_translation/constants.h"
#include "chrome/browser/on_device_translation/language_pack_util.h"
#include "chrome/browser/on_device_translation/pref_names.h"
#include "components/component_updater/component_updater_paths.h"
#include "components/services/on_device_translation/public/cpp/features.h"
#include "components/services/on_device_translation/public/mojom/on_device_translation_service.mojom.h"

#if BUILDFLAG(IS_WIN)
#include "base/strings/utf_string_conversions.h"
#endif  // BUILDFLAG(IS_WIN)

namespace on_device_translation {
namespace {

const char kTranslateKitPackagePaths[] = "translate-kit-packages";

base::FilePath GetFilePathFromGlobalPrefs(std::string_view pref_name) {
  PrefService* global_prefs = g_browser_process->local_state();
  CHECK(global_prefs);
  base::FilePath path_in_pref = global_prefs->GetFilePath(pref_name);
  return path_in_pref;
}

bool GetBooleanFromGlobalPrefs(std::string_view pref_name) {
  PrefService* global_prefs = g_browser_process->local_state();
  CHECK(global_prefs);
  return global_prefs->GetBoolean(pref_name);
}

// The implementation of ComponentManager.
class ComponentManagerImpl : public ComponentManager {
 public:
  ComponentManagerImpl(const ComponentManagerImpl&) = delete;
  ComponentManagerImpl& operator=(const ComponentManagerImpl&) = delete;

  void RegisterTranslateKitComponentImpl() override {
    // Registers the TranslateKit component.
    component_updater::RegisterTranslateKitComponent(
        g_browser_process->component_updater(),
        g_browser_process->local_state(),
        /*force_install=*/true,
        /*registered_callback=*/
        base::BindOnce(
            &component_updater::TranslateKitComponentInstallerPolicy::
                UpdateComponentOnDemand));
  }

  void RegisterTranslateKitLanguagePackComponent(
      LanguagePackKey language_pack) override {
    // Registers the TranslateKit language pack component.
    component_updater::RegisterTranslateKitLanguagePackComponent(
        g_browser_process->component_updater(),
        g_browser_process->local_state(), language_pack,
        base::BindOnce(&component_updater::
                           TranslateKitLanguagePackComponentInstallerPolicy::
                               UpdateComponentOnDemand,
                       language_pack));
  }

  void UninstallTranslateKitLanguagePackComponent(
      LanguagePackKey language_pack) override {
    // Uninstalls the TranslateKit language pack component.
    component_updater::UninstallTranslateKitLanguagePackComponent(
        g_browser_process->component_updater(),
        g_browser_process->local_state(), language_pack);
  }

  base::FilePath GetTranslateKitComponentPathImpl() override {
    // Returns the path from the component updater.
    base::FilePath components_dir;
    base::PathService::Get(component_updater::DIR_COMPONENT_USER,
                           &components_dir);
    CHECK(!components_dir.empty());
    return components_dir.Append(kTranslateKitBinaryInstallationRelativeDir);
  }

 private:
  friend base::NoDestructor<ComponentManagerImpl>;
  ComponentManagerImpl() = default;
  ~ComponentManagerImpl() override = default;
};

}  // namespace

// static
ComponentManager* ComponentManager::component_manager_for_test_ = nullptr;

// static
ComponentManager& ComponentManager::GetInstance() {
  // If there is a testing manager, use it.
  if (component_manager_for_test_) {
    return *component_manager_for_test_;
  }
  // Otherwise, use the production manager.
  static base::NoDestructor<ComponentManagerImpl> instance;
  return *instance.get();
}

// static
base::AutoReset<ComponentManager*> ComponentManager::SetForTesting(
    ComponentManager* manager) {
  return base::AutoReset<ComponentManager*>(&component_manager_for_test_,
                                            manager);
}

ComponentManager::ComponentManager()
    : language_packs_from_command_line_(GetLanguagePackInfoFromCommandLine()) {}

ComponentManager::~ComponentManager() = default;

bool ComponentManager::RegisterTranslateKitComponent() {
  // Only register the component once.
  if (translate_kit_component_registered_) {
    return false;
  }
  translate_kit_component_registered_ = true;
  RegisterTranslateKitComponentImpl();
  return true;
}

// static
std::set<LanguagePackKey> ComponentManager::GetRegisteredLanguagePacks() {
  std::set<LanguagePackKey> registered_pack_keys;
  for (const auto& it : kLanguagePackComponentConfigMap) {
    if (GetBooleanFromGlobalPrefs(GetRegisteredFlagPrefName(*it.second))) {
      registered_pack_keys.insert(it.first);
    }
  }
  return registered_pack_keys;
}

// static
std::set<LanguagePackKey> ComponentManager::GetInstalledLanguagePacks() {
  std::set<LanguagePackKey> installed_pack_keys;
  for (const auto& it : kLanguagePackComponentConfigMap) {
    if (!GetFilePathFromGlobalPrefs(GetComponentPathPrefName(*it.second))
             .empty()) {
      installed_pack_keys.insert(it.first);
    }
  }
  return installed_pack_keys;
}

// static
base::FilePath ComponentManager::GetTranslateKitLibraryPath() {
  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
  if (command_line->HasSwitch(kTranslateKitBinaryPath)) {
    return command_line->GetSwitchValuePath(kTranslateKitBinaryPath);
  }
  return GetFilePathFromGlobalPrefs(prefs::kTranslateKitBinaryPath);
}

// static
bool ComponentManager::HasTranslateKitLibraryPathFromCommandLine() {
  return base::CommandLine::ForCurrentProcess()->HasSwitch(
      kTranslateKitBinaryPath);
}

base::FilePath ComponentManager::GetTranslateKitComponentPath() {
  // If the path is specified from the command line, use it.
  auto path_from_command_line = GetTranslateKitBinaryPathFromCommandLine();
  if (!path_from_command_line.empty()) {
    return path_from_command_line;
  }
  return GetTranslateKitComponentPathImpl();
}

void ComponentManager::GetLanguagePackInfo(
    std::vector<mojom::OnDeviceTranslationLanguagePackagePtr>& packages,
    std::vector<base::FilePath>& package_pathes) {
  CHECK(packages.empty());
  CHECK(package_pathes.empty());
  if (language_packs_from_command_line_) {
    for (const auto& package : *language_packs_from_command_line_) {
      packages.push_back(mojom::OnDeviceTranslationLanguagePackage::New(
          package.language1, package.language2));
      package_pathes.push_back(package.package_path);
    }
    return;
  }

  for (const auto& it : kLanguagePackComponentConfigMap) {
    auto file_path =
        GetFilePathFromGlobalPrefs(GetComponentPathPrefName(*it.second));
    if (!file_path.empty()) {
      packages.push_back(mojom::OnDeviceTranslationLanguagePackage::New(
          std::string(ToLanguageCode(it.second->language1)),
          std::string(ToLanguageCode(it.second->language2))));
      package_pathes.push_back(file_path);
    }
  }
}

// static
std::optional<std::vector<ComponentManager::LanguagePackInfo>>
ComponentManager::GetLanguagePackInfoFromCommandLine() {
  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
  if (!command_line->HasSwitch(kTranslateKitPackagePaths)) {
    return std::nullopt;
  }
  const auto packages_string =
      command_line->GetSwitchValueNative(kTranslateKitPackagePaths);
  std::vector<base::CommandLine::StringType> splitted_strings =
      base::SplitString(packages_string,
#if BUILDFLAG(IS_WIN)
                        L",",
#else   // !BUILDFLAG(IS_WIN)
                        ",",
#endif  // BUILDFLAG(IS_WIN)
                        base::KEEP_WHITESPACE, base::SPLIT_WANT_ALL);
  if (splitted_strings.size() % 3 != 0) {
    LOG(ERROR) << "Invalid --" << kTranslateKitPackagePaths << " flag.";
    return std::nullopt;
  }

  std::vector<LanguagePackInfo> packages;
  auto it = splitted_strings.begin();
  while (it != splitted_strings.end()) {
    if (!base::IsStringASCII(*it) || !base::IsStringASCII(*(it + 1))) {
      LOG(ERROR) << "Invalid --" << kTranslateKitPackagePaths << " flag.";
      return std::nullopt;
    }
    LanguagePackInfo package;
#if BUILDFLAG(IS_WIN)
    package.language1 = base::WideToUTF8(*(it++));
    package.language2 = base::WideToUTF8(*(it++));
#else  // !BUILDFLAG(IS_WIN)
    package.language1 = *(it++);
    package.language2 = *(it++);
#endif
    package.package_path = base::FilePath(*(it++));
    packages.push_back(std::move(package));
  }
  return packages;
}

}  // namespace on_device_translation