// Copyright 2013 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/extensions/api/settings_overrides/settings_overrides_api.h"

#include <stddef.h>

#include <memory>
#include <utility>

#include "base/check_deref.h"
#include "base/lazy_instance.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "chrome/browser/prefs/session_startup_pref.h"
#include "chrome/browser/profiles/profile.h"
#include "chrome/browser/search_engine_choice/search_engine_choice_service_factory.h"
#include "chrome/browser/search_engines/template_url_prepopulate_data_resolver_factory.h"
#include "chrome/browser/search_engines/template_url_service_factory.h"
#include "chrome/common/extensions/manifest_handlers/settings_overrides_handler.h"
#include "chrome/common/pref_names.h"
#include "components/search_engines/search_engine_choice/search_engine_choice_service.h"
#include "components/search_engines/search_engines_pref_names.h"
#include "components/search_engines/template_url.h"
#include "components/search_engines/template_url_data_util.h"
#include "components/search_engines/template_url_prepopulate_data.h"
#include "components/search_engines/template_url_prepopulate_data_resolver.h"
#include "extensions/browser/extension_prefs.h"
#include "extensions/browser/extension_prefs_factory.h"
#include "extensions/browser/extension_prefs_helper.h"
#include "extensions/browser/extension_prefs_helper_factory.h"
#include "extensions/browser/install_prefs_helper.h"
#include "extensions/common/api/types.h"
#include "extensions/common/error_utils.h"
#include "extensions/common/extension_id.h"
#include "extensions/common/manifest_constants.h"

using extensions::api::types::ChromeSettingScope;

namespace extensions {

namespace {

base::LazyInstance<BrowserContextKeyedAPIFactory<SettingsOverridesAPI>>::
    DestructorAtExit g_settings_overrides_api_factory =
        LAZY_INSTANCE_INITIALIZER;

const char kManyStartupPagesWarning[] = "* specifies more than 1 startup URL. "
    "All but the first will be ignored.";

using api::manifest_types::ChromeSettingsOverrides;

std::string SubstituteInstallParam(std::string str,
                                   const std::string& install_parameter) {
  base::ReplaceSubstringsAfterOffset(&str, 0, "__PARAM__", install_parameter);
  return str;
}

std::unique_ptr<TemplateURLData> ConvertSearchProvider(
    const TemplateURLPrepopulateData::Resolver& prepopulate_data_resolver,
    const ChromeSettingsOverrides::SearchProvider& search_provider,
    const std::string& install_parameter) {
  std::unique_ptr<TemplateURLData> data;
  if (search_provider.prepopulated_id) {
    data = prepopulate_data_resolver.GetEngineFromFullList(
        *search_provider.prepopulated_id);

    if (data) {
      // We need to override the prepopulate_id and Sync GUID of the generated
      // engine; otherwise, we will collide the original and also clone the
      // Sync GUID of the original. See https://crbug.com/1166372#c13
      //
      // Note that prepopulate_id must be set first, since GenerateSyncGUID()
      // internally depends on it.
      std::string old_sync_guid = data->sync_guid;
      data->prepopulate_id = 0;
      data->GenerateSyncGUID();
      DCHECK_NE(data->sync_guid, old_sync_guid);
    } else {
      VLOG(1) << "Settings Overrides API can't recognize prepopulated_id="
          << *search_provider.prepopulated_id;
    }
  }

  if (!data)
    data = std::make_unique<TemplateURLData>();

  // `prepopulate_id` must be 0 to avoid collisions with prepopulated
  // engines.
  DCHECK_EQ(0, data->prepopulate_id);

  if (search_provider.name)
    data->SetShortName(base::UTF8ToUTF16(*search_provider.name));
  if (search_provider.keyword)
    data->SetKeyword(base::UTF8ToUTF16(*search_provider.keyword));
  data->SetURL(
      SubstituteInstallParam(search_provider.search_url, install_parameter));
  if (search_provider.suggest_url) {
    data->suggestions_url =
        SubstituteInstallParam(*search_provider.suggest_url, install_parameter);
  }
  if (search_provider.image_url) {
    data->image_url =
        SubstituteInstallParam(*search_provider.image_url, install_parameter);
  }
  if (search_provider.search_url_post_params)
    data->search_url_post_params = *search_provider.search_url_post_params;
  if (search_provider.suggest_url_post_params)
    data->suggestions_url_post_params =
        *search_provider.suggest_url_post_params;
  if (search_provider.image_url_post_params)
    data->image_url_post_params = *search_provider.image_url_post_params;
  if (search_provider.favicon_url) {
    data->favicon_url = GURL(SubstituteInstallParam(
        *search_provider.favicon_url, install_parameter));
  }
  data->safe_for_autoreplace = false;
  if (search_provider.encoding) {
    data->input_encodings.clear();
    data->input_encodings.push_back(*search_provider.encoding);
  }
  data->date_created = base::Time();
  data->last_modified = base::Time();
  if (search_provider.alternate_urls) {
    data->alternate_urls.clear();
    for (const auto& url : *search_provider.alternate_urls) {
      if (!url.empty())
        data->alternate_urls.push_back(
            SubstituteInstallParam(url, install_parameter));
    }
  }
  return data;
}

}  // namespace

SettingsOverridesAPI::SettingsOverridesAPI(content::BrowserContext* context)
    : profile_(Profile::FromBrowserContext(context)),
      url_service_(TemplateURLServiceFactory::GetForProfile(profile_)) {
  extension_registry_observation_.Observe(ExtensionRegistry::Get(profile_));
}

SettingsOverridesAPI::~SettingsOverridesAPI() = default;

BrowserContextKeyedAPIFactory<SettingsOverridesAPI>*
SettingsOverridesAPI::GetFactoryInstance() {
  return g_settings_overrides_api_factory.Pointer();
}

void SettingsOverridesAPI::SetPref(const ExtensionId& extension_id,
                                   const std::string& pref_key,
                                   base::Value value) const {
  ExtensionPrefsHelper* prefs_helper = ExtensionPrefsHelper::Get(profile_);
  // This is not instantiated in unit tests. Historically, the PreferenceAPI
  // instance provided this functionality, and it was not instantiated during
  // unit tests and some tests relied on that.
  if (!prefs_helper)
    return;

  prefs_helper->SetExtensionControlledPref(
      extension_id, pref_key, ChromeSettingScope::kRegular, std::move(value));
}

void SettingsOverridesAPI::UnsetPref(const ExtensionId& extension_id,
                                     const std::string& pref_key) const {
  ExtensionPrefsHelper* prefs_helper = ExtensionPrefsHelper::Get(profile_);
  // Not instantiated in unit tests.
  if (!prefs_helper)
    return;
  prefs_helper->RemoveExtensionControlledPref(extension_id, pref_key,
                                              ChromeSettingScope::kRegular);
}

void SettingsOverridesAPI::OnExtensionLoaded(
    content::BrowserContext* browser_context,
    const Extension* extension) {
  const SettingsOverrides* settings = SettingsOverrides::Get(extension);
  if (settings) {
    std::string install_parameter =
        GetInstallParam(ExtensionPrefs::Get(profile_), extension->id());
    if (settings->homepage) {
      SetPref(extension->id(), prefs::kHomePage,
              base::Value(SubstituteInstallParam(settings->homepage->spec(),
                                                 install_parameter)));
      SetPref(extension->id(), prefs::kHomePageIsNewTabPage,
              base::Value(false));
    }
    if (!settings->startup_pages.empty()) {
      SetPref(extension->id(), prefs::kRestoreOnStartup,
              base::Value(SessionStartupPref::kPrefValueURLs));
      if (settings->startup_pages.size() > 1) {
        VLOG(1) << extensions::ErrorUtils::FormatErrorMessage(
                       kManyStartupPagesWarning,
                       manifest_keys::kSettingsOverride);
      }
      base::Value::List url_list;
      url_list.Append(SubstituteInstallParam(settings->startup_pages[0].spec(),
                                             install_parameter));
      SetPref(extension->id(), prefs::kURLsToRestoreOnStartup,
              base::Value(std::move(url_list)));
    }
    if (settings->search_engine) {
      // Bring the preference to the correct state. Before this code set it
      // to "true" for all search engines. Thus, we should overwrite it for
      // all search engines.
      if (settings->search_engine->is_default) {
        SetPref(extension->id(), prefs::kDefaultSearchProviderEnabled,
                base::Value(true));
      } else {
        UnsetPref(extension->id(), prefs::kDefaultSearchProviderEnabled);
      }
      DCHECK(url_service_);
      RegisterSearchProvider(extension);
    }
  }
}
void SettingsOverridesAPI::OnExtensionUnloaded(
    content::BrowserContext* browser_context,
    const Extension* extension,
    UnloadedExtensionReason reason) {
  const SettingsOverrides* settings = SettingsOverrides::Get(extension);
  if (settings) {
    if (settings->homepage) {
      UnsetPref(extension->id(), prefs::kHomePage);
      UnsetPref(extension->id(), prefs::kHomePageIsNewTabPage);
    }
    if (!settings->startup_pages.empty()) {
      UnsetPref(extension->id(), prefs::kRestoreOnStartup);
      UnsetPref(extension->id(), prefs::kURLsToRestoreOnStartup);
    }
    if (settings->search_engine) {
      if (settings->search_engine->is_default) {
        // Current extension can be overriding DSE.
        UnsetPref(extension->id(),
                  DefaultSearchManager::kDefaultSearchProviderDataPrefName);
      }
      DCHECK(url_service_);
      url_service_->RemoveExtensionControlledTURL(
          extension->id(), TemplateURL::NORMAL_CONTROLLED_BY_EXTENSION);
    }
  }
}

void SettingsOverridesAPI::RegisterSearchProvider(
    const Extension* extension) const {
  DCHECK(url_service_);
  DCHECK(extension);
  const SettingsOverrides* settings = SettingsOverrides::Get(extension);
  DCHECK(settings);
  DCHECK(settings->search_engine);

  ExtensionPrefs* prefs = ExtensionPrefs::Get(profile_);
  std::string install_parameter = GetInstallParam(prefs, extension->id());
  std::unique_ptr<TemplateURLData> data = ConvertSearchProvider(
      CHECK_DEREF(
          TemplateURLPrepopulateData::ResolverFactory::GetForProfile(profile_)),
      *settings->search_engine, install_parameter);
  auto turl = std::make_unique<TemplateURL>(
      *data, TemplateURL::NORMAL_CONTROLLED_BY_EXTENSION, extension->id(),
      GetLastUpdateTime(prefs, extension->id()),
      settings->search_engine->is_default);

  url_service_->Add(std::move(turl));

  if (settings->search_engine->is_default) {
    // Override current DSE pref to have extension overridden value.
    SetPref(extension->id(),
            DefaultSearchManager::kDefaultSearchProviderDataPrefName,
            base::Value(TemplateURLDataToDictionary(*data)));
  }
}

template <>
void BrowserContextKeyedAPIFactory<
    SettingsOverridesAPI>::DeclareFactoryDependencies() {
  DependsOn(ExtensionPrefsFactory::GetInstance());
  DependsOn(ExtensionPrefsHelperFactory::GetInstance());
  DependsOn(TemplateURLServiceFactory::GetInstance());
  DependsOn(search_engines::SearchEngineChoiceServiceFactory::GetInstance());
}

}  // namespace extensions