// Copyright 2020 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/ui/webui/settings/chromeos/search/search_handler.h"

#include "base/strings/string_number_conversions.h"
#include "base/strings/utf_string_conversions.h"
#include "chrome/browser/chromeos/local_search_service/local_search_service.h"
#include "chrome/browser/ui/webui/settings/chromeos/search/search_concept.h"
#include "chrome/browser/ui/webui/settings/chromeos/search/search_result_icon.mojom.h"
#include "chrome/browser/ui/webui/settings/chromeos/search/search_tag_registry.h"
#include "chrome/grit/generated_resources.h"
#include "ui/base/l10n/l10n_util.h"

namespace chromeos {
namespace settings {
namespace {

const int32_t kLocalSearchServiceMaxResults = 10;

// TODO(https://crbug.com/1071700): Delete this function.
std::vector<base::string16> GenerateDummySettingsHierarchy(
    const char* url_path_with_parameters) {
  std::vector<base::string16> hierarchy;
  hierarchy.push_back(l10n_util::GetStringUTF16(IDS_INTERNAL_APP_SETTINGS));
  hierarchy.push_back(base::ASCIIToUTF16(url_path_with_parameters));
  return hierarchy;
}

}  // namespace

// static
const size_t SearchHandler::kNumMaxResults = 5;

SearchHandler::SearchHandler(
    SearchTagRegistry* search_tag_registry,
    local_search_service::LocalSearchService* local_search_service)
    : search_tag_registry_(search_tag_registry),
      index_(local_search_service->GetIndex(
          local_search_service::IndexId::kCrosSettings)) {}

SearchHandler::~SearchHandler() = default;

void SearchHandler::BindInterface(
    mojo::PendingReceiver<mojom::SearchHandler> pending_receiver) {
  receivers_.Add(this, std::move(pending_receiver));
}

std::vector<mojom::SearchResultPtr> SearchHandler::Search(
    const base::string16& query) {
  std::vector<local_search_service::Result> local_search_service_results;
  local_search_service::ResponseStatus response_status = index_->Find(
      query, kLocalSearchServiceMaxResults, &local_search_service_results);

  if (response_status != local_search_service::ResponseStatus::kSuccess) {
    LOG(ERROR) << "Cannot search; LocalSearchService returned "
               << static_cast<int>(response_status)
               << ". Returning empty results array.";
    return {};
  }

  return GenerateSearchResultsArray(local_search_service_results);
}

void SearchHandler::Search(const base::string16& query,
                           SearchCallback callback) {
  std::move(callback).Run(Search(query));
}

std::vector<mojom::SearchResultPtr> SearchHandler::GenerateSearchResultsArray(
    const std::vector<local_search_service::Result>&
        local_search_service_results) {
  std::vector<mojom::SearchResultPtr> search_results;
  for (const auto& result : local_search_service_results) {
    mojom::SearchResultPtr result_ptr = ResultToSearchResult(result);
    if (result_ptr)
      search_results.push_back(std::move(result_ptr));

    // Limit the number of results to return.
    if (search_results.size() == kNumMaxResults)
      break;
  }

  return search_results;
}

mojom::SearchResultPtr SearchHandler::ResultToSearchResult(
    const local_search_service::Result& result) {
  int message_id;

  // The result's ID is expected to be a stringified int.
  if (!base::StringToInt(result.id, &message_id))
    return nullptr;

  const SearchConcept* concept =
      search_tag_registry_->GetCanonicalTagMetadata(message_id);

  // If the concept was not registered, no metadata is available. This can occur
  // if the search tag was dynamically unregistered during the asynchronous
  // Find() call.
  if (!concept)
    return nullptr;

  mojom::SearchResultIdentifierPtr result_id;
  switch (concept->type) {
    case mojom::SearchResultType::kSection:
      result_id =
          mojom::SearchResultIdentifier::NewSection(concept->id.section);
      break;
    case mojom::SearchResultType::kSubpage:
      result_id =
          mojom::SearchResultIdentifier::NewSubpage(concept->id.subpage);
      break;
    case mojom::SearchResultType::kSetting:
      result_id =
          mojom::SearchResultIdentifier::NewSetting(concept->id.setting);
      break;
  }

  // TODO(https://crbug.com/1071700): Generate real hierarchy instead of using
  // GenerateDummySettingsHierarchy().
  return mojom::SearchResult::New(
      l10n_util::GetStringUTF16(message_id), concept->url_path_with_parameters,
      concept->icon, result.score,
      GenerateDummySettingsHierarchy(concept->url_path_with_parameters),
      concept->default_rank, concept->type, std::move(result_id));
}

}  // namespace settings
}  // namespace chromeos