// Copyright 2018 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_OMNIBOX_BROWSER_DOCUMENT_SUGGESTIONS_SERVICE_H_
#define COMPONENTS_OMNIBOX_BROWSER_DOCUMENT_SUGGESTIONS_SERVICE_H_

#include <memory>
#include <optional>
#include <string>

#include "base/memory/raw_ptr.h"
#include "base/memory/scoped_refptr.h"
#include "base/scoped_observation.h"
#include "components/keyed_service/core/keyed_service.h"
#include "components/signin/public/identity_manager/access_token_info.h"
#include "components/signin/public/identity_manager/identity_manager.h"
#include "components/signin/public/identity_manager/tribool.h"
#include "services/network/public/cpp/resource_request.h"
#include "services/network/public/cpp/shared_url_loader_factory.h"
#include "services/network/public/cpp/simple_url_loader.h"

namespace signin {
class PrimaryAccountAccessTokenFetcher;
}  // namespace signin

class GoogleServiceAuthError;

// A service to fetch suggestions from a remote endpoint given a URL.
class DocumentSuggestionsService : public KeyedService,
                                   public signin::IdentityManager::Observer {
 public:
  // null may be passed for params, but no request will be issued.
  DocumentSuggestionsService(
      signin::IdentityManager* identity_manager,
      scoped_refptr<network::SharedURLLoaderFactory> url_loader_factory);

  ~DocumentSuggestionsService() override;
  DocumentSuggestionsService(const DocumentSuggestionsService&) = delete;
  DocumentSuggestionsService& operator=(const DocumentSuggestionsService&) =
      delete;

  using CreationCallback =
      base::OnceCallback<void(network::ResourceRequest* request)>;
  using StartCallback =
      base::OnceCallback<void(std::unique_ptr<network::SimpleURLLoader> loader,
                              const std::string& request_body)>;
  using CompletionCallback =
      base::OnceCallback<void(const network::SimpleURLLoader* source,
                              std::optional<std::string> response_body)>;

  // Returns whether the user's primary account is available.
  bool HasPrimaryAccount();

  // Test-only method to set the account state to be valid for enabling
  // documents suggestions or not.
  void SetAccountStateForTesting(bool valid);

  // Creates and starts a document suggestion request for |query|.
  // May obtain an OAuth2 token for the signed-in user.
  void CreateDocumentSuggestionsRequest(const std::u16string& query,
                                        bool is_incognito,
                                        CreationCallback creation_callback,
                                        StartCallback start_callback,
                                        CompletionCallback completion_callback);

  // Stops creating the request. Already created requests aren't affected.
  void StopCreatingDocumentSuggestionsRequest();

  signin::Tribool account_is_workspace_managed() {
    return account_is_workspace_managed_;
  }

  bool should_backoff() { return should_backoff_; }
  void set_should_backoff(bool should_backoff) {
    should_backoff_ = should_backoff;
  }

 private:
  // Returns whether Enterprise features are applied to the primary account -
  // aka Dasher account, obtained from the user account capability.
  signin::Tribool IsAccountWorkspaceManaged();

  // Called when an access token request completes (successfully or not).
  void AccessTokenAvailable(std::unique_ptr<network::ResourceRequest> request,
                            std::string request_body,
                            net::NetworkTrafficAnnotationTag traffic_annotation,
                            StartCallback start_callback,
                            CompletionCallback completion_callback,
                            GoogleServiceAuthError error,
                            signin::AccessTokenInfo access_token_info);

  // Activates a loader for |request|, wiring it up to |completion_callback|,
  // and calls |start_callback|. If |request_body| isn't empty, it will be
  // attached as upload bytes.
  void StartDownloadAndTransferLoader(
      std::unique_ptr<network::ResourceRequest> request,
      std::string request_body,
      net::NetworkTrafficAnnotationTag traffic_annotation,
      StartCallback start_callback,
      CompletionCallback completion_callback);

  // signin::IdentityManager::Observer implementation:
  void OnPrimaryAccountChanged(
      const signin::PrimaryAccountChangeEvent& event_details) override;
  void OnExtendedAccountInfoUpdated(const AccountInfo& info) override;
  void OnIdentityManagerShutdown(
      signin::IdentityManager* identity_manager) override;

  scoped_refptr<network::SharedURLLoaderFactory> url_loader_factory_;

  raw_ptr<signin::IdentityManager> identity_manager_;

  base::ScopedObservation<signin::IdentityManager, DocumentSuggestionsService>
      identity_manager_observation_{this};

  // Override for HasPrimaryAccount(). For testing only.
  bool has_primary_account_for_testing_ = false;
  // Override for IsAccountWorkspaceManaged(). For testing only.
  bool account_is_workspace_managed_for_testing_ = false;

  // Whether the primary account is a Dasher one. Obtained from the user account
  // capability. Updated when primary account signin state or capability change.
  signin::Tribool account_is_workspace_managed_;

  // Helper for fetching OAuth2 access tokens. Non-null when we have a token
  // available, or while a token fetch is in progress.
  std::unique_ptr<signin::PrimaryAccountAccessTokenFetcher> token_fetcher_;

  // Whether the document provider should stop issuing requests.
  bool should_backoff_ = false;
};

#endif  // COMPONENTS_OMNIBOX_BROWSER_DOCUMENT_SUGGESTIONS_SERVICE_H_