// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CHROME_BROWSER_SIGNIN_BOUND_SESSION_CREDENTIALS_BOUND_SESSION_REFRESH_COOKIE_FETCHER_H_
#define CHROME_BROWSER_SIGNIN_BOUND_SESSION_CREDENTIALS_BOUND_SESSION_REFRESH_COOKIE_FETCHER_H_

#include <optional>
#include <ostream>

#include "base/containers/flat_set.h"
#include "base/functional/callback_forward.h"
#include "net/traffic_annotation/network_traffic_annotation.h"

// This class makes the network request to the Gaia cookie rotation endpoint to
// refresh bound Google authentication cookies. A new fetcher instance should be
// created per request.
class BoundSessionRefreshCookieFetcher {
 public:
  // These values are persisted to logs. Entries should not be renumbered and
  // numeric values should never be reused.
  enum class Result {
    kSuccess = 0,
    kConnectionError = 1,
    kServerTransientError = 2,
    kServerPersistentError = 3,
    kServerUnexepectedResponse = 4,
    kChallengeRequiredUnexpectedFormat = 5,
    kChallengeRequiredLimitExceeded = 6,
    kSignChallengeFailed = 7,
    kChallengeRequiredSessionIdMismatch = 8,
    kMaxValue = kChallengeRequiredSessionIdMismatch,
  };

  // Enumerates different reasons for triggering a refresh request. Used mainly
  // for metrics.
  enum class Trigger {
    kOther,
    kNewSession,
    kStartup,
    kBlockedRequest,
    kCookieExpired,
    kPreemptiveRefresh,
    kRetryWithBackoff,
    kConnectionChanged,
  };

  static constexpr char kRotationChallengeHeader[] =
      "Sec-Session-Google-Challenge";
  static constexpr char kRotationChallengeResponseHeader[] =
      "Sec-Session-Google-Response";
  static constexpr char kRotationDebugHeader[] =
      "Sec-Session-Google-Rotation-Debug-Info";
  // Not constexpr to avoid inlining the long definition here.
  static const net::NetworkTrafficAnnotationTag kTrafficAnnotation;

  static bool IsPersistentError(Result result);
  static bool IsTransientError(Result result);

  // Reports the result of the fetch request.
  using RefreshCookieCompleteCallback = base::OnceCallback<void(Result)>;

  BoundSessionRefreshCookieFetcher() = default;
  virtual ~BoundSessionRefreshCookieFetcher() = default;

  BoundSessionRefreshCookieFetcher(const BoundSessionRefreshCookieFetcher&) =
      delete;
  BoundSessionRefreshCookieFetcher& operator=(
      const BoundSessionRefreshCookieFetcher&) = delete;

  // Starts the network request to the Gaia rotation endpoint. `callback` is
  // called with the fetch results upon completion. Should be called no more
  // than once per instance.
  virtual void Start(
      RefreshCookieCompleteCallback callback,
      std::optional<std::string> sec_session_challenge_response) = 0;

  // Returns whether the fetcher had received a challenge.
  virtual bool IsChallengeReceived() const = 0;
  virtual std::optional<std::string> TakeSecSessionChallengeResponseIfAny() = 0;
  // Returns names of the cookies that haven't been refreshed by this fetcher.
  virtual base::flat_set<std::string> GetNonRefreshedCookieNames() = 0;
  // Returns `Trigger` for this refresh.
  virtual Trigger GetTrigger() const = 0;
};

std::ostream& operator<<(
    std::ostream& os,
    const BoundSessionRefreshCookieFetcher::Result& result);

#endif  // CHROME_BROWSER_SIGNIN_BOUND_SESSION_CREDENTIALS_BOUND_SESSION_REFRESH_COOKIE_FETCHER_H_