/*
 * Copyright 2019 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef FCP_SECAGG_SERVER_SECAGG_SERVER_R1_SHARE_KEYS_STATE_H_
#define FCP_SECAGG_SERVER_SECAGG_SERVER_R1_SHARE_KEYS_STATE_H_

#include <memory>
#include <string>

#include "fcp/secagg/server/secagg_server_state.h"

namespace fcp {
namespace secagg {

// This class is the State for the SecAggServer when it is in the
// Round 1: Share Keys state. This state collects encrypted key shares from
// clients, and at the end of the round, delivers the appropriate shares to the
// right clients. It should transition to Round 2: Masked Input Collection, but
// might transition to Aborted if too many clients abort.

class SecAggServerR1ShareKeysState : public SecAggServerState {
 public:
  SecAggServerR1ShareKeysState(
      std::unique_ptr<SecAggServerProtocolImpl> impl,
      int number_of_clients_failed_after_sending_masked_input,
      int number_of_clients_failed_before_sending_masked_input,
      int number_of_clients_terminated_without_unmasking);

  ~SecAggServerR1ShareKeysState() override;

  // Handles a share keys response or abort message from a client.
  absl::Status HandleMessage(
      uint32_t client_id, const ClientToServerWrapperMessage& message) override;

  bool IsNumberOfIncludedInputsCommitted() const override;

  int MinimumMessagesNeededForNextRound() const override;

  int NumberOfPendingClients() const override;

  absl::StatusOr<std::unique_ptr<SecAggServerState>> ProceedToNextRound()
      override;

  // This will return true only after minimum_number_of_clients_to_proceed
  // clients have sent messages (and not subsequently aborted).
  bool ReadyForNextRound() const override;

 private:
  void HandleAbortClient(uint32_t client_id,
                         ClientDropReason reason_code) override;
};

}  // namespace secagg
}  // namespace fcp

#endif  // FCP_SECAGG_SERVER_SECAGG_SERVER_R1_SHARE_KEYS_STATE_H_
