/*
 * Copyright (c) 2021 Cisco and/or its affiliates.
 * 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.
 */

#pragma once

#include <hicn/transport/interfaces/callbacks.h>
#include <hicn/transport/interfaces/socket_consumer.h>
#include <hicn/transport/interfaces/statistics.h>
#include <hicn/transport/utils/object_pool.h>
#include <protocols/data_processing_events.h>
#include <protocols/fec_base.h>
#include <protocols/indexer.h>
#include <protocols/protocol.h>
#include <protocols/reassembly.h>

#include <array>
#include <atomic>

namespace transport {

namespace protocol {

using namespace core;

class IndexVerificationManager;

using ReadCallback = interface::ConsumerSocket::ReadCallback;

class TransportProtocol
    : public ContentObjectProcessingEventCallback,
      public Protocol,
      public std::enable_shared_from_this<TransportProtocol> {
  static constexpr std::size_t interest_pool_size = 4096;

  friend class ManifestIndexManager;

 public:
  TransportProtocol(implementation::ConsumerSocket *icn_socket,
                    Indexer *indexer, Reassembly *reassembly);

  virtual ~TransportProtocol();

  virtual int start();

  using Protocol::stop;

  virtual void resume();

  /**
   * @brief Get the size of any additional header added by the specific
   * transport implementation.
   *
   * @return The header length in bytes.
   */
  virtual std::size_t transportHeaderLength() { return 0; }

  virtual void scheduleNextInterests() = 0;

  // Events generated by the indexing
  virtual void onContentReassembled(const std::error_code &ec);
  virtual void onPacketDropped(Interest &interest,
                               ContentObject &content_object,
                               const std::error_code &ec) override = 0;
  virtual void onReassemblyFailed(std::uint32_t missing_segment) override = 0;

 protected:
  virtual void onContentObjectReceived(Interest &i, ContentObject &c,
                                       std::error_code &ec) = 0;
  virtual void onInterestTimeout(Interest::Ptr &i, const Name &n) = 0;

  virtual void sendInterest(const Name &interest_name,
                            std::array<uint32_t, MAX_AGGREGATED_INTEREST>
                                *additional_suffixes = nullptr,
                            uint32_t len = 0);

  template <typename FECHandler, typename AllocatorHandler>
  void enableFEC(FECHandler &&fec_handler,
                 AllocatorHandler &&allocator_handler) {
    if (!fec_decoder_) {
      // Try to get FEC from environment
      const char *fec_str = std::getenv("TRANSPORT_FEC_TYPE");
      if (fec_str && (fec_type_ == fec::FECType::UNKNOWN)) {
        LOG(INFO) << "Using FEC " << fec_str;
        fec_type_ = fec::FECUtils::fecTypeFromString(fec_str);
      }

      if (fec_type_ == fec::FECType::UNKNOWN) {
        return;
      }

      fec_decoder_ = fec::FECUtils::getDecoder(
          fec_type_, indexer_verifier_->getFirstSuffix());
      fec_decoder_->setFECCallback(std::forward<FECHandler>(fec_handler));
      fec_decoder_->setBufferCallback(
          std::forward<AllocatorHandler>(allocator_handler));
      indexer_verifier_->enableFec(fec_type_);
    }
  }

  virtual void reset();

 private:
  // Consumer Callback
  void onContentObject(Interest &i, ContentObject &c) override;
  void onTimeout(Interest::Ptr &i, const Name &n) override;
  void onError(const std::error_code &ec) override;

 protected:
  implementation::ConsumerSocket *socket_;
  std::unique_ptr<Indexer> indexer_verifier_;
  std::unique_ptr<Reassembly> reassembly_;
  std::unique_ptr<fec::ConsumerFEC> fec_decoder_;
  // True if it si the first time we schedule an interest
  std::atomic<bool> is_first_;
  interface::TransportStatistics *stats_;

  // Callbacks
  interface::ConsumerInterestCallback *on_interest_retransmission_;
  interface::ConsumerInterestCallback *on_interest_output_;
  interface::ConsumerInterestCallback *on_interest_timeout_;
  interface::ConsumerInterestCallback *on_interest_satisfied_;
  interface::ConsumerContentObjectCallback *on_content_object_input_;
  interface::ConsumerContentObjectCallback *on_content_object_;
  interface::ConsumerTimerCallback *stats_summary_;
  interface::StrategyCallback *on_fwd_strategy_;
  interface::StrategyCallback *on_rec_strategy_;
  ReadCallback *on_payload_;

  bool is_async_;

  fec::FECType fec_type_;
};

}  // end namespace protocol
}  // end namespace transport