/*
 *  Copyright (c) 2021 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */
#ifndef NET_DCSCTP_PUBLIC_DCSCTP_MESSAGE_H_
#define NET_DCSCTP_PUBLIC_DCSCTP_MESSAGE_H_

#include <cstdint>
#include <utility>
#include <vector>

#include "api/array_view.h"
#include "net/dcsctp/public/types.h"
#include "rtc_base/copy_on_write_buffer.h"

namespace dcsctp {

// An SCTP message is a group of bytes sent and received as a whole on a
// specified stream identifier (`stream_id`), and with a payload protocol
// identifier (`ppid`).
class DcSctpMessage {
 public:
  // For best performance, please use the other constructor for zero-copy.
  DcSctpMessage(StreamID stream_id, PPID ppid, std::vector<uint8_t> payload)
      : stream_id_(stream_id), ppid_(ppid), payload_(payload) {}

  explicit DcSctpMessage(StreamID stream_id,
                         PPID ppid,
                         rtc::CopyOnWriteBuffer payload,
                         bool)
      : stream_id_(stream_id), ppid_(ppid), payload_(std::move(payload)) {}

  DcSctpMessage(DcSctpMessage&& other) = default;
  DcSctpMessage& operator=(DcSctpMessage&& other) = default;
  DcSctpMessage(const DcSctpMessage&) = delete;
  DcSctpMessage& operator=(const DcSctpMessage&) = delete;

  // The stream identifier to which the message is sent.
  StreamID stream_id() const { return stream_id_; }

  // The payload protocol identifier (ppid) associated with the message.
  PPID ppid() const { return ppid_; }

  // The payload of the message.
  rtc::ArrayView<const uint8_t> payload() const { return payload_; }
  const rtc::CopyOnWriteBuffer& buffer_payload() const { return payload_; }

  // When destructing the message, extracts the payload.
  // Deprecated method - please use `ReleaseBufferPayload`.
  ABSL_DEPRECATED("Use ReleaseBufferPayload instead")
  std::vector<uint8_t> ReleasePayload() && {
    return std::vector<uint8_t>(payload_.cdata(),
                                payload_.cdata() + payload_.size());
  }

  // When destructing the message, extracts the payload.
  rtc::CopyOnWriteBuffer ReleaseBufferPayload() && {
    return std::move(payload_);
  }

 private:
  StreamID stream_id_;
  PPID ppid_;
  rtc::CopyOnWriteBuffer payload_;
};
}  // namespace dcsctp

#endif  // NET_DCSCTP_PUBLIC_DCSCTP_MESSAGE_H_