src/connectivity/bluetooth/core/bt-host/l2cap/low_energy_command_handler.h

// Copyright 2020 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef SRC_CONNECTIVITY_BLUETOOTH_CORE_BT_HOST_L2CAP_LOW_ENERGY_COMMAND_HANDLER_H_
#define SRC_CONNECTIVITY_BLUETOOTH_CORE_BT_HOST_L2CAP_LOW_ENERGY_COMMAND_HANDLER_H_

#include "src/connectivity/bluetooth/core/bt-host/common/byte_buffer.h"
#include "src/connectivity/bluetooth/core/bt-host/l2cap/command_handler.h"
#include "src/connectivity/bluetooth/core/bt-host/l2cap/l2cap_defs.h"

namespace bt::l2cap::internal {
class LowEnergyCommandHandler final : public CommandHandler {
 public:
  class ConnectionParameterUpdateResponse final : public Response {
   public:
    using PayloadT = ConnectionParameterUpdateResponsePayload;
    static constexpr const char* kName = "Connection Parameter Update Response";

    using Response::Response;  // Inherit ctor
    bool Decode(const ByteBuffer& payload_buf);

    ConnectionParameterUpdateResult result() const { return result_; }

   private:
    friend class LowEnergyCommandHandler;

    ConnectionParameterUpdateResult result_;
  };

  class ConnectionParameterUpdateResponder final : public Responder {
   public:
    explicit ConnectionParameterUpdateResponder(SignalingChannel::Responder* sig_responder);

    void Send(ConnectionParameterUpdateResult result);
  };

  // |sig| must be valid for the lifetime of this object.
  // |command_failed_callback| is called if an outbound request timed out with
  // RTX or ERTX timers after retransmission (if configured). The call may come
  // after the lifetime of this object.
  explicit LowEnergyCommandHandler(SignalingChannelInterface* sig,
                                   fit::closure request_fail_callback = nullptr);
  ~LowEnergyCommandHandler() = default;
  DISALLOW_COPY_AND_ASSIGN_ALLOW_MOVE(LowEnergyCommandHandler);

  // Outbound request sending methods. Response callbacks are required to be
  // non-empty. The callbacks are wrapped and moved into the SignalingChannel
  // and may outlive LowEnergyCommandHandler.

  using ConnectionParameterUpdateResponseCallback =
      fit::function<void(const ConnectionParameterUpdateResponse& rsp)>;
  bool SendConnectionParameterUpdateRequest(uint16_t interval_min, uint16_t interval_max,
                                            uint16_t slave_latency, uint16_t timeout_multiplier,
                                            ConnectionParameterUpdateResponseCallback cb);

  // Inbound request delegate registration methods. The callbacks are wrapped
  // and moved into the SignalingChannel and may outlive LowEnergyCommandHandler. It
  // is expected that any request delegates registered will span the lifetime of
  // its signaling channel and hence link, so no unregistration is provided.
  // However each call to register will replace any currently registered request
  // delegate.

  using ConnectionParameterUpdateRequestCallback = fit::function<void(
      uint16_t interval_min, uint16_t interval_max, uint16_t slave_latency,
      uint16_t timeout_multiplier, ConnectionParameterUpdateResponder* responder)>;
  void ServeConnectionParameterUpdateRequest(ConnectionParameterUpdateRequestCallback cb);
};
}  // namespace bt::l2cap::internal

#endif  // SRC_CONNECTIVITY_BLUETOOTH_CORE_BT_HOST_L2CAP_LOW_ENERGY_COMMAND_HANDLER_H_