// Copyright 2019 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_UI_LIB_INPUT_REPORT_INSTANCE_DRIVER_INSTANCE_H_
#define SRC_UI_LIB_INPUT_REPORT_INSTANCE_DRIVER_INSTANCE_H_

#include <array>

#include <ddktl/device.h>
#include <ddktl/protocol/empty-protocol.h>
#include <fbl/intrusive_double_list.h>
#include <fbl/mutex.h>
#include <fbl/ring_buffer.h>

#include "src/ui/lib/hid-input-report/descriptors.h"
#include "src/ui/lib/hid-input-report/device.h"
#include "src/ui/lib/hid-input-report/fidl.h"
#include "src/ui/lib/hid-input-report/mouse.h"

namespace input_report_instance {

namespace fuchsia_input_report = ::llcpp::fuchsia::input::report;

class InputReportInstance;

class InputReportBase {
 public:
  virtual void RemoveInstanceFromList(InputReportInstance* instance) = 0;
  virtual const hid_input_report::ReportDescriptor* GetDescriptors(size_t* size) = 0;
  virtual zx_status_t SendOutputReport(fuchsia_input_report::OutputReport report) = 0;
};

using InstanceDeviceType = ddk::Device<InputReportInstance, ddk::Closable, ddk::Messageable>;

class InputReportInstance : public InstanceDeviceType,
                            fuchsia_input_report::InputDevice::Interface,
                            public fbl::DoublyLinkedListable<InputReportInstance*> {
 public:
  InputReportInstance(zx_device_t* parent) : InstanceDeviceType(parent) {}

  // The |InputReportBase| is responsible for creating |InputReportInstance| and adding it to
  // the LinkedList of instances that are owned by the base. The Instance is a child driver
  // of the base and can not outlive the base. The Instance driver must remove itself from
  // the LinkedList of it's Base driver during DdkClose.
  zx_status_t Bind(InputReportBase* base);

  zx_status_t DdkMessage(fidl_msg_t* msg, fidl_txn_t* txn);
  void DdkRelease() { delete this; }
  zx_status_t DdkClose(uint32_t flags);

  void ReceiveReport(const hid_input_report::InputReport& input_report);

  // FIDL functions.
  void GetReportsEvent(GetReportsEventCompleter::Sync _completer);
  void GetReports(GetReportsCompleter::Sync _completer);
  void GetDescriptor(GetDescriptorCompleter::Sync _completer);
  void SendOutputReport(::llcpp::fuchsia::input::report::OutputReport report,
                        SendOutputReportCompleter::Sync completer);

 private:
  fbl::Mutex report_lock_;
  zx::event reports_event_ __TA_GUARDED(report_lock_);
  // The ring buffer stores the hid reports as they are sent to the instance.
  fbl::RingBuffer<hid_input_report::InputReport, fuchsia_input_report::MAX_DEVICE_REPORT_COUNT>
      reports_data_ __TA_GUARDED(report_lock_);
  // These two arrays store the information to build the FIDL tables.
  std::array<hid_input_report::FidlInputReport, fuchsia_input_report::MAX_DEVICE_REPORT_COUNT>
      reports_fidl_data_ __TA_GUARDED(report_lock_);
  std::array<fuchsia_input_report::InputReport, fuchsia_input_report::MAX_DEVICE_REPORT_COUNT>
      reports_ __TA_GUARDED(report_lock_);

  InputReportBase* base_ = nullptr;
};

}  // namespace input_report_instance

#endif  // SRC_UI_LIB_INPUT_REPORT_INSTANCE_DRIVER_INSTANCE_H_