// Copyright 2022 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_ACPI_MULTIPLY_ACPI_MULTIPLY_H_
#define SRC_ACPI_MULTIPLY_ACPI_MULTIPLY_H_

#include <fidl/fuchsia.driver.framework/cpp/markers.h>
#include <fidl/fuchsia.driver.framework/cpp/wire_types.h>
#include <fidl/fuchsia.hardware.acpi/cpp/markers.h>
#include <fidl/sample.acpi.multiply/cpp/wire.h>
#include <lib/async/cpp/irq.h>
#include <lib/driver2/logger.h>
#include <lib/driver2/namespace.h>
#include <lib/fdf/cpp/dispatcher.h>
#include <lib/mmio/mmio-buffer.h>
#include <lib/sys/component/llcpp/outgoing_directory.h>
#include <lib/zx/interrupt.h>

#include <list>

namespace acpi_multiply {

// Sample driver for a virtual "multiplier" device described using ACPI.
class AcpiMultiplyDriver : public fidl::WireServer<sample_acpi_multiply::Device> {
 public:
  AcpiMultiplyDriver(async_dispatcher_t* dispatcher,
                     fidl::WireSharedClient<fuchsia_driver_framework::Node> node,
                     driver::Namespace ns, driver::Logger logger)
      : dispatcher_(dispatcher),
        node_(std::move(node)),
        outgoing_(component::OutgoingDirectory::Create(dispatcher)),
        ns_(std::move(ns)),
        logger_(std::move(logger)) {}

  virtual ~AcpiMultiplyDriver() = default;

  static constexpr const char* Name() { return "acpi-multiply"; }

  static zx::status<std::unique_ptr<AcpiMultiplyDriver>> Start(
      fuchsia_driver_framework::wire::DriverStartArgs& start_args,
      fdf::UnownedDispatcher dispatcher,
      fidl::WireSharedClient<fuchsia_driver_framework::Node> node, driver::Namespace ns,
      driver::Logger logger);

  // sample.acpi.multiply/Device:
  void Multiply(MultiplyRequestView request, MultiplyCompleter::Sync& completer);

 private:
  struct Operation {
    // Operands to the multiply.
    uint32_t a;
    uint32_t b;
    // Completer.
    MultiplyCompleter::Async completer;
  };

  zx::status<> Run(fidl::ServerEnd<fuchsia_io::Directory> outgoing_dir);

  void HandleIrq(async_dispatcher_t* dispatcher, async::IrqBase* irq, zx_status_t status,
                 const zx_packet_interrupt_t* interrupt);

  void DoMultiply(Operation operation) __TA_REQUIRES(completer_lock_);

  async_dispatcher_t* const dispatcher_;
  std::optional<fdf::MmioBuffer> mmio_;
  zx::interrupt irq_;
  async::IrqMethod<AcpiMultiplyDriver, &AcpiMultiplyDriver::HandleIrq> irq_method_{this};
  fidl::WireSyncClient<fuchsia_hardware_acpi::Device> acpi_;

  // TODO(fxbug.dev/99975): This will no longer be necessary once interrupts can be handled without
  // spawning a separate dispatcher thread.
  std::mutex completer_lock_;
  std::optional<MultiplyCompleter::Async> cur_completer_ __TA_GUARDED(completer_lock_);
  std::list<Operation> operation_queue_ __TA_GUARDED(completer_lock_);

  fidl::WireSharedClient<fuchsia_driver_framework::Node> node_;

  component::OutgoingDirectory outgoing_;
  driver::Namespace ns_;
  driver::Logger logger_;

  // Used by the self-test.
  fidl::WireClient<sample_acpi_multiply::Device> client_;
};

}  // namespace acpi_multiply

#endif /* SRC_ACPI_MULTIPLY_ACPI_MULTIPLY_H_ */