/*
 * Copyright 2018 The Android Open Source Project
 *
 * 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 <chrono>      // for milliseconds
#include <cstddef>     // for size_t
#include <functional>  // for function
#include <map>
#include <memory>  // for shared_ptr
#include <optional>
#include <string>  // for string
#include <vector>  // for vector

#include "hci/address.h"                // for Address
#include "model/devices/hci_device.h"   // for HciDevice
#include "model/setup/async_manager.h"  // for AsyncUserId, AsyncTaskId
#include "phy.h"                        // for Phy, Phy::Type
#include "phy_layer.h"
#include "rootcanal/configuration.pb.h"

namespace rootcanal {
class Device;

using ::bluetooth::hci::Address;

class TestModel {
public:
  TestModel(std::function<AsyncUserId()> get_user_id,
            std::function<AsyncTaskId(AsyncUserId, std::chrono::milliseconds, const TaskCallback&)>
                    event_scheduler,
            std::function<AsyncTaskId(AsyncUserId, std::chrono::milliseconds,
                                      std::chrono::milliseconds, const TaskCallback&)>
                    periodic_event_scheduler,
            std::function<void(AsyncUserId)> cancel_tasks_from_user,
            std::function<void(AsyncTaskId)> cancel,
            std::function<std::shared_ptr<Device>(const std::string&, int, Phy::Type)>
                    connect_to_remote,
            std::array<uint8_t, 5> bluetooth_address_prefix = {0xda, 0x4c, 0x10, 0xde, 0x17});
  virtual ~TestModel();

  TestModel(TestModel& model) = delete;
  TestModel& operator=(const TestModel& model) = delete;

  void SetReuseDeviceAddresses(bool reuse_device_addresses) {
    reuse_device_addresses_ = reuse_device_addresses;
  }

  // Allow derived classes to use custom phy layer.
  virtual std::unique_ptr<PhyLayer> CreatePhyLayer(PhyLayer::Identifier id, Phy::Type type);

  // Allow derived classes to use custom phy devices.
  virtual std::shared_ptr<PhyDevice> CreatePhyDevice(std::string type,
                                                     std::shared_ptr<Device> device);

  // Test model commands

  PhyDevice::Identifier AddDevice(std::shared_ptr<Device> device);
  void RemoveDevice(PhyDevice::Identifier id);
  PhyLayer::Identifier AddPhy(Phy::Type type);
  void RemovePhy(PhyLayer::Identifier id);
  void AddDeviceToPhy(PhyDevice::Identifier device_id, PhyLayer::Identifier phy_id);
  void RemoveDeviceFromPhy(PhyDevice::Identifier device_id, PhyLayer::Identifier phy_id);

  // Runtime implementation.

  // Handle incoming remote connections
  void AddLinkLayerConnection(std::shared_ptr<Device> dev, Phy::Type phy_type);
  // Add an HCI device, return its index
  PhyDevice::Identifier AddHciConnection(std::shared_ptr<HciDevice> dev,
                                         std::optional<Address> address = {});
  // Handle closed remote connections (both hci & link layer)
  void OnConnectionClosed(PhyDevice::Identifier device_id, AsyncUserId user_id);

  // Connect to a remote device
  void AddRemote(const std::string& server, int port, Phy::Type phy_type);

  // Set the device's Bluetooth address
  void SetDeviceAddress(PhyDevice::Identifier device_id, Address device_address);

  void SetDeviceConfiguration(PhyDevice::Identifier device_id,
                              rootcanal::configuration::Controller const& configuration);

  // Let devices know about the passage of time
  void Tick();
  void StartTimer();
  void StopTimer();
  void SetTimerPeriod(std::chrono::milliseconds new_period);

  // List the devices that the test knows about
  const std::string& List();

  // Clear all devices and phys.
  void Reset();

private:
  Address GenerateBluetoothAddress(uint32_t device_id) const;

  std::map<PhyLayer::Identifier, std::shared_ptr<PhyLayer>> phy_layers_;
  std::map<PhyDevice::Identifier, std::shared_ptr<PhyDevice>> phy_devices_;
  std::string list_string_;

  // Generator for device identifiers.
  bool reuse_device_addresses_{true};

  // Prefix used to generate public device addresses for hosts
  // connecting over TCP.
  std::array<uint8_t, 5> bluetooth_address_prefix_;

  // Callbacks to schedule tasks.
  std::function<AsyncUserId()> get_user_id_;
  std::function<AsyncTaskId(AsyncUserId, std::chrono::milliseconds, const TaskCallback&)>
          schedule_task_;
  std::function<AsyncTaskId(AsyncUserId, std::chrono::milliseconds, std::chrono::milliseconds,
                            const TaskCallback&)>
          schedule_periodic_task_;
  std::function<void(AsyncTaskId)> cancel_task_;
  std::function<void(AsyncUserId)> cancel_tasks_from_user_;
  std::function<std::shared_ptr<Device>(const std::string&, int, Phy::Type)> connect_to_remote_;

  AsyncUserId model_user_id_;
  AsyncTaskId timer_tick_task_{kInvalidTaskId};
  std::chrono::milliseconds timer_period_{};
};

}  // namespace rootcanal