/*
 * Copyright (C) 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 <memory>
#include <string>
#include <unordered_map>
#include <vector>

#include <fruit/fruit.h>

#include "common/libs/utils/result.h"
#include "host/libs/config/command_source.h"
#include "host/libs/config/cuttlefish_config.h"

namespace cuttlefish {
namespace vm_manager {

// Class for tagging that the CommandSource is a dependency command for the
// VmManager.
class VmmDependencyCommand : public virtual StatusCheckCommandSource {};

// Superclass of every guest VM manager.
class VmManager {
 public:
  // This is the number of HVC virtual console ports that should be configured
  // by the VmManager. Because crosvm currently allocates these ports as the
  // first PCI devices, and it does not control the allocation of PCI ID
  // assignments, the number of these ports affects the PCI paths for
  // subsequent PCI devices, and these paths are hard-coded in SEPolicy.
  // Fortunately, HVC virtual console ports can be set up to be "sink" devices,
  // so even if they are disabled and the guest isn't using them, they don't
  // need to consume host resources, except for the PCI ID. Use this trick to
  // keep the number of PCI IDs assigned constant for all flags/vm manager
  // combinations.
  // - /dev/hvc0 = kernel console
  // - /dev/hvc1 = serial console
  // - /dev/hvc2 = serial logging
  // - /dev/hvc3 = keymaster
  // - /dev/hvc4 = gatekeeper
  // - /dev/hvc5 = bt
  // - /dev/hvc6 = gnss
  // - /dev/hvc7 = location
  // - /dev/hvc8 = confirmationui
  // - /dev/hvc9 = uwb
  // - /dev/hvc10 = oemlock
  // - /dev/hvc11 = keymint
  // - /dev/hvc12 = NFC
  // - /dev/hvc13 = sensors
  // - /dev/hvc14 = MCU control
  // - /dev/hvc15 = MCU UART
  static const int kDefaultNumHvcs = 16;

  // This is the number of virtual disks (block devices) that should be
  // configured by the VmManager. Related to the description above regarding
  // HVC ports, this problem can also affect block devices (which are
  // enumerated second) if not all of the block devices are available. Unlike
  // HVC virtual console ports, block devices cannot be configured to be sinks,
  // so we once again leverage HVC virtual console ports to "bump up" the last
  // assigned virtual disk PCI ID (i.e. 2 disks = 7 hvcs, 1 disks = 8 hvcs)
  static constexpr int kMaxDisks = 3;

  // This is the number of virtual disks that contribute to the named partition
  // list (/dev/block/by-name/*) under Android. The partitions names from
  // multiple disks *must not* collide. Normally we have one set of partitions
  // from the powerwashed disk (operating system disk) and another set from
  // the persistent disk
  static const int kDefaultNumBootDevices = 2;

  static constexpr const int kNetPciDeviceNum = 1;

  // LINT.IfChange(virtio_gpu_pci_address)
  static constexpr const int kGpuPciSlotNum = 2;
  // LINT.ThenChange(../../../shared/sepolicy/vendor/genfs_contexts:virtio_gpu_pci_address)

  virtual ~VmManager() = default;

  virtual bool IsSupported() = 0;

  virtual Result<std::unordered_map<std::string, std::string>>
  ConfigureGraphics(const CuttlefishConfig::InstanceSpecific& instance) = 0;

  virtual Result<std::unordered_map<std::string, std::string>>
  ConfigureBootDevices(const CuttlefishConfig::InstanceSpecific& instance) = 0;

  // Starts the VMM. It will usually build a command and pass it to the
  // command_starter function, although it may start more than one. The
  // command_starter function allows to customize the way vmm commands are
  // started/tracked/etc.
  virtual Result<std::vector<MonitorCommand>> StartCommands(
      const CuttlefishConfig& config,
      std::vector<VmmDependencyCommand*>& dependencyCommands) = 0;

  // Block until the restore work is finished and the guest is running. Only
  // called if a snapshot is being restored.
  //
  // If FD becomes readable or closed, gives up and returns false.
  //
  // Must be thread safe.
  virtual Result<bool> WaitForRestoreComplete(SharedFD) const {
    return CF_ERR("not implemented");
  }
};

fruit::Component<fruit::Required<const CuttlefishConfig,
                                 const CuttlefishConfig::InstanceSpecific>,
                 VmManager>
VmManagerComponent();

std::unique_ptr<VmManager> GetVmManager(VmmMode vmm, Arch arch);

Result<std::unordered_map<std::string, std::string>>
ConfigureMultipleBootDevices(const std::string& pci_path, int pci_offset,
                             int num_disks);

} // namespace vm_manager
} // namespace cuttlefish