// Package prot defines any structures used in the communication between the HCS
// and the GCS. Some of these structures are also used outside the bridge as
// good ways of packaging parameters to core calls.
package prot

import (
	"encoding/json"
	"strconv"

	v1 "github.com/containerd/cgroups/v3/cgroup1/stats"
	oci "github.com/opencontainers/runtime-spec/specs-go"
	"github.com/pkg/errors"

	"github.com/Microsoft/hcsshim/internal/bridgeutils/commonutils"
	hcsschema "github.com/Microsoft/hcsshim/internal/hcs/schema2"
	"github.com/Microsoft/hcsshim/internal/protocol/guestrequest"
	"github.com/Microsoft/hcsshim/internal/protocol/guestresource"
)

//////////// Code for the Message Header ////////////
// Message Identifiers as present in the message header are subdivided into
// various pieces of information.
//
// +---+----+-----+----+
// | T | CC | III | VV |
// +---+----+-----+----+
//
// T   - 4 Bits    Type
// CC  - 8 Bits    Category
// III - 12 Bits   Message Id
// VV  - 8 Bits    Version

const (
	messageTypeMask     = 0xF0000000
	messageCategoryMask = 0x0FF00000
	messageIDMask       = 0x000FFF00
	messageVersionMask  = 0x000000FF
	messageIDShift      = 8
	messageVersionShift = 0
)

// MessageType is the type of the message.
type MessageType uint32

const (
	// MtNone is the default MessageType.
	MtNone = 0
	// MtRequest is the MessageType when a request is received.
	MtRequest = 0x10000000
	// MtResponse is the MessageType used to send a response.
	MtResponse = 0x20000000
	// MtNotification is the MessageType used to send a notification not
	// initiated by a request.
	MtNotification = 0x30000000
)

// MessageCategory allows splitting the identifier namespace to easily route
// similar messages for common processing.
type MessageCategory uint32

const (
	// McNone is the default category.
	McNone = 0
	// McComputeSystem is the category to define message types for compute
	// systems.
	McComputeSystem = 0x00100000
)

// GetResponseIdentifier returns the response version of the given request
// identifier. So, for example, an input of ComputeSystemCreateV1 would result
// in an output of ComputeSystemResponseCreateV1.
func GetResponseIdentifier(identifier MessageIdentifier) MessageIdentifier {
	return MessageIdentifier(MtResponse | (uint32(identifier) & ^uint32(messageTypeMask)))
}

// MessageIdentifier describes the Type field of a MessageHeader struct.
type MessageIdentifier uint32

const (
	// MiNone is the unknown identifier.
	MiNone = 0

	// ComputeSystemCreateV1 is the create container request.
	ComputeSystemCreateV1 = 0x10100101
	// ComputeSystemStartV1 is the start container request.
	ComputeSystemStartV1 = 0x10100201
	// ComputeSystemShutdownGracefulV1 is the graceful shutdown container
	// request.
	ComputeSystemShutdownGracefulV1 = 0x10100301
	// ComputeSystemShutdownForcedV1 is the forceful shutdown container request.
	ComputeSystemShutdownForcedV1 = 0x10100401
	// ComputeSystemExecuteProcessV1 is the execute process request.
	ComputeSystemExecuteProcessV1 = 0x10100501
	// ComputeSystemWaitForProcessV1 is the wait for process exit request.
	ComputeSystemWaitForProcessV1 = 0x10100601
	// ComputeSystemSignalProcessV1 is the signal process request.
	ComputeSystemSignalProcessV1 = 0x10100701
	// ComputeSystemResizeConsoleV1 is the resize console tty request.
	ComputeSystemResizeConsoleV1 = 0x10100801
	// ComputeSystemGetPropertiesV1 is the list process properties request.
	ComputeSystemGetPropertiesV1 = 0x10100901
	// ComputeSystemModifySettingsV1 is the modify container request.
	ComputeSystemModifySettingsV1 = 0x10100a01
	// ComputeSystemNegotiateProtocolV1 is the protocol negotiation request.
	ComputeSystemNegotiateProtocolV1 = 0x10100b01
	// ComputeSystemDumpStacksV1 is the dump stack request
	ComputeSystemDumpStacksV1 = 0x10100c01
	// ComputeSystemDeleteContainerStateV1 is the delete container request.
	ComputeSystemDeleteContainerStateV1 = 0x10100d01

	// ComputeSystemResponseCreateV1 is the create container response.
	ComputeSystemResponseCreateV1 = 0x20100101
	// ComputeSystemResponseStartV1 is the start container response.
	ComputeSystemResponseStartV1 = 0x20100201
	// ComputeSystemResponseShutdownGracefulV1 is the graceful shutdown
	// container response.
	ComputeSystemResponseShutdownGracefulV1 = 0x20100301
	// ComputeSystemResponseShutdownForcedV1 is the forceful shutdown container
	// response.
	ComputeSystemResponseShutdownForcedV1 = 0x20100401
	// ComputeSystemResponseExecuteProcessV1 is the execute process response.
	ComputeSystemResponseExecuteProcessV1 = 0x20100501
	// ComputeSystemResponseWaitForProcessV1 is the wait for process exit
	// response.
	ComputeSystemResponseWaitForProcessV1 = 0x20100601
	// ComputeSystemResponseSignalProcessV1 is the signal process response.
	ComputeSystemResponseSignalProcessV1 = 0x20100701
	// ComputeSystemResponseResizeConsoleV1 is the resize console tty response.
	ComputeSystemResponseResizeConsoleV1 = 0x20100801
	// ComputeSystemResponseGetPropertiesV1 is the list process properties
	// response.
	ComputeSystemResponseGetPropertiesV1 = 0x20100901
	// ComputeSystemResponseModifySettingsV1 is the modify container response.
	ComputeSystemResponseModifySettingsV1 = 0x20100a01
	// ComputeSystemResponseNegotiateProtocolV1 is the protocol negotiation
	// response.
	ComputeSystemResponseNegotiateProtocolV1 = 0x20100b01
	// ComputeSystemResponseDumpStacksV1 is the dump stack response
	ComputeSystemResponseDumpStacksV1 = 0x20100c01

	// ComputeSystemNotificationV1 is the notification identifier.
	ComputeSystemNotificationV1 = 0x30100101
)

// String returns the string representation of the message identifier.
func (mi MessageIdentifier) String() string {
	switch mi {
	case MiNone:
		return "None"
	case ComputeSystemCreateV1:
		return "ComputeSystemCreateV1"
	case ComputeSystemStartV1:
		return "ComputeSystemStartV1"
	case ComputeSystemShutdownGracefulV1:
		return "ComputeSystemShutdownGracefulV1"
	case ComputeSystemShutdownForcedV1:
		return "ComputeSystemShutdownForcedV1"
	case ComputeSystemExecuteProcessV1:
		return "ComputeSystemExecuteProcessV1"
	case ComputeSystemWaitForProcessV1:
		return "ComputeSystemWaitForProcessV1"
	case ComputeSystemSignalProcessV1:
		return "ComputeSystemSignalProcessV1"
	case ComputeSystemResizeConsoleV1:
		return "ComputeSystemResizeConsoleV1"
	case ComputeSystemGetPropertiesV1:
		return "ComputeSystemGetPropertiesV1"
	case ComputeSystemModifySettingsV1:
		return "ComputeSystemModifySettingsV1"
	case ComputeSystemNegotiateProtocolV1:
		return "ComputeSystemNegotiateProtocolV1"
	case ComputeSystemDumpStacksV1:
		return "ComputeSystemDumpStacksV1"
	case ComputeSystemDeleteContainerStateV1:
		return "ComputeSystemDeleteContainerStateV1"
	case ComputeSystemResponseCreateV1:
		return "ComputeSystemResponseCreateV1"
	case ComputeSystemResponseStartV1:
		return "ComputeSystemResponseStartV1"
	case ComputeSystemResponseShutdownGracefulV1:
		return "ComputeSystemResponseShutdownGracefulV1"
	case ComputeSystemResponseShutdownForcedV1:
		return "ComputeSystemResponseShutdownForcedV1"
	case ComputeSystemResponseExecuteProcessV1:
		return "ComputeSystemResponseExecuteProcessV1"
	case ComputeSystemResponseWaitForProcessV1:
		return "ComputeSystemResponseWaitForProcessV1"
	case ComputeSystemResponseSignalProcessV1:
		return "ComputeSystemResponseSignalProcessV1"
	case ComputeSystemResponseResizeConsoleV1:
		return "ComputeSystemResponseResizeConsoleV1"
	case ComputeSystemResponseGetPropertiesV1:
		return "ComputeSystemResponseGetPropertiesV1"
	case ComputeSystemResponseModifySettingsV1:
		return "ComputeSystemResponseModifySettingsV1"
	case ComputeSystemResponseNegotiateProtocolV1:
		return "ComputeSystemResponseNegotiateProtocolV1"
	case ComputeSystemResponseDumpStacksV1:
		return "ComputeSystemResponseDumpStacksV1"
	case ComputeSystemNotificationV1:
		return "ComputeSystemNotificationV1"
	default:
		return strconv.FormatUint(uint64(mi), 10)
	}
}

// SequenceID is used to correlate requests and responses.
type SequenceID uint64

// MessageHeader is the common header present in all communications messages.
type MessageHeader struct {
	Type MessageIdentifier
	Size uint32
	ID   SequenceID
}

// MessageHeaderSize is the size in bytes of the MessageHeader struct.
const MessageHeaderSize = 16

/////////////////////////////////////////////////////

// ProtocolVersion is a type for the selected HCS<->GCS protocol version of
// messages
type ProtocolVersion uint32

// Protocol versions.
const (
	PvInvalid ProtocolVersion = 0
	PvV4      ProtocolVersion = 4
	PvMax     ProtocolVersion = PvV4
)

// ProtocolSupport specifies the protocol versions to be used for HCS-GCS
// communication.
type ProtocolSupport struct {
	MinimumVersion         string `json:",omitempty"`
	MaximumVersion         string `json:",omitempty"`
	MinimumProtocolVersion uint32
	MaximumProtocolVersion uint32
}

// OsType defines the operating system type identifier of the guest hosting the
// GCS.
type OsType string

// OsTypeLinux is the OS type the HCS expects for a Linux GCS
const OsTypeLinux OsType = "Linux"

// GcsCapabilities specifies the abilities and scenarios supported by this GCS.
type GcsCapabilities struct {
	// True if a create message should be sent for the hosting system itself.
	SendHostCreateMessage bool `json:",omitempty"`
	// True if a start message should be sent for the hosting system itself. If
	// SendHostCreateMessage is false, a start message will not be sent either.
	SendHostStartMessage bool `json:",omitempty"`
	// True if an HVSocket ModifySettings request should be sent immediately
	// after the create/start messages are sent (if they're sent at all). This
	// ModifySettings request would be to configure the local and parent
	// Hyper-V socket addresses of the VM, and would have a RequestType of
	// Update.
	HVSocketConfigOnStartup bool            `json:"HvSocketConfigOnStartup,omitempty"`
	SupportedSchemaVersions []SchemaVersion `json:",omitempty"`
	RuntimeOsType           OsType          `json:",omitempty"`
	// GuestDefinedCapabilities define any JSON object that will be directly
	// passed to a client of the HCS. This can be useful to pass runtime
	// specific capabilities not tied to the platform itself.
	GuestDefinedCapabilities GcsGuestCapabilities `json:",omitempty"`
}

// GcsGuestCapabilities represents the customized guest capabilities supported
// by this GCS.
type GcsGuestCapabilities struct {
	NamespaceAddRequestSupported  bool `json:",omitempty"`
	SignalProcessSupported        bool `json:",omitempty"`
	DumpStacksSupported           bool `json:",omitempty"`
	DeleteContainerStateSupported bool `json:",omitempty"`
}

// ocspancontext is the internal JSON representation of the OpenCensus
// `trace.SpanContext` for fowarding to a GCS that supports it.
type ocspancontext struct {
	// TraceID is the `hex` encoded string of the OpenCensus
	// `SpanContext.TraceID` to propagate to the guest.
	TraceID string `json:",omitempty"`
	// SpanID is the `hex` encoded string of the OpenCensus `SpanContext.SpanID`
	// to propagate to the guest.
	SpanID string `json:",omitempty"`

	// TraceOptions is the OpenCensus `SpanContext.TraceOptions` passed through
	// to propagate to the guest.
	TraceOptions uint32 `json:",omitempty"`

	// Tracestate is the `base64` encoded string of marshaling the OpenCensus
	// `SpanContext.TraceState.Entries()` to JSON.
	//
	// If `SpanContext.Tracestate == nil ||
	// len(SpanContext.Tracestate.Entries()) == 0` this will be `""`.
	Tracestate string `json:",omitempty"`
}

// MessageBase is the base type embedded in all messages sent from the HCS to
// the GCS, as well as ContainerNotification which is sent from GCS to HCS.
type MessageBase struct {
	ContainerID string `json:"ContainerId"`
	ActivityID  string `json:"ActivityId"`

	// OpenCensusSpanContext is the encoded OpenCensus `trace.SpanContext` if
	// set when making the request.
	//
	// NOTE: This is not a part of the protocol but because its a JSON protocol
	// adding fields is a non-breaking change. If the guest supports it this is
	// just additive context.
	OpenCensusSpanContext *ocspancontext `json:"ocsc,omitempty"`
}

// NegotiateProtocol is the message from the HCS used to determine the protocol
// version that will be used for future communication.
type NegotiateProtocol struct {
	MessageBase
	MinimumVersion uint32
	MaximumVersion uint32
}

// ContainerCreate is the message from the HCS specifying to create a container
// in the utility VM. This message won't actually create a Linux container
// inside the utility VM, but will set up the infrustructure needed to start one
// once the container's initial process is executed.
type ContainerCreate struct {
	MessageBase
	ContainerConfig   string
	SupportedVersions ProtocolSupport `json:",omitempty"`
}

// NotificationType defines a type of notification to be sent back to the HCS.
type NotificationType string

const (
	// NtNone indicates nothing to be sent back to the HCS
	NtNone = NotificationType("None")
	// NtGracefulExit indicates a graceful exit notification to be sent back to
	// the HCS
	NtGracefulExit = NotificationType("GracefulExit")
	// NtForcedExit indicates a forced exit notification to be sent back to the
	// HCS
	NtForcedExit = NotificationType("ForcedExit")
	// NtUnexpectedExit indicates an unexpected exit notification to be sent
	// back to the HCS
	NtUnexpectedExit = NotificationType("UnexpectedExit")
	// NtReboot indicates a reboot notification to be sent back to the HCS
	NtReboot = NotificationType("Reboot")
	// NtConstructed indicates a constructed notification to be sent back to the
	// HCS
	NtConstructed = NotificationType("Constructed")
	// NtStarted indicates a started notification to be sent back to the HCS
	NtStarted = NotificationType("Started")
	// NtPaused indicates a paused notification to be sent back to the HCS
	NtPaused = NotificationType("Paused")
	// NtUnknown indicates an unknown notification to be sent back to the HCS
	NtUnknown = NotificationType("Unknown")
)

// ActiveOperation defines an operation to be associated with a notification
// sent back to the HCS.
type ActiveOperation string

const (
	// AoNone indicates no active operation
	AoNone = ActiveOperation("None")
	// AoConstruct indicates a construct active operation
	AoConstruct = ActiveOperation("Construct")
	// AoStart indicates a start active operation
	AoStart = ActiveOperation("Start")
	// AoPause indicates a pause active operation
	AoPause = ActiveOperation("Pause")
	// AoResume indicates a resume active operation
	AoResume = ActiveOperation("Resume")
	// AoShutdown indicates a shutdown active operation
	AoShutdown = ActiveOperation("Shutdown")
	// AoTerminate indicates a terminate active operation
	AoTerminate = ActiveOperation("Terminate")
)

// ContainerNotification is a message sent from the GCS to the HCS to indicate
// some kind of event. At the moment, it is only used for container exit
// notifications.
type ContainerNotification struct {
	MessageBase
	Type       NotificationType
	Operation  ActiveOperation
	Result     int32
	ResultInfo string `json:",omitempty"`
}

// ExecuteProcessVsockStdioRelaySettings defines the port numbers for each
// stdio socket for a process.
type ExecuteProcessVsockStdioRelaySettings struct {
	StdIn  uint32 `json:",omitempty"`
	StdOut uint32 `json:",omitempty"`
	StdErr uint32 `json:",omitempty"`
}

// ExecuteProcessSettings defines the settings for a single process to be
// executed either inside or outside the container namespace.
type ExecuteProcessSettings struct {
	ProcessParameters       string
	VsockStdioRelaySettings ExecuteProcessVsockStdioRelaySettings
}

// ContainerExecuteProcess is the message from the HCS specifying to execute a
// process either inside or outside the container namespace.
type ContainerExecuteProcess struct {
	MessageBase
	Settings ExecuteProcessSettings
}

// ContainerResizeConsole is the message from the HCS specifying to change the
// console size for the given process.
type ContainerResizeConsole struct {
	MessageBase
	ProcessID uint32 `json:"ProcessId"`
	Height    uint16
	Width     uint16
}

// ContainerWaitForProcess is the message from the HCS specifying to wait until
// the given process exits. After receiving this message, the corresponding
// response should not be sent until the process has exited.
type ContainerWaitForProcess struct {
	MessageBase
	ProcessID   uint32 `json:"ProcessId"`
	TimeoutInMs uint32
}

// InfiniteWaitTimeout is the value for ContainerWaitForProcess.TimeoutInMs that
// indicates that no timeout should be in effect.
const InfiniteWaitTimeout = 0xffffffff

// ContainerSignalProcess is the message from the HCS specifying to send a
// signal to the given process.
type ContainerSignalProcess struct {
	MessageBase
	ProcessID uint32               `json:"ProcessId"`
	Options   SignalProcessOptions `json:",omitempty"`
}

// ContainerGetProperties is the message from the HCS requesting certain
// properties of the container, such as a list of its processes.
type ContainerGetProperties struct {
	MessageBase
	Query string
}

// PropertyType is the type of property, such as memory or virtual disk, which
// is to be modified for the container.
type PropertyType string

const (
	// PtMemory is the property type for memory
	PtMemory = PropertyType("Memory")
	// PtCPUGroup is the property type for CPU group
	PtCPUGroup = PropertyType("CpuGroup")
	// PtStatistics is the property type for statistics
	PtStatistics = PropertyType("Statistics")
	// PtProcessList is the property type for a process list
	PtProcessList = PropertyType("ProcessList")
	// PtPendingUpdates is the property type for determining if there are
	// pending updates
	PtPendingUpdates = PropertyType("PendingUpdates")
	// PtTerminateOnLastHandleClosed is the property type for exiting when the
	// last handle is closed
	PtTerminateOnLastHandleClosed = PropertyType("TerminateOnLastHandleClosed")
	// PtMappedDirectory is the property type for mapped directories
	PtMappedDirectory = PropertyType("MappedDirectory")
	// PtSystemGUID is the property type for the system GUID
	PtSystemGUID = PropertyType("SystemGUID")
	// PtNetwork is the property type for networking
	PtNetwork = PropertyType("Network")
	// PtMappedPipe is the property type for mapped pipes
	PtMappedPipe = PropertyType("MappedPipe")
	// PtMappedVirtualDisk is the property type for mapped virtual disks
	PtMappedVirtualDisk = PropertyType("MappedVirtualDisk")
)

// RequestType is the type of operation to perform on a given property type.
type RequestType string

const (
	// RtAdd is the "Add" request type of operation
	RtAdd = RequestType("Add")
	// RtRemove is the "Remove" request type of operation
	RtRemove = RequestType("Remove")
	// RtUpdate is the "Update" request type of operation
	RtUpdate = RequestType("Update")
)

// ResourceModificationRequestResponse details a container resource which should
// be modified, how, and with what parameters.
type ResourceModificationRequestResponse struct {
	ResourceType PropertyType
	RequestType  RequestType `json:",omitempty"`
	Settings     interface{} `json:",omitempty"`
}

// containerModifySettings is the message from the HCS specifying how a certain
// container resource should be modified.
type containerModifySettings struct {
	MessageBase
	Request interface{}
}

// UnmarshalContainerModifySettings unmarshals the given bytes into a
// ContainerModifySettings message. This function is required because properties
// such as `Settings` can be of many types identified by the `ResourceType` and
// require dynamic unmarshalling.
func UnmarshalContainerModifySettings(b []byte) (*containerModifySettings, error) {
	// Unmarshal the message.
	var request containerModifySettings
	var requestRawSettings json.RawMessage
	request.Request = &requestRawSettings
	if err := commonutils.UnmarshalJSONWithHresult(b, &request); err != nil {
		return nil, errors.Wrap(err, "failed to unmarshal ContainerModifySettings")
	}

	var msr guestrequest.ModificationRequest
	var msrRawSettings json.RawMessage
	msr.Settings = &msrRawSettings
	if err := commonutils.UnmarshalJSONWithHresult(requestRawSettings, &msr); err != nil {
		return &request, errors.Wrap(err, "failed to unmarshal request.Settings as ModifySettingRequest")
	}

	if msr.RequestType == "" {
		msr.RequestType = guestrequest.RequestTypeAdd
	}

	// Fill in the ResourceType-specific fields.
	switch msr.ResourceType {
	case guestresource.ResourceTypeSCSIDevice:
		msd := &guestresource.SCSIDevice{}
		if err := commonutils.UnmarshalJSONWithHresult(msrRawSettings, msd); err != nil {
			return &request, errors.Wrap(err, "failed to unmarshal settings as SCSIDevice")
		}
		msr.Settings = msd
	case guestresource.ResourceTypeMappedVirtualDisk:
		mvd := &guestresource.LCOWMappedVirtualDisk{}
		if err := commonutils.UnmarshalJSONWithHresult(msrRawSettings, mvd); err != nil {
			return &request, errors.Wrap(err, "failed to unmarshal settings as MappedVirtualDiskV2")
		}
		msr.Settings = mvd
	case guestresource.ResourceTypeMappedDirectory:
		md := &guestresource.LCOWMappedDirectory{}
		if err := commonutils.UnmarshalJSONWithHresult(msrRawSettings, md); err != nil {
			return &request, errors.Wrap(err, "failed to unmarshal settings as MappedDirectoryV2")
		}
		msr.Settings = md
	case guestresource.ResourceTypeVPMemDevice:
		vpd := &guestresource.LCOWMappedVPMemDevice{}
		if err := commonutils.UnmarshalJSONWithHresult(msrRawSettings, vpd); err != nil {
			return &request, errors.Wrap(err, "failed to unmarshal hosted settings as MappedVPMemDeviceV2")
		}
		msr.Settings = vpd
	case guestresource.ResourceTypeCombinedLayers:
		cl := &guestresource.LCOWCombinedLayers{}
		if err := commonutils.UnmarshalJSONWithHresult(msrRawSettings, cl); err != nil {
			return &request, errors.Wrap(err, "failed to unmarshal settings as CombinedLayersV2")
		}
		msr.Settings = cl
	case guestresource.ResourceTypeNetwork:
		na := &guestresource.LCOWNetworkAdapter{}
		if err := commonutils.UnmarshalJSONWithHresult(msrRawSettings, na); err != nil {
			return &request, errors.Wrap(err, "failed to unmarshal settings as NetworkAdapterV2")
		}
		msr.Settings = na
	case guestresource.ResourceTypeVPCIDevice:
		vd := &guestresource.LCOWMappedVPCIDevice{}
		if err := commonutils.UnmarshalJSONWithHresult(msrRawSettings, vd); err != nil {
			return &request, errors.Wrap(err, "failed to unmarshal settings as MappedVPCIDeviceV2")
		}
		msr.Settings = vd
	case guestresource.ResourceTypeContainerConstraints:
		cc := &guestresource.LCOWContainerConstraints{}
		if err := commonutils.UnmarshalJSONWithHresult(msrRawSettings, cc); err != nil {
			return &request, errors.Wrap(err, "failed to unmarshal settings as ContainerConstraintsV2")
		}
		msr.Settings = cc
	case guestresource.ResourceTypeSecurityPolicy:
		enforcer := &guestresource.ConfidentialOptions{}
		if err := commonutils.UnmarshalJSONWithHresult(msrRawSettings, enforcer); err != nil {
			return &request, errors.Wrap(err, "failed to unmarshal settings as ConfidentialOptions")
		}
		msr.Settings = enforcer
	case guestresource.ResourceTypePolicyFragment:
		fragment := &guestresource.SecurityPolicyFragment{}
		if err := commonutils.UnmarshalJSONWithHresult(msrRawSettings, fragment); err != nil {
			return &request, errors.Wrap(err, "failed to unmarshal settings as SecurityPolicyFragment")
		}
		msr.Settings = fragment
	default:
		return &request, errors.Errorf("invalid ResourceType '%s'", msr.ResourceType)
	}
	request.Request = &msr
	return &request, nil
}

// MessageResponseBase is the base type embedded in all messages sent from the
// GCS to the HCS except for ContainerNotification.
type MessageResponseBase struct {
	Result       int32
	ActivityID   string                    `json:"ActivityId,omitempty"`
	ErrorMessage string                    `json:",omitempty"` // Only used by hcsshim external bridge
	ErrorRecords []commonutils.ErrorRecord `json:",omitempty"`
}

// Base returns the response base by reference.
func (mrp *MessageResponseBase) Base() *MessageResponseBase {
	return mrp
}

// NegotiateProtocolResponse is the message to the HCS responding to a
// NegotiateProtocol message. It specifies the preferred protocol version and
// available capabilities of the GCS.
type NegotiateProtocolResponse struct {
	MessageResponseBase
	Version      uint32
	Capabilities GcsCapabilities
}

type DumpStacksResponse struct {
	MessageResponseBase
	GuestStacks string
}

// ContainerCreateResponse is the message to the HCS responding to a
// ContainerCreate message. It serves a protocol negotiation function as well
// for protocol versions 3 and lower, returning protocol version information to
// the HCS.
type ContainerCreateResponse struct {
	MessageResponseBase
	SelectedVersion         string `json:",omitempty"`
	SelectedProtocolVersion uint32
}

// ContainerExecuteProcessResponse is the message to the HCS responding to a
// ContainerExecuteProcess message. It provides back the process's pid.
type ContainerExecuteProcessResponse struct {
	MessageResponseBase
	ProcessID uint32 `json:"ProcessId"`
}

// ContainerWaitForProcessResponse is the message to the HCS responding to a
// ContainerWaitForProcess message. It is only sent when the process has exited.
type ContainerWaitForProcessResponse struct {
	MessageResponseBase
	ExitCode uint32
}

// ContainerGetPropertiesResponse is the message to the HCS responding to a
// ContainerGetProperties message. It contains a string representing the
// properties requested.
type ContainerGetPropertiesResponse struct {
	MessageResponseBase
	Properties string
}

/* types added on to the current official protocol types */

// NetworkAdapter represents a network interface and its associated
// configuration.
type NetworkAdapter struct {
	AdapterInstanceID    string `json:"AdapterInstanceId"`
	FirewallEnabled      bool
	NatEnabled           bool
	MacAddress           string `json:",omitempty"`
	AllocatedIPAddress   string `json:"AllocatedIpAddress,omitempty"`
	HostIPAddress        string `json:"HostIpAddress,omitempty"`
	HostIPPrefixLength   uint8  `json:"HostIpPrefixLength,omitempty"`
	AllocatedIPv6Address string `json:"AllocatedIpv6Address,omitempty"`
	HostIPv6Address      string `json:"HostIpv6Address,omitempty"`
	HostIPv6PrefixLength uint8  `json:"HostIpv6PrefixLength,omitempty"`
	HostDNSServerList    string `json:"HostDnsServerList,omitempty"`
	HostDNSSuffix        string `json:"HostDnsSuffix,omitempty"`
	EnableLowMetric      bool   `json:",omitempty"`
	EncapOverhead        uint16 `json:",omitempty"`
}

// MappedVirtualDisk represents a disk on the host which is mapped into a
// directory in the guest.
type MappedVirtualDisk struct {
	ContainerPath     string
	Lun               uint8 `json:",omitempty"`
	CreateInUtilityVM bool  `json:",omitempty"`
	ReadOnly          bool  `json:",omitempty"`
	AttachOnly        bool  `json:",omitempty"`
}

// MappedDirectory represents a directory on the host which is mapped to a
// directory on the guest through a technology such as Plan9.
type MappedDirectory struct {
	ContainerPath     string
	CreateInUtilityVM bool   `json:",omitempty"`
	ReadOnly          bool   `json:",omitempty"`
	Port              uint32 `json:",omitempty"`
}

// VMHostedContainerSettings is the set of settings used to specify the initial
// configuration of a container.
type VMHostedContainerSettings struct {
	Layers []hcsschema.Layer
	// SandboxDataPath is in this case the identifier (such as the SCSI number)
	// of the sandbox device.
	SandboxDataPath    string
	MappedVirtualDisks []MappedVirtualDisk
	MappedDirectories  []MappedDirectory
	NetworkAdapters    []NetworkAdapter `json:",omitempty"`
}

// SchemaVersion defines the version of the schema that should be deserialized.
type SchemaVersion struct {
	Major uint32 `json:",omitempty"`
	Minor uint32 `json:",omitempty"`
}

// Cmp compares s and v and returns:
//
//	-1 if s <  v
//	0 if s == v
//	1 if s >  v
func (s *SchemaVersion) Cmp(v SchemaVersion) int {
	if s.Major == v.Major {
		if s.Minor == v.Minor {
			return 0
		} else if s.Minor < v.Minor {
			return -1
		}
		return 1
	} else if s.Major < v.Major {
		return -1
	}
	return 1
}

// VMHostedContainerSettingsV2 defines the portion of the
// ContainerCreate.ContainerConfig that is sent via a V2 call. This correlates
// to the 'HostedSystem' on the HCS side but rather than sending the 'Container'
// field the Linux GCS accepts an oci.Spec directly.
type VMHostedContainerSettingsV2 struct {
	SchemaVersion    SchemaVersion
	OCIBundlePath    string    `json:"OciBundlePath,omitempty"`
	OCISpecification *oci.Spec `json:"OciSpecification,omitempty"`
	// ScratchDirPath represents the path inside the UVM at which the container scratch
	// directory is present.  Usually, this is the path at which the container scratch
	// VHD is mounted inside the UVM. But in case of scratch sharing this is a
	// directory under the UVM scratch directory.
	ScratchDirPath string
}

// ProcessParameters represents any process which may be started in the utility
// VM. This covers three cases:
// 1.) It is an external process, i.e. a process running inside the utility VM
// but not inside any container. In this case, don't specify the
// OCISpecification field, but specify all other fields.
// 2.) It is the first process in a container. In this case, specify only the
// OCISpecification field, and not the other fields.
// 3.) It is a container process, but not the first process in that container.
// In this case, don't specify the OCISpecification field, but specify all
// other fields. This is the same as if it were an external process.
type ProcessParameters struct {
	// CommandLine is a space separated list of command line parameters. For
	// example, the command which sleeps for 100 seconds would be represented by
	// the CommandLine string "sleep 100".
	CommandLine string `json:",omitempty"`
	// CommandArgs is a list of strings representing the command to execute. If
	// it is not empty, it will be used by the GCS. If it is empty, CommandLine
	// will be used instead.
	CommandArgs      []string          `json:",omitempty"`
	WorkingDirectory string            `json:",omitempty"`
	Environment      map[string]string `json:",omitempty"`
	EmulateConsole   bool              `json:",omitempty"`
	CreateStdInPipe  bool              `json:",omitempty"`
	CreateStdOutPipe bool              `json:",omitempty"`
	CreateStdErrPipe bool              `json:",omitempty"`
	// If IsExternal is false, the process will be created inside a container.
	// If true, it will be created external to any container. The latter is
	// useful if, for example, you want to start up a shell in the utility VM
	// for debugging/diagnostic purposes.
	IsExternal bool `json:"CreateInUtilityVM,omitempty"`
	// If this is the first process created for this container, this field must
	// be specified. Otherwise, it must be left blank and the other fields must
	// be specified.
	OCISpecification *oci.Spec `json:"OciSpecification,omitempty"`

	OCIProcess *oci.Process `json:"OciProcess,omitempty"`
}

// SignalProcessOptions represents the options for signaling a process.
type SignalProcessOptions struct {
	Signal int32
}

// ProcessDetails represents information about a given process.
type ProcessDetails struct {
	ProcessID uint32 `json:"ProcessId"`
}

// PropertyQuery is a query to specify which properties are requested.
type PropertyQuery struct {
	PropertyTypes []PropertyType `json:",omitempty"`
}

// Properties represents the properties of a compute system.
type Properties struct {
	ProcessList []ProcessDetails `json:",omitempty"`
}

type PropertiesV2 struct {
	ProcessList []ProcessDetails `json:"ProcessList,omitempty"`
	Metrics     *v1.Metrics      `json:"LCOWMetrics,omitempty"`
}
