tasks/components/nexusoperations/tasks.go

package nexusoperations

import (
	"errors"
	"fmt"
	"time"

	enumspb "go.temporal.io/api/enums/v1"
	"go.temporal.io/api/serviceerror"
	enumsspb "github.com/hanzoai/tasks/api/enums/v1"
	persistencespb "github.com/hanzoai/tasks/api/persistence/v1"
	"github.com/hanzoai/tasks/common/persistence/serialization"
	"github.com/hanzoai/tasks/service/history/consts"
	"github.com/hanzoai/tasks/service/history/hsm"
	"google.golang.org/protobuf/proto"
)

const (
	TaskTypeInvocation         = "nexusoperations.Invocation"
	TaskTypeBackoff            = "nexusoperations.Backoff"
	TaskTypeCancelation        = "nexusoperations.Cancelation"
	TaskTypeCancelationBackoff = "nexusoperations.CancelationBackoff"
	// NOTE: the name `Timeout` is used for backward compatibility with existing persisted tasks and predates the addition of more flexible timeout types.
	TaskTypeScheduleToCloseTimeout = "nexusoperations.Timeout"
	TaskTypeScheduleToStartTimeout = "nexusoperations.ScheduleToStartTimeout"
	TaskTypeStartToCloseTimeout    = "nexusoperations.StartToCloseTimeout"
)

var errSerializationCast = errors.New("cannot serialize HSM task. unable to cast to expected type")

type ScheduleToCloseTimeoutTask struct {
	deadline time.Time
}

var _ hsm.Task = ScheduleToCloseTimeoutTask{}

func (ScheduleToCloseTimeoutTask) Type() string {
	return TaskTypeScheduleToCloseTimeout
}

func (t ScheduleToCloseTimeoutTask) Deadline() time.Time {
	return t.deadline
}

func (ScheduleToCloseTimeoutTask) Destination() string {
	return ""
}

// Validate checks if the timeout task is still valid to execute for the given node state.
func (t ScheduleToCloseTimeoutTask) Validate(ref *persistencespb.StateMachineRef, node *hsm.Node) error {
	if err := node.CheckRunning(); err != nil {
		return err
	}
	op, err := hsm.MachineData[Operation](node)
	if err != nil {
		return err
	}
	if !TransitionTimedOut.Possible(op) {
		return fmt.Errorf(
			"%w: %w: cannot timeout machine in state %v",
			consts.ErrStaleReference,
			hsm.ErrInvalidTransition,
			op.State(),
		)
	}
	return nil
}

type TimeoutTaskSerializer struct{}

func (TimeoutTaskSerializer) Deserialize(data []byte, attrs hsm.TaskAttributes) (hsm.Task, error) {
	return ScheduleToCloseTimeoutTask{deadline: attrs.Deadline}, nil
}

func (TimeoutTaskSerializer) Serialize(hsm.Task) ([]byte, error) {
	return nil, nil
}

type InvocationTask struct {
	EndpointName string
	Attempt      int32
}

var _ hsm.Task = InvocationTask{}

func (InvocationTask) Type() string {
	return TaskTypeInvocation
}

func (InvocationTask) Deadline() time.Time {
	return hsm.Immediate
}

func (t InvocationTask) Destination() string {
	return t.EndpointName
}

func (InvocationTask) Validate(ref *persistencespb.StateMachineRef, node *hsm.Node) error {
	if err := node.CheckRunning(); err != nil {
		return err
	}
	return hsm.ValidateState[enumsspb.NexusOperationState, Operation](node, enumsspb.NEXUS_OPERATION_STATE_SCHEDULED)
}

type InvocationTaskSerializer struct{}

func (InvocationTaskSerializer) Deserialize(data []byte, attrs hsm.TaskAttributes) (hsm.Task, error) {
	var info persistencespb.NexusInvocationTaskInfo
	err := proto.Unmarshal(data, &info)
	if err != nil {
		return nil, serialization.NewDeserializationError(enumspb.ENCODING_TYPE_PROTO3, err)
	}
	return InvocationTask{EndpointName: attrs.Destination, Attempt: info.Attempt}, nil
}

func (InvocationTaskSerializer) Serialize(task hsm.Task) ([]byte, error) {
	switch task := task.(type) {
	case InvocationTask:
		return proto.Marshal(&persistencespb.NexusInvocationTaskInfo{Attempt: task.Attempt})
	default:
		return nil, serviceerror.NewInternalf("unknown HSM task type while serializing: %v", task)
	}
}

type BackoffTask struct {
	deadline time.Time
}

var _ hsm.Task = BackoffTask{}

func (BackoffTask) Type() string {
	return TaskTypeBackoff
}

func (t BackoffTask) Deadline() time.Time {
	return t.deadline
}

func (t BackoffTask) Destination() string {
	return ""
}

func (t BackoffTask) Validate(_ *persistencespb.StateMachineRef, node *hsm.Node) error {
	if err := node.CheckRunning(); err != nil {
		return err
	}
	return hsm.ValidateState[enumsspb.NexusOperationState, Operation](node, enumsspb.NEXUS_OPERATION_STATE_BACKING_OFF)
}

type BackoffTaskSerializer struct{}

func (BackoffTaskSerializer) Deserialize(data []byte, attrs hsm.TaskAttributes) (hsm.Task, error) {
	return BackoffTask{deadline: attrs.Deadline}, nil
}

func (BackoffTaskSerializer) Serialize(hsm.Task) ([]byte, error) {
	return nil, nil
}

type CancelationTask struct {
	EndpointName string
	Attempt      int32
}

var _ hsm.Task = CancelationTask{}

func (CancelationTask) Type() string {
	return TaskTypeCancelation
}

func (CancelationTask) Deadline() time.Time {
	return hsm.Immediate
}

func (t CancelationTask) Destination() string {
	return t.EndpointName
}

func (CancelationTask) Validate(ref *persistencespb.StateMachineRef, node *hsm.Node) error {
	if err := node.CheckRunning(); err != nil {
		return err
	}
	return hsm.ValidateState[enumspb.NexusOperationCancellationState, Cancelation](node, enumspb.NEXUS_OPERATION_CANCELLATION_STATE_SCHEDULED)
}

type CancelationTaskSerializer struct{}

func (CancelationTaskSerializer) Deserialize(data []byte, attrs hsm.TaskAttributes) (hsm.Task, error) {
	var info persistencespb.NexusCancelationTaskInfo
	err := proto.Unmarshal(data, &info)
	if err != nil {
		return nil, serialization.NewDeserializationError(enumspb.ENCODING_TYPE_PROTO3, err)
	}
	return CancelationTask{EndpointName: attrs.Destination, Attempt: info.Attempt}, nil
}

func (CancelationTaskSerializer) Serialize(task hsm.Task) ([]byte, error) {
	switch task := task.(type) {
	case CancelationTask:
		return proto.Marshal(&persistencespb.NexusCancelationTaskInfo{Attempt: task.Attempt})
	default:
		return nil, serviceerror.NewInternalf("unknown HSM task type while serializing: %v", task)
	}
}

type CancelationBackoffTask struct {
	deadline time.Time
}

var _ hsm.Task = CancelationBackoffTask{}

func (CancelationBackoffTask) Type() string {
	return TaskTypeCancelationBackoff
}

func (t CancelationBackoffTask) Deadline() time.Time {
	return t.deadline
}

func (CancelationBackoffTask) Destination() string {
	return ""
}

func (CancelationBackoffTask) Validate(ref *persistencespb.StateMachineRef, node *hsm.Node) error {
	if err := node.CheckRunning(); err != nil {
		return err
	}
	return hsm.ValidateState[enumspb.NexusOperationCancellationState, Cancelation](node, enumspb.NEXUS_OPERATION_CANCELLATION_STATE_BACKING_OFF)
}

type CancelationBackoffTaskSerializer struct{}

func (CancelationBackoffTaskSerializer) Deserialize(data []byte, attrs hsm.TaskAttributes) (hsm.Task, error) {
	return CancelationBackoffTask{deadline: attrs.Deadline}, nil
}

func (CancelationBackoffTaskSerializer) Serialize(hsm.Task) ([]byte, error) {
	return nil, nil
}

type ScheduleToStartTimeoutTask struct {
	deadline time.Time
}

var _ hsm.Task = ScheduleToStartTimeoutTask{}

func (ScheduleToStartTimeoutTask) Type() string {
	return TaskTypeScheduleToStartTimeout
}

func (t ScheduleToStartTimeoutTask) Deadline() time.Time {
	return t.deadline
}

func (ScheduleToStartTimeoutTask) Destination() string {
	return ""
}

// Validate checks if the schedule-to-start timeout task is still valid.
// Only valid if operation is still in SCHEDULED or BACKING_OFF state.
func (t ScheduleToStartTimeoutTask) Validate(ref *persistencespb.StateMachineRef, node *hsm.Node) error {
	if err := node.CheckRunning(); err != nil {
		return err
	}
	op, err := hsm.MachineData[Operation](node)
	if err != nil {
		return err
	}
	// Only timeout if we haven't started yet
	switch op.State() {
	case enumsspb.NEXUS_OPERATION_STATE_SCHEDULED,
		enumsspb.NEXUS_OPERATION_STATE_BACKING_OFF:
		return nil
	default:
		// Already started or completed, timeout not applicable
		return fmt.Errorf(
			"%w: %w: cannot apply schedule-to-start timeout to machine in state %v",
			consts.ErrStaleReference,
			hsm.ErrInvalidTransition,
			op.State(),
		)
	}
}

type ScheduleToStartTimeoutTaskSerializer struct{}

func (ScheduleToStartTimeoutTaskSerializer) Deserialize(data []byte, attrs hsm.TaskAttributes) (hsm.Task, error) {
	return ScheduleToStartTimeoutTask{deadline: attrs.Deadline}, nil
}

func (ScheduleToStartTimeoutTaskSerializer) Serialize(hsm.Task) ([]byte, error) {
	return nil, nil
}

type StartToCloseTimeoutTask struct {
	deadline time.Time
}

var _ hsm.Task = StartToCloseTimeoutTask{}

func (StartToCloseTimeoutTask) Type() string {
	return TaskTypeStartToCloseTimeout
}

func (t StartToCloseTimeoutTask) Deadline() time.Time {
	return t.deadline
}

func (StartToCloseTimeoutTask) Destination() string {
	return ""
}

// Validate checks if the start-to-close timeout task is still valid.
// Only valid if operation is in STARTED state.
func (t StartToCloseTimeoutTask) Validate(ref *persistencespb.StateMachineRef, node *hsm.Node) error {
	if err := node.CheckRunning(); err != nil {
		return err
	}
	op, err := hsm.MachineData[Operation](node)
	if err != nil {
		return err
	}
	// Only timeout if we're in started state
	if op.State() != enumsspb.NEXUS_OPERATION_STATE_STARTED {
		return fmt.Errorf(
			"%w: %w: cannot apply start-to-close timeout to machine in state %v",
			consts.ErrStaleReference,
			hsm.ErrInvalidTransition,
			op.State(),
		)
	}
	return nil
}

type StartToCloseTimeoutTaskSerializer struct{}

func (StartToCloseTimeoutTaskSerializer) Deserialize(data []byte, attrs hsm.TaskAttributes) (hsm.Task, error) {
	return StartToCloseTimeoutTask{deadline: attrs.Deadline}, nil
}

func (StartToCloseTimeoutTaskSerializer) Serialize(hsm.Task) ([]byte, error) {
	return nil, nil
}

func RegisterTaskSerializers(reg *hsm.Registry) error {
	if err := reg.RegisterTaskSerializer(TaskTypeScheduleToCloseTimeout, TimeoutTaskSerializer{}); err != nil {
		return err
	}
	if err := reg.RegisterTaskSerializer(TaskTypeInvocation, InvocationTaskSerializer{}); err != nil {
		return err
	}
	if err := reg.RegisterTaskSerializer(TaskTypeBackoff, BackoffTaskSerializer{}); err != nil {
		return err
	}
	if err := reg.RegisterTaskSerializer(TaskTypeCancelation, CancelationTaskSerializer{}); err != nil {
		return err
	}
	if err := reg.RegisterTaskSerializer(TaskTypeCancelationBackoff, CancelationBackoffTaskSerializer{}); err != nil { // nolint:revive
		return err
	}
	if err := reg.RegisterTaskSerializer(TaskTypeScheduleToStartTimeout, ScheduleToStartTimeoutTaskSerializer{}); err != nil {
		return err
	}
	return reg.RegisterTaskSerializer(TaskTypeStartToCloseTimeout, StartToCloseTimeoutTaskSerializer{})
}