fsm_instance.go

package msm

import (
	"reflect"
	"time"

	"go.uber.org/zap"
)

type FSMState struct {
	Id          int64     `gorm:"primaryKey;autoIncrement"`
	CreatedAt   time.Time // special name handled by GORM
	UpdatedAt   time.Time // special name handled by GORM
	Fsm         string    `gorm:"index:idx_fsm_term"`
	State       string
	Storage     string `gorm:"type:json"`
	Terminated  bool   `gorm:"index:idx_fsm_term"`
	Description string `gorm:"index"`
}

func (f *FSMState) FsmID() FsmID {
	return FsmID{
		Fsm: f.Fsm,
		Id:  f.Id,
	}
}

type FSMInstance struct {
	FSMState
	Manager *FSM
	Storage reflect.Value // To be casted on a call
}

func (fi *FSMInstance) iProcess(response Response) {
	eventKey := TransitionKey{
		State: State(fi.State),
		Event: reflect.TypeOf(response.Event),
	}
	eventValue := reflect.ValueOf(response.Event)
	if eventKey.Event.Kind() != reflect.Ptr {
		eventKey.Event = reflect.PointerTo(eventKey.Event)
		eventValue = ptr(eventValue)
	}

	transforms, ok := fi.Manager.Table[eventKey]

	if !ok {
		// Silently quit if it was an anonymous event
		switch response.Event.(type) {
		case *None:
			return
		default:
		}

		for _, callback := range fi.Manager.Manager.Callbacks {
			callback.NoTransition(fi, State(fi.State), response.Source, response.Event)
		}
		return
	}
	for _, transform := range transforms {
		guardOut := reflect.ValueOf(transform.Guard).Call([]reflect.Value{
			reflect.ValueOf(fi),
			fi.Storage,
			reflect.ValueOf(State(fi.State)),
			reflect.ValueOf(response.Source),
			eventValue,
		})
		guardAllow := guardOut[0].Bool()
		if guardAllow {
			for _, callback := range fi.Manager.Manager.Callbacks {
				callback.ChangeState(fi, State(fi.State), response.Source, response.Event, transform.NewState)
			}

			reflect.ValueOf(transform.Action).Call([]reflect.Value{
				reflect.ValueOf(fi),
				fi.Storage,
				reflect.ValueOf(State(fi.State)),
				reflect.ValueOf(response.Source),
				eventValue,
			})
			fi.State = string(transform.NewState)

			fi.Terminated = fi.Manager.Terminals[State(fi.State)]

			fi.Manager.SaveFSM(fi)

			// Check if there is anonymous transition
			fi.iProcess(Response{
				Source: "internal",
				Event:  &None{},
			})

			return
		}
	}
	for _, callback := range fi.Manager.Manager.Callbacks {
		callback.NoTransition(fi, State(fi.State), response.Source, response.Event)
	}
}

func (fi *FSMInstance) Request(dest string, request RequestPayload) {
	fi.Manager.request(fi, dest, request)
}

func (fi *FSMInstance) IsTerminated() bool {
	isTerminated := fi.Manager.Terminals[State(fi.State)]
	return isTerminated
}

func (fi *FSMInstance) SetDescription(name string) {
	fi.Description = name
}

func (fi *FSMInstance) ID() FsmID {
	return FsmID{
		Fsm: fi.Manager.Name,
		Id:  fi.Id,
	}
}

func (fi *FSMInstance) Log() *zap.Logger {
	return fi.Manager.Log()
}