@@ -0,0 +1,133 @@
+package state
+
+import (
+	"log"
+
+	"alin.ovh/erl/command"
+)
+
+type State int
+
+const (
+	NotStarted State = iota
+	Running
+	Exited
+)
+
+func (s State) String() string {
+	switch s {
+	case NotStarted:
+		return "NotStarted"
+	case Running:
+		return "Running"
+	case Exited:
+		return "Exited"
+	default:
+		return "Unknown"
+	}
+}
+
+type Event int
+
+const (
+	Start Event = iota
+	Signal
+	Exit
+	Restart
+)
+
+func (e Event) String() string {
+	switch e {
+	case Start:
+		return "Start"
+	case Signal:
+		return "Shutdown"
+	case Exit:
+		return "Stopped"
+	case Restart:
+		return "Restart"
+	default:
+		return "Unknown"
+	}
+}
+
+type Action func()
+
+type StateMachine struct {
+	log          *log.Logger
+	currentState State
+	transitions  map[State]map[Event]State
+	actions      map[State]map[Event]Action
+}
+
+func New(cmd command.Command, log *log.Logger) *StateMachine {
+	sm := &StateMachine{
+		log:          log,
+		currentState: NotStarted,
+		transitions:  make(map[State]map[Event]State),
+		actions:      make(map[State]map[Event]Action),
+	}
+
+	sm.transitions[NotStarted] = map[Event]State{
+		Start: Running,
+	}
+	sm.transitions[Running] = map[Event]State{
+		Signal:  Exited,
+		Exit:    Exited,
+		Restart: Running,
+	}
+	sm.transitions[Exited] = map[Event]State{
+		Start:   Running,
+		Restart: Running,
+	}
+
+	wait := func(cmd command.Command) {
+		err := cmd.Wait()
+		if err != nil {
+			log.Printf("Error waiting for command: %v\n", err)
+		}
+		sm.SendEvent(Exit)
+	}
+	start := func() {
+		err := cmd.Start()
+		if err != nil {
+			log.Printf("Failed to start command: %v", err)
+		}
+
+		go wait(cmd)
+	}
+	stop := func() {
+		err := cmd.Stop()
+		if err != nil {
+			log.Printf("Error stopping command: %v\n", err)
+		}
+	}
+	restart := func() {
+		stop()
+		start()
+	}
+
+	sm.actions[NotStarted] = map[Event]Action{
+		Start: start,
+	}
+	sm.actions[Running] = map[Event]Action{
+		Signal:  stop,
+		Restart: restart,
+	}
+	sm.actions[Exited] = map[Event]Action{
+		Start:   start,
+		Restart: start,
+	}
+
+	return sm
+}
+
+func (sm *StateMachine) SendEvent(ev Event) {
+	currentState := sm.currentState
+	if nextState, ok := sm.transitions[currentState][ev]; ok {
+		sm.currentState = nextState
+		if action, ok := sm.actions[currentState][ev]; ok {
+			action()
+		}
+	}
+}