package westworldwithmessaging

import (
	"fmt"
	"sync"
)

// eatStew is the Go version of the (not yet pasted) singleton class
// EatStew from the book. Same pattern as every other state:
// unexported type, one shared instance, reached only through the
// function below.
type eatStew struct{}

var (
	eatStewInstance *eatStew
	eatStewOnce     sync.Once
)

// EatStew is the Go stand-in for "EatStew::Instance()".
func EatStew() *eatStew {
	eatStewOnce.Do(func() {
		eatStewInstance = &eatStew{}
	})
	return eatStewInstance
}

var _ State[Miner] = (*eatStew)(nil)

// The book never pasted this state's actual source - it only ever
// referenced EatStew::Instance() as a switch target. This whole
// implementation is reverse-engineered from a sample run of the
// finished program, which shows this exact sequence: Bob enters
// (one line), eats (one line, then immediately heads back to
// whatever he was doing - a single-tick state, same shape as
// QuenchThirst), and leaving prints one more line before he's back
// in GoHomeAndSleepTilRested.

// Enter announces that dinner smells good.
func (s *eatStew) Enter(m *Miner) {
	fmt.Printf("\n%s: Smells reaaal goood, Elsa!", GetNameOfEntity(m.ID()))
}

// Execute is the entire meal: announce it, then head back to
// whatever state he was in before dinner interrupted him. The sample
// output never shows more than one "Tastes real good too!" line, so
// - like QuenchThirst - this doesn't loop across multiple ticks.
func (s *eatStew) Execute(m *Miner) {
	fmt.Printf("\n%s: Tastes real good too!", GetNameOfEntity(m.ID()))
	m.ChangeState(GoHomeAndSleepTilRested())
}

// Exit thanks Elsa for the meal on the way out.
func (s *eatStew) Exit(m *Miner) {
	fmt.Printf("\n%s: Thank ya li'l lady. Ah better get back to whatever ah wuz doin'", GetNameOfEntity(m.ID()))
}

// OnMessage is required now that State[T] includes it. The sample
// output doesn't show Bob reacting to any message while eating, so
// false ("not handled") is the correct default.
func (s *eatStew) OnMessage(m *Miner, msg Telegram) bool {
	return false
}