Card.Then

Add a callback to the Card interface to be invoked after an option is selected. This will most frequently be used for cards that always want to shuffle themselves back into the deck regardless of the Option selected.

cardsim/card.go

@@ -16,6 +16,11 @@ type Card[C StatsCollection] interface {
 	// Options returns the possible actions the player can take for this card.
 	// There must be at least one option.
 	Options(p *Player[C]) ([]CardOption[C], error)
+
+	// Then is invoked after an option is selected and executed. The selected
+	// option is provided as an argument. This allows cards to do certain
+	// cleanup for every action -- for example, returning to the deck.
+	Then(p *Player[C], option CardOption[C]) error
 }
 
 // A CardOption represents a choice a player could make for some card.
@@ -35,11 +40,12 @@ type CardOption[C StatsCollection] interface {
 	Enact(p *Player[C]) (Message, error)
 }
 
-// A BasicCard is a Card with fixed title, text, and options.
+// A BasicCard is a Card with fixed title, text, options, and optional post-option callback.
 type BasicCard[C StatsCollection] struct {
 	CardTitle   Message
 	CardText    Message
 	CardOptions []CardOption[C]
+	AfterOption func(p *Player[C], option CardOption[C]) error
 }
 
 func (b *BasicCard[C]) Title(p *Player[C]) (Message, error) {
@@ -54,6 +60,13 @@ func (b *BasicCard[C]) Options(_ *Player[C]) ([]CardOption[C], error) {
 	return b.CardOptions, nil
 }
 
+func (b *BasicCard[C]) Then(p *Player[C], option CardOption[C]) error {
+	if b.AfterOption == nil {
+		return nil
+	}
+	return b.AfterOption(p, option)
+}
+
 // A BasicOption is a CardOption with fixed text, effects, and output.
 type BasicOption[C StatsCollection] struct {
 	Text   Message