Rename 'maze' -> 'constrictor', remove use of food

constrictor.go

@@ -0,0 +1,54 @@
+package rules
+
+import ()
+
+type ConstrictorRuleset struct {
+	StandardRuleset
+}
+
+func (r *ConstrictorRuleset) CreateInitialBoardState(width int32, height int32, snakeIDs []string) (*BoardState, error) {
+	initialBoardState, err := r.StandardRuleset.CreateInitialBoardState(width, height, snakeIDs)
+	if err != nil {
+		return nil, err
+	}
+
+	err = r.applyConstrictorRules(initialBoardState)
+	if err != nil {
+		return nil, err
+	}
+
+	return initialBoardState, nil
+}
+
+func (r *ConstrictorRuleset) CreateNextBoardState(prevState *BoardState, moves []SnakeMove) (*BoardState, error) {
+
+	nextState, err := r.StandardRuleset.CreateNextBoardState(prevState, moves)
+	if err != nil {
+		return nil, err
+	}
+
+	err = r.applyConstrictorRules(nextState)
+	if err != nil {
+		return nil, err
+	}
+
+	return nextState, nil
+}
+
+func (r *ConstrictorRuleset) applyConstrictorRules(b *BoardState) error {
+	// Remove all food from the board
+	b.Food = []Point{}
+
+	// Set all snakes to max health and ensure they grow next turn
+	for i := 0; i < len(b.Snakes); i++ {
+		b.Snakes[i].Health = SnakeMaxHealth
+
+		tail := b.Snakes[i].Body[len(b.Snakes[i].Body)-1]
+		subTail := b.Snakes[i].Body[len(b.Snakes[i].Body)-2]
+		if tail != subTail {
+			r.growSnake(&b.Snakes[i])
+		}
+	}
+
+	return nil
+}