package block_test

import (
	"testing"

	"github.com/df-mc/dragonfly/server/block"
	"github.com/df-mc/dragonfly/server/block/cube"
	"github.com/df-mc/dragonfly/server/entity"
	"github.com/df-mc/dragonfly/server/world"
)

// TestTorchBreaksWithoutSupport verifies that a torch is broken by a neighbour
// update on the tick after its supporting block is removed, using a
// synchronous World to make the tick deterministic.
func TestTorchBreaksWithoutSupport(t *testing.T) {
	w := world.Config{Synchronous: true, Entities: entity.DefaultRegistry}.New()
	defer w.Close()

	support, torch := cube.Pos{0, 0, 0}, cube.Pos{0, 1, 0}
	<-w.Exec(func(tx *world.Tx) {
		tx.SetBlock(support, block.Stone{}, nil)
		tx.SetBlock(torch, block.Torch{Facing: cube.FaceDown}, nil)
		tx.SetBlock(support, block.Air{}, nil)
	})
	w.AdvanceTick()

	<-w.Exec(func(tx *world.Tx) {
		if b := tx.Block(torch); b != (block.Air{}) {
			t.Errorf("expected torch to break after removing its support, got %v", b)
		}
	})
}