refactor(iblock): use delegation, no inheritance

With this, we can encapsulate the BlockImplementation type.

src/main/kotlin/blocks/implementation/BlockImplementation.kt → src/main/kotlin/blocks/implementation/BlockLogic.kt

@@ -5,8 +5,10 @@ import blocks.Rotation
 import movements.Direction
 import movements.Position
 
-abstract class BlockImplementation(private val FORMATS_OF_BLOCK: List<List<Position>>, private var initialPosition: Position):
-    Block {
+internal class BlockLogic(
+    private val FORMATS_OF_BLOCK: List<List<Position>>,
+    private var initialPosition: Position
+) : Block {
 
     private var currentFormatIndex = 0
 

src/main/kotlin/blocks/implementation/IBlock.kt

@@ -1,13 +1,25 @@
 package blocks.implementation
 
+import blocks.Block
+import blocks.Rotation
+import movements.Direction
 import movements.Position
 
-class IBlock(initialPosition: Position) : BlockImplementation(TYPES, initialPosition)
-
-private val TYPES = listOf(
+internal val TYPES = listOf(
     listOf(Position(1, 0), Position(1, 1), Position(1, 2), Position(1, 3)),
     listOf(Position(0, 2), Position(1, 2), Position(2, 2), Position(3, 2)),
     listOf(Position(2, 0), Position(2, 1), Position(2, 2), Position(2, 3)),
     listOf(Position(0, 1), Position(1, 1), Position(2, 1), Position(3, 1)),
 )
 
+class IBlock(initialPosition: Position) : Block {
+
+    private val blockImplementation = BlockLogic(TYPES, initialPosition)
+
+    override fun getNeededPositions(): Collection<Position> = blockImplementation.getNeededPositions()
+
+    override fun rotate(degree: Rotation) = blockImplementation.rotate(degree)
+
+    override fun move(direction: Direction) = blockImplementation.move(direction)
+
+}