Add upper-road stairwell generation

src/test/java/com/majinnaibu/bukkitplugins/metropolis/AvenueStairwayLayoutTest.java

@@ -0,0 +1,87 @@
+/*
+This file is part of Metropolis.
+
+Metropolis is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Metropolis is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with Metropolis. If not, see <https://www.gnu.org/licenses/agpl-3.0.txt>.
+*/
+
+package com.majinnaibu.bukkitplugins.metropolis;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+class AvenueStairwayLayoutTest {
+  @Test
+  void centersStairsAcrossTheAvenueAndAlongThePlotLength() {
+    Cuboid plot = new Cuboid(2, 62, 2, 33, 71, 33);
+
+    List<AvenueStairwayLayout.Step> steps =
+        AvenueStairwayLayout.centeredEastAvenue(plot, 4, 2, 62, 14);
+
+    assertEquals(28, steps.size());
+    assertEquals(new AvenueStairwayLayout.Step(35, 63, 12), steps.get(0));
+    assertEquals(new AvenueStairwayLayout.Step(36, 63, 12), steps.get(1));
+    assertEquals(new AvenueStairwayLayout.Step(35, 64, 13), steps.get(2));
+    assertEquals(new AvenueStairwayLayout.Step(36, 76, 25), steps.get(27));
+  }
+
+  @Test
+  void opensOnlyTheThreeUpperRoadBlocksBeforeTheTopStair() {
+    Cuboid plot = new Cuboid(2, 62, 2, 33, 71, 33);
+
+    List<AvenueStairwayLayout.Step> openings =
+        AvenueStairwayLayout.upperRoadOpening(plot, 4, 2, 62, 14, 3);
+
+    assertEquals(6, openings.size());
+    assertEquals(new AvenueStairwayLayout.Step(35, 76, 22), openings.get(0));
+    assertEquals(new AvenueStairwayLayout.Step(35, 76, 23), openings.get(1));
+    assertEquals(new AvenueStairwayLayout.Step(35, 76, 24), openings.get(2));
+    assertEquals(new AvenueStairwayLayout.Step(36, 76, 24), openings.get(5));
+  }
+
+  @Test
+  void upperRoadFlightPreservesTheLowerRoadAndPlansInvertedBacking() {
+    Cuboid plot = new Cuboid(2, 62, 2, 33, 71, 33);
+
+    AvenueStairwayLayout.Flight flight = AvenueStairwayLayout.forUpperRoad(plot, 4, 2, 62, 14, 3);
+
+    assertEquals(28, flight.stairBlocks().size());
+    assertEquals(new AvenueStairwayLayout.Step(35, 63, 12), flight.stairBlocks().getFirst());
+    assertEquals(new AvenueStairwayLayout.Step(36, 76, 25), flight.stairBlocks().getLast());
+    assertEquals(26, flight.invertedBackingBlocks().size());
+    assertEquals(
+        new AvenueStairwayLayout.Step(35, 63, 13), flight.invertedBackingBlocks().getFirst());
+    assertTrue(flight.stairBlocks().stream().allMatch(step -> step.y() > 62));
+    assertTrue(flight.invertedBackingBlocks().stream().allMatch(step -> step.y() > 62));
+    assertEquals(6, flight.roadOpenings().size());
+    assertTrue(flight.roadOpenings().stream().allMatch(step -> step.y() == 76));
+  }
+
+  @Test
+  void rejectsAStairRunThatCannotFitWithinThePlotLength() {
+    Cuboid plot = new Cuboid(2, 62, 2, 33, 71, 13);
+
+    assertTrue(AvenueStairwayLayout.centeredEastAvenue(plot, 4, 2, 62, 14).isEmpty());
+  }
+
+  @Test
+  void rejectsStairsThatAreNotNarrowerThanTheAvenue() {
+    Cuboid plot = new Cuboid(2, 62, 2, 33, 71, 33);
+
+    assertTrue(AvenueStairwayLayout.centeredEastAvenue(plot, 4, 4, 62, 14).isEmpty());
+  }
+}