NearbyHouse support

README.md

@@ -50,9 +50,17 @@ With Maven, you can add it as a dependency like this:
   ...
 ```
 
-Maven understands "RELEASE" as latest non-SNAPSHOT version. It is recommended to
-replace that with a specific version to prevent getting versions with breaking changes
-unintentionally.
+Maven understands "RELEASE" as latest non-SNAPSHOT version. It is recommended to replace that with a specific version to
+prevent getting versions with breaking changes unintentionally.
+
+## Customizing
+
+The puzzles generated by the library can customized by defining Attributes and Facts. Attributes are the traits
+of the people in the puzzle like name or favourite pet, while Facts are clues that the players get to solve the puzzle.
+You can select from the predefined implementations or implement yourself the Java interfaces with the same names.
+
+`customQuestionPuzzle()` in `Demo.java` demonstrated how to select specific types of Attributes and Facts when
+generating puzzles.
 
 ## Install library from source
 

src/main/java/zebra4j/AbstractPuzzleGenerator.java

@@ -33,11 +33,13 @@
 import zebra4j.fact.BothTrue;
 import zebra4j.fact.Different;
 import zebra4j.fact.Fact;
+import zebra4j.fact.NearbyHouse;
 
 @AllArgsConstructor
 public abstract class AbstractPuzzleGenerator<P> {
 
-	public static final Set<Fact.Type> DEFAULT_FACT_TYPES = SetUtils.unmodifiableSet(BothTrue.TYPE, Different.TYPE);
+	public static final Set<Fact.Type> DEFAULT_FACT_TYPES = SetUtils.unmodifiableSet(BothTrue.TYPE, Different.TYPE,
+			NearbyHouse.TYPE);
 
 	private final Random rnd;
 	protected final PuzzleSolution solution;

src/main/java/zebra4j/PuzzleSolver.java

@@ -86,8 +86,7 @@ private PuzzleSolution fromChocoSolution(Solution choco, ZebraModel model) {
 		}
 		for (IntVar var : retrieveVars(choco)) {
 			int person = choco.getIntVal(var);
-			Attribute attribute = model.toAttribute(var.getName());
-			allAttributes[person].add(attribute);
+			model.toOptionalAttribute(var.getName()).ifPresent(attr -> allAttributes[person].add(attr));
 		}
 		PuzzleSolutionBuilder builder = new PuzzleSolutionBuilder(false);
 		Stream.of(allAttributes).forEach(list -> builder.add(new SolutionPerson(list)));

src/main/java/zebra4j/ZebraModel.java

@@ -22,6 +22,7 @@
 
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Optional;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -55,10 +56,16 @@ public String varName(Attribute attr) {
 	}
 
 	public Attribute toAttribute(String name) {
+		return toOptionalAttribute(name).get();
+	}
+
+	public Optional<Attribute> toOptionalAttribute(String name) {
 		Matcher m = VAR_REGEX.matcher(name);
-		m.matches();
+		if (!m.matches()) {
+			return Optional.empty();
+		}
 		int attributeId = Integer.parseInt(m.group(2));
 		AttributeType attrType = typeMap.get(m.group(1));
-		return attrType.fromUniqueInt(attributeId);
+		return Optional.of(attrType.fromUniqueInt(attributeId));
 	}
 }

src/main/java/zebra4j/fact/NearbyHouse.java

@@ -0,0 +1,148 @@
+/*-
+ * #%L
+ * zebra4j
+ * %%
+ * Copyright (C) 2020 Marin Nozhchev
+ * %%
+ * This program 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.
+ * 
+ * This program 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 General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * #L%
+ */
+package zebra4j.fact;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+
+import org.chocosolver.solver.constraints.Constraint;
+import org.chocosolver.solver.variables.IntVar;
+
+import lombok.Value;
+import zebra4j.AllDifferentType;
+import zebra4j.AtHouse;
+import zebra4j.Attribute;
+import zebra4j.PersonName;
+import zebra4j.PuzzleSolution;
+import zebra4j.SolutionPerson;
+import zebra4j.ZebraModel;
+
+/**
+ * Facts/clues about people with certain attributes living in adjacent or nearby
+ * houses.
+ * 
+ * <p>
+ * equals/hashCode treats NearbyHouse(PersonA, PersonB) as different from
+ * NearbyHouse(B, A) even though they are semantically the same.
+ */
+@Value
+public class NearbyHouse implements Fact {
+
+	private static final int MAX_DISTANCE = 2;
+
+	public static final Type TYPE = new Type() {
+
+		@Override
+		public List<Fact> generate(PuzzleSolution solution) {
+			List<Fact> result = new ArrayList<>();
+			List<SolutionPerson> people = new ArrayList<>(solution.getPeople());
+			for (int i = 0; i < people.size(); ++i) {
+				SolutionPerson leftPerson = people.get(i);
+				Attribute leftHouse = leftPerson.findAttribute(AtHouse.TYPE);
+				if (leftHouse == null) {
+					continue;
+				}
+				int leftPos = leftHouse.asUniqueInt();
+				for (int j = i + 1; j < people.size(); ++j) {
+					SolutionPerson rightPerson = people.get(j);
+					Attribute rightHouse = rightPerson.findAttribute(AtHouse.TYPE);
+					if (rightHouse == null) {
+						continue;
+					}
+					int rightPos = rightHouse.asUniqueInt();
+
+					int distance = Math.abs(leftPos - rightPos);
+
+					if (distance > MAX_DISTANCE) {
+						continue;
+					}
+
+					for (Attribute leftAttr : leftPerson.asList()) {
+						Attribute rightAttr = rightPerson.findAttribute(leftAttr.type());
+						if (rightAttr != null && leftAttr.type() instanceof AllDifferentType) {
+							result.add(new NearbyHouse(distance, leftAttr, rightAttr));
+						}
+					}
+				}
+			}
+			return result;
+		}
+	};
+
+	private final int distance;
+	private final Attribute left, right;
+
+	@Override
+	public void postTo(ZebraModel model) {
+		List<Constraint> constraints = new ArrayList<>();
+
+		int numHouses = countHouses(model);
+		IntVar leftAttrVar = model.getVariableFor(left);
+		IntVar rightAttrVar = model.getVariableFor(right);
+		for (int leftPos = 1; leftPos <= numHouses - distance; ++leftPos) {
+			IntVar leftHouseVar = model.getVariableFor(new AtHouse(leftPos));
+			int rightPos = leftPos + distance;
+			IntVar rightHouseVar = model.getVariableFor(new AtHouse(rightPos));
+			Constraint consLeft = model.getChocoModel().arithm(leftHouseVar, "=", leftAttrVar);
+			Constraint consRight = model.getChocoModel().arithm(rightHouseVar, "=", rightAttrVar);
+			constraints.add(model.getChocoModel().and(consLeft, consRight));
+
+			consLeft = model.getChocoModel().arithm(leftHouseVar, "=", rightAttrVar);
+			consRight = model.getChocoModel().arithm(rightHouseVar, "=", leftAttrVar);
+			constraints.add(model.getChocoModel().and(consLeft, consRight));
+		}
+
+		model.getChocoModel().or(constraints.toArray(new Constraint[0])).post();
+	}
+
+	private static int countHouses(ZebraModel model) {
+		int result = 0;
+		while (model.getVariableFor(new AtHouse(result + 1)) != null) {
+			++result;
+		}
+		return result;
+	}
+
+	@Override
+	public boolean appliesTo(PuzzleSolution solution) {
+		Optional<Integer> leftHousePos = getHousePosition(solution, left);
+		Optional<Integer> rightHousePos = getHousePosition(solution, right);
+		return leftHousePos.isPresent() && rightHousePos.isPresent()
+				&& Math.abs(leftHousePos.get() - rightHousePos.get()) == distance;
+	}
+
+	@Override
+	public String toString() {
+		String dist = distance == 1 ? "в съседна къща на" : String.format("през %s къща от", distance - 1);
+		if (left instanceof PersonName) {
+			return String.format("%s живее %s %s", left.description(), dist, right.description());
+		}
+		return String.format("Този който е %s живее %s този който е %s.", left.description(), dist,
+				right.description());
+	}
+
+	private static Optional<Integer> getHousePosition(PuzzleSolution solution, Attribute attribute) {
+		return solution.findPerson(attribute).flatMap(person -> Optional.ofNullable(person.findAttribute(AtHouse.TYPE)))
+				.map(house -> house.asUniqueInt());
+	}
+
+}

src/test/java/zebra4j/fact/BothTrueTest.java

@@ -55,13 +55,14 @@ public static void testPostTo(Fact.Type type) {
 		// must not contain Criminal
 		PuzzleSolution solution = PuzzleGeneratorTest.sampleSolution();
 		List<Fact> facts = type.generate(solution);
-		testPostTo(facts.get(0), solution);
+		assertTrue(!facts.isEmpty());
+		facts.stream().forEach(fact -> testPostTo(fact, solution));
 	}
 
 	public static void testPostTo(Fact fact, PuzzleSolution solution) {
 		assertTrue(fact.appliesTo(solution));
 		Puzzle puzzle = new Puzzle(solution.getAttributeSets(), Collections.singleton(fact));
-		new PuzzleSolver(puzzle).solve().stream()
-				.forEach(anySolution -> assertTrue(anySolution.toString(), fact.appliesTo(anySolution)));
+		new PuzzleSolver(puzzle).solve().stream().forEach(
+				anySolution -> assertTrue(fact + " \n " + anySolution.toString(), fact.appliesTo(anySolution)));
 	}
 }

src/test/java/zebra4j/fact/NearbyHouseTest.java

@@ -0,0 +1,37 @@
+/*-
+ * #%L
+ * zebra4j
+ * %%
+ * Copyright (C) 2020 Marin Nozhchev
+ * %%
+ * This program 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.
+ * 
+ * This program 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 General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * #L%
+ */
+package zebra4j.fact;
+
+import org.junit.Test;
+
+public class NearbyHouseTest {
+
+	@Test
+	public void testGenerate() {
+		BothTrueTest.testGenerate(NearbyHouse.TYPE);
+	}
+
+	@Test
+	public void testPostTo() {
+		BothTrueTest.testPostTo(NearbyHouse.TYPE);
+	}
+
+}

src/test/resources/logback-test.xml

@@ -33,5 +33,5 @@
   <root level="info">
     <appender-ref ref="STDOUT" />
   </root>
-  <logger name="zebra4j" level="debug" /> 
+  <logger name="zebra4j" level="info" /> 
 </configuration>