Adds MultiPV support in AbstractEngine and UCI

pom.xml

@@ -9,7 +9,7 @@
 		<version>1.0.8</version>
 	</parent>
 	<artifactId>jchess-uci</artifactId>
-	<version>2.0.2-SNAPSHOT</version>
+	<version>2.0.3-SNAPSHOT</version>
 
 	<properties>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

src/main/java/com/fathzer/jchess/uci/ClassicalOptions.java

@@ -42,8 +42,8 @@ public static CheckOption limitStrength(Consumer<Boolean> trigger) {
 		return new CheckOption(LIMIT_STRENGTH_NAME, trigger, false);
 	}
 
-	public static SpinOption<Integer> multiPV(Consumer<Integer> trigger, int maxValue) {
-		return new IntegerSpinOption(MULTI_PV_NAME, trigger, 1, 1, maxValue);
+	public static SpinOption<Integer> multiPV(Consumer<Integer> trigger) {
+		return new IntegerSpinOption(MULTI_PV_NAME, trigger, 1, 1, 256);
 	}
 
 	public static CheckOption ownBook(Consumer<Boolean> trigger, boolean defaultValue) {

src/main/java/com/fathzer/jchess/uci/GoReply.java

@@ -154,14 +154,20 @@ public String toString() {
 	 * @return The line or an empty optional if no information is available
 	 */
 	public Optional<String> getMainInfoString() {
-		if (info==null) {
-			return Optional.empty();
-		}
+		return getInfoString(0);
+	}
+
+	/** Gets the uci info line to return just before sending the reply.
+	 * @param index The move index (0 for the best move or the index or the extra moves passed to {@code Info#setExtraMoves(List)} +1
+	 * @return The line or an empty optional if no information is available
+	 */
+	public Optional<String> getInfoString(int index) {
 		final StringBuilder builder = new StringBuilder();
 		if (info.depth>0) {
 			builder.append("depth ").append(info.depth);
 		}
-		final Optional<Score> score = info.scoreBuilder.apply(bestMove);
+		final UCIMove move = index==0 ? bestMove : info.extraMoves.get(index-1);
+		final Optional<Score> score = info.scoreBuilder.apply(move);
 		if (score.isPresent()) {
 			if (!builder.isEmpty()) {
 				builder.append(' ');
@@ -174,13 +180,13 @@ public Optional<String> getMainInfoString() {
 			}
 			builder.append("hashfull ").append(info.hashFull);
 		}
-		final Optional<List<UCIMove>> pv = info.pvBuilder.apply(bestMove);
+		final Optional<List<UCIMove>> pv = info.pvBuilder.apply(move);
 		if (pv.isPresent()) {
 			if (!builder.isEmpty()) {
 				builder.append(' ');
 			}
 			final String moves = String.join(" ", pv.get().stream().map(UCIMove::toString).toList());
-			builder.append("multipv 1 pv ").append(moves);
+			builder.append("multipv ").append(index+1).append(" pv ").append(moves);
 		}
 		return builder.isEmpty() ? Optional.empty() : Optional.of("info "+builder);
 	}

src/main/java/com/fathzer/jchess/uci/UCI.java

@@ -210,7 +210,12 @@ protected void doGo(Deque<String> tokens) {
 				final boolean started = doBackground(() -> {
 					final GoReply goReply = task.get();
 					final Optional<String> mainInfo = goReply.getMainInfoString();
-					mainInfo.ifPresent(this::out);
+					if (mainInfo.isPresent()) {
+						this.out(mainInfo.get());
+						for (int i = 1; i <= goReply.getInfo().get().getExtraMoves().size(); i++) {
+							this.out(goReply.getInfoString(i).get());
+						}
+					}
 					out(goReply.toString());
 				}, task::stop, e -> err(GO_CMD, e));
 				if (!started) {

src/main/java/com/fathzer/jchess/uci/extended/SpeedTest.java

@@ -59,7 +59,7 @@ public SpeedTest(AbstractEngine<M, B> engine) {
 	private Result<M> fill(String fen) {
 		uciEngine.newGame();
 		uciEngine.setStartPosition(fen);
-		return new Result<>(fen, uciEngine.getEngine().getBestMoves(uciEngine.get()));
+		return new Result<>(fen, uciEngine.getEngine().getBestMoves(uciEngine.get()).getBestMoves());
 	}
 
 	/** Launches the test.

src/main/java/com/fathzer/jchess/uci/helper/AbstractEngine.java

@@ -6,6 +6,7 @@
 import java.util.Map;
 import java.util.Optional;
 import java.util.function.Supplier;
+import java.util.stream.Collectors;
 
 import com.fathzer.games.MoveGenerator;
 import com.fathzer.games.MoveGenerator.MoveConfidence;
@@ -14,7 +15,7 @@
 import com.fathzer.games.ai.evaluation.Evaluation.Type;
 import com.fathzer.games.ai.evaluation.Evaluator;
 import com.fathzer.games.ai.iterativedeepening.IterativeDeepeningEngine;
-import com.fathzer.games.ai.iterativedeepening.IterativeDeepeningEngine.BestMove;
+import com.fathzer.games.ai.iterativedeepening.SearchHistory;
 import com.fathzer.games.ai.time.TimeManager;
 import com.fathzer.games.ai.transposition.TranspositionTable;
 import com.fathzer.jchess.uci.GoReply;
@@ -98,6 +99,7 @@ public List<Option<?>> getOptions() {
 			options.add(new ComboOption("evaluation", this::setEvaluator, defaultEvaluator, evaluatorBuilders.keySet()));
 		}
 		options.add(ClassicalOptions.threads(this.engine::setParallelism, defaultThreads));
+		options.add(ClassicalOptions.multiPV(this.engine.getDeepeningPolicy()::setSize));
 		options.add(new IntegerSpinOption("depth", this.engine.getDeepeningPolicy()::setDepth, defaultDepth, 1, 128));
 		options.add(new LongSpinOption("maxtime", this.engine.getDeepeningPolicy()::setMaxTime, defaultMaxTime, 1, Long.MAX_VALUE));
 		return options;
@@ -130,24 +132,27 @@ public GoReply get() {
 				final UCIEngineSearchConfiguration<M, B> c = new UCIEngineSearchConfiguration<>(timeManager);
 				final UCIEngineSearchConfiguration.EngineConfiguration previous = c.configure(engine, options, board);
 				final List<M> candidates = options.getMoveToSearch().stream().map(AbstractEngine.this::toMove).toList();
-				final Optional<BestMove<M>> best = engine.getBestMove(board, candidates.isEmpty() ? null : candidates);
+				final SearchHistory<M> search = engine.getBestMoves(board, candidates.isEmpty() ? null : candidates);
 				c.set(engine, previous);
-				if (best.isEmpty()) {
+				if (search.isEmpty()) {
 					return new GoReply(null);
 				}
-				final EvaluatedMove<M> move = best.get().move();
+				final EvaluatedMove<M> move = getChoice(search);
 				final GoReply goReply = new GoReply(toUCI(move.getContent()));
-				final Info info = new Info(best.get().depth());
+				final Info info = new Info(search.getDepth());
 				final TranspositionTable<M> tt = engine.getTranspositionTable();
 				final int entryCount = tt.getEntryCount();
 				if (entryCount>0) {
 					info.setHashFull((int)(1000L*entryCount/tt.getSize()));
 				}
-				info.setScoreBuilder(m -> toScore(toMove(m), move));
+				final List<EvaluatedMove<M>> bestMoves = search.getBestMoves();
+				final Map<String, Optional<Score>> scores = bestMoves.stream().collect(Collectors.toMap(em -> toUCI(em.getContent()).toString(), em -> toScore(em.getEvaluation())));
+				info.setScoreBuilder(m -> scores.get(m.toString()));
 				info.setPvBuilder(m -> {
 					final List<UCIMove> list = tt.collectPV(board, toMove(m), info.getDepth()).stream().map(x -> toUCI(x)).toList();
 					return list.isEmpty() ? Optional.empty() : Optional.of(list);
 				});
+				info.setExtraMoves(bestMoves.stream().filter(em -> !move.getContent().equals(em.getContent())).map(em->toUCI(em.getContent())).toList());
 				goReply.setInfo(info);
 				return goReply;
 			}
@@ -160,10 +165,13 @@ public void stop() {
 		};
 	}
 
-	private Optional<Score> toScore(M m, EvaluatedMove<M> known) {
-		final Evaluation evaluation = known.getEvaluation();
+	private EvaluatedMove<M> getChoice(SearchHistory<M> history) {
+		return history.getBestMoves().get(0);
+	}
+
+	private Optional<Score> toScore(Evaluation evaluation) {
 		final Type type = evaluation.getType();
-		if (!m.equals(known.getContent()) || type==Type.UNKNOWN) {
+		if (type==Type.UNKNOWN) {
 			return Optional.empty();
 		}
 		final Score score;

src/main/java/com/fathzer/jchess/uci/helper/UCIEngineSearchConfiguration.java

@@ -14,10 +14,12 @@ public class UCIEngineSearchConfiguration<M, B extends MoveGenerator<M>> {
 	public static class EngineConfiguration {
 		private long maxTime;
 		private int depth;
+		private boolean deepenOnForced;
 
 		private EngineConfiguration(IterativeDeepeningEngine<?, ?> engine) {
 			maxTime = engine.getDeepeningPolicy().getMaxTime();
 			depth = engine.getDeepeningPolicy().getDepth();
+			deepenOnForced = engine.getDeepeningPolicy().isDeepenOnForced();
 		}
 	}
 
@@ -35,6 +37,7 @@ public EngineConfiguration configure(IterativeDeepeningEngine<M, B> engine, GoPa
 		}
 		if (options.getDepth()>0) {
 			engine.getDeepeningPolicy().setDepth(options.getDepth());
+			engine.getDeepeningPolicy().setDeepenOnForced(true);
 		}
 		if (timeOptions.getMoveTimeMs()>0) {
 			engine.getDeepeningPolicy().setMaxTime(timeOptions.getMoveTimeMs());
@@ -50,6 +53,7 @@ public EngineConfiguration configure(IterativeDeepeningEngine<M, B> engine, GoPa
 	public void set(IterativeDeepeningEngine<M, B> engine, EngineConfiguration c) {
 		engine.getDeepeningPolicy().setMaxTime(c.maxTime);
 		engine.getDeepeningPolicy().setDepth(c.depth);
+		engine.getDeepeningPolicy().setDeepenOnForced(c.deepenOnForced);
 	}
 
 	public long getMaxTime(B board, long remainingMs, long incrementMs, int movesToGo) {