[LIB-9] Set of entities for PGN parsing and formatting

[chesshog.git] / chesshog-format / src / main / java / org / hedgecode / chess / pgn / token / VariationToken.java

diff --git a/chesshog-format/src/main/java/org/hedgecode/chess/pgn/token/VariationToken.java b/chesshog-format/src/main/java/org/hedgecode/chess/pgn/token/VariationToken.java
new file mode 100644 (file)
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+++ b/chesshog-format/src/main/java/org/hedgecode/chess/pgn/token/VariationToken.java
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+/*
+ * Copyright (c) 2018-2020. Developed by Hedgecode.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.hedgecode.chess.pgn.token;
+
+import java.util.regex.Pattern;
+
+import org.hedgecode.chess.pgn.entity.Moves;
+import org.hedgecode.chess.pgn.entity.Variation;
+import org.hedgecode.chess.position.ParseException;
+
+/**
+ * VariationToken
+ *
+ * @author Dmitry Samoshin aka gotty
+ */
+public class VariationToken implements Token<Moves> {
+
+    private static final char OPEN_VARIATION = '(';
+    private static final char CLOSE_VARIATION = ')';
+
+    private static final String VARIATION_REGEX = "^\\s*\\(([^)]+)\\)";
+    private static final Pattern VARIATION_PATTERN = Pattern.compile(VARIATION_REGEX);
+
+    @Override
+    public int token(Moves moves, String pgn) throws ParseException {
+        int startToken  = pgn.indexOf(OPEN_VARIATION);
+        int endToken = endToken(pgn, startToken);
+        Variation variation = new Variation();
+        Token<Variation> variationToken = new MovesToken<>();
+        variationToken.token(
+                variation, pgn.substring(startToken + 1, endToken)
+        );
+        moves.currentMove().addVariation(variation);
+        return endToken + 1;
+    }
+
+    private int endToken(String pgn, int startToken) throws ParseException {
+        int open = pgn.indexOf(OPEN_VARIATION, startToken + 1);
+        int close = pgn.indexOf(CLOSE_VARIATION, startToken + 1);
+        while (open >= 0 && open < close) {
+            open = pgn.indexOf(OPEN_VARIATION, open + 1);
+            close = pgn.indexOf(CLOSE_VARIATION, close + 1);
+        }
+        if (close == -1) {
+            throw new ParseException("parse.pgn.incorrect.variation", pgn);
+        }
+        return close;
+    }
+
+}