Introducing Antlr4 for cpsPath parsing

-created new module for cpPathParser
-added antlr rule for cpsPathWithSingleLeafCondition
-added antlr rule for cpsPathWithDescendant (and with leaf conditions)
-added antlr rule for ancestor axis
-added unit test (copied from existing CpsPathQuerySpec)
-udpated cps-ri to use new cpPathQuery from parser module
-'imported' lexer rules from publix xPath grammar
-Re-used existing CpsPathException but conversion happens in cps-ri to prevent additional dependency in cps-path-parser module

Issue-ID: CPS-376

Change-Id: I2c5df98969402cbf69f6573c52705879450ce606
Signed-off-by: ToineSiebelink <toine.siebelink@est.tech>

3 files changed, 10 insertions, 204 deletions

diff --git a/cps-ri/src/main/java/org/onap/cps/spi/impl/CpsDataPersistenceServiceImpl.java b/cps-ri/src/main/java/org/onap/cps/spi/impl/CpsDataPersistenceServiceImpl.java
index 10440924e9..af1eca33e6 100644
--- a/cps-ri/src/main/java/org/onap/cps/spi/impl/CpsDataPersistenceServiceImpl.java
+++ b/cps-ri/src/main/java/org/onap/cps/spi/impl/CpsDataPersistenceServiceImpl.java
@@ -36,16 +36,17 @@ import java.util.Set;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 import javax.transaction.Transactional;
+import org.onap.cps.cpspath.parser.CpsPathQuery;
+import org.onap.cps.cpspath.parser.CpsPathQueryType;
 import org.onap.cps.spi.CpsDataPersistenceService;
 import org.onap.cps.spi.FetchDescendantsOption;
 import org.onap.cps.spi.entities.AnchorEntity;
 import org.onap.cps.spi.entities.DataspaceEntity;
 import org.onap.cps.spi.entities.FragmentEntity;
 import org.onap.cps.spi.exceptions.AlreadyDefinedException;
+import org.onap.cps.spi.exceptions.CpsPathException;
 import org.onap.cps.spi.model.DataNode;
 import org.onap.cps.spi.model.DataNodeBuilder;
-import org.onap.cps.spi.query.CpsPathQuery;
-import org.onap.cps.spi.query.CpsPathQueryType;
 import org.onap.cps.spi.repository.AnchorRepository;
 import org.onap.cps.spi.repository.DataspaceRepository;
 import org.onap.cps.spi.repository.FragmentRepository;
@@ -171,7 +172,12 @@ public class CpsDataPersistenceServiceImpl implements CpsDataPersistenceService
         final FetchDescendantsOption fetchDescendantsOption) {
         final var dataspaceEntity = dataspaceRepository.getByName(dataspaceName);
         final var anchorEntity = anchorRepository.getByDataspaceAndName(dataspaceEntity, anchorName);
-        final var cpsPathQuery = CpsPathQuery.createFrom(cpsPath);
+        final CpsPathQuery cpsPathQuery;
+        try {
+            cpsPathQuery = CpsPathQuery.createFrom(cpsPath);
+        } catch (final IllegalStateException e) {
+            throw new CpsPathException(e.getMessage());
+        }
         List<FragmentEntity> fragmentEntities;
         if (CpsPathQueryType.XPATH_LEAF_VALUE.equals(cpsPathQuery.getCpsPathQueryType())) {
             fragmentEntities = fragmentRepository
@@ -283,7 +289,7 @@ public class CpsDataPersistenceServiceImpl implements CpsDataPersistenceService
         fragmentRepository.save(fragmentEntity);
     }
 
-    private boolean isRootXpath(final String xpath) {
+    private static boolean isRootXpath(final String xpath) {
         return "/".equals(xpath) || "".equals(xpath);
     }
 }
diff --git a/cps-ri/src/main/java/org/onap/cps/spi/query/CpsPathQuery.java b/cps-ri/src/main/java/org/onap/cps/spi/query/CpsPathQuery.java
deleted file mode 100644
index 401667eaa4..0000000000
--- a/cps-ri/src/main/java/org/onap/cps/spi/query/CpsPathQuery.java
+++ /dev/null
@@ -1,161 +0,0 @@
-/*
- * ============LICENSE_START=======================================================
- *  Copyright (C) 2021 Nordix Foundation
- *  Modifications Copyright (C) 2021 Bell Canada.
- *  ================================================================================
- *  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.
- *
- *  SPDX-License-Identifier: Apache-2.0
- *  ============LICENSE_END=========================================================
- */
-
-package org.onap.cps.spi.query;
-
-import static org.springframework.util.StringUtils.isEmpty;
-
-import java.util.HashMap;
-import java.util.Map;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
-import lombok.AccessLevel;
-import lombok.Getter;
-import lombok.Setter;
-import org.onap.cps.spi.exceptions.CpsPathException;
-
-@Getter
-@Setter(AccessLevel.PRIVATE)
-public class CpsPathQuery {
-
-    private CpsPathQueryType cpsPathQueryType;
-    private String xpathPrefix;
-    private String leafName;
-    private Object leafValue;
-    private String descendantName;
-    private Map<String, Object> leavesData;
-    private String ancestorSchemaNodeIdentifier;
-
-    private static final String NON_CAPTURING_GROUP_1_TO_99_YANG_CONTAINERS = "((?:\\/[^\\/]+){1,99})";
-
-    private static final String YANG_LEAF_VALUE_EQUALS_CONDITION =
-        "\\[\\s{0,9}@(\\S+?)\\s{0,9}=\\s{0,9}(.*?)\\s{0,9}\\]";
-
-    private static final Pattern QUERY_CPS_PATH_WITH_SINGLE_LEAF_PATTERN =
-        Pattern.compile(NON_CAPTURING_GROUP_1_TO_99_YANG_CONTAINERS + YANG_LEAF_VALUE_EQUALS_CONDITION);
-
-    private static final Pattern DESCENDANT_ANYWHERE_PATTERN = Pattern.compile("\\/\\/([^\\/][^:]+)");
-
-    private static final Pattern LEAF_INTEGER_VALUE_PATTERN = Pattern.compile("[-+]?\\d+");
-
-    private static final Pattern LEAF_STRING_VALUE_IN_SINGLE_QUOTES_PATTERN = Pattern.compile("'(.*)'");
-    private static final Pattern LEAF_STRING_VALUE_IN_DOUBLE_QUOTES_PATTERN = Pattern.compile("\"(.*)\"");
-
-    private static final String YANG_MULTIPLE_LEAF_VALUE_EQUALS_CONDITION = "\\[(.*?)\\s{0,9}]";
-
-    private static final Pattern DESCENDANT_ANYWHERE_PATTERN_WITH_MULTIPLE_LEAF_PATTERN =
-        Pattern.compile(DESCENDANT_ANYWHERE_PATTERN + YANG_MULTIPLE_LEAF_VALUE_EQUALS_CONDITION);
-
-    private static final String INDIVIDUAL_LEAF_DETAIL_PATTERN = ("\\s{1,9}and\\s{1,9}");
-
-    private static final Pattern LEAF_VALUE_PATTERN = Pattern.compile("@(?>(\\S+?)=(.*))");
-
-    private static final Pattern ANCESTOR_AXIS_PATTERN = Pattern.compile("(?>(\\S+)\\/ancestor::\\/?(\\S+))");
-
-    /**
-     * Returns a cps path query.
-     *
-     * @param cpsPathSource cps path
-     * @return a CpsPath object.
-     */
-    public static CpsPathQuery createFrom(final String cpsPathSource) {
-        var cpsPath = cpsPathSource;
-        final var cpsPathQuery = new CpsPathQuery();
-        var matcher = ANCESTOR_AXIS_PATTERN.matcher(cpsPath);
-        if (matcher.matches()) {
-            cpsPath = matcher.group(1);
-            cpsPathQuery.setAncestorSchemaNodeIdentifier(matcher.group(2));
-        }
-        matcher = QUERY_CPS_PATH_WITH_SINGLE_LEAF_PATTERN.matcher(cpsPath);
-        if (matcher.matches()) {
-            cpsPathQuery.setParametersForSingleLeafValue(cpsPath, matcher);
-            return cpsPathQuery;
-        }
-        matcher = DESCENDANT_ANYWHERE_PATTERN_WITH_MULTIPLE_LEAF_PATTERN.matcher(cpsPath);
-        if (matcher.matches()) {
-            cpsPathQuery.setParametersForDescendantWithLeafValues(cpsPath, matcher);
-            return cpsPathQuery;
-        }
-        matcher = DESCENDANT_ANYWHERE_PATTERN.matcher(cpsPath);
-        if (matcher.matches()) {
-            cpsPathQuery.setParametersForDescendantAnywhere(matcher);
-            return cpsPathQuery;
-        }
-        throw new CpsPathException("Invalid cps path.",
-            String.format("Cannot interpret or parse cps path '%s'.", cpsPath));
-    }
-
-    /**
-     * Has ancestor axis been populated.
-     *
-     * @return boolean value.
-     */
-    public boolean hasAncestorAxis() {
-        return !(isEmpty(ancestorSchemaNodeIdentifier));
-    }
-
-    private void setParametersForSingleLeafValue(final String cpsPath, final Matcher matcher) {
-        setCpsPathQueryType(CpsPathQueryType.XPATH_LEAF_VALUE);
-        setXpathPrefix(matcher.group(1));
-        setLeafName(matcher.group(2));
-        setLeafValue(convertLeafValueToCorrectType(matcher.group(3), cpsPath));
-    }
-
-    private void setParametersForDescendantWithLeafValues(final String cpsPath, final Matcher matcher) {
-        setCpsPathQueryType(CpsPathQueryType.XPATH_HAS_DESCENDANT_WITH_LEAF_VALUES);
-        setDescendantName(matcher.group(1));
-        final Map<String, Object> leafData = new HashMap<>();
-        for (final String leafValuePair : matcher.group(2).split(INDIVIDUAL_LEAF_DETAIL_PATTERN)) {
-            final var descendentMatcher = LEAF_VALUE_PATTERN.matcher(leafValuePair);
-            if (descendentMatcher.matches()) {
-                leafData.put(descendentMatcher.group(1),
-                    convertLeafValueToCorrectType(descendentMatcher.group(2), cpsPath));
-            } else {
-                throw new CpsPathException("Invalid cps path.",
-                    String.format("Cannot interpret or parse attributes in cps path '%s'.", cpsPath));
-            }
-        }
-        setLeavesData(leafData);
-    }
-
-    private void setParametersForDescendantAnywhere(final Matcher matcher) {
-        setCpsPathQueryType(CpsPathQueryType.XPATH_HAS_DESCENDANT_ANYWHERE);
-        setDescendantName(matcher.group(1));
-    }
-
-    private static Object convertLeafValueToCorrectType(final String leafValueString, final String cpsPath) {
-        final var stringValueWithSingleQuotesMatcher =
-                LEAF_STRING_VALUE_IN_SINGLE_QUOTES_PATTERN.matcher(leafValueString);
-        if (stringValueWithSingleQuotesMatcher.matches()) {
-            return stringValueWithSingleQuotesMatcher.group(1);
-        }
-        final var stringValueWithDoubleQuotesMatcher =
-                LEAF_STRING_VALUE_IN_DOUBLE_QUOTES_PATTERN.matcher(leafValueString);
-        if (stringValueWithDoubleQuotesMatcher.matches()) {
-            return stringValueWithDoubleQuotesMatcher.group(1);
-        }
-        final var integerValueMatcher = LEAF_INTEGER_VALUE_PATTERN.matcher(leafValueString);
-        if (integerValueMatcher.matches()) {
-            return Integer.valueOf(leafValueString);
-        }
-        throw new CpsPathException("Unsupported leaf value.",
-            String.format("Unsupported leaf value '%s' in cps path '%s'.", leafValueString, cpsPath));
-    }
-}
diff --git a/cps-ri/src/main/java/org/onap/cps/spi/query/CpsPathQueryType.java b/cps-ri/src/main/java/org/onap/cps/spi/query/CpsPathQueryType.java
deleted file mode 100644
index 3ae54ba22a..0000000000
--- a/cps-ri/src/main/java/org/onap/cps/spi/query/CpsPathQueryType.java
+++ /dev/null
@@ -1,39 +0,0 @@
-/*
- * ============LICENSE_START=======================================================
- *  Copyright (C) 2021 Nordix Foundation
- *  Modifications Copyright (C) 2020-2021 Bell Canada.
- *  ================================================================================
- *  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.
- *
- *  SPDX-License-Identifier: Apache-2.0
- *  ============LICENSE_END=========================================================
- */
-
-package org.onap.cps.spi.query;
-
-/**
- * The enum Cps path query type.
- */
-public enum CpsPathQueryType {
-    /**
-     * Xpath descendant anywhere type e.g. //nodeName .
-     */
-    XPATH_HAS_DESCENDANT_ANYWHERE,
-    /**
-     * Xpath descendant anywhere type e.g. //nodeName[@leafName=leafValue] .
-     */
-    XPATH_HAS_DESCENDANT_WITH_LEAF_VALUES,
-    /**
-     * Xpath leaf value cps path query type e.g. /cps-path[@leafName=leafValue] .
-     */
-    XPATH_LEAF_VALUE
-}