Data fragment update by xpath - parsing and validation

Issue-ID: CPS-58
Change-Id: I6363c39d7046afc3b20dcd1224d6399b043c4386
Signed-off-by: Ruslan Kashapov <ruslan.kashapov@pantheon.tech>

5 files changed, 212 insertions, 36 deletions

diff --git a/cps-service/src/main/java/org/onap/cps/spi/model/DataNodeBuilder.java b/cps-service/src/main/java/org/onap/cps/spi/model/DataNodeBuilder.java
index 67e93dd82b..ea0626c2b2 100644
--- a/cps-service/src/main/java/org/onap/cps/spi/model/DataNodeBuilder.java
+++ b/cps-service/src/main/java/org/onap/cps/spi/model/DataNodeBuilder.java
@@ -43,9 +43,21 @@ public class DataNodeBuilder {
 
     private NormalizedNode<?, ?> normalizedNodeTree;
     private String xpath;
+    private String parentNodeXpath = "";
     private Map<String, Object> leaves = Collections.emptyMap();
     private Collection<DataNode> childDataNodes = Collections.emptySet();
 
+    /**
+     * To use parent node xpath for creating {@link DataNode}.
+     *
+     * @param parentNodeXpath xpath of a parent node
+     * @return this {@link DataNodeBuilder} object
+     */
+    public DataNodeBuilder withParentNodeXpath(final String parentNodeXpath) {
+        this.parentNodeXpath = parentNodeXpath;
+        return this;
+    }
+
 
     /**
      * To use {@link NormalizedNode} for creating {@link DataNode}.
@@ -115,9 +127,9 @@ public class DataNodeBuilder {
     }
 
     private DataNode buildFromNormalizedNodeTree() {
-        final DataNode formalRootDataNode = new DataNodeBuilder().withXpath("").build();
-        addDataNodeFromNormalizedNode(formalRootDataNode, normalizedNodeTree);
-        return formalRootDataNode.getChildDataNodes().iterator().next();
+        final DataNode parentDataNode = new DataNodeBuilder().withXpath(parentNodeXpath).build();
+        addDataNodeFromNormalizedNode(parentDataNode, normalizedNodeTree);
+        return parentDataNode.getChildDataNodes().iterator().next();
     }
 
     private static void addDataNodeFromNormalizedNode(final DataNode currentDataNode,
diff --git a/cps-service/src/main/java/org/onap/cps/utils/YangUtils.java b/cps-service/src/main/java/org/onap/cps/utils/YangUtils.java
index 389b8967a9..733378ecba 100755..100644
--- a/cps-service/src/main/java/org/onap/cps/utils/YangUtils.java
+++ b/cps-service/src/main/java/org/onap/cps/utils/YangUtils.java
@@ -2,6 +2,7 @@
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2020 Nordix Foundation
  *  Modifications Copyright (C) 2021 Bell Canada. All rights reserved.
+ *  Modifications Copyright (C) 2021 Pantheon.tech
  *  ================================================================================
  *  Licensed under the Apache License, Version 2.0 (the "License");
  *  you may not use this file except in compliance with the License.
@@ -23,9 +24,14 @@ package org.onap.cps.utils;
 import com.google.gson.stream.JsonReader;
 import java.io.IOException;
 import java.io.StringReader;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
+import java.util.Optional;
 import java.util.stream.Collectors;
+import lombok.AccessLevel;
+import lombok.NoArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.onap.cps.spi.exceptions.DataValidationException;
 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
@@ -36,36 +42,58 @@ import org.opendaylight.yangtools.yang.data.codec.gson.JSONCodecFactorySupplier;
 import org.opendaylight.yangtools.yang.data.codec.gson.JsonParserStream;
 import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNormalizedNodeStreamWriter;
 import org.opendaylight.yangtools.yang.data.impl.schema.NormalizedNodeResult;
+import org.opendaylight.yangtools.yang.model.api.DataNodeContainer;
+import org.opendaylight.yangtools.yang.model.api.DataSchemaNode;
 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
 
 @Slf4j
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
 public class YangUtils {
 
+    private static final String XPATH_DELIMITER_REGEX = "\\/";
+    private static final String XPATH_NODE_KEY_ATTRIBUTES_REGEX = "\\[.+";
 
-    private YangUtils() {
-        // Private constructor fo security reasons
+    /**
+     * Parses jsonData into NormalizedNode according to given schema context.
+     *
+     * @param jsonData      json data as string
+     * @param schemaContext schema context describing associated data model
+     * @return the NormalizedNode object
+     */
+    public static NormalizedNode<?, ?> parseJsonData(final String jsonData, final SchemaContext schemaContext) {
+        return parseJsonData(jsonData, schemaContext, Optional.empty());
     }
 
     /**
-     * Parse a string containing json data for a certain model (schemaContext).
+     * Parses jsonData into NormalizedNode according to given schema context.
      *
-     * @param jsonData      a string containing json data for the given model
-     * @param schemaContext the SchemaContext for the given data
-     * @return the NormalizedNode representing the json data
+     * @param jsonData        json data fragment as string
+     * @param schemaContext   schema context describing associated data model
+     * @param parentNodeXpath the xpath referencing the parent node current data fragment belong to
+     * @return the NormalizedNode object
      */
-    public static NormalizedNode<?, ?> parseJsonData(final String jsonData, final SchemaContext schemaContext) {
+    public static NormalizedNode<?, ?> parseJsonData(final String jsonData, final SchemaContext schemaContext,
+        final String parentNodeXpath) {
+        final DataSchemaNode parentSchemaNode = getDataSchemaNodeByXpath(parentNodeXpath, schemaContext);
+        return parseJsonData(jsonData, schemaContext, Optional.of(parentSchemaNode));
+    }
+
+    private static NormalizedNode<?, ?> parseJsonData(final String jsonData, final SchemaContext schemaContext,
+        final Optional<DataSchemaNode> optionalParentSchemaNode) {
         final JSONCodecFactory jsonCodecFactory = JSONCodecFactorySupplier.DRAFT_LHOTKA_NETMOD_YANG_JSON_02
-                .getShared(schemaContext);
+            .getShared(schemaContext);
         final NormalizedNodeResult normalizedNodeResult = new NormalizedNodeResult();
         final NormalizedNodeStreamWriter normalizedNodeStreamWriter = ImmutableNormalizedNodeStreamWriter
-                .from(normalizedNodeResult);
-        try {
-            try (final JsonParserStream jsonParserStream = JsonParserStream
-                    .create(normalizedNodeStreamWriter, jsonCodecFactory)) {
-                final JsonReader jsonReader = new JsonReader(new StringReader(jsonData));
-                jsonParserStream.parse(jsonReader);
-            }
-        } catch (final IOException e) {
+            .from(normalizedNodeResult);
+
+        try (final JsonParserStream jsonParserStream = optionalParentSchemaNode.isPresent()
+            ? JsonParserStream.create(normalizedNodeStreamWriter, jsonCodecFactory, optionalParentSchemaNode.get())
+            : JsonParserStream.create(normalizedNodeStreamWriter, jsonCodecFactory)
+        ) {
+            final JsonReader jsonReader = new JsonReader(new StringReader(jsonData));
+            jsonParserStream.parse(jsonReader);
+
+        } catch (final IOException | IllegalStateException e) {
             throw new DataValidationException("Failed to parse json data.", String
                 .format("Exception occurred on parsing string %s.", jsonData), e);
         }
@@ -74,6 +102,7 @@ public class YangUtils {
 
     /**
      * Create an xpath form a Yang Tools NodeIdentifier (i.e. PathArgument).
+     *
      * @param nodeIdentifier the NodeIdentifier
      * @return an xpath
      */
@@ -83,13 +112,13 @@ public class YangUtils {
 
         if (nodeIdentifier instanceof YangInstanceIdentifier.NodeIdentifierWithPredicates) {
             xpathBuilder.append(getKeyAttributesStatement(
-                    (YangInstanceIdentifier.NodeIdentifierWithPredicates) nodeIdentifier));
+                (YangInstanceIdentifier.NodeIdentifierWithPredicates) nodeIdentifier));
         }
         return xpathBuilder.toString();
     }
 
     private static String getKeyAttributesStatement(
-            final YangInstanceIdentifier.NodeIdentifierWithPredicates nodeIdentifier) {
+        final YangInstanceIdentifier.NodeIdentifierWithPredicates nodeIdentifier) {
         final List<String> keyAttributes = nodeIdentifier.entrySet().stream().map(
             entry -> {
                 final String name = entry.getKey().getLocalName();
@@ -105,4 +134,49 @@ public class YangUtils {
             return "[" + String.join(" and ", keyAttributes) + "]";
         }
     }
+
+    private static DataSchemaNode getDataSchemaNodeByXpath(final String parentNodeXpath,
+        final SchemaContext schemaContext) {
+        final String[] xpathNodeIdSequence = xpathToNodeIdSequence(parentNodeXpath);
+        return findDataSchemaNodeByXpathNodeIdSequence(xpathNodeIdSequence, schemaContext.getChildNodes());
+    }
+
+    private static String[] xpathToNodeIdSequence(final String xpath) {
+        final String[] xpathNodeIdSequence = Arrays.stream(xpath.split(XPATH_DELIMITER_REGEX))
+            .map(identifier -> identifier.replaceFirst(XPATH_NODE_KEY_ATTRIBUTES_REGEX, ""))
+            .filter(identifier -> !identifier.isEmpty())
+            .toArray(String[]::new);
+        if (xpathNodeIdSequence.length < 1) {
+            throw new DataValidationException("Invalid xpath.", "Xpath contains no node identifiers.");
+        }
+        return xpathNodeIdSequence;
+    }
+
+    private static DataSchemaNode findDataSchemaNodeByXpathNodeIdSequence(final String[] xpathNodeIdSequence,
+        final Collection<? extends DataSchemaNode> dataSchemaNodes) {
+        final String currentXpathNodeId = xpathNodeIdSequence[0];
+        final DataSchemaNode currentDataSchemaNode = dataSchemaNodes.stream()
+            .filter(dataSchemaNode -> currentXpathNodeId.equals(dataSchemaNode.getQName().getLocalName()))
+            .findFirst().orElseThrow(() -> schemaNodeNotFoundException(currentXpathNodeId));
+        if (xpathNodeIdSequence.length <= 1) {
+            return currentDataSchemaNode;
+        }
+        if (currentDataSchemaNode instanceof DataNodeContainer) {
+            return findDataSchemaNodeByXpathNodeIdSequence(
+                getNextLevelXpathNodeIdSequence(xpathNodeIdSequence),
+                ((DataNodeContainer) currentDataSchemaNode).getChildNodes());
+        }
+        throw schemaNodeNotFoundException(xpathNodeIdSequence[1]);
+    }
+
+    private static String[] getNextLevelXpathNodeIdSequence(final String[] xpathNodeIdSequence) {
+        final String[] nextXpathNodeIdSequence = new String[xpathNodeIdSequence.length - 1];
+        System.arraycopy(xpathNodeIdSequence, 1, nextXpathNodeIdSequence, 0, nextXpathNodeIdSequence.length);
+        return nextXpathNodeIdSequence;
+    }
+
+    private static DataValidationException schemaNodeNotFoundException(final String schemaNodeIdentifier) {
+        return new DataValidationException("Invalid xpath.",
+            String.format("No schema node was found for xpath identifier '%s'.", schemaNodeIdentifier));
+    }
 }
diff --git a/cps-service/src/test/groovy/org/onap/cps/model/DataNodeBuilderSpec.groovy b/cps-service/src/test/groovy/org/onap/cps/model/DataNodeBuilderSpec.groovy
index d881e77ade..dca648b04c 100644
--- a/cps-service/src/test/groovy/org/onap/cps/model/DataNodeBuilderSpec.groovy
+++ b/cps-service/src/test/groovy/org/onap/cps/model/DataNodeBuilderSpec.groovy
@@ -1,7 +1,25 @@
+/*
+ *  ============LICENSE_START=======================================================
+ *  Copyright (C) 2021 Pantheon.tech
+ *  ================================================================================
+ *  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.model
 
 import org.onap.cps.TestUtils
-import org.onap.cps.spi.model.DataNode
 import org.onap.cps.spi.model.DataNodeBuilder
 import org.onap.cps.utils.YangUtils
 import org.onap.cps.yang.YangTextSchemaSourceSetBuilder
@@ -17,16 +35,16 @@ class DataNodeBuilderSpec extends Specification {
             '/test-tree/branch[@name=\'Right\']/nest': [name: 'Big', birds: ['Owl', 'Raven', 'Crow']]
     ]
 
-    def 'Converting Normalized Node (tree) to a DataNode (tree).'() {
-        given: 'a Yang module'
+    def 'Converting NormalizedNode (tree) to a DataNode (tree).'() {
+        given: 'the schema context for expected model'
             def yangResourceNameToContent = TestUtils.getYangResourcesAsMap('test-tree.yang')
             def schemaContext = YangTextSchemaSourceSetBuilder.of(yangResourceNameToContent) getSchemaContext()
-        and: 'a normalized node for that model'
+        and: 'the json data parsed into normalized node object'
             def jsonData = TestUtils.getResourceFileContent('test-tree.json')
             def normalizedNode = YangUtils.parseJsonData(jsonData, schemaContext)
-        when: 'the normalized node is converted to a DataNode (tree)'
+        when: 'the normalized node is converted to a data node'
             def result = new DataNodeBuilder().withNormalizedNodeTree(normalizedNode).build()
-            def mappedResult = treeToFlatMapByXpath(new HashMap<>(), result)
+            def mappedResult = TestUtils.getFlattenMapByXpath(result)
         then: '5 DataNode objects with unique xpath were created in total'
             mappedResult.size() == 5
         and: 'all expected xpaths were built'
@@ -37,6 +55,26 @@ class DataNodeBuilderSpec extends Specification {
             }
     }
 
+    def 'Converting NormalizedNode (tree) to a DataNode (tree) for known parent node.'() {
+        given: 'a schema context for expected model'
+            def yangResourceNameToContent = TestUtils.getYangResourcesAsMap('test-tree.yang')
+            def schemaContext = YangTextSchemaSourceSetBuilder.of(yangResourceNameToContent) getSchemaContext()
+        and: 'the json data parsed into normalized node object'
+            def jsonData = '{ "branch": [{ "name": "Branch", "nest": { "name": "Nest", "birds": ["bird"] } }] }'
+            def normalizedNode = YangUtils.parseJsonData(jsonData, schemaContext, "/test-tree")
+        when: 'the normalized node is converted to a data node with parent node xpath defined'
+            def result = new DataNodeBuilder()
+                    .withNormalizedNodeTree(normalizedNode)
+                    .withParentNodeXpath("/test-tree")
+                    .build()
+            def mappedResult = TestUtils.getFlattenMapByXpath(result)
+        then: '2 DataNode objects with unique xpath were created in total'
+            mappedResult.size() == 2
+        and: 'all expected xpaths were built'
+            mappedResult.keySet()
+                    .containsAll(['/test-tree/branch[@name=\'Branch\']', '/test-tree/branch[@name=\'Branch\']/nest'])
+    }
+
     def static assertLeavesMaps(actualLeavesMap, expectedLeavesMap) {
         expectedLeavesMap.each { key, value ->
             {
@@ -51,10 +89,4 @@ class DataNodeBuilderSpec extends Specification {
         }
     }
 
-    def treeToFlatMapByXpath(Map<String, DataNode> flatMap, DataNode dataNodeTree) {
-        flatMap.put(dataNodeTree.getXpath(), dataNodeTree)
-        dataNodeTree.getChildDataNodes()
-                .forEach(childDataNode -> treeToFlatMapByXpath(flatMap, childDataNode))
-        return flatMap
-    }
 }
diff --git a/cps-service/src/test/groovy/org/onap/cps/utils/YangUtilsSpec.groovy b/cps-service/src/test/groovy/org/onap/cps/utils/YangUtilsSpec.groovy
index e6e5d6a366..826cdd8c71 100644
--- a/cps-service/src/test/groovy/org/onap/cps/utils/YangUtilsSpec.groovy
+++ b/cps-service/src/test/groovy/org/onap/cps/utils/YangUtilsSpec.groovy
@@ -1,6 +1,7 @@
 /*
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2020 Nordix Foundation
+ *  Modifications Copyright (C) 2021 Pantheon.tech
  *  ================================================================================
  *  Licensed under the Apache License, Version 2.0 (the "License");
  *  you may not use this file except in compliance with the License.
@@ -20,14 +21,14 @@
 package org.onap.cps.utils
 
 import org.onap.cps.TestUtils
+import org.onap.cps.spi.exceptions.DataValidationException
 import org.onap.cps.yang.YangTextSchemaSourceSetBuilder
 import org.opendaylight.yangtools.yang.common.QName
-import org.opendaylight.yangtools.yang.common.Revision
 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode
 import spock.lang.Specification
 import spock.lang.Unroll
 
-class YangUtilsSpec extends Specification{
+class YangUtilsSpec extends Specification {
     def 'Parsing a valid Json String.'() {
         given: 'a yang model (file)'
             def jsonData = org.onap.cps.TestUtils.getResourceFileContent('bookstore.json')
@@ -48,10 +49,45 @@ class YangUtilsSpec extends Specification{
         when: 'invalid data is parsed'
             YangUtils.parseJsonData(invalidJson, schemaContext)
         then: 'an exception is thrown'
-            thrown(IllegalStateException)
+            thrown(DataValidationException)
         where: 'the following invalid json is provided'
             invalidJson                                       | description
             '{incomplete json'                                | 'incomplete json'
             '{"test:bookstore": {"address": "Parnell st." }}' | 'json with un-modelled data'
     }
+
+    @Unroll
+    def 'Parsing json data fragment by xpath for #scenario.'() {
+        given: 'schema context'
+            def yangResourcesMap = TestUtils.getYangResourcesAsMap('test-tree.yang')
+            def schemaContext = YangTextSchemaSourceSetBuilder.of(yangResourcesMap).getSchemaContext()
+        when: 'json string is parsed'
+            def result = YangUtils.parseJsonData(jsonData, schemaContext, parentNodeXpath)
+        then: 'result represents a node of expected type'
+            result.nodeType == QName.create('org:onap:cps:test:test-tree', '2020-02-02', nodeName)
+        where:
+            scenario                    | jsonData                                                                      | parentNodeXpath                       || nodeName
+            'list element as container' | '{ "branch": { "name": "B", "nest": { "name": "N", "birds": ["bird"] } } }'   | '/test-tree'                          || 'branch'
+            'list element within list'  | '{ "branch": [{ "name": "B", "nest": { "name": "N", "birds": ["bird"] } }] }' | '/test-tree'                          || 'branch'
+            'container element'         | '{ "nest": { "name": "N", "birds": ["bird"] } }'                              | '/test-tree/branch[@name=\'Branch\']' || 'nest'
+    }
+
+    @Unroll
+    def 'Parsing json data fragment by xpath error scenario: #scenario.'() {
+        given: 'schema context'
+            def yangResourcesMap = TestUtils.getYangResourcesAsMap('test-tree.yang')
+            def schemaContext = YangTextSchemaSourceSetBuilder.of(yangResourcesMap).getSchemaContext()
+        when: 'json string is parsed'
+            YangUtils.parseJsonData('{"nest": {"name" : "Nest", "birds": ["bird"]}}', schemaContext,
+                    parentNodeXpath)
+        then: 'expected exception is thrown'
+            thrown(DataValidationException)
+        where:
+            scenario                             | parentNodeXpath
+            'xpath has no identifiers'           | '/'
+            'xpath has no valid identifiers'     | '/[@name=\'Name\']'
+            'invalid parent path'                | '/test-bush'
+            'another invalid parent path'        | '/test-tree/branch[@name=\'Branch\']/nest/name/last-name'
+            'fragment does not belong to parent' | '/test-tree/'
+    }
 }
diff --git a/cps-service/src/test/java/org/onap/cps/TestUtils.java b/cps-service/src/test/java/org/onap/cps/TestUtils.java
index 4ec4e4a004..bf59e1713c 100644
--- a/cps-service/src/test/java/org/onap/cps/TestUtils.java
+++ b/cps-service/src/test/java/org/onap/cps/TestUtils.java
@@ -1,6 +1,7 @@
 /*
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2020 Nordix Foundation
+ *  Modifications Copyright (C) 2021 Pantheon.tech
  *  ================================================================================
  *  Licensed under the Apache License, Version 2.0 (the "License");
  *  you may not use this file except in compliance with the License.
@@ -24,6 +25,7 @@ import java.io.File;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.util.Map;
+import org.onap.cps.spi.model.DataNode;
 
 /**
  * Common convenience methods for testing.
@@ -69,4 +71,24 @@ public class TestUtils {
         }
         return yangResourceNameToContentBuilder.build();
     }
+
+    /**
+     * Represents given data node object as flatten map by xpath.
+     * For easy finding child node within hierarchy.
+     *
+     * @param dataNode data node representing a root of tree structure
+     * @return the map containing all the data nodes from given structure where key is xpath, value is datanode object
+     */
+    public static Map<String, DataNode> getFlattenMapByXpath(final DataNode dataNode) {
+        final ImmutableMap.Builder<String, DataNode> dataNodeMapBuilder = ImmutableMap.builder();
+        buildFlattenMapByXpath(dataNode, dataNodeMapBuilder);
+        return dataNodeMapBuilder.build();
+    }
+
+    private static void buildFlattenMapByXpath(final DataNode dataNode,
+        final ImmutableMap.Builder<String, DataNode> dataNodeMapBuilder) {
+        dataNodeMapBuilder.put(dataNode.getXpath(), dataNode);
+        dataNode.getChildDataNodes()
+            .forEach(childDataNode -> buildFlattenMapByXpath(childDataNode, dataNodeMapBuilder));
+    }
 }