[Cps Path Parser] Fixes for parent path & normalization

This commit fixes issues with Cps Path Parser related to
path normalization and parent path generation when using
descendant paths and ancestor axis.

Issue-ID: CPS-2365
Signed-off-by: danielhanrahan <daniel.hanrahan@est.tech>
Change-Id: I728fc379b134bd62c39a7085650930450c8a8597

2 files changed, 33 insertions, 26 deletions

diff --git a/cps-path-parser/src/main/antlr4/org/onap/cps/cpspath/parser/antlr4/CpsPath.g4 b/cps-path-parser/src/main/antlr4/org/onap/cps/cpspath/parser/antlr4/CpsPath.g4
index be8d968fcb..444702db48 100644
--- a/cps-path-parser/src/main/antlr4/org/onap/cps/cpspath/parser/antlr4/CpsPath.g4
+++ b/cps-path-parser/src/main/antlr4/org/onap/cps/cpspath/parser/antlr4/CpsPath.g4
@@ -29,19 +29,21 @@ grammar CpsPath ;
 
 cpsPath : ( prefix | descendant ) multipleLeafConditions? textFunctionCondition? containsFunctionCondition? ancestorAxis? EOF ;
 
-ancestorAxis : SLASH KW_ANCESTOR COLONCOLON ancestorPath ;
+slash : SLASH ;
 
-ancestorPath : yangElement ( SLASH yangElement)* ;
+ancestorAxis : KW_ANCESTOR_AXIS_PREFIX ancestorPath ;
 
-textFunctionCondition : SLASH leafName OB KW_TEXT_FUNCTION EQ StringLiteral CB ;
+ancestorPath : yangElement ( slash yangElement)* ;
+
+textFunctionCondition : slash leafName OB KW_TEXT_FUNCTION EQ StringLiteral CB ;
 
 containsFunctionCondition : OB KW_CONTAINS_FUNCTION OP AT leafName COMMA StringLiteral CP CB ;
 
-parent : ( SLASH yangElement)* ;
+parent : ( slash yangElement)* ;
 
-prefix : parent SLASH containerName ;
+prefix : parent slash containerName ;
 
-descendant : SLASH prefix ;
+descendant : slash prefix ;
 
 yangElement : containerName listElementRef? ;
 
@@ -85,7 +87,8 @@ KW_ANCESTOR : 'ancestor' ;
 KW_AND : 'and' ;
 KW_TEXT_FUNCTION: 'text()' ;
 KW_OR : 'or' ;
-KW_CONTAINS_FUNCTION: 'contains' ;
+KW_CONTAINS_FUNCTION : 'contains' ;
+KW_ANCESTOR_AXIS_PREFIX : SLASH KW_ANCESTOR COLONCOLON ;
 
 IntegerLiteral : FragDigits ;
 // Add below type definitions for leafvalue comparision in https://jira.onap.org/browse/CPS-440
diff --git a/cps-path-parser/src/main/java/org/onap/cps/cpspath/parser/CpsPathBuilder.java b/cps-path-parser/src/main/java/org/onap/cps/cpspath/parser/CpsPathBuilder.java
index ac535f5efc..ed7dbecc18 100644
--- a/cps-path-parser/src/main/java/org/onap/cps/cpspath/parser/CpsPathBuilder.java
+++ b/cps-path-parser/src/main/java/org/onap/cps/cpspath/parser/CpsPathBuilder.java
@@ -36,6 +36,8 @@ import org.onap.cps.cpspath.parser.antlr4.CpsPathParser.TextFunctionConditionCon
 
 public class CpsPathBuilder extends CpsPathBaseListener {
 
+    private static final String NO_PARENT_PATH = "";
+
     private static final String OPEN_BRACKET = "[";
 
     private static final String CLOSE_BRACKET = "]";
@@ -46,7 +48,7 @@ public class CpsPathBuilder extends CpsPathBaseListener {
 
     private final StringBuilder normalizedXpathBuilder = new StringBuilder();
 
-    private final StringBuilder normalizedAncestorPathBuilder = new StringBuilder();
+    private int startIndexOfAncestorSchemaNodeIdentifier = 0;
 
     private boolean processingAncestorAxis = false;
 
@@ -55,13 +57,24 @@ public class CpsPathBuilder extends CpsPathBaseListener {
     private final List<String> booleanOperators = new ArrayList<>();
 
     @Override
+    public void exitSlash(final CpsPathParser.SlashContext ctx) {
+        normalizedXpathBuilder.append("/");
+    }
+
+    @Override
     public void exitPrefix(final PrefixContext ctx) {
         cpsPathQuery.setXpathPrefix(normalizedXpathBuilder.toString());
     }
 
     @Override
     public void exitParent(final CpsPathParser.ParentContext ctx) {
-        cpsPathQuery.setNormalizedParentPath(normalizedXpathBuilder.toString());
+        final String normalizedParentPath;
+        if (normalizedXpathBuilder.toString().equals("/")) {
+            normalizedParentPath = NO_PARENT_PATH;
+        } else {
+            normalizedParentPath = normalizedXpathBuilder.toString();
+        }
+        cpsPathQuery.setNormalizedParentPath(normalizedParentPath);
     }
 
     @Override
@@ -87,8 +100,7 @@ public class CpsPathBuilder extends CpsPathBaseListener {
     @Override
     public void exitDescendant(final DescendantContext ctx) {
         cpsPathQuery.setCpsPathPrefixType(DESCENDANT);
-        cpsPathQuery.setDescendantName(normalizedXpathBuilder.substring(1));
-        normalizedXpathBuilder.insert(0, "/");
+        cpsPathQuery.setDescendantName(normalizedXpathBuilder.substring(2));
     }
 
     @Override
@@ -107,12 +119,15 @@ public class CpsPathBuilder extends CpsPathBaseListener {
     @Override
     public void enterAncestorAxis(final AncestorAxisContext ctx) {
         processingAncestorAxis = true;
+        normalizedXpathBuilder.append("/ancestor::");
+        startIndexOfAncestorSchemaNodeIdentifier = normalizedXpathBuilder.length();
     }
 
     @Override
     public void exitAncestorAxis(final AncestorAxisContext ctx) {
-        cpsPathQuery.setAncestorSchemaNodeIdentifier(normalizedAncestorPathBuilder.substring(1));
         processingAncestorAxis = false;
+        cpsPathQuery.setAncestorSchemaNodeIdentifier(
+                normalizedXpathBuilder.substring(startIndexOfAncestorSchemaNodeIdentifier));
     }
 
     @Override
@@ -130,17 +145,11 @@ public class CpsPathBuilder extends CpsPathBaseListener {
     @Override
     public void enterListElementRef(final CpsPathParser.ListElementRefContext ctx) {
         normalizedXpathBuilder.append(OPEN_BRACKET);
-        if (processingAncestorAxis) {
-            normalizedAncestorPathBuilder.append(OPEN_BRACKET);
-        }
     }
 
     @Override
     public void exitListElementRef(final CpsPathParser.ListElementRefContext ctx) {
         normalizedXpathBuilder.append(CLOSE_BRACKET);
-        if (processingAncestorAxis) {
-            normalizedAncestorPathBuilder.append(CLOSE_BRACKET);
-        }
     }
 
     CpsPathQuery build() {
@@ -153,20 +162,15 @@ public class CpsPathBuilder extends CpsPathBaseListener {
     @Override
     public void exitContainerName(final CpsPathParser.ContainerNameContext ctx) {
         final String containerName = ctx.getText();
-        normalizedXpathBuilder.append("/")
-                .append(containerName);
-        containerNames.add(containerName);
-        if (processingAncestorAxis) {
-            normalizedAncestorPathBuilder.append("/").append(containerName);
+        normalizedXpathBuilder.append(containerName);
+        if (!processingAncestorAxis) {
+            containerNames.add(containerName);
         }
     }
 
     private void leafContext(final String leafName, final String operator, final Object comparisonValue) {
         leafConditions.add(new CpsPathQuery.LeafCondition(leafName, operator, comparisonValue));
         appendCondition(normalizedXpathBuilder, leafName, operator, comparisonValue);
-        if (processingAncestorAxis) {
-            appendCondition(normalizedAncestorPathBuilder, leafName, operator, comparisonValue);
-        }
     }
 
     private void appendCondition(final StringBuilder currentNormalizedPathBuilder, final String name,