cps-path-parser/src/main/java/org/onap/cps/cpspath/parser/CpsPathBuilder.java

   1 /*
   2  *  ============LICENSE_START=======================================================
   3  *  Copyright (C) 2021-2022 Nordix Foundation
   4  *  Modifications Copyright (C) 2023 TechMahindra Ltd
   5  *  ================================================================================
   6  *  Licensed under the Apache License, Version 2.0 (the "License");
   7  *  you may not use this file except in compliance with the License.
   8  *  You may obtain a copy of the License at
   9  *
  10  *        http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  *  Unless required by applicable law or agreed to in writing, software
  13  *  distributed under the License is distributed on an "AS IS" BASIS,
  14  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  *  See the License for the specific language governing permissions and
  16  *  limitations under the License.
  17  *
  18  *  SPDX-License-Identifier: Apache-2.0
  19  *  ============LICENSE_END=========================================================
  20  */
  21
  22 package org.onap.cps.cpspath.parser;
  23
  24 import static org.onap.cps.cpspath.parser.CpsPathPrefixType.DESCENDANT;
  25
  26 import java.util.ArrayList;
  27 import java.util.LinkedHashMap;
  28 import java.util.List;
  29 import java.util.Map;
  30 import org.onap.cps.cpspath.parser.antlr4.CpsPathBaseListener;
  31 import org.onap.cps.cpspath.parser.antlr4.CpsPathParser;
  32 import org.onap.cps.cpspath.parser.antlr4.CpsPathParser.AncestorAxisContext;
  33 import org.onap.cps.cpspath.parser.antlr4.CpsPathParser.DescendantContext;
  34 import org.onap.cps.cpspath.parser.antlr4.CpsPathParser.IncorrectPrefixContext;
  35 import org.onap.cps.cpspath.parser.antlr4.CpsPathParser.LeafConditionContext;
  36 import org.onap.cps.cpspath.parser.antlr4.CpsPathParser.MultipleLeafConditionsContext;
  37 import org.onap.cps.cpspath.parser.antlr4.CpsPathParser.PrefixContext;
  38 import org.onap.cps.cpspath.parser.antlr4.CpsPathParser.TextFunctionConditionContext;
  39
  40 public class CpsPathBuilder extends CpsPathBaseListener {
  41
  42     private static final String OPEN_BRACKET = "[";
  43
  44     private static final String CLOSE_BRACKET = "]";
  45
  46     final CpsPathQuery cpsPathQuery = new CpsPathQuery();
  47
  48     final Map<String, Object> leavesData = new LinkedHashMap<>();
  49
  50     final StringBuilder normalizedXpathBuilder = new StringBuilder();
  51
  52     final StringBuilder normalizedAncestorPathBuilder = new StringBuilder();
  53
  54     boolean processingAncestorAxis = false;
  55
  56     private List<String> containerNames = new ArrayList<>();
  57
  58     final List<String> booleanOperators = new ArrayList<>();
  59
  60     final List<String> comparativeOperators = new ArrayList<>();
  61
  62     @Override
  63     public void exitInvalidPostFix(final CpsPathParser.InvalidPostFixContext ctx) {
  64         throw new PathParsingException(ctx.getText());
  65     }
  66
  67     @Override
  68     public void exitPrefix(final PrefixContext ctx) {
  69         cpsPathQuery.setXpathPrefix(normalizedXpathBuilder.toString());
  70     }
  71
  72     @Override
  73     public void exitParent(final CpsPathParser.ParentContext ctx) {
  74         cpsPathQuery.setNormalizedParentPath(normalizedXpathBuilder.toString());
  75     }
  76
  77     @Override
  78     public void exitIncorrectPrefix(final IncorrectPrefixContext ctx) {
  79         throw new PathParsingException("CPS path can only start with one or two slashes (/)");
  80     }
  81
  82     @Override
  83     public void exitLeafCondition(final LeafConditionContext ctx) {
  84         Object comparisonValue;
  85         if (ctx.IntegerLiteral() != null) {
  86             comparisonValue = Integer.valueOf(ctx.IntegerLiteral().getText());
  87         } else if (ctx.StringLiteral() != null) {
  88             final boolean wasWrappedInDoubleQuote = ctx.StringLiteral().getText().startsWith("\"");
  89             comparisonValue = stripFirstAndLastCharacter(ctx.StringLiteral().getText());
  90             if (wasWrappedInDoubleQuote) {
  91                 comparisonValue = String.valueOf(comparisonValue).replace("'", "\\'");
  92             }
  93         } else {
  94             throw new PathParsingException(
  95                     "Unsupported comparison value encountered in expression" + ctx.getText());
  96         }
  97         leafContext(ctx.leafName(), comparisonValue);
  98     }
  99
 100     @Override
 101     public void exitBooleanOperators(final CpsPathParser.BooleanOperatorsContext ctx) {
 102         final CpsPathBooleanOperatorType cpsPathBooleanOperatorType = CpsPathBooleanOperatorType.fromString(
 103                 ctx.getText());
 104         booleanOperators.add(cpsPathBooleanOperatorType.getValues());
 105     }
 106
 107     @Override
 108     public void exitComparativeOperators(final CpsPathParser.ComparativeOperatorsContext ctx) {
 109         final CpsPathComparativeOperator cpsPathComparativeOperator = CpsPathComparativeOperator.fromString(
 110                 ctx.getText());
 111         comparativeOperators.add(cpsPathComparativeOperator.getLabel());
 112     }
 113
 114     @Override
 115     public void exitDescendant(final DescendantContext ctx) {
 116         cpsPathQuery.setCpsPathPrefixType(DESCENDANT);
 117         cpsPathQuery.setDescendantName(normalizedXpathBuilder.substring(1));
 118         normalizedXpathBuilder.insert(0, "/");
 119     }
 120
 121     @Override
 122     public void enterMultipleLeafConditions(final MultipleLeafConditionsContext ctx)  {
 123         normalizedXpathBuilder.append(OPEN_BRACKET);
 124         leavesData.clear();
 125     }
 126
 127     @Override
 128     public void exitMultipleLeafConditions(final MultipleLeafConditionsContext ctx) {
 129         normalizedXpathBuilder.append(CLOSE_BRACKET);
 130         cpsPathQuery.setLeavesData(leavesData);
 131     }
 132
 133     @Override
 134     public void enterAncestorAxis(final AncestorAxisContext ctx) {
 135         processingAncestorAxis = true;
 136     }
 137
 138     @Override
 139     public void exitAncestorAxis(final AncestorAxisContext ctx) {
 140         cpsPathQuery.setAncestorSchemaNodeIdentifier(normalizedAncestorPathBuilder.substring(1));
 141         processingAncestorAxis = false;
 142     }
 143
 144     @Override
 145     public void exitTextFunctionCondition(final TextFunctionConditionContext ctx) {
 146         cpsPathQuery.setTextFunctionConditionLeafName(ctx.leafName().getText());
 147         cpsPathQuery.setTextFunctionConditionValue(stripFirstAndLastCharacter(ctx.StringLiteral().getText()));
 148     }
 149
 150     @Override
 151     public void exitContainsFunctionCondition(final CpsPathParser.ContainsFunctionConditionContext ctx) {
 152         cpsPathQuery.setContainsFunctionConditionLeafName(ctx.leafName().getText());
 153         cpsPathQuery.setContainsFunctionConditionValue(stripFirstAndLastCharacter(ctx.StringLiteral().getText()));
 154     }
 155
 156     @Override
 157     public void enterListElementRef(final CpsPathParser.ListElementRefContext ctx) {
 158         normalizedXpathBuilder.append(OPEN_BRACKET);
 159         if (processingAncestorAxis) {
 160             normalizedAncestorPathBuilder.append(OPEN_BRACKET);
 161         }
 162     }
 163
 164     @Override
 165     public void exitListElementRef(final CpsPathParser.ListElementRefContext ctx) {
 166         normalizedXpathBuilder.append(CLOSE_BRACKET);
 167         if (processingAncestorAxis) {
 168             normalizedAncestorPathBuilder.append(CLOSE_BRACKET);
 169         }
 170     }
 171
 172     CpsPathQuery build() {
 173         cpsPathQuery.setNormalizedXpath(normalizedXpathBuilder.toString());
 174         cpsPathQuery.setContainerNames(containerNames);
 175         cpsPathQuery.setBooleanOperators(booleanOperators);
 176         cpsPathQuery.setComparativeOperators(comparativeOperators);
 177         return cpsPathQuery;
 178     }
 179
 180     private static String stripFirstAndLastCharacter(final String wrappedString) {
 181         return wrappedString.substring(1, wrappedString.length() - 1);
 182     }
 183
 184     @Override
 185     public void exitContainerName(final CpsPathParser.ContainerNameContext ctx) {
 186         final String containerName = ctx.getText();
 187         normalizedXpathBuilder.append("/")
 188                 .append(containerName);
 189         containerNames.add(containerName);
 190         if (processingAncestorAxis) {
 191             normalizedAncestorPathBuilder.append("/").append(containerName);
 192         }
 193     }
 194
 195     private void leafContext(final CpsPathParser.LeafNameContext ctx, final Object comparisonValue) {
 196         leavesData.put(ctx.getText(), comparisonValue);
 197         appendCondition(normalizedXpathBuilder, ctx.getText(), comparisonValue);
 198         if (processingAncestorAxis) {
 199             appendCondition(normalizedAncestorPathBuilder, ctx.getText(), comparisonValue);
 200         }
 201     }
 202
 203     private void appendCondition(final StringBuilder currentNormalizedPathBuilder, final String name,
 204                                  final Object value) {
 205         final char lastCharacter = currentNormalizedPathBuilder.charAt(currentNormalizedPathBuilder.length() - 1);
 206         final boolean isStartOfExpression = lastCharacter == '[';
 207         if (!isStartOfExpression) {
 208             currentNormalizedPathBuilder.append(" ").append(getLastElement(booleanOperators)).append(" ");
 209         }
 210         currentNormalizedPathBuilder.append("@")
 211                                     .append(name)
 212                                     .append(getLastElement(comparativeOperators))
 213                                     .append("'")
 214                                     .append(value)
 215                                     .append("'");
 216     }
 217
 218     private String getLastElement(final List<String> listOfStrings) {
 219         return listOfStrings.get(listOfStrings.size() - 1);
 220     }
 221 }