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

   1 /*
   2  *  ============LICENSE_START=======================================================
   3  *  Copyright (C) 2021-2023 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.List;
  28 import org.onap.cps.cpspath.parser.antlr4.CpsPathBaseListener;
  29 import org.onap.cps.cpspath.parser.antlr4.CpsPathParser;
  30 import org.onap.cps.cpspath.parser.antlr4.CpsPathParser.AncestorAxisContext;
  31 import org.onap.cps.cpspath.parser.antlr4.CpsPathParser.DescendantContext;
  32 import org.onap.cps.cpspath.parser.antlr4.CpsPathParser.IncorrectPrefixContext;
  33 import org.onap.cps.cpspath.parser.antlr4.CpsPathParser.LeafConditionContext;
  34 import org.onap.cps.cpspath.parser.antlr4.CpsPathParser.MultipleLeafConditionsContext;
  35 import org.onap.cps.cpspath.parser.antlr4.CpsPathParser.PrefixContext;
  36 import org.onap.cps.cpspath.parser.antlr4.CpsPathParser.TextFunctionConditionContext;
  37
  38 public class CpsPathBuilder extends CpsPathBaseListener {
  39
  40     private static final String OPEN_BRACKET = "[";
  41
  42     private static final String CLOSE_BRACKET = "]";
  43
  44     private final CpsPathQuery cpsPathQuery = new CpsPathQuery();
  45
  46     private final List<CpsPathQuery.DataLeaf> leavesData = new ArrayList<>();
  47
  48     private final StringBuilder normalizedXpathBuilder = new StringBuilder();
  49
  50     private final StringBuilder normalizedAncestorPathBuilder = new StringBuilder();
  51
  52     private boolean processingAncestorAxis = false;
  53
  54     private final List<String> containerNames = new ArrayList<>();
  55
  56     private final List<String> booleanOperators = new ArrayList<>();
  57
  58     private final List<String> comparativeOperators = new ArrayList<>();
  59
  60     @Override
  61     public void exitInvalidPostFix(final CpsPathParser.InvalidPostFixContext ctx) {
  62         throw new PathParsingException(ctx.getText());
  63     }
  64
  65     @Override
  66     public void exitPrefix(final PrefixContext ctx) {
  67         cpsPathQuery.setXpathPrefix(normalizedXpathBuilder.toString());
  68     }
  69
  70     @Override
  71     public void exitParent(final CpsPathParser.ParentContext ctx) {
  72         cpsPathQuery.setNormalizedParentPath(normalizedXpathBuilder.toString());
  73     }
  74
  75     @Override
  76     public void exitIncorrectPrefix(final IncorrectPrefixContext ctx) {
  77         throw new PathParsingException("CPS path can only start with one or two slashes (/)");
  78     }
  79
  80     @Override
  81     public void exitLeafCondition(final LeafConditionContext ctx) {
  82         Object comparisonValue;
  83         if (ctx.IntegerLiteral() != null) {
  84             comparisonValue = Integer.valueOf(ctx.IntegerLiteral().getText());
  85         } else if (ctx.StringLiteral() != null) {
  86             final boolean wasWrappedInDoubleQuote = ctx.StringLiteral().getText().startsWith("\"");
  87             comparisonValue = stripFirstAndLastCharacter(ctx.StringLiteral().getText());
  88             if (wasWrappedInDoubleQuote) {
  89                 comparisonValue = String.valueOf(comparisonValue).replace("'", "\\'");
  90             }
  91         } else {
  92             throw new PathParsingException(
  93                     "Unsupported comparison value encountered in expression" + ctx.getText());
  94         }
  95         leafContext(ctx.leafName(), comparisonValue);
  96     }
  97
  98     @Override
  99     public void exitBooleanOperators(final CpsPathParser.BooleanOperatorsContext ctx) {
 100         booleanOperators.add(ctx.getText());
 101     }
 102
 103     @Override
 104     public void exitComparativeOperators(final CpsPathParser.ComparativeOperatorsContext ctx) {
 105         comparativeOperators.add(ctx.getText());
 106     }
 107
 108     @Override
 109     public void exitDescendant(final DescendantContext ctx) {
 110         cpsPathQuery.setCpsPathPrefixType(DESCENDANT);
 111         cpsPathQuery.setDescendantName(normalizedXpathBuilder.substring(1));
 112         normalizedXpathBuilder.insert(0, "/");
 113     }
 114
 115     @Override
 116     public void enterMultipleLeafConditions(final MultipleLeafConditionsContext ctx)  {
 117         normalizedXpathBuilder.append(OPEN_BRACKET);
 118         leavesData.clear();
 119         booleanOperators.clear();
 120         comparativeOperators.clear();
 121     }
 122
 123     @Override
 124     public void exitMultipleLeafConditions(final MultipleLeafConditionsContext ctx) {
 125         normalizedXpathBuilder.append(CLOSE_BRACKET);
 126         cpsPathQuery.setLeavesData(leavesData);
 127     }
 128
 129     @Override
 130     public void enterAncestorAxis(final AncestorAxisContext ctx) {
 131         processingAncestorAxis = true;
 132     }
 133
 134     @Override
 135     public void exitAncestorAxis(final AncestorAxisContext ctx) {
 136         cpsPathQuery.setAncestorSchemaNodeIdentifier(normalizedAncestorPathBuilder.substring(1));
 137         processingAncestorAxis = false;
 138     }
 139
 140     @Override
 141     public void exitTextFunctionCondition(final TextFunctionConditionContext ctx) {
 142         cpsPathQuery.setTextFunctionConditionLeafName(ctx.leafName().getText());
 143         cpsPathQuery.setTextFunctionConditionValue(stripFirstAndLastCharacter(ctx.StringLiteral().getText()));
 144     }
 145
 146     @Override
 147     public void exitContainsFunctionCondition(final CpsPathParser.ContainsFunctionConditionContext ctx) {
 148         cpsPathQuery.setContainsFunctionConditionLeafName(ctx.leafName().getText());
 149         cpsPathQuery.setContainsFunctionConditionValue(stripFirstAndLastCharacter(ctx.StringLiteral().getText()));
 150     }
 151
 152     @Override
 153     public void enterListElementRef(final CpsPathParser.ListElementRefContext ctx) {
 154         normalizedXpathBuilder.append(OPEN_BRACKET);
 155         if (processingAncestorAxis) {
 156             normalizedAncestorPathBuilder.append(OPEN_BRACKET);
 157         }
 158     }
 159
 160     @Override
 161     public void exitListElementRef(final CpsPathParser.ListElementRefContext ctx) {
 162         normalizedXpathBuilder.append(CLOSE_BRACKET);
 163         if (processingAncestorAxis) {
 164             normalizedAncestorPathBuilder.append(CLOSE_BRACKET);
 165         }
 166     }
 167
 168     CpsPathQuery build() {
 169         cpsPathQuery.setNormalizedXpath(normalizedXpathBuilder.toString());
 170         cpsPathQuery.setContainerNames(containerNames);
 171         cpsPathQuery.setBooleanOperators(booleanOperators);
 172         cpsPathQuery.setComparativeOperators(comparativeOperators);
 173         return cpsPathQuery;
 174     }
 175
 176     private static String stripFirstAndLastCharacter(final String wrappedString) {
 177         return wrappedString.substring(1, wrappedString.length() - 1);
 178     }
 179
 180     @Override
 181     public void exitContainerName(final CpsPathParser.ContainerNameContext ctx) {
 182         final String containerName = ctx.getText();
 183         normalizedXpathBuilder.append("/")
 184                 .append(containerName);
 185         containerNames.add(containerName);
 186         if (processingAncestorAxis) {
 187             normalizedAncestorPathBuilder.append("/").append(containerName);
 188         }
 189     }
 190
 191     private void leafContext(final CpsPathParser.LeafNameContext ctx, final Object comparisonValue) {
 192         leavesData.add(new CpsPathQuery.DataLeaf(ctx.getText(), comparisonValue));
 193         appendCondition(normalizedXpathBuilder, ctx.getText(), comparisonValue);
 194         if (processingAncestorAxis) {
 195             appendCondition(normalizedAncestorPathBuilder, ctx.getText(), comparisonValue);
 196         }
 197     }
 198
 199     private void appendCondition(final StringBuilder currentNormalizedPathBuilder, final String name,
 200                                  final Object value) {
 201         final char lastCharacter = currentNormalizedPathBuilder.charAt(currentNormalizedPathBuilder.length() - 1);
 202         final boolean isStartOfExpression = lastCharacter == '[';
 203         if (!isStartOfExpression) {
 204             currentNormalizedPathBuilder.append(" ").append(getLastElement(booleanOperators)).append(" ");
 205         }
 206         currentNormalizedPathBuilder.append("@")
 207                                     .append(name)
 208                                     .append(getLastElement(comparativeOperators))
 209                                     .append("'")
 210                                     .append(value)
 211                                     .append("'");
 212     }
 213
 214     private String getLastElement(final List<String> listOfStrings) {
 215         return listOfStrings.get(listOfStrings.size() - 1);
 216     }
 217 }