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         final Object comparisonValue;
  83         if (ctx.IntegerLiteral() != null) {
  84             comparisonValue = Integer.valueOf(ctx.IntegerLiteral().getText());
  85         } else if (ctx.StringLiteral() != null) {
  86             comparisonValue = unwrapQuotedString(ctx.StringLiteral().getText());
  87         } else {
  88             throw new PathParsingException("Unsupported comparison value encountered in expression" + ctx.getText());
  89         }
  90         leafContext(ctx.leafName(), comparisonValue);
  91     }
  92
  93     @Override
  94     public void exitBooleanOperators(final CpsPathParser.BooleanOperatorsContext ctx) {
  95         booleanOperators.add(ctx.getText());
  96     }
  97
  98     @Override
  99     public void exitComparativeOperators(final CpsPathParser.ComparativeOperatorsContext ctx) {
 100         comparativeOperators.add(ctx.getText());
 101     }
 102
 103     @Override
 104     public void exitDescendant(final DescendantContext ctx) {
 105         cpsPathQuery.setCpsPathPrefixType(DESCENDANT);
 106         cpsPathQuery.setDescendantName(normalizedXpathBuilder.substring(1));
 107         normalizedXpathBuilder.insert(0, "/");
 108     }
 109
 110     @Override
 111     public void enterMultipleLeafConditions(final MultipleLeafConditionsContext ctx)  {
 112         normalizedXpathBuilder.append(OPEN_BRACKET);
 113         leavesData.clear();
 114         booleanOperators.clear();
 115         comparativeOperators.clear();
 116     }
 117
 118     @Override
 119     public void exitMultipleLeafConditions(final MultipleLeafConditionsContext ctx) {
 120         normalizedXpathBuilder.append(CLOSE_BRACKET);
 121         cpsPathQuery.setLeavesData(leavesData);
 122     }
 123
 124     @Override
 125     public void enterAncestorAxis(final AncestorAxisContext ctx) {
 126         processingAncestorAxis = true;
 127     }
 128
 129     @Override
 130     public void exitAncestorAxis(final AncestorAxisContext ctx) {
 131         cpsPathQuery.setAncestorSchemaNodeIdentifier(normalizedAncestorPathBuilder.substring(1));
 132         processingAncestorAxis = false;
 133     }
 134
 135     @Override
 136     public void exitTextFunctionCondition(final TextFunctionConditionContext ctx) {
 137         cpsPathQuery.setTextFunctionConditionLeafName(ctx.leafName().getText());
 138         cpsPathQuery.setTextFunctionConditionValue(unwrapQuotedString(ctx.StringLiteral().getText()));
 139     }
 140
 141     @Override
 142     public void exitContainsFunctionCondition(final CpsPathParser.ContainsFunctionConditionContext ctx) {
 143         cpsPathQuery.setContainsFunctionConditionLeafName(ctx.leafName().getText());
 144         cpsPathQuery.setContainsFunctionConditionValue(unwrapQuotedString(ctx.StringLiteral().getText()));
 145     }
 146
 147     @Override
 148     public void enterListElementRef(final CpsPathParser.ListElementRefContext ctx) {
 149         normalizedXpathBuilder.append(OPEN_BRACKET);
 150         if (processingAncestorAxis) {
 151             normalizedAncestorPathBuilder.append(OPEN_BRACKET);
 152         }
 153     }
 154
 155     @Override
 156     public void exitListElementRef(final CpsPathParser.ListElementRefContext ctx) {
 157         normalizedXpathBuilder.append(CLOSE_BRACKET);
 158         if (processingAncestorAxis) {
 159             normalizedAncestorPathBuilder.append(CLOSE_BRACKET);
 160         }
 161     }
 162
 163     CpsPathQuery build() {
 164         cpsPathQuery.setNormalizedXpath(normalizedXpathBuilder.toString());
 165         cpsPathQuery.setContainerNames(containerNames);
 166         cpsPathQuery.setBooleanOperators(booleanOperators);
 167         cpsPathQuery.setComparativeOperators(comparativeOperators);
 168         return cpsPathQuery;
 169     }
 170
 171     @Override
 172     public void exitContainerName(final CpsPathParser.ContainerNameContext ctx) {
 173         final String containerName = ctx.getText();
 174         normalizedXpathBuilder.append("/")
 175                 .append(containerName);
 176         containerNames.add(containerName);
 177         if (processingAncestorAxis) {
 178             normalizedAncestorPathBuilder.append("/").append(containerName);
 179         }
 180     }
 181
 182     private void leafContext(final CpsPathParser.LeafNameContext ctx, final Object comparisonValue) {
 183         leavesData.add(new CpsPathQuery.DataLeaf(ctx.getText(), comparisonValue));
 184         appendCondition(normalizedXpathBuilder, ctx.getText(), comparisonValue);
 185         if (processingAncestorAxis) {
 186             appendCondition(normalizedAncestorPathBuilder, ctx.getText(), comparisonValue);
 187         }
 188     }
 189
 190     private void appendCondition(final StringBuilder currentNormalizedPathBuilder, final String name,
 191                                  final Object value) {
 192         final char lastCharacter = currentNormalizedPathBuilder.charAt(currentNormalizedPathBuilder.length() - 1);
 193         final boolean isStartOfExpression = lastCharacter == '[';
 194         if (!isStartOfExpression) {
 195             currentNormalizedPathBuilder.append(" ").append(getLastElement(booleanOperators)).append(" ");
 196         }
 197         currentNormalizedPathBuilder.append("@")
 198                                     .append(name)
 199                                     .append(getLastElement(comparativeOperators))
 200                                     .append("'")
 201                                     .append(value.toString().replace("'", "''"))
 202                                     .append("'");
 203     }
 204
 205     private static String getLastElement(final List<String> listOfStrings) {
 206         return listOfStrings.get(listOfStrings.size() - 1);
 207     }
 208
 209     private static String unwrapQuotedString(final String wrappedString) {
 210         final boolean wasWrappedInSingleQuote = wrappedString.startsWith("'");
 211         final String value = stripFirstAndLastCharacter(wrappedString);
 212         if (wasWrappedInSingleQuote) {
 213             return value.replace("''", "'");
 214         } else {
 215             return value.replace("\"\"", "\"");
 216         }
 217     }
 218
 219     private static String stripFirstAndLastCharacter(final String wrappedString) {
 220         return wrappedString.substring(1, wrappedString.length() - 1);
 221     }
 222 }