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