common/src/main/java/org/onap/so/client/graphinventory/entities/DSLQueryBuilder.java

   1 /*-
   2  * ============LICENSE_START=======================================================
   3  * ONAP - SO
   4  * ================================================================================
   5  * Copyright (C) 2017 - 2019 AT&T Intellectual Property. All rights reserved.
   6  * ================================================================================
   7  * Licensed under the Apache License, Version 2.0 (the "License");
   8  * you may not use this file except in compliance with the License.
   9  * You may obtain a copy of the License at
  10  *
  11  *      http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  * Unless required by applicable law or agreed to in writing, software
  14  * distributed under the License is distributed on an "AS IS" BASIS,
  15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  * See the License for the specific language governing permissions and
  17  * limitations under the License.
  18  * ============LICENSE_END=========================================================
  19  */
  20
  21 package org.onap.so.client.graphinventory.entities;
  22
  23 import java.util.ArrayList;
  24 import java.util.Arrays;
  25 import java.util.List;
  26 import java.util.stream.Collectors;
  27
  28 import org.onap.so.client.aai.entities.QueryStep;
  29 import org.onap.so.client.graphinventory.GraphInventoryObjectName;
  30
  31 import com.google.common.base.Joiner;
  32
  33
  34 public class DSLQueryBuilder<S, E> implements QueryStep {
  35
  36         private List<QueryStep> steps = new ArrayList<>();
  37         private String suffix = "";
  38
  39         public DSLQueryBuilder() {
  40
  41         }
  42         public DSLQueryBuilder(DSLNode node) {
  43                 steps.add(node);
  44         }
  45
  46         public DSLQueryBuilder<S, DSLNode> node(DSLNode node) {
  47                 steps.add(node);
  48
  49                 return (DSLQueryBuilder<S, DSLNode>) this;
  50         }
  51         public DSLQueryBuilder<S, E> output() {
  52                 if (steps.get(steps.size() -1) instanceof DSLNode) {
  53                         ((DSLNode)steps.get(steps.size() -1)).output();
  54                 }
  55                 return this;
  56         }
  57
  58         public <E2> DSLQueryBuilder<S, E2> union(final DSLQueryBuilder<?, E2>... union) {
  59
  60                 List<DSLQueryBuilder<?, ?>> unions = Arrays.asList(union);
  61                 steps.add(() -> {
  62                         StringBuilder query = new StringBuilder();
  63
  64                         query.append("> [ ").append(
  65                                         Joiner.on(", ").join(
  66                                                 unions.stream().map(item -> item.build()).collect(Collectors.toList())))
  67                                         .append(" ]");
  68                         return query.toString();
  69                 });
  70
  71                 return (DSLQueryBuilder<S, E2>) this;
  72         }
  73
  74         public DSLQueryBuilder<S, E> where(DSLQueryBuilder<?, ?> where) {
  75
  76                 steps.add(() -> {
  77                         StringBuilder query = new StringBuilder();
  78                         query.append(where.build()).append(")");
  79                         String result = query.toString();
  80                         if (!result.startsWith(">")) {
  81                                 result = "> " + result;
  82                         }
  83                         return "(" + result;
  84                 });
  85                 return this;
  86         }
  87
  88         public DSLQueryBuilder<S, E> to(DSLQueryBuilder<?, ?> to) {
  89                 steps.add(() -> {
  90                         StringBuilder query = new StringBuilder();
  91
  92                         query.append("> ").append(to.build());
  93                         return query.toString();
  94                 });
  95                 return this;
  96         }
  97
  98         public DSLQueryBuilder<S, E> to(GraphInventoryObjectName name) {
  99                 return to(__.node(name));
 100         }
 101
 102         public DSLQueryBuilder<S, E> to(GraphInventoryObjectName name, DSLNodeKey... key) {
 103                 return to(__.node(name, key));
 104         }
 105
 106         public DSLQueryBuilder<S, E> limit(int limit) {
 107                 suffix = " LIMIT " + limit;
 108                 return this;
 109         }
 110
 111         @Override
 112         public String build() {
 113                 return compile();
 114         }
 115
 116         @Override
 117         public String toString() {
 118                 return build();
 119         }
 120
 121         @Override
 122         public boolean equals(Object o) {
 123                 if (o != null) {
 124                         if (o instanceof QueryStep) {
 125                                 return ((QueryStep)o).build().equals(this.build());
 126                         } else if (o instanceof String) {
 127                                 return o.equals(this.build());
 128                         }
 129                 }
 130                 return false;
 131         }
 132
 133         @Override
 134         public int hashCode() {
 135
 136                 return build().hashCode();
 137         }
 138
 139         private String compile() {
 140                 return Joiner.on(" ").join(steps.stream().map(item -> item.build()).collect(Collectors.toList())) + suffix;
 141         }
 142
 143         protected QueryStep getFirst() {
 144                 return steps.get(0);
 145         }
 146 }