001/*
002 * (C) Copyright 2017 Nuxeo (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     Florent Guillaume
018 */
019package org.nuxeo.ecm.core.query.sql.model;
020
021import java.util.ArrayList;
022import java.util.Arrays;
023import java.util.List;
024import java.util.Map.Entry;
025
026import org.nuxeo.ecm.core.query.QueryParseException;
027
028/**
029 * Transforms a query into the same query, doing a copy in the process.
030 * <p>
031 * Can be used as a base class for more complex transformations.
032 *
033 * @since 9.10
034 */
035public class IdentityQueryTransformer implements QueryTransformer {
036
037    @Override
038    public SQLQuery transform(SQLQuery node) {
039        SelectClause select = transform(node.select);
040        FromClause from = transform(node.from);
041        WhereClause where = transform(node.where);
042        GroupByClause groupBy = transform(node.groupBy);
043        HavingClause having = transform(node.having);
044        OrderByClause orderBy = transform(node.orderBy);
045        long limit = transformLimit(node.limit);
046        long offset = transformOffset(node.offset);
047        return new SQLQuery(select, from, where, groupBy, having, orderBy, limit, offset);
048    }
049
050    @Override
051    public SelectClause transform(SelectClause node) {
052        return new SelectClause(transform(node.elements), node.distinct);
053    }
054
055    @Override
056    public SelectList transform(SelectList node) {
057        SelectList list = new SelectList();
058        for (Entry<String, Operand> es : node.entrySet()) {
059            list.put(es.getKey(), transform(es.getValue()));
060        }
061        return list;
062    }
063
064    @Override
065    public FromClause transform(FromClause node) {
066        return new FromClause(transform(node.elements));
067    }
068
069    @Override
070    public FromList transform(FromList node) {
071        FromList list = new FromList();
072        list.putAll(node);
073        return list;
074    }
075
076    @Override
077    public WhereClause transform(WhereClause node) {
078        return new WhereClause(transform(node.predicate));
079    }
080
081    @Override
082    public GroupByClause transform(GroupByClause node) {
083        if (node == null) {
084            return null;
085        }
086        String[] elements = node.elements;
087        if (elements != null) {
088            return new GroupByClause(Arrays.asList(elements));
089        } else {
090            return new GroupByClause();
091        }
092    }
093
094    @Override
095    public HavingClause transform(HavingClause node) {
096        if (node == null) {
097            return null;
098        }
099        return new HavingClause(transform(node.predicate));
100    }
101
102    @Override
103    public OrderByClause transform(OrderByClause node) {
104        if (node == null) {
105            return null;
106        }
107        return new OrderByClause(transform(node.elements));
108    }
109
110    @Override
111    public OrderByList transform(OrderByList node) {
112        OrderByList list = new OrderByList();
113        for (OrderByExpr value : node) {
114            list.add(transform(value));
115        }
116        return list;
117    }
118
119    @Override
120    public OrderByExpr transform(OrderByExpr node) {
121        return new OrderByExpr(transform(node.reference), node.isDescending);
122    }
123
124    @Override
125    public long transformLimit(long limit) {
126        return limit;
127    }
128
129    @Override
130    public long transformOffset(long offset) {
131        return offset;
132    }
133
134    @Override
135    public Operand transform(Operand node) {
136        if (node instanceof Literal) {
137            return transform((Literal) node);
138        } else if (node instanceof LiteralList) {
139            return transform((LiteralList) node);
140        } else if (node instanceof Function) {
141            return transform((Function) node);
142        } else if (node instanceof MultiExpression) {
143            return transform((MultiExpression) node);
144        } else if (node instanceof Predicate) {
145            return transform((Predicate) node);
146        } else if (node instanceof Expression) {
147            return transform((Expression) node);
148        } else if (node instanceof Reference) {
149            return transform((Reference) node);
150        } else {
151            throw new QueryParseException("Unknown operand: " + node);
152        }
153    }
154
155    @Override
156    public Expression transform(Expression node) {
157        if (node instanceof Predicate) {
158            return transform((Predicate) node);
159        }
160        Expression expr = new Expression(transform(node.lvalue), transform(node.operator), transform(node.rvalue));
161        expr.info = node.info;
162        return expr;
163    }
164
165    @Override
166    public Predicate transform(Predicate node) {
167        if (node instanceof MultiExpression) {
168            return transform((MultiExpression) node);
169        }
170        Predicate predicate = new Predicate(transform(node.lvalue), transform(node.operator), transform(node.rvalue));
171        predicate.info = node.info;
172        return predicate;
173    }
174
175    @Override
176    public MultiExpression transform(MultiExpression node) {
177        List<Predicate> predicates = new ArrayList<>(node.predicates.size());
178        for (Predicate predicate : node.predicates) {
179            predicates.add(transform(predicate));
180        }
181        MultiExpression expr = new MultiExpression(transform(node.operator), predicates);
182        expr.info = node.info;
183        return expr;
184    }
185
186    @Override
187    public Operator transform(Operator node) {
188        return node;
189    }
190
191    @Override
192    public Reference transform(Reference node) {
193        Reference ref = new Reference(node.name, node.cast, node.esHint);
194        ref.info = node.info;
195        return ref;
196    }
197
198    @Override
199    public ReferenceList transform(ReferenceList node) {
200        ReferenceList list = new ReferenceList();
201        for (Reference ref : node) {
202            list.add(transform(ref));
203        }
204        return list;
205    }
206
207    @Override
208    public Operand transform(Function node) {
209        return new Function(node.name, transform(node.args));
210    }
211
212    @Override
213    public OperandList transform(OperandList node) {
214        OperandList list = new OperandList();
215        for (Operand oper : node) {
216            list.add(transform(oper));
217        }
218        return list;
219    }
220
221    @Override
222    public Literal transform(Literal node) {
223        if (node instanceof BooleanLiteral) {
224            return transform((BooleanLiteral) node);
225        } else if (node instanceof DateLiteral) {
226            return transform((DateLiteral) node);
227        } else if (node instanceof DoubleLiteral) {
228            return transform((DoubleLiteral) node);
229        } else if (node instanceof IntegerLiteral) {
230            return transform((IntegerLiteral) node);
231        } else if (node instanceof StringLiteral) {
232            return transform((StringLiteral) node);
233        } else {
234            throw new QueryParseException("Unknown literal: " + node);
235        }
236    }
237
238    @Override
239    public LiteralList transform(LiteralList node) {
240        LiteralList list = new LiteralList();
241        for (Literal lit : node) {
242            list.add(transform(lit));
243        }
244        return list;
245    }
246
247    @Override
248    public Literal transform(BooleanLiteral node) {
249        return node;
250    }
251
252    @Override
253    public Literal transform(DateLiteral node) {
254        return node;
255    }
256
257    @Override
258    public Literal transform(DoubleLiteral node) {
259        return node;
260    }
261
262    @Override
263    public Literal transform(IntegerLiteral node) {
264        return node;
265    }
266
267    @Override
268    public Literal transform(StringLiteral node) {
269        return node;
270    }
271
272}