1 /*
2  * Copyright (C) 2021 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.queryable.queries;
18 
19 import com.android.queryable.Queryable;
20 
21 import java.io.Serializable;
22 import java.util.ArrayList;
23 import java.util.HashSet;
24 import java.util.List;
25 import java.util.Set;
26 
27 /** Implementation of {@link StringQuery}. */
28 public final class StringQueryHelper<E extends Queryable>
29         implements StringQuery<E>, Serializable{
30 
31     private static final long serialVersionUID = 1;
32 
33     private final transient E mQuery;
34     private String mEqualsValue;
35     private Set<String> mNotEqualsValues = new HashSet<>();
36 
StringQueryHelper()37     StringQueryHelper() {
38         mQuery = (E) this;
39     }
40 
StringQueryHelper(E query)41     public StringQueryHelper(E query) {
42         mQuery = query;
43     }
44 
45     @Override
isEqualTo(String string)46     public E isEqualTo(String string) {
47         mEqualsValue = string;
48         return mQuery;
49     }
50 
51     @Override
isNotEqualTo(String string)52     public E isNotEqualTo(String string) {
53         mNotEqualsValues.add(string);
54         return mQuery;
55     }
56 
57     @Override
matches(String value)58     public boolean matches(String value) {
59         if (mEqualsValue != null && !mEqualsValue.equals(value)) {
60             return false;
61         }
62         if (mNotEqualsValues.contains(value)) {
63             return false;
64         }
65 
66         return true;
67     }
68 
matches(StringQueryHelper<?> stringQueryHelper, String value)69     public static boolean matches(StringQueryHelper<?> stringQueryHelper, String value) {
70         return stringQueryHelper.matches(value);
71     }
72 
73     /**
74      * True if this query has not been configured.
75      */
isEmpty()76     public boolean isEmpty() {
77         return mEqualsValue == null && mNotEqualsValues.isEmpty();
78     }
79 
80     /**
81      * True if this query is for an exact string match.
82      */
isQueryingForExactMatch()83     public boolean isQueryingForExactMatch() {
84         return mEqualsValue != null;
85     }
86 
87     @Override
describeQuery(String fieldName)88     public String describeQuery(String fieldName) {
89         List<String> queryStrings = new ArrayList<>();
90         if (mEqualsValue != null) {
91             queryStrings.add(fieldName + "=\"" + mEqualsValue + "\"");
92         }
93 
94         for (String notEquals : mNotEqualsValues) {
95             queryStrings.add(fieldName + "!=\"" + notEquals + "\"");
96         }
97 
98         return Queryable.joinQueryStrings(queryStrings);
99     }
100 }
101