1/*
2 * Copyright (c) 2018, Daniel Gultsch All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without modification,
5 * are permitted provided that the following conditions are met:
6 *
7 * 1. Redistributions of source code must retain the above copyright notice, this
8 * list of conditions and the following disclaimer.
9 *
10 * 2. Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation and/or
12 * other materials provided with the distribution.
13 *
14 * 3. Neither the name of the copyright holder nor the names of its contributors
15 * may be used to endorse or promote products derived from this software without
16 * specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
20 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
21 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
22 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
24 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
25 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
27 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30package eu.siacs.conversations.utils;
31
32import java.util.ArrayList;
33import java.util.Arrays;
34import java.util.List;
35import java.util.Locale;
36
37
38public class FtsUtils {
39
40 private static final List<String> KEYWORDS = Arrays.asList("OR", "AND");
41
42 public static List<String> parse(String input) {
43 List<String> term = new ArrayList<>();
44 for (String part : input.replace('"',' ').split("\\s+")) {
45 if (part.isEmpty()) {
46 continue;
47 }
48 final String cleaned = clean(part);
49 if (isKeyword(cleaned) || cleaned.contains("*")) {
50 term.add(part);
51 } else if (!cleaned.isEmpty()) {
52 term.add(cleaned);
53 }
54 }
55 return term;
56 }
57
58 public static String toMatchString(List<String> terms) {
59 StringBuilder builder = new StringBuilder();
60 for (String term : terms) {
61 if (builder.length() != 0) {
62 builder.append(' ');
63 }
64 if (isKeyword(term)) {
65 builder.append(term.toUpperCase(Locale.ENGLISH));
66 } else if (term.contains("*") || term.startsWith("-")) {
67 builder.append(term);
68 } else {
69 builder.append(term).append('*');
70 }
71 }
72 return builder.toString();
73 }
74
75 static boolean isKeyword(String term) {
76 return KEYWORDS.contains(term.toUpperCase(Locale.ENGLISH));
77 }
78
79 private static int getStartIndex(String term) {
80 int length = term.length();
81 int index = 0;
82 while (term.charAt(index) == '*') {
83 ++index;
84 if (index >= length) {
85 break;
86 }
87 }
88 return index;
89 }
90
91 private static int getEndIndex(String term) {
92 int index = term.length() - 1;
93 while (term.charAt(index) == '*') {
94 --index;
95 if (index < 0) {
96 break;
97 }
98 }
99 return index;
100 }
101
102 private static String clean(String input) {
103 int begin = getStartIndex(input);
104 int end = getEndIndex(input);
105 if (begin > end) {
106 return "";
107 } else {
108 return input.substring(begin, end + 1);
109 }
110 }
111
112 public static String toUserEnteredString(List<String> term) {
113 final StringBuilder builder = new StringBuilder();
114 for(String part : term) {
115 if (builder.length() != 0) {
116 builder.append(' ');
117 }
118 builder.append(part);
119 }
120 return builder.toString();
121 }
122}