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
37public class FtsUtils {
38
39	private static List<String> KEYWORDS = Arrays.asList("OR", "AND");
40
41	public static List<String> parse(String input) {
42		List<String> term = new ArrayList<>();
43		for (String part : input.split("\\s+")) {
44			if (part.isEmpty()) {
45				continue;
46			}
47			final String cleaned = part.substring(getStartIndex(part), getEndIndex(part) +1);
48			if (isKeyword(cleaned)) {
49				term.add(part);
50			} else {
51				term.add(cleaned);
52			}
53		}
54		return term;
55	}
56
57	public static String toMatchString(List<String> terms) {
58		StringBuilder builder = new StringBuilder();
59		for (String term : terms) {
60			if (builder.length() != 0) {
61				builder.append(' ');
62			}
63			if (isKeyword(term)) {
64				builder.append(term.toUpperCase(Locale.ENGLISH));
65			} else if (term.contains("*") || term.startsWith("-")) {
66				builder.append(term);
67			} else {
68				builder.append('*').append(term).append('*');
69			}
70		}
71		return builder.toString();
72	}
73
74	public static boolean isKeyword(String term) {
75		return KEYWORDS.contains(term.toUpperCase(Locale.ENGLISH));
76	}
77
78	private static int getStartIndex(String term) {
79		int index = 0;
80		while (term.charAt(index) == '*') {
81			++index;
82		}
83		return index;
84	}
85
86	private static int getEndIndex(String term) {
87		int index = term.length() - 1;
88		while (term.charAt(index) == '*') {
89			--index;
90		}
91		return index;
92	}
93
94}