perf: replace regex swear filter with Aho-Corasick O(n) trie + add FilterResult unit tests

src/main/java/com/loki/lochat/core/filter/filters/SwearFilter.java

@@ -1,6 +1,7 @@
 package com.loki.lochat.core.filter.filters;
 
 import com.loki.lochat.core.filter.FilterResult;
+import com.loki.lochat.utils.text.AhoCorasick;
 
 import org.bukkit.configuration.file.FileConfiguration;
 import org.bukkit.entity.Player;
@@ -10,32 +11,14 @@ import java.io.BufferedReader;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.nio.charset.StandardCharsets;
-import java.util.HashSet;
+import java.util.ArrayList;
-import java.util.Map;
+import java.util.List;
-import java.util.Set;
-import java.util.regex.Pattern;
 
 public class SwearFilter {
     private final boolean enabled;
     private final boolean replaceMode;
     private final String replacement;
-    private final Set<Pattern> swearPatterns = new HashSet<>();
+    private AhoCorasick ahoCorasick;
-    
-    // Карта замены латиницы на кириллицу для обхода фильтра
-    private static final Map<Character, Character> LATIN_TO_CYRILLIC = Map.ofEntries(
-        Map.entry('a', 'а'), Map.entry('A', 'А'),
-        Map.entry('e', 'е'), Map.entry('E', 'Е'),
-        Map.entry('o', 'о'), Map.entry('O', 'О'),
-        Map.entry('p', 'р'), Map.entry('P', 'Р'),
-        Map.entry('c', 'с'), Map.entry('C', 'С'),
-        Map.entry('y', 'у'), Map.entry('Y', 'У'),
-        Map.entry('x', 'х'), Map.entry('X', 'Х'),
-        Map.entry('k', 'к'), Map.entry('K', 'К'),
-        Map.entry('m', 'м'), Map.entry('M', 'М'),
-        Map.entry('h', 'н'), Map.entry('H', 'Н'),
-        Map.entry('t', 'т'), Map.entry('T', 'Т'),
-        Map.entry('b', 'в'), Map.entry('B', 'В')
-    );
 
     public SwearFilter(FileConfiguration config, JavaPlugin plugin) {
         this.enabled = config.getBoolean("filters.swear.enabled", true);
@@ -48,51 +31,17 @@ public class SwearFilter {
     }
 
     private void loadWordList(JavaPlugin plugin) {
+        List<String> words = new ArrayList<>();
         try (InputStream is = plugin.getResource("badwords.txt");
              BufferedReader reader = new BufferedReader(new InputStreamReader(is, StandardCharsets.UTF_8))) {
-            
             reader.lines()
                 .map(String::trim)
                 .filter(line -> !line.isEmpty() && !line.startsWith("#"))
-                .forEach(word -> {
+                .forEach(words::add);
-                    // Создаем паттерн с учетом возможной замены букв
-                    String regex = buildFlexiblePattern(word);
-                    swearPatterns.add(Pattern.compile(regex, Pattern.CASE_INSENSITIVE | Pattern.UNICODE_CASE));
-                });
         } catch (Exception e) {
             plugin.getLogger().warning("Failed to load badwords.txt: " + e.getMessage());
         }
-    }
+        this.ahoCorasick = new AhoCorasick(words);
-    
-    /**
-     * Создает гибкий паттерн, который ловит замены букв (х->x, о->o и т.д.)
-     */
-    private String buildFlexiblePattern(String word) {
-        StringBuilder pattern = new StringBuilder();
-        
-        for (char c : word.toLowerCase().toCharArray()) {
-            // Для каждой буквы создаем группу с возможными заменами
-            switch (c) {
-                case 'а' -> pattern.append("[аaА@]");
-                case 'е' -> pattern.append("[еeЕ3]");
-                case 'о' -> pattern.append("[оoО0]");
-                case 'р' -> pattern.append("[рpР]");
-                case 'с' -> pattern.append("[сcС]");
-                case 'у' -> pattern.append("[уyУ]");
-                case 'х' -> pattern.append("[хxХ]");
-                case 'к' -> pattern.append("[кkК]");
-                case 'м' -> pattern.append("[мmМ]");
-                case 'н' -> pattern.append("[нhНN]");
-                case 'т' -> pattern.append("[тtТ]");
-                case 'в' -> pattern.append("[вbВ]");
-                case 'и' -> pattern.append("[иiИ1]");
-                case 'з' -> pattern.append("[з3З]");
-                case 'б' -> pattern.append("[б6Б]");
-                default -> pattern.append(Pattern.quote(String.valueOf(c)));
-            }
-        }
-        
-        return pattern.toString();
     }
 
     public FilterResult filter(Player player, String message) {
@@ -100,23 +49,13 @@ public class SwearFilter {
             return FilterResult.ok(message);
         }
 
-        for (Pattern pattern : swearPatterns) {
+        if (ahoCorasick.matches(message)) {
-            if (pattern.matcher(message).find()) {
             if (replaceMode) {
-                    return FilterResult.ok(replaceSwear(message));
+                return FilterResult.ok(ahoCorasick.replaceAll(message, replacement));
             }
             return FilterResult.blocked("Сообщение содержит запрещенные слова");
         }
-        }
 
         return FilterResult.ok(message);
     }
-
-    private String replaceSwear(String message) {
-        String result = message;
-        for (Pattern pattern : swearPatterns) {
-            result = pattern.matcher(result).replaceAll(replacement);
-        }
-        return result;
-    }
 }

src/main/java/com/loki/lochat/utils/text/AhoCorasick.java

@@ -0,0 +1,172 @@
+package com.loki.lochat.utils.text;
+
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.Deque;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public final class AhoCorasick {
+
+    private static final Map<Character, Character> NORMALIZE = new HashMap<>();
+
+    static {
+        NORMALIZE.put('a', 'а');
+        NORMALIZE.put('A', 'А');
+        NORMALIZE.put('e', 'е');
+        NORMALIZE.put('E', 'Е');
+        NORMALIZE.put('o', 'о');
+        NORMALIZE.put('O', 'О');
+        NORMALIZE.put('p', 'р');
+        NORMALIZE.put('P', 'Р');
+        NORMALIZE.put('c', 'с');
+        NORMALIZE.put('C', 'С');
+        NORMALIZE.put('y', 'у');
+        NORMALIZE.put('Y', 'У');
+        NORMALIZE.put('x', 'х');
+        NORMALIZE.put('X', 'Х');
+        NORMALIZE.put('k', 'к');
+        NORMALIZE.put('K', 'К');
+        NORMALIZE.put('m', 'м');
+        NORMALIZE.put('M', 'М');
+        NORMALIZE.put('h', 'н');
+        NORMALIZE.put('H', 'Н');
+        NORMALIZE.put('n', 'н');
+        NORMALIZE.put('N', 'Н');
+        NORMALIZE.put('t', 'т');
+        NORMALIZE.put('T', 'Т');
+        NORMALIZE.put('b', 'в');
+        NORMALIZE.put('B', 'В');
+
+        NORMALIZE.put('@', 'а');
+        NORMALIZE.put('0', 'о');
+        NORMALIZE.put('3', 'е');
+        NORMALIZE.put('1', 'и');
+        NORMALIZE.put('6', 'б');
+    }
+
+    private final Node root;
+
+    public AhoCorasick(List<String> words) {
+        this.root = new Node((char) 0);
+        buildTrie(words);
+        buildFailLinks();
+    }
+
+    private void buildTrie(List<String> words) {
+        for (String word : words) {
+            if (word.isEmpty()) {
+                continue;
+            }
+            Node node = root;
+            for (char c : word.toCharArray()) {
+                char normalized = normalize(c);
+                Node current = node;
+                node = node.children.computeIfAbsent(normalized, ch -> new Node(ch, current));
+            }
+            node.output = true;
+            node.word = word;
+        }
+    }
+
+    private void buildFailLinks() {
+        Deque<Node> queue = new ArrayDeque<>();
+        for (Node node : root.children.values()) {
+            node.fail = root;
+            queue.addLast(node);
+        }
+        while (!queue.isEmpty()) {
+            Node current = queue.pollFirst();
+            for (Node child : current.children.values()) {
+                Node fail = current.fail;
+                while (fail != root && !fail.children.containsKey(child.c)) {
+                    fail = fail.fail;
+                }
+                if (fail != root || fail.children.containsKey(child.c)) {
+                    Node f = fail.children.get(child.c);
+                    child.fail = f != null ? f : root;
+                } else {
+                    child.fail = root;
+                }
+                child.output = child.output || child.fail.output;
+                if (child.fail.output && child.word == null) {
+                    child.word = child.fail.word;
+                }
+                queue.addLast(child);
+            }
+        }
+    }
+
+    public boolean matches(String text) {
+        Node node = root;
+        for (int i = 0; i < text.length(); i++) {
+            char c = normalize(text.charAt(i));
+            while (node != root && !node.children.containsKey(c)) {
+                node = node.fail;
+            }
+            node = node.children.getOrDefault(c, root);
+            if (node.output) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public String replaceAll(String text, String replacement) {
+        Node node = root;
+        int lastEnd = 0;
+        StringBuilder result = new StringBuilder();
+        for (int i = 0; i < text.length(); i++) {
+            char c = normalize(text.charAt(i));
+            while (node != root && !node.children.containsKey(c)) {
+                node = node.fail;
+            }
+            node = node.children.getOrDefault(c, root);
+            if (node.output && node.word != null) {
+                result.append(text, lastEnd, i - node.word.length() + 1);
+                result.append(replacement);
+                lastEnd = i + 1;
+            }
+        }
+        result.append(text, lastEnd, text.length());
+        return result.toString();
+    }
+
+    public List<String> findMatches(String text) {
+        List<String> found = new ArrayList<>();
+        Node node = root;
+        for (int i = 0; i < text.length(); i++) {
+            char c = normalize(text.charAt(i));
+            while (node != root && !node.children.containsKey(c)) {
+                node = node.fail;
+            }
+            node = node.children.getOrDefault(c, root);
+            if (node.output && node.word != null) {
+                found.add(node.word);
+            }
+        }
+        return found;
+    }
+
+    private static char normalize(char c) {
+        return NORMALIZE.getOrDefault(c, Character.toLowerCase(c));
+    }
+
+    private static final class Node {
+        final char c;
+        final Map<Character, Node> children = new HashMap<>();
+        Node fail;
+        boolean output;
+        String word;
+
+        Node(char c) {
+            this.c = c;
+            this.fail = this;
+        }
+
+        Node(char c, Node parent) {
+            this.c = c;
+        }
+    }
+}

src/test/java/com/loki/lochat/core/filter/FilterResultTest.java

@@ -0,0 +1,65 @@
+package com.loki.lochat.core.filter;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class FilterResultTest {
+
+    @Test
+    void ok_allowed() {
+        FilterResult r = FilterResult.ok("hello");
+        assertTrue(r.allowed());
+        assertNull(r.blockReason());
+        assertEquals("hello", r.filteredMessage());
+    }
+
+    @Test
+    void ok_getMessage() {
+        FilterResult r = FilterResult.ok("hello");
+        assertEquals("hello", r.getMessage());
+    }
+
+    @Test
+    void blocked_notAllowed() {
+        FilterResult r = FilterResult.blocked("bad word");
+        assertFalse(r.allowed());
+        assertEquals("bad word", r.blockReason());
+        assertNull(r.filteredMessage());
+    }
+
+    @Test
+    void ok_nullMessage() {
+        FilterResult r = FilterResult.ok(null);
+        assertTrue(r.allowed());
+        assertNull(r.filteredMessage());
+    }
+
+    @Test
+    void blocked_nullReason() {
+        FilterResult r = FilterResult.blocked(null);
+        assertFalse(r.allowed());
+        assertNull(r.blockReason());
+    }
+
+    @Test
+    void record_equals() {
+        FilterResult a = FilterResult.ok("hello");
+        FilterResult b = FilterResult.ok("hello");
+        assertEquals(a, b);
+        assertEquals(a.hashCode(), b.hashCode());
+    }
+
+    @Test
+    void record_notEquals() {
+        FilterResult a = FilterResult.ok("hello");
+        FilterResult b = FilterResult.blocked("bad");
+        assertNotEquals(a, b);
+    }
+
+    @Test
+    void record_toString() {
+        FilterResult r = FilterResult.ok("test");
+        assertTrue(r.toString().contains("test"));
+    }
+}

src/test/java/com/loki/lochat/utils/text/AhoCorasickTest.java

@@ -0,0 +1,145 @@
+package com.loki.lochat.utils.text;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class AhoCorasickTest {
+
+    @Test
+    void matches_simpleWord() {
+        AhoCorasick ac = new AhoCorasick(List.of("хуй"));
+        assertTrue(ac.matches("это хуй"));
+        assertTrue(ac.matches("хуй"));
+        assertFalse(ac.matches("привет"));
+    }
+
+    @Test
+    void matches_multipleWords() {
+        AhoCorasick ac = new AhoCorasick(List.of("хуй", "пизда", "ебать"));
+        assertTrue(ac.matches("старый хуй"));
+        assertTrue(ac.matches("полная пизда"));
+        assertTrue(ac.matches("ебать копать"));
+        assertFalse(ac.matches("нормальный текст"));
+    }
+
+    @Test
+    void matches_overlappingWords() {
+        AhoCorasick ac = new AhoCorasick(List.of("хуй", "хуе"));
+        assertTrue(ac.matches("хуе"));
+        assertTrue(ac.matches("хуй"));
+    }
+
+    @Test
+    void matches_subword() {
+        AhoCorasick ac = new AhoCorasick(List.of("хуй"));
+        assertFalse(ac.matches("ху"));
+        assertFalse(ac.matches(""));
+    }
+
+    @Test
+    void matches_latinToCyrillicSubstitution() {
+        AhoCorasick ac = new AhoCorasick(List.of("хуй", "пизда"));
+        assertTrue(ac.matches("xуй"));
+        assertTrue(ac.matches("xyй"));
+        assertTrue(ac.matches("хyй"));
+    }
+
+    @Test
+    void matches_caseInsensitive() {
+        AhoCorasick ac = new AhoCorasick(List.of("хуй"));
+        assertTrue(ac.matches("ХУЙ"));
+        assertTrue(ac.matches("Хуй"));
+        assertTrue(ac.matches("хуй"));
+    }
+
+    @Test
+    void matches_mixedSubstitutions() {
+        AhoCorasick ac = new AhoCorasick(List.of("ебать"));
+        assertTrue(ac.matches("3бать"));
+        assertTrue(ac.matches("ебaть"));
+    }
+
+    @Test
+    void replaceAll_replacesMatches() {
+        AhoCorasick ac = new AhoCorasick(List.of("хуй", "пизда"));
+        assertEquals("*** текст", ac.replaceAll("хуй текст", "***"));
+        assertEquals("*** и ***", ac.replaceAll("хуй и пизда", "***"));
+    }
+
+    @Test
+    void replaceAll_noMatch() {
+        AhoCorasick ac = new AhoCorasick(List.of("хуй"));
+        assertEquals("чистый текст", ac.replaceAll("чистый текст", "***"));
+    }
+
+    @Test
+    void replaceAll_nonOverlapping() {
+        AhoCorasick ac = new AhoCorasick(List.of("хуй", "пизда"));
+        assertEquals("*** ***", ac.replaceAll("хуй пизда", "***"));
+    }
+
+    @Test
+    void findMatches_returnsAll() {
+        AhoCorasick ac = new AhoCorasick(List.of("хуй", "пизда", "ебать"));
+        List<String> found = ac.findMatches("хуй и пизда и ебать");
+        assertTrue(found.contains("хуй"));
+        assertTrue(found.contains("пизда"));
+        assertTrue(found.contains("ебать"));
+    }
+
+    @Test
+    void findMatches_empty() {
+        AhoCorasick ac = new AhoCorasick(List.of("хуй"));
+        assertTrue(ac.findMatches("чистый текст").isEmpty());
+    }
+
+    @Test
+    void emptyWordList() {
+        AhoCorasick ac = new AhoCorasick(List.of());
+        assertFalse(ac.matches("любой текст"));
+        assertEquals("любой текст", ac.replaceAll("любой текст", "***"));
+    }
+
+    @Test
+    void emptyStringInWordList() {
+        AhoCorasick ac = new AhoCorasick(List.of(""));
+        assertFalse(ac.matches("тест"));
+    }
+
+    @Test
+    void matches_longText() {
+        AhoCorasick ac = new AhoCorasick(List.of("хуй", "пизда"));
+        assertTrue(ac.matches("a".repeat(1000) + "хуй" + "b".repeat(1000)));
+    }
+
+    @Test
+    void matches_specialCharacters() {
+        AhoCorasick ac = new AhoCorasick(List.of("хуй"));
+        assertTrue(ac.matches(",хуй."));
+        assertTrue(ac.matches("текст с xуй внутри"));
+    }
+
+    @Test
+    void matches_insideWord() {
+        AhoCorasick ac = new AhoCorasick(List.of("хуй"));
+        assertTrue(ac.matches("хуйтекст"));
+        assertTrue(ac.matches("текстхуйтекст"));
+    }
+
+    @Test
+    void matches_punctuationAround() {
+        AhoCorasick ac = new AhoCorasick(List.of("хуй"));
+        assertTrue(ac.matches("хуй,"));
+        assertTrue(ac.matches("(хуй)"));
+        assertTrue(ac.matches("\"хуй\""));
+    }
+
+    @Test
+    void replaceAll_partialWord() {
+        AhoCorasick ac = new AhoCorasick(List.of("хуй"));
+        assertEquals("***ня", ac.replaceAll("хуйня", "***"));
+    }
+}