feat: improve bbcode converter by moving headlines to front and handling wrapped bold tags (closes #1101)

backend/src/main/java/io/papermc/hangar/util/BBCodeConverter.java

@@ -2,6 +2,8 @@ package io.papermc.hangar.util;
 
 import java.util.HashMap;
 import java.util.Map;
+import java.util.regex.Pattern;
+import org.apache.commons.lang3.StringUtils;
 import org.jetbrains.annotations.Nullable;
 
 public class BBCodeConverter {
@@ -13,6 +15,11 @@ public class BBCodeConverter {
     private static final char TAG_SUFFIX = ']';
     private static final char ARG_PREFIX = '=';
 
+    // https://regex101.com/r/MWDUfk/1
+    private static final Pattern headlinePattern = Pattern.compile("([^#]+)(#+ )(.+)");
+    // https://regex101.com/r/s4Nxgc/1
+    private static final Pattern boldNewlinePattern = Pattern.compile("(\\*\\*)(.*?)(\\n)?(.*?)(\\*\\*)");
+
     private String currentTag;
     private String currentArg;
     private String currentContent;
@@ -202,7 +209,7 @@ public class BBCodeConverter {
             }
         }
 
-        return s;
+        return cleanup(s);
     }
 
     private @Nullable String removeTrailingWhitespaces(String s) {
@@ -333,4 +340,34 @@ public class BBCodeConverter {
         }
         return s;
     }
+
+    private static String cleanup( String input) {
+        final String[] lines = input.split("\n");
+        for (int i = 0; i < lines.length; i++) {
+            final String line = lines[i];
+            // move headlines to the start
+            if (!line.startsWith("#") && line.contains("#")) {
+                lines[i] = headlinePattern.matcher(line).replaceAll("$2$1$3");
+            }
+        }
+        input = String.join("\n", lines);
+
+        // make bold wrap around newlines correctly
+        input = boldNewlinePattern.matcher(input).replaceAll((matchResult) -> {
+            // $1$2$1$3$5$4$5
+            StringBuilder sb = new StringBuilder();
+            if (StringUtils.isNotBlank(matchResult.group(2))) {
+                sb.append(matchResult.group(1)).append(matchResult.group(2)).append(matchResult.group(1));
+            }
+            if (matchResult.group(3) != null) {
+                sb.append(matchResult.group(3));
+            }
+            if (StringUtils.isNotBlank(matchResult.group(4))) {
+                sb.append(matchResult.group(5)).append(matchResult.group(4)).append(matchResult.group(5));
+            }
+            return sb.toString();
+        });
+
+        return input;
+    }
 }

backend/src/test/java/io/papermc/hangar/util/BBCodeConverterTest.java

@@ -26,7 +26,7 @@ class BBCodeConverterTest {
     @Test
     void testList() {
         final String result = this.converter.convertToMarkdown("[list]\n[*]Element 1\n[*]Element 2\n[/list]");
-        Assertions.assertEquals("\n* Element 1\n* Element 2\n", result);
+        Assertions.assertEquals("\n* Element 1\n* Element 2", result);
     }
 
     @Test
@@ -174,4 +174,38 @@ class BBCodeConverterTest {
         final String result = this.converter.convertToMarkdown(input);
         Assertions.assertEquals(expected, result);
     }
+
+    @Test
+    void testMoveHeadingToFront() {
+        final String input = "[B][SIZE=5]Dum[/SIZE][/B]";
+        final String expected = "### **Dum**";
+        final String result = this.converter.convertToMarkdown(input);
+        Assertions.assertEquals(expected, result);
+    }
+
+    @Test
+    void testWrapBoldAroundNewline() {
+        final String input = "[B]Dum\nDum[/B]";
+        final String expected = "**Dum**\n**Dum**";
+        final String result = this.converter.convertToMarkdown(input);
+        Assertions.assertEquals(expected, result);
+    }
+
+    @Test
+    void testBoldList() {
+        final String input = """
+                [LIST]
+                [*][B]bold[/B] not
+                [*][B]bold[/B] not
+                [*][B]bold[/B] not
+                [/LIST]
+                """;
+        final String expected = """
+
+                * **bold** not
+                * **bold** not
+                * **bold** not""";
+        final String result = this.converter.convertToMarkdown(input);
+        Assertions.assertEquals(expected, result);
+    }
 }

backend/src/test/resources/io/papermc/hangar/utils/BBCodeConverted.txt

@@ -1,5 +1,5 @@
-**
-This plugin lets you activate a maintenance mode on your BungeeCord as well as Spigot server, which will prevent players without a permission to join the server.**
+
+**This plugin lets you activate a maintenance mode on your BungeeCord as well as Spigot server, which will prevent players without a permission to join the server.**
 **Whatever version you want to use, just place the plugin inside your plugin folder of your server running Spigot or BungeeCord!**
 
 
@@ -27,7 +27,7 @@ IMPORTANT: If using the plugin on a Spigot server, the plugin **[ProtocolLib](ht
 
 <center></center>
 
-<center>### Did you find a bug? Use the [**issue tracker**](https://github.com/kennytv/maintenance/issues)
+### <center>Did you find a bug? Use the [**issue tracker**](https://github.com/kennytv/maintenance/issues)
 Other questions or problems? Click the wonderful icon below ✨
 
 [](https://discord.gg/vgcuzhq)