Fix same case rename

build.gradle.kts

@@ -91,6 +91,7 @@ dependencies {
     compileOnly("com.github.TechFortress:GriefPrevention:17.0.0")
     compileOnly("com.discordsrv:discordsrv:1.28.0")
     implementation("com.google.code.gson:gson:2.10.1")
+    testImplementation("org.purpurmc.purpur:purpur-api:1.19.4-R0.1-SNAPSHOT")
     testImplementation("org.junit.jupiter:junit-jupiter-api:5.11.3")
     testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine:5.11.3")
     testImplementation("org.junit.jupiter:junit-jupiter-params:5.11.3")

src/main/java/net/trueog/unionsog/Union.java

@@ -199,6 +199,25 @@ public class Union implements Serializable, Comparable<Union> {
 
     }
 
+    /**
+     * Renames the union. When the new name is just the tag in a different case, the
+     * displayed tag is re-cased to match, so a union can fix its capitalization
+     * even though the tag itself can never change.
+     *
+     * @param name the new name
+     */
+    public void rename(String name) {
+
+        if (colorTag != null && Helper.cleanTag(name).equals(tag)) {
+
+            colorTag = ChatUtils.applyCase(colorTag, ChatUtils.stripColors(name));
+
+        }
+
+        this.name = name;
+
+    }
+
     /**
      * Returns the union's description
      *

src/main/java/net/trueog/unionsog/commands/staff/StaffCommands.java

@@ -399,8 +399,13 @@ public class StaffCommands extends BaseCommand {
         }
 
         Union union = unionInput.getUnion();
-        union.setName(unionName);
+        union.rename(unionName);
         storage.updateUnion(union);
+        for (UnionPlayer member : union.getOnlineMembers()) {
+
+            cm.updateDisplayName(member.toPlayer());
+
+        }
 
         ChatBlock.sendMessageKey(sender, "you.have.successfully.renamed.the.union", unionName);
 

src/main/java/net/trueog/unionsog/managers/ProposalManager.java

@@ -297,8 +297,14 @@ public final class ProposalManager {
 
                 union.addBb(proposer != null ? proposer.getName() : union.getName(),
                         lang("union.renamed.to.0", proposal.getTarget()));
-                union.setName(proposal.getTarget());
+                union.rename(proposal.getTarget());
                 plugin.getStorageManager().updateUnion(union);
+                for (UnionPlayer member : union.getOnlineMembers()) {
+
+                    plugin.getUnionManager().updateDisplayName(member.toPlayer());
+
+                }
+
                 break;
 
             }

src/main/java/net/trueog/unionsog/utils/ChatUtils.java

@@ -89,6 +89,46 @@ public class ChatUtils {
 
     }
 
+    /**
+     * Replaces the visible characters of a colored string with the characters of a
+     * plain one, keeping every color code in place. The plain string is expected to
+     * match the colored string's stripped text ignoring case; leftover characters
+     * on either side are kept as they are.
+     *
+     * @param colored the colored string to take the color codes from
+     * @param plain   the plain string to take the characters from
+     * @return the colored string with the plain string's characters
+     */
+    public static String applyCase(@NotNull String colored, @NotNull String plain) {
+
+        Pattern pattern = HEX_COLOR_SUPPORT ? HEX_STRIP_COLOR_PATTERN : STRIP_COLOR_PATTERN;
+        Matcher matcher = pattern.matcher(colored);
+        StringBuilder result = new StringBuilder();
+        int from = 0;
+        int at = 0;
+        while (matcher.find()) {
+
+            for (int i = from; i < matcher.start(); i++) {
+
+                result.append(at < plain.length() ? plain.charAt(at++) : colored.charAt(i));
+
+            }
+
+            result.append(matcher.group());
+            from = matcher.end();
+
+        }
+
+        for (int i = from; i < colored.length(); i++) {
+
+            result.append(at < plain.length() ? plain.charAt(at++) : colored.charAt(i));
+
+        }
+
+        return result.toString();
+
+    }
+
     public static String getLastColorCode(String msg) {
 
         if (msg.length() < 2) {

src/test/java/net/trueog/unionsog/utils/ChatUtilsApplyCaseTest.java

@@ -0,0 +1,44 @@
+package net.trueog.unionsog.utils;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class ChatUtilsApplyCaseTest {
+
+    @Test
+    void recasesPlainTag() {
+
+        assertEquals("OGS", ChatUtils.applyCase("OGs", "OGS"));
+
+    }
+
+    @Test
+    void keepsLeadingColorCode() {
+
+        assertEquals("§bOGS", ChatUtils.applyCase("§bOGs", "OGS"));
+
+    }
+
+    @Test
+    void keepsEmbeddedColorCodes() {
+
+        assertEquals("§4O§6GS", ChatUtils.applyCase("§4O§6Gs", "OGS"));
+
+    }
+
+    @Test
+    void keepsHexColorCode() {
+
+        assertEquals("§x§f§f§0§0§0§0OGS", ChatUtils.applyCase("§x§f§f§0§0§0§0OGs", "OGS"));
+
+    }
+
+    @Test
+    void keepsLeftoverCharactersWhenLengthsDiffer() {
+
+        assertEquals("OGs", ChatUtils.applyCase("OGs", "OG"));
+
+    }
+
+}