Finish up the pagination of the help system

core/src/main/java/co/aikar/commands/CommandContexts.java

@@ -167,7 +167,11 @@ public class CommandContexts <R extends CommandExecutionContext<?, ? extends Com
                 search = c.getArgs();
             }
             CommandHelp commandHelp = manager.generateCommandHelp();
-            commandHelp.setPage(page, 15);
+            commandHelp.setPage(page);
+            Integer perPage = c.getFlagValue("perpage", (Integer) null);
+            if (perPage != null) {
+                commandHelp.setPerPage(perPage);
+            }
             commandHelp.setSearch(search);
             return commandHelp;
         });

core/src/main/java/co/aikar/commands/CommandHelp.java

@@ -29,7 +29,6 @@ import org.jetbrains.annotations.NotNull;
 
 import java.util.*;
 import java.util.regex.Pattern;
-import java.util.stream.Stream;
 
 @SuppressWarnings("WeakerAccess")
 public class CommandHelp {
@@ -37,12 +36,13 @@ public class CommandHelp {
     private final CommandIssuer issuer;
     private final List<HelpEntry> helpEntries = new ArrayList<>();
     private int page;
-    private int perPage = 15;
+    private int perPage;
     private List<String> search;
 
     public CommandHelp(CommandManager manager, RootCommand rootCommand, CommandIssuer issuer) {
         this.manager = manager;
         this.issuer = issuer;
+        this.perPage = manager.defaultHelpPerPage;
 
         SetMultimap<String, RegisteredCommand> subCommands = rootCommand.getSubCommands();
         Set<RegisteredCommand> seen = new HashSet<>();
@@ -107,16 +107,23 @@ public class CommandHelp {
     }
 
     public void showHelp(CommandIssuer issuer, MessageKeyProvider format) {
-        Iterator<HelpEntry> results = getHelpEntries().stream()
+        List<HelpEntry> helpEntries = getHelpEntries();
+        Iterator<HelpEntry> results = helpEntries.stream()
                 .filter(HelpEntry::shouldShow)
                 .sorted(Comparator.comparingInt(helpEntry -> helpEntry.getSearchScore() * -1)).iterator();
         if (!results.hasNext()) {
             issuer.sendMessage(MessageType.ERROR, MessageKeys.NO_COMMAND_MATCHED_SEARCH, "{search}", ACFUtil.join(this.search, " "));
-            results = getHelpEntries().iterator();
+            helpEntries = getHelpEntries();
+            results = helpEntries.iterator();
         }
+        int totalResults = helpEntries.size();
         int min = (this.page-1) * this.perPage; // TODO: per page configurable?
         int max = min + this.perPage;
         int i = 0;
+        if (min >= totalResults) {
+            issuer.sendMessage(MessageType.HELP, MessageKeys.HELP_NO_RESULTS);
+            return;
+        }
 
         while (results.hasNext()) {
             HelpEntry e = results.next();
@@ -132,6 +139,13 @@ public class CommandHelp {
                 issuer.sendMessageInternal(ACFUtil.rtrim(msg));
             }
         }
+        if (min > 0 || results.hasNext()) {
+            issuer.sendMessage(MessageType.HELP, MessageKeys.HELP_PAGE_INFORMATION,
+                    "{page}", "" + this.page,
+                    "{totalpages}", ""+ (int)Math.ceil((float)totalResults / (float)this.perPage),
+                    "{results}", "" + totalResults
+            );
+        }
     }
 
     /**
@@ -154,9 +168,17 @@ public class CommandHelp {
         return helpEntries;
     }
 
-    public void setPage(int page, int perPage) {
+    public void setPerPage(int perPage) {
+        this.perPage = perPage;
+    }
+
+    public void setPage(int page) {
         this.page = page;
-        this.perPage = 15;
+    }
+
+    public void setPage(int page, int perPage) {
+        this.setPage(page);
+        this.setPerPage(perPage);
     }
 
     public void setSearch(List<String> search) {

core/src/main/java/co/aikar/commands/CommandManager.java

@@ -52,6 +52,7 @@ public abstract class CommandManager <I, FT, F extends MessageFormatter<FT>> {
     protected Set<Locale> supportedLanguages = Sets.newHashSet(Locales.ENGLISH, Locales.GERMAN, Locales.SPANISH, Locales.CZECH);
     protected Map<MessageType, F> formatters = new IdentityHashMap<>();
     protected F defaultFormatter;
+    protected int defaultHelpPerPage = 10;
     private Set<String> unstableAPIs = Sets.newHashSet();
 
     public static CommandOperationContext getCurrentCommandOperationContext() {
@@ -141,6 +142,18 @@ public abstract class CommandManager <I, FT, F extends MessageFormatter<FT>> {
         return new CommandHelp(this, rootCommand, issuer);
     }
 
+    /** @deprecated Unstable API */ @Deprecated @UnstableAPI
+    public int getDefaultHelpPerPage() {
+        verifyUnstableAPI("help");
+        return defaultHelpPerPage;
+    }
+
+    /** @deprecated Unstable API */ @Deprecated @UnstableAPI
+    public void setDefaultHelpPerPage(int defaultHelpPerPage) {
+        verifyUnstableAPI("help");
+        this.defaultHelpPerPage = defaultHelpPerPage;
+    }
+
     /**
      * Registers a command with ACF
      *

core/src/main/java/co/aikar/commands/MessageKeys.java

@@ -45,7 +45,10 @@ public enum MessageKeys implements MessageKeyProvider {
     NOT_ALLOWED_ON_CONSOLE,
     COULD_NOT_FIND_PLAYER,
     HELP_FORMAT,
-    NO_COMMAND_MATCHED_SEARCH;
+    NO_COMMAND_MATCHED_SEARCH,
+    HELP_PAGE_INFORMATION,
+    HELP_NO_RESULTS
+    ;
 
     private final MessageKey key = MessageKey.of("acf-core." + this.name().toLowerCase());
     public MessageKey getMessageKey() {