feat: Implement list command

src/main/java/com/onarandombox/MultiverseCore/MultiverseCore.java

@@ -33,6 +33,7 @@ import com.onarandombox.MultiverseCore.commands.CreateCommand;
 import com.onarandombox.MultiverseCore.commands.DebugCommand;
 import com.onarandombox.MultiverseCore.commands.DeleteCommand;
 import com.onarandombox.MultiverseCore.commands.GameruleCommand;
+import com.onarandombox.MultiverseCore.commands.ListCommand;
 import com.onarandombox.MultiverseCore.commands.LoadCommand;
 import com.onarandombox.MultiverseCore.commands.RegenCommand;
 import com.onarandombox.MultiverseCore.commands.ReloadCommand;
@@ -204,6 +205,7 @@ public class MultiverseCore extends JavaPlugin implements MVCore {
         this.commandManager.registerCommand(new DebugCommand(this));
         this.commandManager.registerCommand(new DeleteCommand(this));
         this.commandManager.registerCommand(new GameruleCommand(this));
+        this.commandManager.registerCommand(new ListCommand(this));
         this.commandManager.registerCommand(new LoadCommand(this));
         this.commandManager.registerCommand(new RegenCommand(this));
         this.commandManager.registerCommand(new ReloadCommand(this));

src/main/java/com/onarandombox/MultiverseCore/commands/ListCommand.java

@@ -0,0 +1,126 @@
+package com.onarandombox.MultiverseCore.commands;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import co.aikar.commands.BukkitCommandIssuer;
+import co.aikar.commands.InvalidCommandArgument;
+import co.aikar.commands.annotation.CommandAlias;
+import co.aikar.commands.annotation.CommandCompletion;
+import co.aikar.commands.annotation.CommandPermission;
+import co.aikar.commands.annotation.Description;
+import co.aikar.commands.annotation.Subcommand;
+import co.aikar.commands.annotation.Syntax;
+import com.onarandombox.MultiverseCore.MultiverseCore;
+import com.onarandombox.MultiverseCore.api.MVWorld;
+import com.onarandombox.MultiverseCore.commandtools.flags.CommandFlagGroup;
+import com.onarandombox.MultiverseCore.commandtools.flags.CommandValueFlag;
+import com.onarandombox.MultiverseCore.commandtools.flags.ParsedCommandFlags;
+import com.onarandombox.MultiverseCore.display.ContentDisplay;
+import com.onarandombox.MultiverseCore.display.filters.ContentFilter;
+import com.onarandombox.MultiverseCore.display.filters.DefaultContentFilter;
+import com.onarandombox.MultiverseCore.display.filters.RegexContentFilter;
+import com.onarandombox.MultiverseCore.display.handlers.PagedSendHandler;
+import com.onarandombox.MultiverseCore.display.parsers.ListContentProvider;
+import org.bukkit.ChatColor;
+import org.bukkit.World;
+import org.bukkit.entity.Player;
+import org.jetbrains.annotations.NotNull;
+
+@CommandAlias("mv")
+public class ListCommand extends MultiverseCoreCommand {
+    public ListCommand(@NotNull MultiverseCore plugin) {
+        super(plugin);
+
+        registerFlagGroup(CommandFlagGroup.builder("mvlist")
+                .add(CommandValueFlag.builder("--filter", ContentFilter.class)
+                        .addAlias("-f")
+                        .context((value) -> {
+                            try {
+                                return RegexContentFilter.fromString(value);
+                            } catch (IllegalArgumentException e) {
+                                throw new InvalidCommandArgument("Invalid filter: " + value);
+                            }
+                        })
+                        .build())
+                .add(CommandValueFlag.builder("--page", Integer.class)
+                        .addAlias("-p")
+                        .context((value) -> {
+                            try {
+                                return Integer.parseInt(value);
+                            } catch (NumberFormatException e) {
+                                throw new InvalidCommandArgument("Invalid page number: " + value);
+                            }
+                        })
+                        .build())
+                .build());
+    }
+
+    @Subcommand("list")
+    @CommandPermission("multiverse.core.list.worlds")
+    @CommandCompletion("@flags:groupName=mvlist")
+    @Syntax("--filter [filter] --page [page]")
+    @Description("Displays a listing of all worlds that you can enter.")
+    public void onListCommand(BukkitCommandIssuer issuer,
+
+                              @Syntax("--filter [filter] --page [page]")
+                              @Description("Filters the list of worlds by the given regex and displays the given page.")
+                              String[] flags
+    ) {
+        ParsedCommandFlags parsedFlags = parseFlags(flags);
+        ContentDisplay.create()
+                .addContent(ListContentProvider.forContent(getListContents(issuer)))
+                .withSendHandler(PagedSendHandler.create()
+                        .withHeader("%s====[ Multiverse World List ]====", ChatColor.GOLD)
+                        .withTargetPage(parsedFlags.flagValue("--page", 1, Integer.class))
+                        .withFilter(parsedFlags.flagValue("--filter", DefaultContentFilter.get(), ContentFilter.class))
+                        .withLinesPerPage(4)) //TODO Change back after testing
+                .send(issuer);
+    }
+
+    private List<String> getListContents(BukkitCommandIssuer issuer) {
+        Player player = issuer.isPlayer() ? issuer.getPlayer() : null;
+        List<String> worldList =  new ArrayList<>();
+
+        this.plugin.getMVWorldManager().getMVWorlds().stream()
+                .filter(world -> player == null || plugin.getMVPerms().canEnterWorld(player, world))
+                .filter(world -> canSeeWorld(player, world))
+                .map(world -> hiddenText(world) + world.getColoredWorldString() + " - " + parseColouredEnvironment(world.getEnvironment()))
+                .sorted()
+                .forEach(worldList::add);
+
+        this.plugin.getMVWorldManager().getUnloadedWorlds().stream()
+                .filter(world -> plugin.getMVPerms().hasPermission(issuer.getIssuer(), "multiverse.access." + world, true))
+                .map(world -> ChatColor.GRAY + world + " - UNLOADED")
+                .sorted()
+                .forEach(worldList::add);
+
+        return worldList;
+    }
+
+    private boolean canSeeWorld(Player player, MVWorld world) {
+        return !world.isHidden()
+                || player == null
+                || this.plugin.getMVPerms().hasPermission(player, "multiverse.core.modify", true);
+    }
+
+    private String hiddenText(MVWorld world) {
+        return (world.isHidden()) ? String.format("%s[H] ", ChatColor.GRAY) : "";
+    }
+
+    private String parseColouredEnvironment(World.Environment env) {
+        ChatColor color = ChatColor.GOLD;
+        switch (env) {
+            case NETHER:
+                color = ChatColor.RED;
+                break;
+            case NORMAL:
+                color = ChatColor.GREEN;
+                break;
+            case THE_END:
+                color = ChatColor.AQUA;
+                break;
+        }
+        return color + env.toString();
+    }
+}