Adds in-game command info, and fixes some permission bugs

src/main/java/net/knarcraft/paidsigns/command/PaidSignsTabCommand.java

@@ -0,0 +1,81 @@
+package net.knarcraft.paidsigns.command;
+
+import net.knarcraft.paidsigns.PaidSigns;
+import org.bukkit.ChatColor;
+import org.bukkit.command.Command;
+import org.bukkit.command.CommandSender;
+import org.bukkit.command.PluginCommand;
+import org.bukkit.command.TabExecutor;
+import org.bukkit.entity.Player;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class PaidSignsTabCommand implements TabExecutor {
+
+    private static final ChatColor successColor = ChatColor.GREEN;
+    private static final ChatColor commandColor = ChatColor.YELLOW;
+
+    @Override
+    public boolean onCommand(@NotNull CommandSender sender, @NotNull Command command, @NotNull String label, @NotNull String[] args) {
+        sender.sendMessage(commandColor + "[] denote optional parameters");
+        sender.sendMessage(commandColor + "<> denote required parameters");
+        sender.sendMessage(commandColor + "{} denote required permission");
+        sender.sendMessage(commandColor + "In some cases, commands with required parameters can be called with no parameters");
+        if (sender instanceof Player) {
+            showPlayerCommands(sender);
+        }
+        return true;
+    }
+
+    /**
+     * Shows all commands available to the sending player
+     *
+     * @param sender <p>The player which sent the command</p>
+     */
+    private void showPlayerCommands(CommandSender sender) {
+        sender.sendMessage(commandColor + "Commands:");
+
+        showCommandInfo("addPaidSign", sender);
+        showCommandInfo("addPaidSignCondition", sender);
+        showCommandInfo("listPaidSigns", sender);
+        showCommandInfo("editPaidSign", sender);
+        showCommandInfo("removePaidSignCondition", sender);
+        showCommandInfo("removePaidSign", sender);
+        showCommandInfo("reload", sender);
+    }
+
+    /**
+     * Shows information about the given command
+     *
+     * @param command <p>The command to get information about</p>
+     * @param sender  <p>The sender asking to see command info</p>
+     */
+    private void showCommandInfo(String command, CommandSender sender) {
+        PluginCommand pluginCommand = PaidSigns.getInstance().getCommand(command);
+        if (pluginCommand != null) {
+            String permission = pluginCommand.getPermission();
+            if (permission == null || sender.hasPermission(permission)) {
+                String commandInfo = "\n" + commandColor + pluginCommand.getUsage().replace("<command>",
+                        pluginCommand.getName()) + ": " + successColor + pluginCommand.getDescription();
+                if (sender.hasPermission("paidsigns.admin")) {
+                    if (permission == null) {
+                        permission = "None";
+                    }
+                    commandInfo += commandColor + " {" + permission + "}";
+                }
+                sender.sendMessage(commandInfo);
+            }
+        }
+    }
+
+    @Nullable
+    @Override
+    public List<String> onTabComplete(@NotNull CommandSender sender, @NotNull Command command, @NotNull String label,
+                                      @NotNull String[] args) {
+        return new ArrayList<>();
+    }
+
+}