Empire Minecraft's Command System

annotation_CommandAlias.java

package com.empireminecraft.commands.annotation;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

@Retention(RetentionPolicy.RUNTIME)
public @interface CommandAlias {
    String value();
}

annotation_CommandCompletion.java

package com.empireminecraft.commands.annotation;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

@Retention(RetentionPolicy.RUNTIME)
public @interface CommandCompletion {
    String value();
}

annotation_CommandPermission.java

package com.empireminecraft.commands.annotation;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

@Retention(RetentionPolicy.RUNTIME)
public @interface CommandPermission {
    String value();
}

annotation_Default.java

package com.empireminecraft.commands.annotation;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

@Retention(RetentionPolicy.RUNTIME)
public @interface Default {
    String value() default "";
}

annotation_Optional.java

package com.empireminecraft.commands.annotation;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

@Retention(RetentionPolicy.RUNTIME)
public @interface Optional {
}

annotation_Split.java

package com.empireminecraft.commands.annotation;


import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

@Retention(RetentionPolicy.RUNTIME)
public @interface Split {
    String value();
}

annotation_Subcommand.java

package com.empireminecraft.commands.annotation;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

@Retention(RetentionPolicy.RUNTIME)
public @interface Subcommand {
    String value();
}

annotation_Syntax.java

package com.empireminecraft.commands.annotation;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

@Retention(RetentionPolicy.RUNTIME)
public @interface Syntax {
    String value();
}

annotation_Values.java

package com.empireminecraft.commands.annotation;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

@Retention(RetentionPolicy.RUNTIME)
public @interface Values {
    String value();
}

contexts_AnyPlayer.java

package com.empireminecraft.commands.contexts;

import com.empireminecraft.commands.InvalidCommandArgument;
import com.empireminecraft.data.EmpireUser;
import com.empireminecraft.systems.db.EmpireDb;
import com.empireminecraft.util.Util;
import lombok.Data;
import org.bukkit.entity.Player;

import java.sql.SQLException;

@Data public class AnyPlayer {
    final EmpireUser user;

    public Player getPlayer() {
        return user.player;
    }

    public static ContextResolver<AnyPlayer> getResolver() {
        return (p, sender, args, isLast) -> {
            String who = args.remove(0);
            final String origwho = who;
            EmpireUser user = EmpireUser.getUser(who);
            if (user == null) {
                try {
                    // TODO: cache?
                    who = EmpireDb.getFirstColumn(
                        "SELECT name FROM user WHERE name LIKE ? ORDER BY name LIMIT 1",
                        Util.simplifyString(who) + "%");
                    if (who != null) {
                        user = EmpireUser.getUser(who);
                    }
                } catch (SQLException e) {
                    Util.printException(e);
                }
            }
            if (user == null) {
                throw new InvalidCommandArgument("Could not find a player with the username  " + origwho);
            }
            return new AnyPlayer(user);
        };
    }
}

contexts_CommandContexts.java

package com.empireminecraft.commands.contexts;

import com.empireminecraft.commands.contexts.ContextResolver.SenderAwareContextResolver;
import com.empireminecraft.commands.InvalidCommandArgument;
import com.empireminecraft.commands.annotation.Split;
import com.empireminecraft.commands.annotation.Values;
import com.empireminecraft.data.EmpireUser;
import com.empireminecraft.systems.residence.protection.ClaimedResidence;
import com.empireminecraft.util.RegexPatterns;
import com.empireminecraft.util.UserUtil;
import com.empireminecraft.util.Util;
import com.google.common.collect.Maps;
import org.bukkit.command.CommandSender;
import org.bukkit.configuration.InvalidConfigurationException;
import org.bukkit.entity.Player;
import org.spigotmc.SneakyThrow;

import java.util.Map;

public final class CommandContexts {
    static final Map<Class<?>, ContextResolver<?>> contextMap = Maps.newHashMap();

    private CommandContexts() {}

    public static void registerContexts() {
        registerSenderAwareContext(ClaimedResidence.class, ClaimedResidence.getResolver());
        registerContext(Integer.class, (p, sender, args, isLast) -> {
            try {
                return Integer.parseInt(args.remove(0));
            } catch (NumberFormatException e) {
                throw new InvalidCommandArgument("Must be a number");
            }
        });
        registerContext(Long.class, (p, sender, args, isLast) -> {
            try {
                return Long.parseLong(args.remove(0));
            } catch (NumberFormatException e) {
                throw new InvalidCommandArgument("Must be a number");
            }
        });
        registerContext(Float.class, (p, sender, args, isLast) -> {
            try {
                return Float.parseFloat(args.remove(0));
            } catch (NumberFormatException e) {
                throw new InvalidCommandArgument("Must be a number");
            }
        });
        registerContext(Double.class, (p, sender, args, isLast) -> {
            try {
                return Double.parseDouble(args.remove(0));
            } catch (NumberFormatException e) {
                throw new InvalidCommandArgument("Must be a number");
            }
        });
        registerContext(Boolean.class, (p, sender, args, isLast) -> {
            switch (args.remove(0)) {
                case "t":
                case "true":
                case "on":
                case "y":
                case "yes":
                case "1":
                    return true;
            }
            return false;
        });
        registerContext(String.class, (p, sender, args, isLast) -> {
            final Values values = p.getAnnotation(Values.class);
            if (values != null) {
                return args.remove(0);
            }
            if (isLast) {
                return Util.join(args);
            }
            return args.remove(0);
        });
        registerContext(String[].class, (p, sender, args, isLast) -> {
            Split split = p.getAnnotation(Split.class);
            if (split != null) {
                return RegexPatterns.getPattern(split.value()).split(args.remove(0));
            } else if (!isLast) {
                SneakyThrow.sneaky(new InvalidConfigurationException("Weird Command signature... String[] should be last or @Split"));
            }

            String[] result = args.toArray(new String[args.size()]);
            args.clear();
            return result;
        });
        registerContext(EmpireUser.class, (p, sender, args, isLast) -> {
            String who = args.remove(0);
            if (!EmpireUser.validateUsername(who)) {
                throw new InvalidCommandArgument("Invalid Minecraft Name Format. 3-16 characters");
            }
            EmpireUser user = EmpireUser.getUser(who);
            if (user == null) {
                throw new InvalidCommandArgument("Could not find user " + who);
            }
            return user;
        });
        registerContext(OnlinePlayer.class, (p, sender, args, isLast) -> {
            Player player = UserUtil.findPlayerSmart(sender, args.remove(0));
            if (player == null) {
                throw new InvalidCommandArgument();
            }
            return new OnlinePlayer(player);
        });
        registerContext(AnyPlayer.class, AnyPlayer.getResolver());
        registerSenderAwareContext(CommandSender.class, (p, sender, args, isLast) -> sender);
        registerSenderAwareContext(Player.class, (p, sender, args, isLast) -> sender instanceof Player ? (Player) sender : null);
    }

    public static <T> void registerSenderAwareContext(Class<T> context, SenderAwareContextResolver<T> supplier) {
        contextMap.put(context, supplier);
    }
    public static <T> void registerContext(Class<T> context, ContextResolver<T> supplier) {
        contextMap.put(context, supplier);
    }

    public static ContextResolver<?> getResolver(Class<?> type) {
        Class<?> rootType = type;
        do {
            if (type == Object.class) {
                break;
            }

            final ContextResolver<?> resolver = contextMap.get(type);
            if (resolver != null) {
                return resolver;
            }
        } while ((type = type.getSuperclass()) != null);

        Util.printException(new InvalidConfigurationException("No context resolver defined for " + rootType.getName()));
        return null;
    }
}

contexts_ContextResolver.java

package com.empireminecraft.commands.contexts;

import com.empireminecraft.commands.InvalidCommandArgument;
import org.bukkit.command.CommandSender;

import java.lang.reflect.Parameter;
import java.util.List;

@FunctionalInterface
public interface ContextResolver <C> {
    C getContext(Parameter p, CommandSender sender, List<String> args, boolean isLast) throws InvalidCommandArgument;
    interface SenderAwareContextResolver <C> extends ContextResolver <C> {}
}

contexts_OnlinePlayer.java

package com.empireminecraft.commands.contexts;

import com.empireminecraft.data.EmpireUser;
import lombok.Data;
import org.bukkit.entity.Player;

@Data public class OnlinePlayer {
    public final Player player;
    public EmpireUser getUser() {
        return EmpireUser.getUser(player);
    }
}

EmpireCommand.java

package com.empireminecraft.commands;

import com.empireminecraft.commands.annotation.CommandAlias;
import com.empireminecraft.commands.annotation.CommandPermission;
import com.empireminecraft.commands.annotation.Default;
import com.empireminecraft.commands.annotation.Subcommand;
import com.empireminecraft.config.EmpireServer;
import com.empireminecraft.config.PlayerSettingKey;
import com.empireminecraft.config.language.MiscLang;
import com.empireminecraft.data.EmpireUser;
import com.empireminecraft.features.items.CustomItems;
import com.empireminecraft.features.survival.mobs.CustomMob;
import com.empireminecraft.systems.db.EmpireDb;
import com.empireminecraft.util.RegexPatterns;
import com.empireminecraft.util.UserUtil;
import com.empireminecraft.util.Util;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
import lombok.AllArgsConstructor;
import org.apache.commons.lang.StringUtils;
import org.bukkit.Bukkit;
import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.configuration.InvalidConfigurationException;
import org.bukkit.entity.EntityType;
import org.bukkit.entity.Player;
import org.bukkit.util.StringUtil;
import org.spigotmc.SneakyThrow;

import java.lang.reflect.Method;
import java.sql.SQLException;
import java.util.*;
import java.util.stream.Collectors;
import java.util.stream.Stream;

public abstract class EmpireCommand extends Command {

    private final Map<String, RegisteredCommand> subCommands = new HashMap<>();
    private final Map<String, RegisteredCommand> aliases = new HashMap<>();

    protected String origCommandLabel;
    protected String[] origArgs;

    public EmpireCommand() {
        this(null);
    }

    public EmpireCommand(String cmd) {
        super(cmd);
        CommandAlias rootCmdAlias = this.getClass().getAnnotation(CommandAlias.class);
        if (cmd == null) {
            if (rootCmdAlias == null) {
                cmd = "__" + this.getClass().getSimpleName();
            } else {
                cmd = RegexPatterns.PIPE.split(rootCmdAlias.value())[0];
            }
            setName(cmd);
            setLabel(cmd);
        }
        this.description = cmd + " commands";
        this.usageMessage = "/" + cmd;

        final CommandPermission perm = this.getClass().getAnnotation(CommandPermission.class);
        if (perm != null) {
            this.setPermission(perm.value());
        }
        Set<Method> methods = Sets.newHashSet();
        Collections.addAll(methods, this.getClass().getDeclaredMethods());
        Collections.addAll(methods, this.getClass().getMethods());

        boolean foundDefault = false;
        for (Method method : methods) {
            method.setAccessible(true);
            String sublist = null;
            final Subcommand sub = method.getAnnotation(Subcommand.class);
            final Default def = method.getAnnotation(Default.class);

            final CommandAlias commandAliases = method.getAnnotation(CommandAlias.class);

            if (def != null) {
                if (!foundDefault) {
                    registerSubcommand(method, "__default");
                    foundDefault = true;
                } else {
                    SneakyThrow.sneaky(new InvalidConfigurationException("Multiple @Default commands"));
                }
            }
            if (sub != null) {
                sublist = sub.value();
            } else if (commandAliases != null) {
                sublist = commandAliases.value();
            }
            if (sublist != null) {
                registerSubcommand(method, sublist);
            }
        }

        try {
            Method unknown = this.getClass().getMethod("onUnknown", CommandSender.class, String.class, String[].class);
            unknown.setAccessible(true);
            registerSubcommand(unknown, "__unknown");
        } catch (NoSuchMethodException ignored) {}

        List<String> cmdList = new ArrayList<>();

        cmdList.addAll(this.aliases.keySet());

        if (rootCmdAlias != null) {
            Collections.addAll(cmdList, RegexPatterns.PIPE.split(rootCmdAlias.value()));
        }

        cmdList.remove(cmd);

        if (!cmdList.isEmpty()) {
            this.setAliases(cmdList);
        }

        Bukkit.getServer().getCommandMap().register("empire", this);
    }

    private void registerSubcommand(Method method, final String subCommand) {
        final String[] subCommandParts = RegexPatterns.SPACE.split(subCommand);
        List<String> cmdList = getSubCommandPossibilityList(subCommandParts);

        // Strip pipes off for auto complete addition
        for (int i = 0; i < subCommandParts.length; i++) {
            subCommandParts[i] = RegexPatterns.PIPE.split(subCommandParts[i])[0];
        }
        String prefSubCommand = StringUtils.join(subCommandParts, " ");
        final CommandAlias cmdAlias = method.getAnnotation(CommandAlias.class);

        final String[] aliasNames = cmdAlias != null ? RegexPatterns.PIPE.split(cmdAlias.value().toLowerCase()) : null;
        String cmdName = aliasNames != null ? aliasNames[0] : getLabel() + " ";
        RegisteredCommand cmd = new RegisteredCommand(this, cmdName, method, prefSubCommand);

        for (String subcmd : cmdList) {
            subCommands.put(subcmd, cmd);
        }

        if (aliasNames != null) {
            for (String name : aliasNames) {
                aliases.put(name.toLowerCase(), cmd);
            }
        }

    }

    /**
     * Takes a string like "foo|bar baz|qux" and generates a list of
     * - foo baz
     * - foo qux
     * - bar baz
     * - bar qux
     *
     * For every possible sub command combination
     *
     * @param subCommandParts
     * @return List of all sub command possibilities
     */
    private static List<String> getSubCommandPossibilityList(String[] subCommandParts) {
        int i = 0;
        ArrayList<String> current = null;
        while (true) {
            ArrayList<String> newList = new ArrayList<>();

            if (i < subCommandParts.length) {
                for (String s1 : RegexPatterns.PIPE.split(subCommandParts[i])) {
                    if (current != null) {
                        newList.addAll(current.stream().map(s -> s + " " + s1).collect(Collectors.toList()));
                    } else {
                        newList.add(s1);
                    }
                }
            }

            if (i + 1 < subCommandParts.length) {
                current = newList;
                i = i + 1;
                continue;
            }

            return newList;
        }
    }

    @Override
    public final boolean execute(CommandSender sender, String commandLabel, String[] args) {
        if (!testPermission(sender)) {
            return false;
        }
        commandLabel = commandLabel.toLowerCase();
        if (preCommand(sender, commandLabel, args)) {
            return false;
        }

        origCommandLabel = commandLabel;
        origArgs = args;

        final RegisteredCommand alias = aliases.get(commandLabel);
        if (alias != null) {
            executeCommand(sender, args, alias);
            return false;
        }
        if (args.length == 0) {
            onDefault(sender, commandLabel);
            return false;
        }

        CommandSearch cmd = findSubCommand(args);
        if (cmd != null) {
            final String[] execargs = Arrays.copyOfRange(args, cmd.argIndex, args.length);
            executeCommand(sender, execargs, cmd.cmd);
            return false;
        }

        if (!onUnknown(sender, commandLabel, args)) {
            help(sender, args);
        }
        return false;
    }

    private CommandSearch findSubCommand(String[] args) {
        for (int i = args.length; i >= 0; i--) {
            String checkSub = StringUtils.join(args, " ", 0, i).toLowerCase();
            final RegisteredCommand cmd = subCommands.get(checkSub);
            if (cmd != null) {
                return new CommandSearch(cmd, i);
            }
        }
        return null;
    }

    private static void executeCommand(CommandSender sender, String[] args, RegisteredCommand cmd) {
        if (cmd.perm == null || sender.hasPermission(cmd.perm.value())) {
            List<String> sargs = Lists.newArrayList(args);
            cmd.invoke(sender, sargs);
        } else {
            Util.sendMsg(sender, MiscLang.COMMAND_PERM_ERROR);
        }
    }

    public boolean canExecute(CommandSender sender, RegisteredCommand cmd) {
        return true;
    }

    @Override
    public List<String> tabComplete(CommandSender sender, String commandLabel, String[] args)
        throws IllegalArgumentException {

        commandLabel = commandLabel.toLowerCase();
        RegisteredCommand cmd = aliases.get(commandLabel);

        if (cmd == null) {
            final CommandSearch search = findSubCommand(args);
            if (search != null) {
                cmd = search.cmd;
                args = Arrays.copyOfRange(args, search.argIndex, args.length);
            }
        }

        String argString = StringUtils.join(args, " ").toLowerCase();
        final String[] split = RegexPatterns.SPACE.split(argString+"!"); // add ! incase ends in space

        if (cmd != null) {
            return completeCommand(sender, cmd, args, commandLabel);
        }

        final List<String> cmds = new ArrayList<>();
        // TODO: Why isn't /promoadmin test <tab> finding it? -- What did I mean by this?

        for (Map.Entry<String, RegisteredCommand> entry : subCommands.entrySet()) {
            final String key = entry.getKey();
            if (key.startsWith(argString) && !"__unknown".equals(key)) {
                String prefCommand = entry.getValue().prefSubCommand;

                final String[] psplit = RegexPatterns.SPACE.split(prefCommand);
                cmds.add(psplit[split.length - 1]);
            }
        }

        final RegisteredCommand unknownCommand = subCommands.get("__unknown");
        if (cmds.isEmpty() && unknownCommand != null) {
            return completeCommand(sender, unknownCommand, args, commandLabel);
        }

        return filterTabComplete(args[split.length-1], cmds);
    }

    private List<String> completeCommand(CommandSender sender, RegisteredCommand cmd,
                                         String[] args, String commandLabel) {
        if (args.length >= cmd.nonSenderAwareResolvers) {
            return ImmutableList.of();
        }
        if (args.length != 1 || cmd.complete == null
            || "@players".equals(cmd.complete.value())) {
            return super.tabComplete(sender, commandLabel, args);
        }
        final List<String> cmds = new ArrayList<>();
        String[] complete = RegexPatterns.COLON.split(cmd.complete.value(), 2);
        String last = args.length > 0 ? args[args.length - 1] : null;
        switch (complete[0]) {
            case "@bannedplayers":
                if (!(sender instanceof Player) || UserUtil.isModerator((Player) sender)) {
                    try {
                        cmds.addAll(EmpireDb.<String>getFirstColumnResults(
                            "SELECT u.name FROM user_ban b JOIN user u ON b.user_id = u.user_id WHERE " +
                                "u.name LIKE ?", last + "%"));
                    } catch (SQLException e) {
                        e.printStackTrace();
                    }
                } else {
                    return super.tabComplete(sender, commandLabel, args);
                }
                break;
            case "@allplayers":
                List<String> results = EmpireUser.lookupNames(last, complete.length > 1 ? Util.parseInt(complete[1]) : null);

                cmds.addAll(Bukkit.getOnlinePlayers().stream().map(Player::getName).collect(Collectors.toList()));

                if (results != null) {
                    cmds.addAll(results);
                } else {
                    return super.tabComplete(sender, commandLabel, args);
                }
                break;
            case "@rareitems":
                cmds.addAll(CustomItems.customItems.keySet());
                break;
            case "@mobs":
                for (EntityType entityType : EntityType.values()) {
                    cmds.add(Util.simplifyString(entityType.getName()));
                }
                final Stream<CustomMob> stream = CustomMob.allTypes.values().stream();
                final Stream<String> mobNames = stream.map(customMob -> Util.simplifyString(customMob.customType));
                cmds.addAll(mobNames.collect(Collectors.toList()));
                break;
            case "@psetting":
                for (PlayerSettingKey key : PlayerSettingKey.values()) {
                    cmds.add(key.key);
                }
                break;
            case "@staffplayers":
                List<String> staff = EmpireUser.lookupStaff(last);

                if (staff != null) {
                    cmds.addAll(staff);
                } else {
                    return super.tabComplete(sender, commandLabel, args);
                }
                break;
            case "@servers":
                for (EmpireServer server : EmpireServer.values()) {
                    cmds.add(server.label);
                }
                break;
            default:
                Collections.addAll(cmds, RegexPatterns.PIPE.split(cmd.complete.value()));
        }

        return filterTabComplete(args[args.length - 1], cmds);
    }

    private static List<String> filterTabComplete(String arg, List<String> cmds) {
        List<String> list = new ArrayList<>();
        for (String cmd : cmds) {
            if (cmd != null && (arg.isEmpty() || StringUtil.startsWithIgnoreCase(cmd, arg))) {
                list.add(cmd);
            }
        }
        return list;
    }

    public void help(CommandSender sender, String[] args) {
    }

    public void onDefault(CommandSender sender, String commandLabel) {
        executeDefault(sender);
    }
    public boolean onUnknown(CommandSender sender, String commandLabel, String[] args) {
        if (!executeDefault(sender, args)) {
            help(sender, args);
        }
        return true;
    }
    public boolean executeDefault(CommandSender sender,  String... args) {
        final RegisteredCommand def = subCommands.get("__default");
        if (def != null) {
            executeCommand(sender, args, def);
            return true;
        }
        return false;
    }

    public boolean preCommand(CommandSender sender, String commandLabel, String[] args) {
        return false;
    }

    public void doHelp(CommandSender sender, String... args) {
        help(sender, args);
    }

    public void showSyntax(CommandSender sender,  RegisteredCommand cmd) {
        Util.sendMsg(sender, "&cUsage: /" + cmd.command + " " + cmd.syntax);
    }


    @AllArgsConstructor static class CommandSearch { RegisteredCommand cmd; int argIndex; }
}

InvalidCommandArgument.java

package com.empireminecraft.commands;

public class InvalidCommandArgument extends Exception {
    public InvalidCommandArgument() {
    }
    public InvalidCommandArgument(String message) {
        super(message, null, false, false);
    }
}

RegisteredCommand.java

package com.empireminecraft.commands;

import com.empireminecraft.commands.annotation.*;
import com.empireminecraft.commands.contexts.CommandContexts;
import com.empireminecraft.commands.contexts.ContextResolver;
import com.empireminecraft.commands.contexts.ContextResolver.SenderAwareContextResolver;
import com.empireminecraft.util.RegexPatterns;
import com.empireminecraft.util.Util;
import com.google.common.collect.Lists;
import org.bukkit.command.CommandSender;
import org.bukkit.configuration.InvalidConfigurationException;
import org.spigotmc.SneakyThrow;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Parameter;
import java.util.List;

public class RegisteredCommand {
    public final EmpireCommand scope;
    public final String command;
    public final Method method;
    public final String prefSubCommand;
    public final Parameter[] parameters;
    public final ContextResolver<?>[] resolvers;
    public final String syntax;

    public final CommandPermission perm;
    public final CommandCompletion complete;
    public final int nonSenderAwareResolvers;

    RegisteredCommand(EmpireCommand scope, String command, Method method, String prefSubCommand) {
        this.scope = scope;
        if ("__unknown".equals(prefSubCommand)) {
            prefSubCommand = "";
        }
        this.command = command + (method.getAnnotation(CommandAlias.class) == null && !prefSubCommand.isEmpty() ? " " + prefSubCommand : "");
        this.method = method;
        this.prefSubCommand = prefSubCommand;
        this.perm = method.getAnnotation(CommandPermission.class);
        this.complete = method.getAnnotation(CommandCompletion.class);
        this.parameters = method.getParameters();
        this.resolvers = new ContextResolver[this.parameters.length];
        final Syntax syntaxStr = method.getAnnotation(Syntax.class);

        if (syntaxStr != null) {
            this.syntax = syntaxStr.value();
        } else {
            StringBuilder syntaxB = new StringBuilder(64);
            for (Parameter p : parameters) {
                if (!CommandSender.class.isAssignableFrom(p.getType())) {
                    if (p.getAnnotation(Default.class) != null || p.getAnnotation(Optional.class) != null) {
                        syntaxB.append('[').append(p.getName()).append("] ");
                    } else {
                        syntaxB.append('<').append(p.getName()).append("> ");
                    }
                }
            }
            this.syntax = syntaxB.toString();
        }
        int nonSenderAwareResolvers = 0;
        for (int i = 0; i < parameters.length; i++) {
            final Parameter parameter = parameters[i];
            final Class<?> type = parameter.getType();
            final ContextResolver<?> resolver = CommandContexts.getResolver(type);
            if (resolver != null) {
                resolvers[i] = resolver;
                if (!(resolver instanceof SenderAwareContextResolver)) {
                    nonSenderAwareResolvers++;
                }
            } else {
                SneakyThrow.sneaky(new InvalidConfigurationException(
                    "Parameter " + type.getSimpleName() + " of " + this.command + " has no resolver"));
            }
        }
        this.nonSenderAwareResolvers = nonSenderAwareResolvers;
    }

    public void invoke(CommandSender sender, List<String> args) {
        if (!scope.canExecute(sender, this)) {
            return;
        }
        List<Object> passedArgs = Lists.newArrayList();
        for (int i = 0; i < parameters.length; i++) {
            boolean isLast = i == parameters.length - 1;
            final Parameter parameter = parameters[i];
            final Class<?> type = parameter.getType();
            final ContextResolver<?> resolver = resolvers[i];
            if (resolver != null) {
                try {
                    if (args.isEmpty() && !(isLast && type == String[].class)) {
                        Default def = parameter.getAnnotation(Default.class);
                        Optional opt = parameter.getAnnotation(Optional.class);
                        if (isLast && def != null) {
                            args.add(def.value());
                        } else if (isLast && opt != null) {
                            passedArgs.add(null);
                            continue;
                        } else if (!(resolver instanceof SenderAwareContextResolver)) {
                            scope.showSyntax(sender, this);
                            return;
                        }
                    } else {
                        final Values values = parameter.getAnnotation(Values.class);
                        if (values != null) {
                            final String[] split = RegexPatterns.PIPE.split(values.value());
                            String arg = args.get(0);
                            if (Util.indexOf(arg, split) == -1) {
                                throw new InvalidCommandArgument("Must be one of: " + Util.join(split, ", "));
                            }
                        }
                    }
                    passedArgs.add(resolver.getContext(parameter, sender, args, isLast));
                } catch (InvalidCommandArgument e) {
                    if (e.getMessage() != null) {
                        Util.sendMsg(sender, "&cInvalid Argument: " + e.getMessage());
                    }
                    scope.showSyntax(sender, this);
                    return;
                }
            } else {
                Util.sendMsg(sender, "&cUnexpected Error. Staff have been notified of the bug. Please try again.");
                return;
            }
        }

        try {
            method.invoke(scope, passedArgs.toArray());
        } catch (InvocationTargetException e) {
            Util.sendMsg(sender, "&cI'm sorry, but there was an error performing this command.");
            Util.printException("Exception in command: " + command + " " + Util.join(args), e.getCause());
        } catch (IllegalAccessException e) {
            Util.printException(e);
        }
    }
}