Minestom/src/main/java/net/minestom/server/command/builder/Command.java

package net.minestom.server.command.builder;

import net.minestom.server.command.CommandSender;
import net.minestom.server.command.builder.arguments.Argument;
import net.minestom.server.command.builder.arguments.ArgumentDynamicStringArray;
import net.minestom.server.command.builder.arguments.ArgumentDynamicWord;
import net.minestom.server.command.builder.arguments.ArgumentType;
import net.minestom.server.command.builder.condition.CommandCondition;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

/**
 * Represents a command which have suggestion/auto-completion
 * <p>
 * The command works using a list of valid syntaxes.
 * For instance we could build the command
 * "/health set Notch 50" into multiple argument types -> "/health [set/add/remove] [Username] [Integer]"
 * <p>
 * All the default argument types can be found in {@link ArgumentType}
 * and the syntax be created/registered using {@link #addSyntax(CommandExecutor, Argument[])}.
 * <p>
 * If the command is executed with an incorrect syntax or without any argument, the default {@link CommandExecutor} will be executed,
 * you can set it using {@link #setDefaultExecutor(CommandExecutor)}.
 * <p>
 * Before any syntax to be successfully executed the {@link CommandSender} needs to validate
 * the {@link CommandCondition} sets with {@link #setCondition(CommandCondition)} (ignored if null).
 * <p>
 * Some {@link Argument} could also require additional condition (eg: a number which need to be between 2 values),
 * in this case, if the whole syntax is correct but not the argument condition,
 * you can listen to its error code using {@link #setArgumentCallback(ArgumentCallback, Argument)} or {@link Argument#setCallback(ArgumentCallback)}.
 */
public class Command {

    private String name;
    private String[] aliases;

    private CommandExecutor defaultExecutor;
    private CommandCondition condition;
    private List<CommandSyntax> syntaxes;

    /**
     * Create a {@link Command} with a name and one or multiple aliases
     *
     * @param name    the name of the command
     * @param aliases the command aliases
     * @see #Command(String)
     */
    public Command(String name, String... aliases) {
        this.name = name;
        this.aliases = aliases;

        this.syntaxes = new ArrayList<>();
    }

    /**
     * Create a {@link Command} with a name without any aliases
     *
     * @param name the name of the command
     * @see #Command(String, String...)
     */
    public Command(String name) {
        this(name, new String[0]);
    }

    /**
     * Get the {@link CommandCondition}
     * <p>
     * It is called no matter the syntax used and can be used to check permissions or
     * the {@link CommandSender} type
     *
     * @return the command condition
     */
    public CommandCondition getCondition() {
        return condition;
    }

    /**
     * Set the {@link CommandCondition}
     *
     * @param commandCondition the new command condition
     */
    public void setCondition(CommandCondition commandCondition) {
        this.condition = commandCondition;
    }

    /**
     * Set an {@link ArgumentCallback}
     * <p>
     * The argument callback is called when there's an error in the argument
     *
     * @param callback the callback for the argument
     * @param argument the argument which get the callback
     */
    public void setArgumentCallback(ArgumentCallback callback, Argument argument) {
        argument.setCallback(callback);
    }

    /**
     * Add a new syntax in the command
     * <p>
     * A syntax is simply a list of arguments
     *
     * @param executor the executor to call when the syntax is successfully received
     * @param args     all the arguments of the syntax
     */
    public void addSyntax(CommandExecutor executor, Argument... args) {
        CommandSyntax syntax = new CommandSyntax(args);
        syntax.setExecutor(executor);
        this.syntaxes.add(syntax);
    }

    /**
     * Get the main command's name
     *
     * @return the main command's name
     */
    public String getName() {
        return name;
    }

    /**
     * Get the command's aliases
     * <p>
     * Can be null or empty
     *
     * @return the command aliases
     */
    public String[] getAliases() {
        return aliases;
    }

    /**
     * Get the default {@link CommandExecutor} (which is called when there is no argument)
     * or if no corresponding syntax has been found
     *
     * @return the default executor
     */
    public CommandExecutor getDefaultExecutor() {
        return defaultExecutor;
    }

    /**
     * Set the default {@link CommandExecutor} (which is called when there is no argument)
     *
     * @param executor the new default executor
     */
    public void setDefaultExecutor(CommandExecutor executor) {
        this.defaultExecutor = executor;
    }

    /**
     * Get all the syntaxes of this command
     *
     * @return a collection containing all this command syntaxes
     */
    public Collection<CommandSyntax> getSyntaxes() {
        return syntaxes;
    }

    /**
     * Allow for tab auto completion, this is called everytime the player press a key in the chat
     * when in a dynamic argument ({@link ArgumentDynamicWord} and {@link ArgumentDynamicStringArray})
     *
     * @param text the whole player text
     * @return the array containing all the suggestion for the current arg (split " ")
     */
    public String[] onDynamicWrite(String text) {
        return null;
    }

    /**
     * Called when a {@link CommandSender} executes this command.
     * Executed before any syntax callback.
     * <p>
     * WARNING: the {@link CommandCondition} is not executed, and all the {@link CommandSyntax} are not checked,
     * this is called every time a {@link CommandSender} send a command which start by {@link #getName()} or {@link #getAliases()}.
     * <p>
     * Can be used if you wish to still suggest the player syntaxes but want to parse things mostly by yourself.
     *
     * @param sender    the {@link CommandSender}
     * @param arguments the UNCHECKED arguments of the command, some can be null even when unexpected
     * @param command   the raw UNCHECKED received command
     */
    public void globalListener(CommandSender sender, Arguments arguments, String command) {
    }

}