project/src/main/java/internal/hw/crawler/MainController.java

package internal.hw.crawler;

import internal.hw.crawler.commands.Command;
import internal.hw.crawler.commands.CommandArg;
import internal.hw.crawler.views.ConsoleView;

import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class MainController {
    private final Map<String, Command> commands = new HashMap<>();
    private final ConsoleView view;

    public MainController(ConsoleView view) {
        this.view = view;
    }

    public Map<String, Command> getCommands() {
        return Collections.unmodifiableMap(commands);
    }

    public void registerCommand(Command command) {
        commands.put(command.getName(), command);
    }

    public void handleInput(String input) {
        String text = input == null ? "" : input.trim();
        if (text.isEmpty()) {
            return;
        }

        String[] args = text.split("\\s+");
        String cmdName = args[0].toLowerCase();
        Command command = commands.get(cmdName);
        if (command == null) {
            view.printError("Unknown command: " + cmdName);
            return;
        }

        if (!validateArgs(command, args)) {
            return;
        }

        try {
            command.execute(args);
        } catch (Exception e) {
            view.printError("Command failed: " + e.getMessage());
        }
    }

    private boolean validateArgs(Command command, String[] args) {
        List<CommandArg> cmdArgs = command.getArgs();
        long required = cmdArgs.stream().filter(CommandArg::required).count();
        int provided = args.length - 1;

        if (provided < required) {
            view.printError("Usage: " + command.getName() + " " + formatUsage(cmdArgs));
            return false;
        }
        return true;
    }

    private String formatUsage(List<CommandArg> cmdArgs) {
        StringBuilder sb = new StringBuilder();
        for (CommandArg arg : cmdArgs) {
            if (arg.required()) {
                sb.append("<").append(arg.name()).append("> ");
            } else {
                sb.append("[").append(arg.name()).append("] ");
            }
        }
        return sb.toString().trim();
    }
}