import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.Scanner;

public class PasswordManager implements PasswordManagerInterface {

    boolean running = true;
    InputStream inputStream = System.in;
    OutputStream outputStream = System.out;
    ArrayList<Vault> vaults = new ArrayList<>();
    int selectedVaultId = -1;
    ArrayList<String> vaultOperationOptions = new ArrayList<>();

    public static void main(String[] args) {
        PasswordManager pm = new PasswordManager();

        while (pm.running) {
            pm.showMenu();
        }
        System.exit(0);
    }

    public PasswordManager() {
        println("Hello World");
    }

    private void println(String output) {
        try {
            outputStream.write((output + "\n").getBytes(StandardCharsets.UTF_8));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void listVaults() {
        println("Vaults:");
        for (int i = 0; i < vaults.size(); i++) {
            println("- vault id: " + i);
        }
    }

    public void createNewVault() {
        vaults.add(new Vault());
    }

    @Override
    public void openVault() {

    }

    @Override
    public void showMenu() {
        StringBuilder sb = new StringBuilder();
        Scanner scan = new Scanner(inputStream);
        running = true;

        sb.append("\nciip Gruppe 8 - Password Manager\n\n");

        sb.append("Menu:\n");
        sb.append("- list vaults: l\n");
        sb.append("- create new vault: v\n");
        sb.append("- select vault and show operations: v x (replace x with vault id)\n");
        sb.append("- select vault operation: o x (replace o with a operation id for the selected vault)\n");
        sb.append("- exit: e\n");

        println(sb.toString());

        String input = scan.nextLine();

        if (input.equals("e")) {
            running = false;
        } else if (input.equals("l")) {
            listVaults();
        } else if (input.equals("v")) {
            createNewVault();
        } else if (input.startsWith("v")) {
            String vaultAction = (input.replace('v', ' ')).trim();
            int vaultId = -1;

            try {
                vaultId = Integer.parseInt(vaultAction);
            } catch (NumberFormatException e) {
                println("-- please enter a correct vault id");
            }

            if (vaultId >= 0) {
                selectedVaultId = vaultId;
                println("\nVault " + vaultId + " selected.");
                try {
                    int internalOptionCounter = 0;
                    println("\nAvailable vault operations:");

                    for (Method m : Class.forName("Vault").getDeclaredMethods()) {  // returns all declared methods including private or protected
                        try {
                            if (Modifier.isPublic(Class.forName("Vault").getDeclaredMethod(m.getName()).getModifiers())) {  // filter out methods that are not public (using Modifier) or have arguments (using getDeclaredMethod)
                                vaultOperationOptions.add(m.getName());
                                println(internalOptionCounter + " - " + m.getName());
                                internalOptionCounter++;
                            }
                        } catch (NoSuchMethodException ignore) {
                            // println("No method with name " + m.getName() + " found");
                        }
                    }
                } catch (ClassNotFoundException e) {
                    println("-- vaults not implemented yet");
                }
            }
        } else if (input.startsWith("o")) {
            String operation = (input.replace('o', ' ')).trim();
            int operationId = -1;

            try {
                operationId = Integer.parseInt(operation);
            } catch (NumberFormatException e) {
                println("-- please enter a valid operation id");
            }

            if (selectedVaultId < 0) {
                println("-- a vault needs to be selected");
            } else if (operationId >= 0 && operationId < vaultOperationOptions.size()) {
                Vault vault = vaults.get(selectedVaultId);
                try {
                    println("Run selected operation '" + vaultOperationOptions.get(operationId) + "':");
                    vault.getClass().getDeclaredMethod(vaultOperationOptions.get(operationId)).invoke(vault);
                } catch (IllegalAccessException | NoSuchMethodException | InvocationTargetException e) {
                    e.printStackTrace();
                    println("-- selected operation failed");
                }
            } else {
                println("-- please enter a valid operation id");
            }
        }
    }
}