package de.dhbw.klausurVorbereitung;

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

public class Klausurvorbereitung {

    //Schreibe ein JavaDoc
    /**
     * Diese Methode berechnet die Fakultaet mit Hilfe von Rekursion.
     * Abbruchbedingungen sind x < 0, da es hiervon keine Fakultaet gibt und
     * x < 2, da die Fakultaet von diesen Zahlen per Definition gleich 1 ist.
     * @param x eine natuerliche Zahl, von der die Fakultaet gebildet wird.
     * @return Fakultaet von x
     * @throws Illegal-Argument-Exception (unchecked), falls x < 0
     */
    public static int getFoo(int x) {
        if (x < 0) {
            throw new IllegalArgumentException();
        }
        if (x < 2) {
            return 1;
        }
        int foo = x * getFoo(x - 1);
        return foo;
    }


    // Was steht nach Ablauf des Programms in der Konsole
    public static void main(String[] args) {
        // set up data
        String[] namesArray = {"Martin", "Hans", "Christian", "Max"};
        List<String> namesList = new ArrayList<String>();
        for (String s : namesArray) {
            namesList.add(s);
        }
        Collections.sort(namesList, new Comparator<String>() {
            public int compare(String o1, String o2) {
                return o1.length() - o2.length();
            }
        });

        // print data
        for (String s : namesList) {
            System.out.println(s);
        }
        System.out.println();

        // do some work on it and print it again
        List<String> namesList2 = namesList;
        namesList2.remove("Martin");
        namesList.remove(1);
        for (String s : namesList) {
            System.out.println(s);
        }

        // some comparisons
        System.out.println();
        System.out.println(namesList2 == namesList);
        namesList2 = new ArrayList<String>(namesList);
        System.out.println(namesList2.equals(namesList));
    }


    // The following code excerpt contains five compile-time errors. locate and describe them
    public String getText(Collection<String> strings) { // nicht in jedem Fall ein Return-wert
        int result = Double.MAX_VALUE; // Wir versuchen einen Double einem int zuzuweisen
        if (strings = null) { // Zuweisung anstatt Vergleich. null ist kein boolean
            return "";
        }
        for (String s : strings) {
            result -= s.length() // Kein Semikolon
        }
        if (result > 0) {
            return result; // result ist kein String
        }
    }


    /*
    * Given is the following code snippet. Comment on the code:
    *   - what is given in the snippet? What are the snippet`s consequences?
    *   - where might this piece of code be used? What is missing to make it functional in
    *       those situations? Give examples for those situations.
    */
    public class MyClass {
        private MyClass() {
        }
    }
    // public default constructor wurde private gemacht
    // notwendig für einen singleton
    // von außen kann niemand eine Instanz erzeugen
    // singleton wäre in der Klausur ein Bonus



    //Praktischer Teil

    /*
     * TODO Task 1: Exit the program in a controlled manner (15 points)
     * Currently the program cannot be exited, it can just be terminated from outside.
     * It should be possible to exit the program in two
     * ways:
     *  - By clicking to close button in the windows icon bar
     * (upper right corner)
     * By clicking an 'Exit' menu item from the menu bar
     * Before actually exiting the program the user must be challenged
     * ("Do you really..."). Only in case of a positive answer the program should be terminated.
     * The text typed in by the user does not have to be persisted.
     * The classes JOptionPane and System can be used here.
     */

    /*
     * TODO Task 2: Read input text over a network (20 points)
     * Text to be edited can either be entered by a user manually or read
     * via a network connection from another process using socket
     * communication. Write code to read the text from the given server
     * program and display this text instead of the currently edited one
     * in the editor's text area.
     * The users should be informed appropriately in case of errors.
     * All resource must be cleaned up after using them.
     *
     * You can start the server by typing: java -jar server.jar
     * on the command line. The server should write
     *      Text server up and running.
     *      Port: 28060
     * after startup.
     *
     * The following protocol is used:
     * - Client sends: _reuestForText_
     * - Server sends: <some text (as string) >
     * - Client sends: _ack_
     * - Server sends: _ack_
     */
}