import java.util.ArrayList;
import java.util.concurrent.locks.ReentrantLock;
import java.util.concurrent.locks.Condition;

class ConditionsMain {

    public static void main(String[] args) {
        VaksineMonitor monitor = new VaksineMonitor();
        Runnable vaksineProd = new Vaksineprodusent(monitor);
        Runnable sykepleier = new Sykepleier(monitor);

        Thread tVaksineProd = new Thread(vaksineProd);
        Thread tSykepleier = new Thread(sykepleier);
        tVaksineProd.start();
        tSykepleier.start();
    }
    
}

class Vaksineprodusent implements Runnable {

    VaksineMonitor monitor;

    Vaksineprodusent(VaksineMonitor vm) {
        monitor = vm;
    }

    @Override
    public void run() {
        for (int i = 0; i < 10; i++) {
            try {
                Thread.sleep(4000);
                monitor.leggInnVaksine("Vaksine");
            }
            catch (InterruptedException e) {
                System.out.println(e);
            }
        }
    }
}

class Sykepleier implements Runnable {

    VaksineMonitor monitor;

    Sykepleier(VaksineMonitor vm) {
        monitor = vm;
    }

    @Override
    public void run() {
        for (int i = 0; i < 10; i++) {
            String vaksine = monitor.taUtVaksine();
            try {
                Thread.sleep(1000);
                System.out.println("Satt 1 vaksine dose. ");
                Thread.sleep(1000);
                System.out.println("Satt 1 vaksine dose. ");
                Thread.sleep(1000);
                System.out.println("Satt 1 vaksine dose. ");
            } 
            catch (InterruptedException e) {
                System.out.println(e);
            }
        }
    }
}

class VaksineMonitor {
    private ArrayList<String> vaksiner = new ArrayList<>();
    private ReentrantLock lock = new ReentrantLock();

    private Condition ikkeTom = lock.newCondition();

    public String taUtVaksine() {
        lock.lock();
        try {
            while (vaksiner.isEmpty()) {
                ikkeTom.await();
            }
            return vaksiner.remove(0);
        }
        catch (InterruptedException e) {
            System.out.println(e);
        }
        finally {
            lock.unlock(); 
        }
        return "Fikk ikke hentet vaksine";
       
    }

    public void leggInnVaksine(String v) {
        lock.lock();
        try {
            Thread.sleep(3000);
            vaksiner.add(v);
            ikkeTom.signalAll();
        }
        catch (InterruptedException e) {
            System.out.println(e);
        }
        finally {
            lock.unlock();
        }
    } 

}