package lab2;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.Semaphore;

public class BlockingQueue<T> {
    Semaphore e = new Semaphore(1);
    Semaphore d = new Semaphore(1);
    T[] contents;
    int capacity;

    public BlockingQueue(int capacity) {
        contents = (T[]) new Object[capacity];
        this.capacity = capacity;
    }

    @Override
    public String toString() {
        return  Arrays.toString(contents) ;
    }

    public void enqueue(T item) throws InterruptedException {
        e.acquire();
        T[] temp = (T[]) new Object[capacity+1];
        if (capacity >= 0) System.arraycopy(contents, 0, temp, 0, capacity);
        temp[capacity++]=item;
        this.contents = temp;
        System.out.println("e");
        e.release();
    }
    public void dequeue() throws InterruptedException {
        d.acquire();
        T [] temp = (T[]) new Object[capacity-1];
        if (capacity >= 0) System.arraycopy(contents, 0, temp, 0, capacity-1);
        this.contents= temp;
        this.capacity--;
        System.out.println("d");
        d.release();
    }
    public static void main(String[] args) throws InterruptedException {
        BlockingQueue<Integer> bq = new BlockingQueue<>(2);
        List<Thread> list = new ArrayList<>(5);
        Thread t0 = new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    bq.enqueue(30);
                } catch (InterruptedException ex) {
                    ex.printStackTrace();
                }
            }
        });
        list.add(t0);
        Thread t1 = new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    bq.enqueue(20);
                } catch (InterruptedException ex) {
                    ex.printStackTrace();
                }
            }
        });
        list.add(t1);
        Thread t2 = new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    bq.enqueue(5);
                } catch (InterruptedException ex) {
                    ex.printStackTrace();
                }
            }
        });
        list.add(t2);
        Thread t3 = new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    bq.dequeue();
                } catch (InterruptedException ex) {
                    ex.printStackTrace();
                }
            }
        });
        list.add(t3);
        Thread t4 = new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    bq.dequeue();
                } catch (InterruptedException ex) {
                    ex.printStackTrace();
                }
            }
        });
        list.add(t4);
        for( Thread t : list){
            t.start();
        }
        for( Thread t : list){
            t.join();
        }
        System.out.println(bq.toString());
    }


}