import java.util.ArrayList;

/**
 * A priority queue using a sorted array list as its backing store.  Hence, this implements insertion sort.
 * 
 * @param <K> the Key element. This must implement Comparable.
 * @param <V> The Value element.  This could be anything.
 * 
 * For methods that exactly follow the interface, see the documentation in the interface.
 * 
 * @author gtowell
 * Created APRIL 13, 2020
 */
public class PriorityQInsertion<K extends Comparable<K>, V> extends AbstractPriorityQueue<K,V> {

    /** The thing actually holding the data in the priority queue.  Using an ArrayList
     * to get unbounded length.  
     */
    final private ArrayList<Entry<K,V>> pqStore;

    /**
     * Initialize the priority queue
     */
    public PriorityQInsertion() {
        this(Ordering.MIN);
    }
    public PriorityQInsertion(Ordering order) {
        this.order=order;
        pqStore = new ArrayList<>();
    }


    @Override
    public int size() {
        return pqStore.size();
    }

    @Override
    public boolean isEmpty() {
        return pqStore.isEmpty();
    }

    @Override
    public boolean offer(K newK, V newV) {
        Entry<K,V> entry = new Entry<>(newK, newV);
        for (int i=0; i< pqStore.size(); i++) {
            int cmp = pqStore.get(i).doCompare(entry);
            if (cmp==0) {
                return false;
            }
            if (cmp>0) {
                // insert before
                pqStore.add(i, entry);
                System.out.println(pqStore);
                return true;
            }
        }
        // add to the end
        pqStore.add(entry);
        System.out.println(pqStore);
        return true;
    }


    @Override
    public V poll() {
        if (size()==0) return null;
        Entry<K,V> entry = pqStore.get(0);
        pqStore.remove(0);
        return entry.theV;
    }

    @Override
    public V peek() {
        if (size()==0) return null;
        Entry<K,V> entry = pqStore.get(0);
        return entry.theV;
    }

    public static void main(String[] args) {
        PriorityQInsertion<Integer, String> pq = new PriorityQInsertion<Integer, String>(Ordering.MIN);
        pq.offer(1,"Jane");
        pq.offer(10,"WET");
        pq.offer(5, "WAS");
        System.out.println(pq.poll());
        System.out.println(pq.poll());
        System.out.println(pq.poll());
        System.out.println();

        pq = new PriorityQInsertion<>(Ordering.MAX);
        pq.offer(1,"Jane");
        pq.offer(10,"WET");
        pq.offer(5, "WAS");
        System.out.println(pq.poll());
        System.out.println(pq.poll());
        System.out.println(pq.poll());


    }

}