import java.util.NoSuchElementException;

public class MedListRefBased implements List<Medication> {

	private MedicationNode head;
	private MedicationNode tail;
	private int count;

	public MedListRefBased() {
		head = null;//head
		tail = null;//tail
		count = 0;//initialize count
	}

	public void add(Medication k,int index) {
		if(index < 0 || index > count){
			throw new IndexOutOfBoundsException("Index is not in bounds");
		}//exception handling
		MedicationNode add=new MedicationNode(k);
		if(isEmpty()){
			head=add;
			tail=head;//add the new medication as the head and tail
		}else{
			MedicationNode cur=head;
            for(int i=0;i<index-1;i++){
                cur=cur.next;
            }//for
            add = new MedicationNode(k, cur.prev, cur);
            cur.next=add;
            add.prev=cur;
            add.next=cur.next.next;//add the new medication
		}
		count++;
	}//add

	public Medication get(int index) {
		if(index < 0 || index > count){
			throw new IndexOutOfBoundsException("Index is not in bounds");
		}//exception handling
		MedicationNode cur = head;
		for(int i =0; i<index; i++){
			cur = cur.next;
		}//for
		return cur.item;
	}//get

	public boolean isEmpty() {
		if(tail == null && head == null){
			return true;
		}//if
		return false;
	}//isEmpty

	public int size() {
		return count;
	}//size

	public int indexOf(Medication item) {
		int index=0;
		MedicationNode cur=head;
		while(cur!=null){
			if(cur.item==item){
				break;
			}
			cur=cur.next;
			index++;
		}
		return index;
	}//indexOf

	public void remove(int index) {
	if(index < 0 || index > count){
		throw new IndexOutOfBoundsException("Index is not in bounds");
	}//exception handling
		if(index ==0){
			removeFront();
		}else {
			MedicationNode cur=head;
			for(int i=0;i<index-1;i++){
				cur=cur.next;
			}
			cur.next=cur.next.next;
		}

		count--;
	}//remove

	public void remove(Medication item) {
		MedicationNode cur=head;
		if(head.item.equals(item)){
			removeFront();
		}else{
			for(int i=0;i<count;i++){
				if(cur.item.equals(item)){
					cur.prev.next=cur.next;
				}//if
				cur=cur.next;
			}

		}
		count--;
	}//remove

	public void removeAll() {
		head=null;
		tail=null;
		count=0;
	}//removeAll

	public void removeFront(){
		head = head.next;
		head.prev=null;
	}//removeFront

	public String toString() {
		String details="";
		MedicationNode cur=head;
		while(cur!=null){
			details=details + "," + cur.item;
			cur =cur.next;
		}
		return details;
	}//toString



	public static void main(String[] args) {
		Medication a = new Medication("tylenol",500);
		Medication b = new Medication("ibuprofen",100);
		Medication c = new Medication("meperidol",200);
		Medication d = new Medication("cimetidine",300);


		MedListRefBased test = new MedListRefBased();

		test.add(a,0);
		System.out.println(test.toString());
		test.add(b,1);
		System.out.println(test.toString());
		test.add(c,2);
		System.out.println(test.toString());
		test.add(d,0);
		System.out.println(test.toString());

	}
}