#ifndef OU_LINKED_LIST
#define OU_LINKED_LIST

#include "OULink.h"
#include "Comparator.h"
#include "OULinkedListEnumerator.h"

// OULinkedList stands for Ordered, Unique Linked List. It is a linked list that is always maintained in
// order (based on the comparator provided to it when the list is created) and that only contains unique
// items (that is, duplicates are not allowed)
template <typename T>
class OULinkedList {
	// template <typename T>  // not necessary
	// friend class OULinkedListEnumerator;  // not necessary
private:
	Comparator<T>* comparator = NULL;				// used to determine list order and item equality
	unsigned long size = 0;							// actual number of items currently in list
	OULink<T>* first = NULL;						// pointer to first link in list
	OULink<T>* last = NULL;							// pointer to last link in list
public:
	OULinkedList(Comparator<T>* comparator);		// creates empty linked list with comparator
	virtual ~OULinkedList();						// deletes all links and their data items

	// if an equivalent item is not already present, insert item in order and return true
	// if an equivalent item is already present, leave list unchanged and return false
	bool insert(const T* item);

	// if item is greater than item at last, append item at end and return true
	// if item is less than or equal to item at last, leave list unchanged and return false
	bool append(const T* item);  // now const

	// if an equivalent item is already present, replace item and return true
	// if an equivalent item is not already present, leave list unchanged and return false
	bool replace(const T* item);  // now const

	// if an equivalent item is already present, remove item and return true
	// if an equivalent item is not already present, leave list unchanged and return false
	bool remove(const T* item);  // now const

	// if any items are present, return a copy of the first item
	// if no items are present, throw new ExceptionLinkedListAccess
	T get() const;

	// if an equivalent item is present, return a copy of the first such item
	// if an equivalent item is not present, throw a new ExceptionLinkedListAccess
	T find(const T* item) const;

	unsigned long getSize() const;					// returns the current number of items in the list

	OULinkedListEnumerator<T> enumerator() const;	// create an enumerator for this linked list
};

// Implementation goes here

#endif // !OU_LINKED_LIST