#include "AppendableList.h"
#include <cstdlib>
#include <iostream>

using namespace std;

// PRE:
// POST: default constructor
AppendableList::AppendableList()
{
	head = NULL;
	tail = NULL;
	size = 0;
}

// PRE:
// PARAM: list to be copied
// POST: copy constructor
AppendableList::AppendableList(const AppendableList & list)
{
	copyList(list);
}

// PRE:
// PARAM: list to be assigned
// POST: overloaded assignment operator
AppendableList & AppendableList::operator=(const AppendableList & list)
{
	if(this != &list){ // checks for self assignment
		removeAll();
		copyList(list);
	}
	return *this;
}

// PRE:
// POST: overloaded [] operator, returns reference to int
int & AppendableList::operator[](int i)
{
	Node* temp = head;
	for(int j = 0; j < i; j++){
		temp = temp->next;
	}
	return temp->data;
}

// PRE:
// POST: deallocates memory associated with list
AppendableList::~AppendableList()
{
	removeAll();
}

// PRE:
// POST: returns 1 if list is empty, 0 otherwise
int AppendableList::empty()
{
	return head == NULL;
}

// POST: returns number of values stored in list
int AppendableList::length()
{
	return size;
}

// PRE:
// PARAM: value = value to be appended
// POST: adds a new element to the tail of list
void AppendableList::append(int value)
{
	// Build the node to be appended
	Node* newNode = new Node(value);
	
	// List is empty
	if(tail == NULL){
		head = tail = newNode;
	}else{
		// List not empty
		tail->next = newNode;
		tail = newNode;
	}	
	size++;
}

// PRE: i < AL->size
// PARAM: i = index of data to be returned
// POST: returns the date in the ith node in the list
int AppendableList::get(int i)
{
	Node* temp = head;
	for(int j = 0; j < i; j++){
		temp = temp->next;
	}
	return temp->data;
}

// PRE: i < AL->size
// PARAM: i = index of data to be set
//		  value =  new value
// POST: changes the data in the ith node of the list to value
void AppendableList::set(int i, int value)
{
	Node* temp = head;
	for(int j = 0; j < i; j++){
		temp = temp->next;
	}
	temp->data = value;
}

// PRE:
// POST: prints list elements from head to tail
void AppendableList::print()
{
	cout << "{ ";
	printHelper(head);
	cout << "}" << endl;
}

// PRE:
// POST: removes all nodes from list
void AppendableList::removeAll()
{
	Node* current = head;
	while(head != NULL){
		head = head->next;
		delete current;
		current = head;
	}
	head = tail = NULL;
}

// PRE:
// PARAM: current = node to be printed
// POST: prints list elements from current to tail
void AppendableList::printHelper(Node* current)
{
	if(current != NULL){
		cout << current->data << " ";
		printHelper(current->next);
	}
}

// PARAM: list to be copied
// POST: makes a deep copy of list
void AppendableList::copyList(const AppendableList & list)
{
	if(list.head != NULL){
		// Copy front
		Node* original = list.head;
		head = new Node(original->data);
		tail = head;
		original = original->next;
		Node* temp = head;

		// Copy rest of list
		while(original != NULL){
			temp->next = new Node(original->data);
			original = original->next;
			temp = temp->next;
			tail = temp;
		}
	}
	size = list.size;
}