/*
   linkedList.cpp
   CIS 250
   3/15/10
   David Klick

   Linked list specification
*/

#include "linkedList.h"
#include <iostream>
#include <string>
#include <assert.h>
using std::cout;
using std::endl;
using std::string;

linkedList::linkedList() {
   count = 0;
   head = NULL;
}

linkedList::~linkedList() {
   while (head != NULL) {
      node* hold = head->next;
      delete head;
      head = hold;
      count--;
   }
}

int linkedList::length() const {
   return count;
}

void linkedList::print() const {
   node* pos = head;
   while (pos != NULL) {
      cout << pos->data << " ";
      pos = pos->next;
   }
   cout << endl;
}

bool linkedList::search(int val) const {
   bool found = false;
   node* pos = head;
   while (pos != NULL) {
      if (pos->data == val) {
         found = true;
         break;
      }
      pos = pos->next;
   }
   return found;
}

int linkedList::front() const {
   if (head == NULL) throw string("Error: Accessing empty list");
   return head->data;
}

int linkedList::back() const {
   if (head == NULL) throw string("Error: Accessing empty list");
   node* pos = head;
   while (pos->next != NULL) pos = pos->next;
   return pos->data;
}

bool linkedList::isEmpty() const {
   return head == NULL;
}

void linkedList::addFirst(int val) {
   node* elephant = new node;
   assert (elephant != NULL);
   elephant->data = val;
   elephant->next = head;
   head = elephant;
   count++;
}

void linkedList::addLast(int val) {
   node* elephant = new node;
   assert (elephant != NULL);
   elephant->data = val;
   elephant->next = NULL;
   if (head == NULL) {
      head = elephant;
   } else {
      node* pos = head;
      while (pos->next != NULL) pos = pos->next;
      pos->next = elephant;
   }
   count++;
}

void linkedList::add(int val) {
   addLast(val);
}

bool linkedList::remove(int val) {
   if (head == NULL) return false;
   if (head->data == val) {
      node *temp = head;
      head = head->next;
      delete temp;
      count--;
      return true;
   }
   node* prev = head;
   node* curr = prev->next;
   while (curr != NULL) {
      if (curr->data == val) {
         prev->next = curr->next;
         delete curr;
         count--;
         return true;
      } else {
         prev = curr;
         curr = curr->next;
      }
   }
   return false;
}

ostream& operator<<(ostream& out, const linkedList &lst) {
   linkedList::node* current = lst.head;
   while (current != NULL) {
      out << current->data << " ";
      current = current->next;
   }
   return out;
}