#include <iostream>
#include <string>
#include "linked.h"


//Constructor
linklist::linklist()
{

     head = NULL;

}

void linklist::AppendNode( string sym )
{
     
     node *temp1,*temp2;
 
     if( head == NULL )     //If the list is empty start a new one
     {
          head = new node;
          head->symbol = sym;
          head->next = NULL;     //set the new node as the tail
     }
     else //If the head exist then...
     {
          temp1 = head; //Copy the node list

          while( temp1->next != NULL ) //move to the end of the list
          {
               temp1 = temp1->next;
          }


          temp2 = new node;     //create a new node
          temp2->symbol = sym;  //add data to the new node
          temp2->next = NULL;   //make the node point to the end
          temp1->next = temp2;  //set temp1->next to point to the new node
     }

}

void linklist::AddAsFirstNode( string sym )
{

     node *temp1;          //declare a new node

     temp1 = new node;     //create a new node

     temp1->symbol = sym;  //fill the node with data
     temp1->next = head;   //set up the pointer head

     head = temp1;         //sets head as the first node in the list

}

bool linklist::InsertNode( string searchSym, string insertSym )
{

     node *temp1, *temp2;          //Declares temp node pointers
     bool returnValue = false;     //defaults to false     
  
     temp1 = head;                 //sets first node equal to head

     while(temp1 != NULL)    //move until you get to the end of the head
     {
          
    
          if(temp1->symbol == searchSym)
          {
               
               temp2 = new node;              //declares a new node
               temp2->symbol = insertSym;     //files the new node with data
               temp2->next = temp1->next;     //sets temp2 to point to the next node
               temp1->next = temp2;           //points temp1 to the new node
              
               returnValue = true;            //sets the return value to true
          }   
   
          temp1 = temp1->next;     //advance to the next node

     }


     return(returnValue);

}


bool linklist::DeleteNode( string sym )
{

     bool returnValue = false;     //defaults to false
     node *temp1, *temp2;          //declares two node pointers
     
     temp1 = head;                 //sets temp1 to equal head
     
     while(temp1 != NULL)          //checks until the end of the list
     {

          temp2 = temp1;           //sets temp2 equal to the temp1, basically the node before temp1 since 
				   // that is moved "up" the list in the next step
          temp1 = temp1->next;      //moves temp1 "up" the list

          if(head->symbol == sym)     //checks to see if head is the node to delete
          {
               head = temp2->next;    //sets head as the second node
               returnValue = true;       //changes the return value to be true
               temp1 = NULL;          //sets temp1 to NULL to escape the while loop
          }
          else if(temp1->symbol == sym)          //Checks if temp1 is to be deleted
          {
               
               temp2->next = temp1->next;   //points the previous pointer to the next one
                                            //basically "deleting" node temp1
               returnValue = true;          //changes the return value to be true
               temp1 = NULL;                //sets temp1 equal to NULL to escape while loop
          }
     

     }


     return(returnValue);     //returns True of False

}

void linklist::DisplayNodes()
{
     node *temp1;     //Declares a temp node
     
     int i = 0;       //sets the counter to 0 incase the head is empty

     temp1 = head;    //temp1 will equal head    

     while(temp1 != NULL) //continue loop until empty
     {
          i++;   //since the head is not empty add 1 to the counter and display the info

          cout << "Element " << i << " is ";
          cout << temp1->symbol << endl;

          temp1 = temp1->next; //move to next node
     }
   

}


int linklist::CountNodes()
{
     int tempCount = 0;     //if the head is empty the count is zero

     node *temp1;           //declares a temp node

    
     // sets temp1 equal to head, checks until temp1 is NULL,
     // "increments" temp1 by making it equal to the next node
     // on the list until it is NULL.  With each iteration 
     // increase the count.
     for(temp1 = head; temp1 != NULL; temp1 = temp1->next)
     {
          tempCount++;
     }

     return(tempCount);     //returns the number of nodes
}

string linklist::ReturnValue(int num)
{

     node *temp1;	//declares a node pointer
     string tempS;	//holds the contents of the numth element

     temp1 = head;	//sets temp1 to the start of the list

     if(num <= CountNodes() && num > 0) //checks bounds
     {
          for(int i = 1; i < num; i++) // move up the list until the numth 
          {                            // element is found
               temp1 = temp1->next;
          }
          tempS = temp1->symbol;       //set tempS

     }
     else
     {
          tempS="INVALID";
     }

  

     return(tempS);

}     


linklist::~linklist()
{

     node *temp1;     //declares a temp node

     
     while(head != NULL)  //until head is null do the following
     {

          temp1 = head->next; //set temp1 equal to the next node
          delete head;        //delete the first node (making temp1 the new first node)
          head = temp1;       //make head the first node again.
     }

     delete temp1;
}

linklist::~linklist()
{

     node *temp1;     //declares a temp node 

     
     while(head != NULL)  //until head is null do the following
     {

          temp1 = head->next; //set temp1 equal to the next node
          delete head;        //delete the first node (making temp1 the new first node)
          head = temp1;       //make head the first node again.
     }

     delete temp1;
}