#include "listNode.h"
#include "listIterator.h"
#include "list.h"


using namespace std;


// Constructor for Class List
List::List()
{last = first = 0;
 cout << "allocated List " << this << endl;
}

// Copy Constructor for Class List
List::List(const List & fr)
{cout << "Copy Constructructor from List " << &fr << " to List " << this << endl;
   ListNode *ptr, *tptr;
   this->first = this->last = 0;
   ptr = fr.first;
   while(ptr)
     {
       tptr = new ListNode(ptr->GetData());
       if (this->first == 0) {this->first=this->last=tptr;}
                   else  {this->last->SetNext(tptr);
                          this->last = tptr;
                         }
       ptr=ptr->GetNext();
     }
   return;
}


List::~List() {
   cout << "deallocated List " << this << endl;
   this->Erase();
   last = first = 0;
}

void List::operator=(const List & fr){
   cout << "Assignment Operator from List " << &fr << " to List " << this << endl;
   if (this == &fr) return;
   this->Erase();  // Memory leak eliminated.
   this->Concatenate(fr); // Will not work for s = t = m;
   return;
}

List List::operator+(const List & fr){
   cout << "Addition Operator for List " << &fr << " to List " << this << endl;
   List t;
   t.Concatenate(*this);
   t.Concatenate(fr);
   return t;
}


ostream & operator<<(ostream & os, const List & fr)
{
    ListIterator li (fr);
    while( ! li.Done() )
     { os << li.CurrentData() << " Listode " << li.CurrentPtr() << endl;
       li.Advance();
     }
    return os;
}

istream & operator>>(istream & is, List & fr)
{ int contents;
  cout << "Input a List. one element per line and ending with a line with just a zero" <<
endl;
  is >> contents;
  while (contents)
   {fr.InsertSorted(contents);
    is >> contents;
   }
  return is;
}



void List::InsertAfterNode(ListNode *p, int x) // Insert a ListNode after
                                           // certain ListNode in a List
{
    ListNode *t = new ListNode(x); // create and initialize new node
    // insert after p
    t->SetNext( p->GetNext() );
    p->SetNext( t );
    if (last == p) last=t;
}

void List::InsertFront(int x) // Insert a ListNode at the
                              // beginning of a List
{
    ListNode *t = new ListNode(x); // create and initialize new node
    t->SetNext( first );
    if (last == 0) last = t;
    first = t;
}

void List::InsertAtEnd(int x) // Insert a ListNode at the
                              // end of a List
{
    ListNode *t = new ListNode(x); // create and initialize new node
    if (last == 0) first = t;
              else last->SetNext( t );
    last = t;
}

ListNode* List::GetFirst() const
{ return first;}



void List::InsertSorted(int x) { // Insert a ListNode with data value x
    ListNode *p = first;
    if (p == 0) {InsertFront(x); return;}
    if (x == p->GetData()) return;
    if (x < p->GetData()) {InsertFront(x); return;}
    while (p->GetNext())
       {
         if (p->GetNext()->GetData() == x) return;
         if (p->GetNext()->GetData() > x)
              {InsertAfterNode(p,x); return;}
         p = p->GetNext();
       }
    InsertAfterNode(p,x);

}

void List::Concatenate(const List & fr)
{
   ListIterator li (fr);
   while(! li.Done())
     { this->InsertAtEnd(li.CurrentData());
       li.Advance();
     }
   return;
}


void List::Erase() {
   ListNode *ptr, *tempptr;
   ptr = first;
   while(ptr)
     {
       tempptr=ptr->GetNext();
       delete(ptr);
       ptr=tempptr;
     }
   last = first = 0;
}