// File: PersonSet.cpp
// Author: Karl Abrahamson

#include <iostream>
#include "Person.h"
#include "PersonSet.h"
using namespace std;

PersonSet::PersonSet()
{
  who  = NULL;
  next = NULL;
}

PersonSet::PersonSet(const Person* p, const PersonSet* s)
{
  who  = p;
  next = s;
}

bool PersonSet::isEmpty() const
{
  return who == NULL;
}

const Person* PersonSet::getFirst() const
{
  return who;
}

const PersonSet* PersonSet::getRest() const
{
  return next;
}

const PersonSet* PersonSet::insert(const Person* p) const
{
  if(isEmpty()) return new PersonSet(p, this);
  else {
    int c = p->compare(getFirst());
    if(c == 0) return this;
    else if(c < 0) {
      return new PersonSet(p, this);
    }
    else {
      return new PersonSet(getFirst(), getRest()->insert(p));
    }
  }
}

const PersonSet* PersonSet::remove(const Person* p) const
{
  if(isEmpty()) return this;
  else if(p->equal(getFirst())) return getRest();
  else {
    const PersonSet* a = getRest()->remove(p);
    return a->insert(getFirst());
  }
}

int PersonSet::cardinality() const
{
  if(isEmpty()) return 0;
  else return 1 + getRest()->cardinality();
}

long PersonSet::hash() const
{
  if(isEmpty()) return 0;
  else {
    long h1 = strhash(getFirst()->getName());
    long h2 = getRest()->hash();
    return labs(h1/3 + h2/2);
  }
}

bool PersonSet::equal(const PersonSet* s) const
{
  if(isEmpty() != s->isEmpty()) return false;
  if(isEmpty()) return true;
  if(!getFirst()->equal(s->getFirst())) return false;
  return getRest()->equal(s->getRest());
}

void PersonSet::print() const
{
  cout << "{";
  printMems();
  cout << "}";
}

void PersonSet::printMems() const
{
  if(!isEmpty()) {
    who->print();
    if(!next->isEmpty()) {
      cout << ", ";
      next->printMems();
    }
  }
}