package Roommates;

import java.io.*;
/**
 * The class PersonArray contains methods for handling the set of all persons.
 * The set is stored in an array from index one onwards, with the Person with
 * id i stored in array element i.
 */
public class PersonArray implements Cloneable
{
  /** Size of array */
  private int size;
  /** Iterator for array */
  private int index;
  /** Array of Person objects */
  private Person persons[];
  /** Integer giving id of person with list length >1, or 0 if no such person */
  public int NonSingleList;
  
  /*--------------------------------------------------------------------*/

  /**
   * Initialises array of Person objects of size i.
   * @param i the size of the set of persons
   */
  public PersonArray(int i)
  {
    size = i;
    persons = new Person[size+1];
    index = 1;
    NonSingleList = size;
  }

  /*--------------------------------------------------------------------*/

  /**
   * Clone method for PersonArray.
   */
  public Object clone ()
  {
    // Create a new PersonArray object
    PersonArray pObj = new PersonArray(size);
    // Copy data over from all relevant fields
    // pObj.size already initialised by constructor
    pObj.index = index;
    pObj.NonSingleList = NonSingleList;
    for (int i = 1; i <= size; i++)
      // persons has been initialised within indices 1..size
      {
        Person personentry = (Person) persons[i].clone();
	pObj.persons[i] = personentry;
      }
    return pObj;
  }

  /*--------------------------------------------------------------------*/

  /**
   * Adds a Person to the array.
   * @param m a Person object
   */
  public void add(Person p)
  {
    persons[index++] = p;
  }

  /*--------------------------------------------------------------------*/

  /**
   * Returns the Person with id i.
   * @param i a Person's id
   * @return the Person object at position i in the array
   */
  public Person getPerson(int i)
  {
    return persons[i];
  }

  /*--------------------------------------------------------------------*/

  /**
   * Returns the size of the array.
   * @return size of the array
   */
  public int getSize()
  {
    return size;
  }

  /*--------------------------------------------------------------------*/

  /**
   * Prints out all preference lists in the array.
   * @param annotateMatching a boolean indicating whether we should super-
   *        impose a stable matching onto the preference lists
   * @param fo a FormatOutput object
   */
  public void print(boolean annotateMatching, BufferedWriter fo) 
                    throws IOException
  {
    // fo.print("Number of people: ");
    // fo.println(size); 
    for (int i = 1; i<=size; i++)
      {
	persons[i].printPrefs(annotateMatching,size,fo);
	fo.newLine();
      }
  }

  /*--------------------------------------------------------------------*/

  /**
   * Prints out final matching without repeating ordered pairs of the
   * form (a,b) (b,a) -- outputs {a,b} instead
   * @param fo a FormatOutput object
   */
  public void printMatching(BufferedWriter fo) throws IOException
  {
    boolean done [] = new boolean [size+1];
    for (int i=1; i<=size; i++)
      done [i] = false;
    for (int i=1; i<=size; i++)
      if (!done[i])
	{
          Person p = persons[i];
          int j = p.getFirstPerson();
          done[j] = true;
          p.printAssignedTo(fo);
          fo.write("  ");
	}
    fo.newLine();
  }

  /*--------------------------------------------------------------------*/
	
  /**
   * Resets array to first Person.
   */
  public void reset()
  {
    index=1;
  }
  
  /*--------------------------------------------------------------------*/
  
  /**
   * Returns the Person object pointed to by index and moves to the next one.
   * @return a Person object
   */
  public Person next()
  {
    if (index > size)
      return null;
    else
      return persons[index++];
  }

  /*--------------------------------------------------------------------*/
  
  /**
   * Returns id of a person with list length > 1, or 0 if no such person exists.
   * @return an integer object
   */

  public int Find()
  {
    Person p;
    boolean NonSingleListFound = false;
    while ((NonSingleList >=1) && (!NonSingleListFound))
      {
        p = getPerson(NonSingleList);
        if (p.getFirstPerson() != p.getLastPerson())
          NonSingleListFound = true;
        else
          NonSingleList--;
      }
    return NonSingleList;
  }
}