package health;
import java.util.Enumeration;
//import checkers.inference.ownership.quals.*;

/**
 * A class represnting a village in the Columbian health care system
 * simulation.
 **/
public class Village
{
  private Village[] forward;
  private Village   back;
  private List      returned;
  private Hospital  hospital;
  private int       label;
  private int       seed;

  private final static int    IA   = 16807;
  private final static float   IM   = 2147483647;
  private final static float  AM   = ((float)1.0/IM);
  private final static int    IQ   = 127773;
  private final static int    IR   = 2836;
  private final static int   MASK = 123459876;

  /**
   * Construct an empty village.
   * @param level the 
   * @param lab the unique label for the village
   * @param p a reference to the "parent" village
   * @param s the user supplied seed value
   **/
  public Village(int level, int l, Village p, int s)
  {
    back = p;
    label = l;
    forward = new Village[4];
    seed = label * (IQ + s);
    hospital = new Hospital(level);
    returned = new List();
  }

  /**
   * Add a connection from this village to the specifed village.
   * Each village contains connections to four other ones.
   *
   * @param i the village number
   * @param c the village to add
   **/
  public void addVillage(int i, Village c)
  {
    forward[i] = c;
  }

  /**
   * Return true if a patient should stay in this village or
   * move up to the "parent" village.
   * @return true if a patient says in this village
   **/
  public final boolean staysHere()
  {
    float rand = myRand(seed);
    seed = (int)(rand * IM);
    return (rand > 0.1 || back == null);
  }

  /**
   * Create a set of villages.  Villages are represented as a quad tree.
   * Each village contains references to four other villages.  Users
   * specify the number of levels.
   *
   * @param level the number of level of villages.
   * @param label a unique label for the village
   * @param back a link to the "parent" village
   * @param seed the user supplied seed value.
   * @return the village that was created
   **/
  public static final Village createVillage(int level, int label, Village back, int seed)
  {
    if (level == 0) {
      return null;
    } else {
      Village village = new Village(level, label, back, seed);
      for (int i = 3; i >= 0; i--) {
	Village child = createVillage(level - 1, (label * 4) + i + 1, village, seed);
	village.addVillage(i, child);
      }
      return village;
    }
  }

  /**
   * Simulate the Columbian health care system for a village.
   * @return a list of patients refered to the next village
   **/
  public List simulate()
  {
    // the list of patients refered from each child village
    List val[] = new List[4];

    for (int i = 3; i >= 0; i--) {
      Village v = forward[i];
      if (v != null) {
	val[i] = v.simulate();
      }
    }
    
    for (int i = 3; i >= 0; i--) {
      List l = val[i];
      if (l != null) {
	for (Enumeration e = l.elements(); e.hasMoreElements(); ) {
	  Patient p = (Patient)e.nextElement();
	  hospital.putInHospital(p);
	  // remove the patient?
	}
      }
    }
    
    hospital.checkPatientsInside(returned);
    List up = hospital.checkPatientsAssess(this);
    hospital.checkPatientsWaiting();

    // generate new patients
    Patient p = generatePatient();
    if (p != null) {
      hospital.putInHospital(p);
    }

    return up;
  }

  /**
   * Summarize results of the simulation for the Village
   * @return a summary of the simulation results for the village
   **/
  public Results getResults()
  {
    Results fval[] = new Results  /*@RepOwn*/  [4];
    for (int i = 3; i >=0 ; i--) {
      Village v = forward[i];
      if (v != null) {
	fval[i] = v.getResults();
      }
    }

    Results r = new Results();
    for (int i = 3; i >= 0; i--) {
      if (fval[i] != null) {
	r.totalHospitals += fval[i].totalHospitals;
	r.totalPatients += fval[i].totalPatients;
	r.totalTime += fval[i].totalTime;
      }
    }

    for (Enumeration e = returned.elements(); e.hasMoreElements(); ) {
      Patient p = (Patient)e.nextElement();
      r.totalHospitals += (float)p.hospitalsVisited;
      r.totalTime += (float)p.time;
      r.totalPatients += 1.0;
    }

    return r;
  }

  /**
   * Try to generate more patients for the village.
   * @return a new patient or null if a new patient isn't created
   **/
  private Patient generatePatient()
  {
    float rand = myRand(seed);
    seed = (int)(rand * IM);
    Patient p = null;
    if (rand > 0.666) {
      p = new Patient(this);
    }
    return p;
  }

  public String toString()
  {
    return (new Integer(label)).toString();
  }
    
  /**
   * Random number generator.
   **/
  public static float myRand(int idum) 
  {
    idum ^= MASK;
    int k = idum / IQ;
    idum = IA * (idum - k * IQ) - IR * k;
    idum ^= MASK;
    if (idum < 0) 
      idum += IM;
    float answer = AM * idum;
    return answer;
  }

}
