package vtk;

import java.util.HashMap;
import java.util.Map.Entry;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * Information object return by the Garbage collector. This allow the user to
 * monitor what kind of vtkObject and how many have been removed and kept during
 * the Garbage collection call.
 *
 * @author sebastien jourdain - sebastien.jourdain@kitware.com
 */
public class vtkReferenceInformation {
 private int numberOfObjectsToFree;
 private int numberOfObjectsStillReferenced;
 private HashMap<String, AtomicInteger> classesKept;
 private HashMap<String, AtomicInteger> classesRemoved;
 private boolean keepTrackOfClassNames;

 public vtkReferenceInformation(int nbToFree, int nbToKeep, int totalSize) {
 this.numberOfObjectsToFree = nbToFree;
 this.numberOfObjectsStillReferenced = nbToKeep;
 this.keepTrackOfClassNames = false;
 }

 public vtkReferenceInformation(boolean keepTrackOfClassNames) {
 this.numberOfObjectsToFree = 0;
 this.numberOfObjectsStillReferenced = 0;
 this.keepTrackOfClassNames = keepTrackOfClassNames;
 }

 public int getTotalNumberOfObjects() {
 return numberOfObjectsStillReferenced + numberOfObjectsToFree;
 }

 public int getNumberOfObjectsToFree() {
 return numberOfObjectsToFree;
 }

 public int getTotalNumberOfObjectsStillReferenced() {
 return numberOfObjectsStillReferenced;
 }

 public void setNumberOfObjectsStillReferenced(int numberOfObjectsStillReferenced) {
 this.numberOfObjectsStillReferenced = numberOfObjectsStillReferenced;
 }

 public void setNumberOfObjectsToFree(int numberOfObjectsToFree) {
 this.numberOfObjectsToFree = numberOfObjectsToFree;
 }

 public void addFreeObject(String className) {
 this.numberOfObjectsToFree++;
 if (keepTrackOfClassNames) {
 if (classesRemoved == null && className != null) {
 classesRemoved = new HashMap<String, AtomicInteger>();
 }
 AtomicInteger counter = classesRemoved.get(className);
 if (counter == null) {
 classesRemoved.put(className, new AtomicInteger(1));
 } else {
 counter.incrementAndGet();
 }
 }
 }

 public void addKeptObject(String className) {
 this.numberOfObjectsStillReferenced++;
 if (keepTrackOfClassNames && className != null) {
 if (classesKept == null) {
 classesKept = new HashMap<String, AtomicInteger>();
 }
 AtomicInteger counter = classesKept.get(className);
 if (counter == null) {
 classesKept.put(className, new AtomicInteger(1));
 } else {
 counter.incrementAndGet();
 }
 }
 }

 public String listKeptReferenceToString() {
 if (classesKept == null) {
 return "";
 }
 final StringBuilder builder = new StringBuilder(500);
 builder.append("List of classes kept in Java layer:\n");
 for (Entry<String, AtomicInteger> entry : classesKept.entrySet()) {
 builder.append(" - ").append(entry.getKey()).append(": ").append(entry.getValue().toString()).append("\n");
 }
 return builder.toString();
 }

 public String listRemovedReferenceToString() {
 if (classesRemoved == null) {
 return "";
 }
 final StringBuilder builder = new StringBuilder(500);
 builder.append("List of classes removed in Java layer:\n");
 for (Entry<String, AtomicInteger> entry : classesRemoved.entrySet()) {
 builder.append(" - ").append(entry.getKey()).append(": ").append(entry.getValue().toString()).append("\n");
 }
 return builder.toString();
 }

 public String toString() {
 final StringBuilder builder = new StringBuilder(50);
 builder.append("VTK Gabage Collection: free(");
 builder.append(this.numberOfObjectsToFree);
 builder.append(") - keep(");
 builder.append(this.numberOfObjectsStillReferenced);
 builder.append(") - total(");
 builder.append(this.getTotalNumberOfObjects());
 builder.append(")");
 return builder.toString();
 }
}