package class8_1_Command_pbook_start;//package pbook;
//
// Build:
//      javac -cp support/junit-4.10.jar *.java
// Run:
//      java -cp '.:support/*' org.junit.runner.JUnitCore TestDomain TestPolicy
// On windows:
//      javac -cp ".;c:/apps/java/*" *.java
//      java -cp ".;c:/apps/java/*" org.junit.runner.JUnitCore TestDomain TestPolicy
// Note it is NOT best practices to distribute a library along with
// source files; we are doing it in this case because of the large
// variation in student machine setups. At a professional organization, 
// this would be handled through standards.
//

import java.util.*;

// phonebook; iterator guaranteed to process items in alphabetical order
public class PhoneBook implements Iterable<Entry> {
  protected Map<String, Entry> book = new TreeMap<String, Entry>();

  // add entry to phone book; precondition: item not present already
  public void add(Entry e) {
    book.put(e.name(), e);
  }

  // remove entry from phone book; does nothing if name is not in book
  public void remove(String name) {
    book.remove(name);
  }

  // return entry for given name; precondition: name is in book
  public Entry lookup(String name) {
    return book.get(name);
  }

  // return true iff phonebook is empty
  public boolean isEmpty() {
    return book.isEmpty();
  }

  // return iterator over values in map
  public Iterator<Entry> iterator() {
    return book.values().iterator();
  }

  public String toString() {
    StringBuffer result = new StringBuffer();
    for (Entry e : this) {
      result.append(e.toString());
      result.append("\n");
    }
    return result.toString();
  }
}