/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.wicket.examples.repeater;

import java.util.Calendar;
import java.util.Collection;
import java.util.Date;
import java.util.GregorianCalendar;

/**
 * generates random contacts
 * 
 * @author igor
 * 
 */
public class ContactGenerator
{
	private static ContactGenerator instance = new ContactGenerator();
	private static long nextId = 1;

	/**
	 * @return static instance of generator
	 */
	public static ContactGenerator getInstance()
	{
		return instance;
	}

	private final String[] firstNames = { "Jacob", "Emily", "Michael", "Sarah", "Matthew",
			"Brianna", "Nicholas", "Samantha", "Christopher", "Hailey", "Abner", "Abby", "Joshua",
			"Douglas", "Jack", "Keith", "Gerald", "Samuel", "Willie", "Larry", "Jose", "Timothy",
			"Sandra", "Kathleen", "Pamela", "Virginia", "Debra", "Maria", "Linda" };
	private final String[] lastNames = { "Smiith", "Johnson", "Williams", "Jones", "Brown",
			"Donahue", "Bailey", "Rose", "Allen", "Black", "Davis", "Clark", "Hall", "Lee",
			"Baker", "Gonzalez", "Nelson", "Moore", "Wilson", "Graham", "Fisher", "Cruz", "Ortiz",
			"Gomez", "Murray" };

	private ContactGenerator()
	{

	}

	/**
	 * @return unique id
	 */
	public synchronized long generateId()
	{
		return nextId++;
	}

	/**
	 * generates a new contact
	 * 
	 * @return generated contact
	 */
	public Contact generate()
	{
		Contact contact = new Contact(randomString(firstNames), randomString(lastNames));
		contact.setId(generateId());
		contact.setHomePhone(generatePhoneNumber());
		contact.setCellPhone(generatePhoneNumber());
		contact.setBornDate(generateDate());
		
		return contact;
	}

	/**
	 * Generates <code>count</code> number contacts and puts them into <code>collection</code>
	 * collection
	 * 
	 * @param collection
	 * @param count
	 */
	public void generate(Collection<Contact> collection, int count)
	{
		for (int i = 0; i < count; i++)
		{
			collection.add(generate());
		}
	}

	private String generatePhoneNumber()
	{
		return new StringBuilder().append(rint(2, 9))
			.append(rint(0, 9))
			.append(rint(0, 9))
			.append("-555-")
			.append(rint(1, 9))
			.append(rint(0, 9))
			.append(rint(0, 9))
			.append(rint(0, 9))
			.toString();
	}

	private int rint(int min, int max)
	{
		return (int)(Math.random() * (max - min) + min);
	}

	private String randomString(String[] choices)
	{
		return choices[rint(0, choices.length)];
	}

	private Date generateDate()
	{
	    	GregorianCalendar gc = new GregorianCalendar();

	        int year = rint(1950, 1985);

	        gc.set(Calendar.YEAR, year);

	        int dayOfYear = rint(1, gc.getActualMaximum(Calendar.DAY_OF_YEAR));

	        gc.set(Calendar.DAY_OF_YEAR, dayOfYear);
	        
	        return gc.getTime();
	}
	
	
}
