package com.randomcoder.bean;

import java.io.Serializable;
import java.util.*;

import javax.persistence.*;

import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.builder.*;

/**
 * JavaBean representing an article tag or category.
 * 
 * <pre>
 * Copyright (c) 2006, Craig Condit. All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 *   * Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright notice,
 *     this list of conditions and the following disclaimer in the documentation
 *     and/or other materials provided with the distribution.
 *     
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 * </pre>
 */
@NamedQueries
({
	@NamedQuery(name = "Tag.All", query = "from Tag t order by t.displayName"),
	@NamedQuery(name = "Tag.CountAll", query = "select count(t.id) from Tag t"),	
	@NamedQuery(name = "Tag.ByName", query = "from Tag t where t.name = ?"),
	@NamedQuery(name = "Tag.AllTagStatistics", query = "select t, t.articles.size from Tag t order by t.displayName"),
	@NamedQuery(name = "Tag.MostArticles", query = "select max(t.articles.size) from Tag t")
})
@Entity
@Table(name = "tags")
@SequenceGenerator(name = "tags", sequenceName = "tags_seq", allocationSize = 1)
public class Tag implements Serializable, Comparable<Tag>
{
	private static final long serialVersionUID = 3814891608527889241L;

	/**
	 * Tag Comparator (by name).
	 */
	public static final Comparator<Tag> NAME_COMPARATOR = new Comparator<Tag>()
	{
		public int compare(Tag t1, Tag t2)
		{
			String s1 = StringUtils.trimToEmpty(t1.getName());
			String s2 = StringUtils.trimToEmpty(t2.getName());
			return s1.compareTo(s2);
		}
	}; 
	
	/**
	 * Tag Comparator (by display name).
	 */
	public static final Comparator<Tag> DISPLAY_NAME_COMPARATOR = new Comparator<Tag>()
	{
		public int compare(Tag t1, Tag t2)
		{
			String s1 = StringUtils.trimToEmpty(t1.getDisplayName());
			String s2 = StringUtils.trimToEmpty(t2.getDisplayName());
			return s1.compareTo(s2);
		}
	};  
	
	private Long id;
	private String name;
	private String displayName;

	private transient List<Article> articles;
	
	/**
	 * Gets the id for this tag.
	 * @return tag id
	 */
	@Id
	@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "tags")
	@Column(name = "tag_id")
	public Long getId()
	{
		return id;
	}

	/**
	 * Sets the id for this tag.
	 * @param id tag id
	 */
	public void setId(Long id)
	{
		this.id = id;
	}

	/**
	 * Gets the name of this tag.
	 * @return tag name
	 */
	@Column(name = "name", unique = true, nullable = false, length = 255)
	public String getName()
	{
		return name;
	}

	/**
	 * Sets the name of this tag.
	 * @param name
	 */
	public void setName(String name)
	{
		this.name = name;
	}

	/**
	 * Gets the display name of this tag.
	 * @return display name
	 */
	@Column(name = "display_name", nullable = false, length = 255)
	public String getDisplayName()
	{
		return displayName;
	}

	/**
	 * Sets the display name of this tag.
	 * @param displayName display name
	 */
	public void setDisplayName(String displayName)
	{
		this.displayName = displayName;
	}

	/**
	 * Gets the articles which belong to this tag.
	 * @return article list
	 */
	@ManyToMany(cascade = { CascadeType.PERSIST, CascadeType.MERGE }, mappedBy="tags")	
	@OrderBy("creationDate DESC")
	public List<Article> getArticles()
	{
		return articles;
	}
	
	/**
	 * Sets the articles which belong to this tag.
	 * @param articles article list
	 */
	public void setArticles(List<Article> articles)
	{
		this.articles = articles;
	}
	
	/**
	 * Determines if two Tag objects are equal.
	 * @return true if equal, false if not
	 */
	@Override
	public boolean equals(Object obj)
	{
		if (!(obj instanceof Tag)) return false;
		
		Tag tag = (Tag) obj;
			
		// two tags are equal if and only if their names match
		String name1 = StringUtils.trimToEmpty(getName());
		String name2 = StringUtils.trimToEmpty(tag.getName());
		
		return name1.equals(name2);
	}

	/**
	 * Gets the hash code of this tag.
	 * @return hash code
	 */
	@Override
	public int hashCode()
	{
		return StringUtils.trimToEmpty(getName()).hashCode();
	}

	/**
	 * Compares this Tag to another Tag by name.
	 * @return 0 if equal, -1 if this is before, 1 if this is after
	 */
	public int compareTo(Tag o)
	{
		return NAME_COMPARATOR.compare(this, o);
	}

	/**
	 * Gets a string representation of this object, suitable for debugging.
	 * @return string representation of this object
	 */
	@Override
	public String toString()
	{
		return ReflectionToStringBuilder.toString(this, ToStringStyle.SHORT_PREFIX_STYLE);
	}
}