/*
    * Copyright 2000 - 2010 Ivan Khalopik. All Rights Reserved.
    */
   
   package org.greatage.domain;
   
   import org.greatage.util.DescriptionBuilder;
   
   import java.io.Serializable;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  
  /**
   * @author Ivan Khalopik
   * @since 1.0
   */
  public class EntityQuery<PK extends Serializable, E extends Entity<PK>, Q extends EntityQuery<PK, E, Q>>
  		implements EntityFilter<PK, E> {
  
  	private final Class<E> entityClass;
  	private EntityRepository repository;
  	private String queryString;
  	private List<PK> includeKeys;
  	private List<PK> excludeKeys;
  
  	public EntityQuery(final Class<E> entityClass) {
  		this.entityClass = entityClass;
  	}
  
  	public EntityQuery(final EntityRepository repository, final Class<E> entityClass) {
  		this.repository = repository;
  		this.entityClass = entityClass;
  	}
  
  	/**
  	 * Gets entity class.
  	 *
  	 * @return entity class
  	 */
  	public Class<E> getEntityClass() {
  		return entityClass;
  	}
  
  	/**
  	 * Gets search query string for entity full-text search.
  	 *
  	 * @return search query string for entity full-text search
  	 */
  	public String getQueryString() {
  		return queryString;
  	}
  
  	/**
  	 * Gets collection of entity primary keys that will be included into select result.
  	 *
  	 * @return collection of entity primary keys that will be included into select result
  	 */
  	public Collection<PK> getIncludeKeys() {
  		return includeKeys;
  	}
  
  	/**
  	 * Gets collection of entity primary keys that will be excluded from select result.
  	 *
  	 * @return collection of entity primary keys that will be excluded from select result
  	 */
  	public Collection<PK> getExcludeKeys() {
  		return excludeKeys;
  	}
  
  	/**
  	 * Sets search query string for entity full-text search.
  	 *
  	 * @param queryString search query string for entity full-text search
  	 * @return the same query instance
  	 */
  	public Q setQueryString(final String queryString) {
  		this.queryString = queryString;
  		return query();
  	}
  
  	/**
  	 * Sets collection of entity primary keys that will be included into select result.
  	 *
  	 * @param keys collection of entity primary keys that will be included into select result
  	 * @return the same query instance
  	 */
  	public Q includeKeys(final Collection<PK> keys) {
  		if (includeKeys == null) {
  			includeKeys = new ArrayList<PK>();
  		}
  		includeKeys.addAll(keys);
  		return query();
  	}
  
  	/**
  	 * Sets collection of entity primary keys that will be excluded from select result.
  	 *
 	 * @param keys collection of entity primary keys that will be excluded from select result
 	 * @return the same query instance
 	 */
 	public Q excludeKeys(final Collection<PK> keys) {
 		if (excludeKeys == null) {
 			excludeKeys = new ArrayList<PK>();
 		}
 		excludeKeys.addAll(keys);
 		return query();
 	}
 
 	public Q assign(final EntityRepository repository) {
 		this.repository = repository;
 		return query();
 	}
 
 	/**
 	 * Gets entities count selected by this query instance.
 	 *
 	 * @return entities count selected by this query instance
 	 */
 	public int count() {
 		return repository().count(this);
 	}
 
 	/**
 	 * Gets paginated list of entities selected by this query instance.
 	 *
 	 * @param pagination selection pagination
 	 * @return paginated list of entities selected by this query instance or empty list if not found
 	 */
 	public List<E> list(final Pagination pagination) {
 		return repository().find(this, pagination);
 	}
 
 	/**
 	 * Gets list of entities selected by this query instance.
 	 *
 	 * @return list of entities selected by this query instance or empty list if not found
 	 */
 	public List<E> list() {
 		return repository().find(this, Pagination.ALL);
 	}
 
 	/**
 	 * Gets unique entity selected by this query instance.
 	 *
 	 * @return unique entity selected by this query instance
 	 */
 	public E unique() {
 		return repository().findUnique(this);
 	}
 
 
 	/**
 	 * Gets EntityRepository instance assigned to this query.
 	 *
 	 * @return assigned EntityRepository instance
 	 */
 	protected EntityRepository repository() {
 		if (repository == null) {
 			throw new IllegalStateException("This query is not assigned to repository.");
 		}
 		return repository;
 	}
 
 	/**
 	 * Gets this query instance casted to Q generic parameter.
 	 *
 	 * @return the same query instance
 	 */
 	@SuppressWarnings({"unchecked"})
 	protected Q query() {
 		return (Q) this;
 	}
 
 	@Override
 	public String toString() {
 		final DescriptionBuilder builder = new DescriptionBuilder(getClass());
 		builder.append("class", entityClass);
 		builder.append("queryString", queryString);
 		return builder.toString();
 	}
 }