/*
 * Copyright 2005 the original author or authors.
 * 
 * Licensed 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.wamblee.photos.model;

import java.io.IOException;
import java.io.InputStream;


/**
 * Represents a collection of photo albums for one speci 
 */
public interface Album extends PhotoEntry {

	/**
	 * Returns a photo entry with the given path.
	 * A path consists of a number of ids of photo entries 
	 * separated by a forward slash. The path should wtart with
	 * a forward slash. The path is relative to the current 
	 * album. 
	 * @param aPath Photo entry path. 
	 * @return PhotoEntry if found or null otherwise.  
	 */
	PhotoEntry getEntry(String aPath);
	
	/**
	 * Returns a photo entry with the given path.
	 * A path consists of a number of ids of photo entries 
	 * separated by a forward slash. The path should wtart with
	 * a forward slash. The path is relative to the current 
	 * album. 
	 * @param aPath Photo entry path. 
	 * @return PhotoEntry if found or null otherwise.  
	 */
	PhotoEntry getEntry(Path aPath);
	
	
	/**
	 * Returns the photo entry with the given index. 
	 * 0 <= index < size()
	 * @param aIndex Index of the photo. 
	 * @return Photo at given index. 
	 */
	PhotoEntry getEntry(int aIndex); 
	
	/**
	 * Returns the number of entries in the album. 
	 * @return Number of entries. 
	 */
	int size(); 
	
	/**
	 * Adds an image to the album with the given id. 
	 * @param aId Id of the image (excluding file extension). 
	 * @param aImage Image.
	 * @throws IOException In case the image cannot be added.  
	 */
	void addImage(String aId, InputStream aImage) throws IOException;
	
	/**
	 * Adds a new album if this is allowed and no album with the
	 * given 
	 * @param aId Album id. 
	 * @throws IOException In case the album cannot be added. 
	 */
	void addAlbum(String aId) throws IOException;
	
	/**
	 * Removes the given entry if it can be removed. 
	 * @param aId Entry id. 
	 * @throws IOException In case the entry cannot be removed. 
	 */
	void removeEntry(String aId) throws IOException;
	
	/**
	 * Gets the first photo before the entry with the given id.  
	 * @param aId Id of the given entry.   
	 * @return Photo or null if no such photo exists. 
	 */
	Photo findPhotoBefore(String aId); 
	
	/**
	 * Gets the first photo after a given entry. 
	 * @param aId Id of the given entry.  
	 * @return Photo or null if no such photo exists. 
	 */
	Photo findPhotoAfter(String aId);
}