package ca.pfv.spmf.algorithms.frequentpatterns.uapriori;
/* This file is copyright (c) 2008-2013 Philippe Fournier-Viger
* 
* This file is part of the SPMF DATA MINING SOFTWARE
* (http://www.philippe-fournier-viger.com/spmf).
* 
* SPMF is free software: you can redistribute it and/or modify it under the
* terms of the GNU General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later
* version.
* 
* SPMF is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
* A PARTICULAR PURPOSE. See the GNU General Public License for more details.
* You should have received a copy of the GNU General Public License along with
* SPMF. If not, see <http://www.gnu.org/licenses/>.
*/

import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.List;

/**
 * This class represents an itemset (a set of items)
 * as used by the UApriori algorithm uncertain itemset mining.
 *
 * @see AlgoUApriori
 * @see ItemUApriori
 * @author Philippe Fournier-Viger
 */
public class ItemsetUApriori{
	// an itemset is an ordered list of items
	private List<ItemUApriori> items = new ArrayList<ItemUApriori>(); 
	// the expected support
	private double expectedsupport = 0;
	
	/**
	 * Default constructor
	 */
	public ItemsetUApriori(){
		
	}

	/**
	 * Get the expected support of this itemset.
	 * @return expected support value.
	 */
	public double getExpectedSupport() {
		return expectedsupport;
	}
	
	/**
	 * Get the expected support as a five decimals string
	 * @return a string
	 */
	public String getSupportAsString() {
		DecimalFormat format = new DecimalFormat();
		format.setMinimumFractionDigits(0); 
		format.setMaximumFractionDigits(5); 
		return format.format(expectedsupport);
	}
	
	/**
	 * Increase the expected support of this itemset by a given amount.
	 * @param supp the amount of support.
	 */
	void increaseSupportBy(double supp) { 
		expectedsupport += supp;
	}
	
	
	/**
	 * Add an item to that itemset
	 * @param value the item to be added
	 */
	void addItem(ItemUApriori value){
			items.add(value);
	}
	
	/**
	 * Get items from that itemset.
	 * @return a list of integers (items).
	 */
	public List<ItemUApriori> getItems(){
		return items;
	}
	
	/**
	 * Get the item at at a given position in that itemset
	 * @param index the position
	 * @return the item (Integer)
	 */
	public ItemUApriori get(int index){
		return items.get(index);
	}
	
	/**
	 * print this itemset to System.out.
	 */
	public void print(){
		System.out.print(toString());
	}
	
	/**
	 * Print the items in this itemset to System.out.
	 */
	public void printWithoutSupport(){
		StringBuffer r = new StringBuffer ();
		for(ItemUApriori attribute : items){
			r.append(attribute.getId());
			r.append(' ');
		}
		System.out.print(r);
	}
	
	/**
	 * Get a string representation of the items in this itemset.
	 */
	public String toString(){
		StringBuffer r = new StringBuffer ();
		for(ItemUApriori attribute : items){
			r.append(attribute.toString());
			r.append(' ');
		}
		return r.toString();
	}

	/**
	 * Check if this itemset contains a given item.
	 * @param item the item
	 * @return true, if yes, otherwise false.
	 */
	public boolean contains(ItemUApriori item) {
		return items.contains(item);
	}

	/**
	 * Checks if this itemset is lexically smaller than a given itemset of the same size.
	 * @param itemset2 a given itemset
	 * @return true, if yes, otherwise, false
	 */
	boolean isLexicallySmallerthan(ItemsetUApriori itemset2){
		// for each item in this itemset
		for(int i=0; i< items.size(); i++){
			// if it is larger than the item at the same position in itemset2
			// return false
			if(items.get(i).getId() > itemset2.items.get(i).getId()){
				return false;
			}
			// if it is smaller than the item at the same position in itemset2
			// return true
			else if(items.get(i).getId() < itemset2.items.get(i).getId()){
				return true;
			}
		}
		// otherwise return true
		return true;
	}
	
	/**
	 * Check if this itemset is equal to another one.
	 * @param itemset2 the other itemset
	 * @return true if yes, otherwise false
	 */
	public boolean isEqualTo(ItemsetUApriori itemset2){
		// if not the same size, they can't be equal!
		if(items.size() != itemset2.items.size()){
			return false;
		}
		// for each item
		for(ItemUApriori val : items){
			// check if it is contained in the other itemset
			// if not they are not equal.
			if(!itemset2.contains(val)){
				return false;
			}
		}
		// they are equal, then return true
		return true;
	}

	/**
	 * Set the expected support to a given value.
	 * @param expectedsupport the value
	 */
	void setExpectedSupport(double expectedsupport) {
		this.expectedsupport = expectedsupport;
	}

	/**
	 * Make a copy of an itemset but exclude a given item
	 * @param itemToExclude the item
	 * @return the copy
	 */
	ItemsetUApriori cloneItemSetMinusOneItem(ItemUApriori itemToExclude){
		// create a new itemset
		ItemsetUApriori itemset = new ItemsetUApriori();
		// for each item
		for(ItemUApriori item : items){
			// if it is not the one to be excluded, then add it
			if(!item.equals(itemToExclude)){
				itemset.addItem(item);
			}
		}
		// return the itemset
		return itemset;
	}
	
	/**
	 * Get the number of items in this itemset
	 * @return the item count (int)
	 */
	public int size(){
		return items.size();
	}

	/** 
	* check if the item from this itemset are all the same as those of itemset2 
	* except the last item 
	* and that itemset2 is lexically smaller than this itemset. If all these conditions are satisfied,
	* this method return the last item of itemset2. Otherwise it returns null.
	* @return the last item of itemset2, or null.
	* */
	ItemUApriori allTheSameExceptLastItem(ItemsetUApriori itemset2) {
		// if not the same size, then return null
		if(itemset2.size() != items.size()){
			return null;
		}
		for(int i=0; i< items.size(); i++){
			// if they are the last items
			if(i == items.size()-1){ 
				// the one from items should be smaller (lexical order) and different than the one of itemset2
				if(items.get(i).getId() >= itemset2.get(i).getId()){  
					return null;
				}
			}
			// if they are not the last items, they  should be different
			else if(items.get(i).getId() != itemset2.get(i).getId()){ 
				return null; 
			}
		}
		return itemset2.get(itemset2.size()-1);
	}

	/**
	 * Set the items in this itemsets.
	 * @param items a list of items.
	 */
	void setItems(List<ItemUApriori> items) {
		this.items = items;
	}
}
