/*
 * FindBugs - Find Bugs in Java programs
 * Copyright (C) 2006, University of Maryland
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston MA 02111-1307, USA
 */

package edu.umd.cs.findbugs.gui2;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;

import edu.umd.cs.findbugs.BugCollection;
import edu.umd.cs.findbugs.BugInstance;
import edu.umd.cs.findbugs.Project;
import edu.umd.cs.findbugs.filter.Filter;
import edu.umd.cs.findbugs.filter.Matcher;
import edu.umd.cs.findbugs.gui2.BugAspects.SortableValue;

/**
 * BugSet is what we use instead of SortedBugCollections.  BugSet is somewhat poorly named, in that its actually a HashList of bugs, 
 * not a Set of them.  (It can't be a set because we need to be able to sort it, also, HashList is great for doing contains and indexOf, its just slow for removing which we never need to do)  The power of BugSet is in query.  You can query a BugSet with a BugAspects, a list of StringPairs like <priority,high>, <designation,unclassified>
 * and you will get out a new BugSet containing all of the bugs that are both high priority and unclassified.  Also, after the first time a query is made, the results will come back instantly on future calls
 * because the old queries are cached.  Note that this caching can also lead to issues, problems with the BugTreeModel and the JTree getting out of sync, if there comes a time when the model and tree are out of sync
 * but come back into sync if the tree is rebuilt, say by sorting the column headers, it probably means that resetData needs to be called on the model after doing one of its operations.  
 * 
 * @author Dan
 *
 */
public class BugSet implements Iterable<BugLeafNode>{

	private ArrayList<BugLeafNode> mainList;
	private HashMap<SortableValue,BugSet> doneMap;
	private HashMap<SortableValue,Boolean>   doneContainsMap;
	private HashMap<Sortables,String[]> sortablesToStrings;


	private static BugSet mainBugSet=null;

	/** mainBugSet should probably always be the same as the data field in the current BugTreeModel
	 * we haven't run into any issues where it isn't, but if the two aren't equal using ==, problems might occur.
	 * If these problems do occur, See BugTreeModel.resetData() and perhaps adding a setAsRootAndCache() to it would fix the issue.
	 * This is not done right now for fear it might be slow.
	 */
	public static BugSet getMainBugSet()
	{
		return mainBugSet;
	}

	/**
	 * Gets all the string values out of the bugs in the set
	 * @param s The Sortables you want all values for
	 * @return all values of the sortable passed in that occur in this bugset, in order based on the sortable's compare method.
	 */
	public String[] getAll(Sortables s)
	{
		return getDistinctValues(s);
	}

	/**
	 * Creates a filterable dataset from the set passed in.  The first time this is used is from outside to create the main data list
	 * After that BugSet will create new smaller filtered sets and store them using this method.
	 * @param filteredSet
	 */
	BugSet(Collection<? extends BugLeafNode> filteredSet)
	{
		this.mainList=new ArrayList<BugLeafNode>(filteredSet);
		doneMap=new HashMap<SortableValue,BugSet>();
		doneContainsMap=new HashMap<SortableValue,Boolean>();
		cacheSortables();
	}

	BugSet(BugCollection bugCollection) {
		this(Collections.<BugLeafNode>emptyList());
		for(Iterator<BugInstance> i = bugCollection.iterator(); i.hasNext(); )
			mainList.add(new BugLeafNode(i.next()));

	}
	/**
	 * Sets the BugSet passed in to be the mainBugSet, this should always match up with the data set in the BugTreeModel
	 * @param bs
	 */
	static void setAsRootAndCache(BugSet bs)
	{
		mainBugSet=bs;
		bs.sortList();
		bs.cacheSortables();
	}

	static boolean suppress(BugLeafNode p) {
		return !MainFrame.getInstance().shouldDisplayIssue(p.getBug());
	}
	/**
	 * we cache all values of each sortable that appear in the BugSet as we create it using cacheSortables, this makes it
	 * possible to only show branches that actually have bugs in them, and makes it faster by caching the results.
	 */
	void cacheSortables()
	{
		 sortablesToStrings
		    = new HashMap<Sortables,String[]>();
	}

	String[]  getDistinctValues(Sortables key) {
		String[] list = sortablesToStrings.get(key);
		if (list == null) {
			list = computeDistinctValues(key);
			sortablesToStrings.put(key,list);
		}
		return list;
	}

	private static final String [] EMPTY_STRING_ARRAY = new String[0];
	
	String[] computeDistinctValues(Sortables key) {

		if (key == Sortables.DIVIDER)
			return EMPTY_STRING_ARRAY;

		Collection<String> list = new HashSet<String>();

		for (BugLeafNode p : mainList) {
			if (suppress(p))
				continue;
			BugInstance bug = p.getBug();

			String value = key.getFrom(bug);
			list.add(value);

		}
		String result[]  = list.toArray(new String[list.size()]);
		Collections.sort(Arrays.asList(result), new SortableStringComparator(key));
		return result;

	}
	/** used to update the status bar in mainframe with the number of bugs that are filtered out */ 
	static int countFilteredBugs()
	{
		int result = 0;
		for (BugLeafNode bug : getMainBugSet().mainList)
			if (suppress(bug))
				result++;

		return result;
	}

	/**
	 * Copy constructor, also used to make sure things are recalculated
	 * @param copySet
	 */
	//Note: THIS CLEARS THE CACHES OF DONE SETS!
	BugSet(BugSet copySet)
	{
		this.mainList=copySet.mainList;
		doneMap=new HashMap<SortableValue,BugSet>();
		doneContainsMap=new HashMap<SortableValue,Boolean>();
		cacheSortables();
	}


	/**
	 * A String pair has a key and a value.  The key is the general category ie: Type
	 * The value is the value  ie: Malicious Code.  
	 * 
	 * Query looks through a BugLeafNode set with a keyValuePair to see which BugLeafNodes inside
	 * match the value under the category of key.  
	 * 
	 * passing in a key of Abbrev and a value of MS should return a new BugSet with all the Mutable Static bugs in the current set
	 * Note also:  This query will only be performed once, and then stored and reused if the same query is used again.  
	 * @param keyValuePair
	 * @return
	 */
	BugSet query(SortableValue keyValuePair)
	{
		if (doneMap.containsKey(keyValuePair))
			return doneMap.get(keyValuePair);
		ArrayList<BugLeafNode> bugs=new ArrayList<BugLeafNode>();

		for(BugLeafNode b:mainList)
		{
			if (b.matches(keyValuePair))
				bugs.add(b);
		}

		BugSet temp=new BugSet(bugs);
		doneMap.put(keyValuePair,temp);
		return temp;
	}

	/* Sort the contents of the list by the Sortables in the order after the divider, if any. */
	void sortList()
	{

		final List<Sortables> order = MainFrame.getInstance().getSorter().getOrderAfterDivider();

		Collections.sort(mainList, new Comparator<BugLeafNode>(){
			public int compare(BugLeafNode one, BugLeafNode two)
			{
				for (Sortables i : order)
				{
					int result = i.getBugLeafNodeComparator().compare(one, two);
					if (result != 0)
						return result;
				}
				// If still here, they're really equal
				return 0;
			}
		});
	}

	/**
	 * 
	 * Contains takes a key/value pair
	 * 
	 * @param keyValuePair
	 * @return true if a bug leaf from filterNoCache() matches the pair
	 */	
	public boolean contains(SortableValue keyValuePair)
	{
		if (doneContainsMap.containsKey(keyValuePair))
			return doneContainsMap.get(keyValuePair);

		for(BugLeafNode p: filteredBugsCached().mainList)
		{
			if (p.matches(keyValuePair))
			{
				doneContainsMap.put(keyValuePair,true);
				return true;
			}
		}
		doneContainsMap.put(keyValuePair,false);
		return false;
	}


	/**
	 *Gives you back the BugSet containing all bugs that match your query
	 */
	public BugSet query(BugAspects a)
	{
		BugSet result=this;
		for (SortableValue sp:a)
		{
			result=result.query(sp);
		}

		return result;
	}

	public int sizeUnfiltered()
	{
		return mainList.size();
	}

	public int indexOfUnfiltered(BugLeafNode p)
	{
		return mainList.indexOf(p);
	}

	public BugLeafNode getUnfiltered(int index)
	{
		return mainList.get(index);
	}

	public Iterator<BugLeafNode> iterator()
	{	
		return mainList.iterator();
	}

	////////Filtered API

	BugSet(ArrayList<BugLeafNode> filteredSet, boolean cacheSortables)
	{
		this.mainList=new ArrayList<BugLeafNode>(filteredSet);
		doneMap=new HashMap<SortableValue,BugSet>();
		doneContainsMap=new HashMap<SortableValue,Boolean>();
		if (cacheSortables)
			cacheSortables();
	}

	private BugSet filteredBugsNoCache()
	{

		ArrayList<BugLeafNode> people=new ArrayList<BugLeafNode>();
		for(BugLeafNode p:mainList) {
			if (!suppress(p))
				people.add(p);
		}
		return new BugSet(people,false);
	}
	
	BugSet cache = null;
	public void clearCache() {
		cache = null;
	}
	private BugSet filteredBugsCached()
	{
		if (cache == null)
			cache = filteredBugsNoCache();
		return cache;
	}

	public BugSet getBugsMatchingFilter(Matcher m)
	{
		ArrayList<BugLeafNode> people=new ArrayList<BugLeafNode>();
		for(BugLeafNode p:mainList) {
			if(!(m.match(p.getBug())))
				people.add(p);
		}
		return new BugSet(people,false);
	}

	public int size()
	{
		return filteredBugsCached().sizeUnfiltered();
	}

	public int indexOf(BugLeafNode p)
	{
		return filteredBugsCached().indexOfUnfiltered(p);
	}

	public BugLeafNode get(int index)
	{
		return filteredBugsCached().getUnfiltered(index);
	}
}
