///////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2001, Eric D. Friedman All Rights Reserved.
//
// 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 General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
///////////////////////////////////////////////////////////////////////////////

package gnu.trove;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.io.Serializable;
import java.util.Arrays;

/**
 * An open addressed set implementation for int primitives.
 *
 * Created: Sat Nov  3 10:38:17 2001
 *
 * @author Eric D. Friedman
 * @version $Id: TIntHashSet.java,v 1.11 2003/03/19 04:17:04 ericdf Exp $
 */

public class TIntHashSet extends TIntHash implements Serializable {

    /**
     * Creates a new <code>TIntHashSet</code> instance with the default
     * capacity and load factor.
     */
    public TIntHashSet() {
        super();
    }

    /**
     * Creates a new <code>TIntHashSet</code> instance with a prime
     * capacity equal to or greater than <tt>initialCapacity</tt> and
     * with the default load factor.
     *
     * @param initialCapacity an <code>int</code> value
     */
    public TIntHashSet(int initialCapacity) {
        super(initialCapacity);
    }

    /**
     * Creates a new <code>TIntHashSet</code> instance with a prime
     * capacity equal to or greater than <tt>initialCapacity</tt> and
     * with the specified load factor.
     *
     * @param initialCapacity an <code>int</code> value
     * @param loadFactor a <code>float</code> value
     */
    public TIntHashSet(int initialCapacity, float loadFactor) {
        super(initialCapacity, loadFactor);
    }

    /**
     * Creates a new <code>TIntHashSet</code> instance containing the
     * elements of <tt>array</tt>.
     *
     * @param array an array of <code>int</code> primitives
     */
    public TIntHashSet(int[] array) {
        this(array.length);
        addAll(array);
    }

    /**
     * Creates a new <code>TIntHash</code> instance with the default
     * capacity and load factor.
     * @param strategy used to compute hash codes and to compare keys.
     */
    public TIntHashSet(TIntHashingStrategy strategy) {
        super(strategy);
    }

    /**
     * Creates a new <code>TIntHash</code> instance whose capacity
     * is the next highest prime above <tt>initialCapacity + 1</tt>
     * unless that value is already prime.
     *
     * @param initialCapacity an <code>int</code> value
     * @param strategy used to compute hash codes and to compare keys.
     */
    public TIntHashSet(int initialCapacity, TIntHashingStrategy strategy) {
        super(initialCapacity, strategy);
    }

    /**
     * Creates a new <code>TIntHash</code> instance with a prime
     * value at or near the specified capacity and load factor.
     *
     * @param initialCapacity used to find a prime capacity for the table.
     * @param loadFactor used to calculate the threshold over which
     * rehashing takes place.
     * @param strategy used to compute hash codes and to compare keys.
     */
    public TIntHashSet(int initialCapacity, float loadFactor, TIntHashingStrategy strategy) {
        super(initialCapacity, loadFactor, strategy);
    }

    /**
     * Creates a new <code>TIntHashSet</code> instance containing the
     * elements of <tt>array</tt>.
     *
     * @param array an array of <code>int</code> primitives
     * @param strategy used to compute hash codes and to compare keys.
     */
    public TIntHashSet(int[] array, TIntHashingStrategy strategy) {
        this(array.length, strategy);
        addAll(array);
    }

    /**
     * @return a TIntIterator with access to the values in this set
     */
    public TIntIterator iterator() {
        return new TIntIterator(this);
    }

    /**
     * Inserts a value into the set.
     *
     * @param val an <code>int</code> value
     * @return true if the set was modified by the add operation
     */
    public boolean add(int val) {
        int index = insertionIndex(val);

        if (index < 0) {
            return false;       // already present in set, nothing to add
        }

        byte previousState = _states[index];
        _set[index] = val;
        _states[index] = FULL;
        postInsertHook(previousState == FREE);
        
        return true;            // yes, we added something
    }

    /**
     * Expands the set to accomodate new values.
     *
     * @param newCapacity an <code>int</code> value
     */
    protected void rehash(int newCapacity) {
        int oldCapacity = _set.length;
        int oldSet[] = _set;
        byte oldStates[] = _states;

        _set = new int[newCapacity];
        _states = new byte[newCapacity];

        for (int i = oldCapacity; i-- > 0;) {
            if(oldStates[i] == FULL) {
                int o = oldSet[i];
                int index = insertionIndex(o);
                _set[index] = o;
                _states[index] = FULL;
            }
        }
    }

    /**
     * Returns a new array containing the values in the set.
     *
     * @return an <code>int[]</code> value
     */
    public int[] toArray() {
        int[] result = new int[size()];
        int[] set = _set;
        byte[] states = _states;
        
        for (int i = states.length, j = 0; i-- > 0;) {
            if (states[i] == FULL) {
                result[j++] = set[i];
            }
        }
        return result;
    }

    /**
     * Empties the set.
     */
    public void clear() {
        super.clear();
        int[] set = _set;
        byte[] states = _states;

        for (int i = set.length; i-- > 0;) {
            set[i] = (int)0;
            states[i] = FREE;
        }
    }

    /**
     * Compares this set with another set for equality of their stored
     * entries.
     *
     * @param other an <code>Object</code> value
     * @return a <code>boolean</code> value
     */
    public boolean equals(Object other) {
        if (! (other instanceof TIntHashSet)) {
            return false;
        }
        final TIntHashSet that = (TIntHashSet)other;
        if (that.size() != this.size()) {
            return false;
        }
        return forEach(new TIntProcedure() {
            public final boolean execute(int value) {
                return that.contains(value);
            }
        });
    }

    public int hashCode() {
        HashProcedure p = new HashProcedure();
        forEach(p);
        return p.getHashCode();
    }

    private final class HashProcedure implements TIntProcedure {
        private int h = 0;
        
        public int getHashCode() {
            return h;
        }
        
        public final boolean execute(int key) {
            h += _hashingStrategy.computeHashCode(key);
            return true;
        }
    }

    /**
     * Removes <tt>val</tt> from the set.
     *
     * @param val an <code>int</code> value
     * @return true if the set was modified by the remove operation.
     */
    public boolean remove(int val) {
        int index = index(val);
        if (index >= 0) {
            removeAt(index);
            return true;
        }
        return false;
    }

    /**
     * Tests the set to determine if all of the elements in
     * <tt>array</tt> are present.
     *
     * @param array an <code>array</code> of int primitives.
     * @return true if all elements were present in the set.
     */
    public boolean containsAll(int[] array) {
      for (int i = array.length; i-- > 0;) {
            if (! contains(array[i])) {
                return false;
            }
        }
        return true;
    }

    /**
     * Adds all of the elements in <tt>array</tt> to the set.
     *
     * @param array an <code>array</code> of int primitives.
     * @return true if the set was modified by the add all operation.
     */
    public boolean addAll(int[] array) {
        boolean changed = false;
        for (int i = array.length; i-- > 0;) {
            if (add(array[i])) {
                changed = true;
            }
        }
        return changed;
    }

    /**
     * Removes all of the elements in <tt>array</tt> from the set.
     *
     * @param array an <code>array</code> of int primitives.
     * @return true if the set was modified by the remove all operation.
     */
    public boolean removeAll(int[] array) {
        boolean changed = false;
        for (int i = array.length; i-- > 0;) {
            if (remove(array[i])) {
                changed = true;
            }
        }
        return changed;
    }

    /**
     * Removes any values in the set which are not contained in
     * <tt>array</tt>.
     *
     * @param array an <code>array</code> of int primitives.
     * @return true if the set was modified by the retain all operation
     */
    public boolean retainAll(int[] array) {
        boolean changed = false;
        Arrays.sort(array);
        int[] set = _set;
        byte[] states = _states;

        for (int i = set.length; i-- > 0;) {
            if (states[i] == FULL && (Arrays.binarySearch(array,set[i]) < 0)) {
                remove(set[i]);
                changed = true;
            }
        }
        return changed;
    }

    private void writeObject(ObjectOutputStream stream)
        throws IOException {
        stream.defaultWriteObject();

        // number of entries
        stream.writeInt(_size);

        SerializationProcedure writeProcedure = new SerializationProcedure(stream);
        if (! forEach(writeProcedure)) {
            throw writeProcedure.exception;
        }
    }

    private void readObject(ObjectInputStream stream)
        throws IOException, ClassNotFoundException {
        stream.defaultReadObject();

        int size = stream.readInt();
        setUp(size);
        while (size-- > 0) {
            int val = stream.readInt();
            add(val);
        }
    }
} // TIntHashSet