/*
 * Copyright (C) 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */

#ifndef WTF_HashSet_h
#define WTF_HashSet_h

#include <wtf/HashTable.h>
#include <kjs/CommonIdentifiers.h>

namespace WTF
{

template<typename Value, typename HashFunctions, typename Traits> class HashSet;
template<typename Value, typename HashFunctions, typename Traits>
void deleteAllValues(const HashSet<Value, HashFunctions, Traits> &);

template<typename T> struct IdentityExtractor;

template<typename ValueArg, typename HashArg = typename DefaultHash<ValueArg>::Hash,
         typename TraitsArg = HashTraits<ValueArg> > class HashSet
{
private:
    typedef HashArg HashFunctions;
    typedef TraitsArg ValueTraits;

public:
    typedef typename ValueTraits::TraitType ValueType;

private:
    typedef HashTable<ValueType, ValueType, IdentityExtractor<ValueType>,
            HashFunctions, ValueTraits, ValueTraits> HashTableType;

public:
    typedef HashTableIteratorAdapter<HashTableType, ValueType> iterator;
    typedef HashTableConstIteratorAdapter<HashTableType, ValueType> const_iterator;

    void swap(HashSet &);

    int size() const;
    int capacity() const;
    bool isEmpty() const;

    iterator begin();
    iterator end();
    const_iterator begin() const;
    const_iterator end() const;

    iterator find(const ValueType &);
    const_iterator find(const ValueType &) const;
    bool contains(const ValueType &) const;

    // An alternate version of find() that finds the object by hashing and comparing
    // with some other type, to avoid the cost of type conversion. HashTranslator
    // must have the following function members:
    //   static unsigned hash(const T&);
    //   static bool equal(const ValueType&, const T&);
    template<typename T, typename HashTranslator> iterator find(const T &);
    template<typename T, typename HashTranslator> const_iterator find(const T &) const;
    template<typename T, typename HashTranslator> bool contains(const T &) const;

    // The return value is a pair of an iterator to the new value's location,
    // and a bool that is true if an new entry was added.
    pair<iterator, bool> add(const ValueType &);

    // An alternate version of add() that finds the object by hashing and comparing
    // with some other type, to avoid the cost of type conversion if the object is already
    // in the table. HashTranslator must have the following methods:
    //   static unsigned hash(const T&);
    //   static bool equal(const ValueType&, const T&);
    //   static translate(ValueType&, const T&, unsigned hashCode);
    template<typename T, typename HashTranslator> pair<iterator, bool> add(const T &);

    void remove(const ValueType &);
    void remove(iterator);
    void clear();

private:
    friend void deleteAllValues<>(const HashSet &);

    HashTableType m_impl;
};

template<typename T> struct IdentityExtractor {
    static const T &extract(const T &t)
    {
        return t;
    }
};

template<typename ValueType, typename ValueTraits, typename T, typename Translator>
struct HashSetTranslatorAdapter {
    static unsigned hash(const T &key)
    {
        return Translator::hash(key);
    }
    static bool equal(const ValueType &a, const T &b)
    {
        return Translator::equal(a, b);
    }
    static void translate(ValueType &location, const T &key, const T &, unsigned hashCode)
    {
        Translator::translate(location, key, hashCode);
    }
};

template<typename T, typename U, typename V>
inline void HashSet<T, U, V>::swap(HashSet &other)
{
    m_impl.swap(other.m_impl);
}

template<typename T, typename U, typename V>
inline int HashSet<T, U, V>::size() const
{
    return m_impl.size();
}

template<typename T, typename U, typename V>
inline int HashSet<T, U, V>::capacity() const
{
    return m_impl.capacity();
}

template<typename T, typename U, typename V>
inline bool HashSet<T, U, V>::isEmpty() const
{
    return m_impl.isEmpty();
}

template<typename T, typename U, typename V>
inline typename HashSet<T, U, V>::iterator HashSet<T, U, V>::begin()
{
    return m_impl.begin();
}

template<typename T, typename U, typename V>
inline typename HashSet<T, U, V>::iterator HashSet<T, U, V>::end()
{
    return m_impl.end();
}

template<typename T, typename U, typename V>
inline typename HashSet<T, U, V>::const_iterator HashSet<T, U, V>::begin() const
{
    return m_impl.begin();
}

template<typename T, typename U, typename V>
inline typename HashSet<T, U, V>::const_iterator HashSet<T, U, V>::end() const
{
    return m_impl.end();
}

template<typename T, typename U, typename V>
inline typename HashSet<T, U, V>::iterator HashSet<T, U, V>::find(const ValueType &value)
{
    return m_impl.find(value);
}

template<typename T, typename U, typename V>
inline typename HashSet<T, U, V>::const_iterator HashSet<T, U, V>::find(const ValueType &value) const
{
    return m_impl.find(value);
}

template<typename T, typename U, typename V>
inline bool HashSet<T, U, V>::contains(const ValueType &value) const
{
    return m_impl.contains(value);
}

template<typename Value, typename HashFunctions, typename Traits>
template<typename T, typename Translator>
typename HashSet<Value, HashFunctions, Traits>::iterator
inline HashSet<Value, HashFunctions, Traits>::find(const T &value)
{
    typedef HashSetTranslatorAdapter<ValueType, ValueTraits, T, Translator> Adapter;
    return m_impl.template find<T, Adapter>(value);
}

template<typename Value, typename HashFunctions, typename Traits>
template<typename T, typename Translator>
typename HashSet<Value, HashFunctions, Traits>::const_iterator
inline HashSet<Value, HashFunctions, Traits>::find(const T &value) const
{
    typedef HashSetTranslatorAdapter<ValueType, ValueTraits, T, Translator> Adapter;
    return m_impl.template find<T, Adapter>(value);
}

template<typename Value, typename HashFunctions, typename Traits>
template<typename T, typename Translator>
inline bool HashSet<Value, HashFunctions, Traits>::contains(const T &value) const
{
    typedef HashSetTranslatorAdapter<ValueType, ValueTraits, T, Translator> Adapter;
    return m_impl.template contains<T, Adapter>(value);
}

template<typename T, typename U, typename V>
pair<typename HashSet<T, U, V>::iterator, bool> HashSet<T, U, V>::add(const ValueType &value)
{
    return m_impl.add(value);
}

template<typename Value, typename HashFunctions, typename Traits>
template<typename T, typename Translator>
pair<typename HashSet<Value, HashFunctions, Traits>::iterator, bool>
HashSet<Value, HashFunctions, Traits>::add(const T &value)
{
    typedef HashSetTranslatorAdapter<ValueType, ValueTraits, T, Translator> Adapter;
    return m_impl.template addPassingHashCode<T, T, Adapter>(value, value);
}

template<typename T, typename U, typename V>
inline void HashSet<T, U, V>::remove(iterator it)
{
    if (it.m_impl == m_impl.end()) {
        return;
    }
    m_impl.checkTableConsistency();
    m_impl.removeWithoutEntryConsistencyCheck(it.m_impl);
}

template<typename T, typename U, typename V>
inline void HashSet<T, U, V>::remove(const ValueType &value)
{
    remove(find(value));
}

template<typename T, typename U, typename V>
inline void HashSet<T, U, V>::clear()
{
    m_impl.clear();
}

template<typename ValueType, typename HashTableType>
void deleteAllValues(HashTableType &collection)
{
    typedef typename HashTableType::const_iterator iterator;
    iterator end = collection.end();
    for (iterator it = collection.begin(); it != end; ++it) {
        delete *it;
    }
}

template<typename T, typename U, typename V>
inline void deleteAllValues(const HashSet<T, U, V> &collection)
{
    deleteAllValues<typename HashSet<T, U, V>::ValueType>(collection.m_impl);
}

template<typename T, typename U, typename V, typename W>
inline void copyToVector(const HashSet<T, U, V> &collection, W &vector)
{
    typedef typename HashSet<T, U, V>::const_iterator iterator;

    vector.resize(collection.size());

    iterator it = collection.begin();
    iterator end = collection.end();
    for (unsigned i = 0; it != end; ++it, ++i) {
        vector[i] = *it;
    }
}

} // namespace WTF

using WTF::HashSet;

#endif /* WTF_HashSet_h */
