/****************************************************************************
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** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of Qbs.
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** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
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** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
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** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
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****************************************************************************/

#ifndef QBS_NODESET_H
#define QBS_NODESET_H

#include <set>
#include <cstddef>

#include <QSharedData>

namespace qbs {
namespace Internal {

class BuildGraphNode;

class NodeSetData : public QSharedData
{
public:
    std::set<BuildGraphNode *> m_data;
};

class PersistentPool;

/**
  * Set of build graph nodes.
  * This is faster than QSet when iterating over the container.
  */
class NodeSet
{
public:
    NodeSet();

    NodeSet &unite(const NodeSet &other);

    typedef std::set<BuildGraphNode *>::const_iterator const_iterator;
    typedef std::set<BuildGraphNode *>::iterator iterator;
    typedef BuildGraphNode * value_type;

    iterator begin() { return d->m_data.begin(); }
    iterator end() { return d->m_data.end(); }
    const_iterator begin() const { return d->m_data.begin(); }
    const_iterator end() const { return d->m_data.end(); }
    const_iterator constBegin() const { return d->m_data.begin(); }
    const_iterator constEnd() const { return d->m_data.end(); }

    void insert(BuildGraphNode *node)
    {
        d->m_data.insert(node);
    }

    void operator+=(BuildGraphNode *node)
    {
        d->m_data.insert(node);
    }

    NodeSet &operator<<(BuildGraphNode *node)
    {
        d->m_data.insert(node);
        return *this;
    }

    void remove(BuildGraphNode *node);

    bool contains(BuildGraphNode *node) const
    {
        return d->m_data.find(node) != d->m_data.end();
    }

    void clear()
    {
        d->m_data.clear();
    }

    bool isEmpty() const
    {
        return d->m_data.empty();
    }

    int count() const
    {
        return (int)d->m_data.size();
    }

    void reserve(int)
    {
        // no-op
    }

    bool operator==(const NodeSet &other) const { return d->m_data == other.d->m_data; }
    bool operator!=(const NodeSet &other) const { return !(*this == other); }

    void load(PersistentPool &pool);
    void store(PersistentPool &pool) const;


private:
    QSharedDataPointer<NodeSetData> d;
};

template <class T>
class TypeFilter
{
    const NodeSet &m_nodes;
public:
    TypeFilter(const NodeSet &nodes)
        : m_nodes(nodes)
    {
    }

    class const_iterator : public std::iterator<std::forward_iterator_tag, T *>
    {
        const NodeSet &m_nodes;
        NodeSet::const_iterator m_it;
    public:
        const_iterator(const NodeSet &nodes, const NodeSet::const_iterator &it)
            : m_nodes(nodes), m_it(it)
        {
            while (m_it != m_nodes.constEnd() && dynamic_cast<T *>(*m_it) == 0)
                ++m_it;
        }

        bool operator==(const const_iterator &rhs)
        {
            return m_it == rhs.m_it;
        }

        bool operator!=(const const_iterator &rhs)
        {
            return !(*this == rhs);
        }

        const_iterator &operator++()
        {
            for (;;) {
                ++m_it;
                if (m_it == m_nodes.constEnd() || dynamic_cast<T *>(*m_it))
                    return *this;
            }
        }

        T *operator*() const
        {
            return static_cast<T *>(*m_it);
        }
    };

    const_iterator begin() const
    {
        return const_iterator(m_nodes, m_nodes.constBegin());
    }

    const_iterator end() const
    {
        return const_iterator(m_nodes, m_nodes.constEnd());
    }
};

template <class T>
const TypeFilter<T> filterByType(const NodeSet &nodes)
{
    return TypeFilter<T>(nodes);
}

} // namespace Internal
} // namespace qbs

#endif // QBS_NODESET_H