/** @file
 * IPRT / No-CRT - Minimal C++ std::vector.
 */

/*
 * Copyright (C) 2023-2025 Oracle and/or its affiliates.
 *
 * This file is part of VirtualBox base platform packages, as
 * available from https://www.virtualbox.org.
 *
 * This program 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, in version 3 of the
 * License.
 *
 * This program 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 this program; if not, see <https://www.gnu.org/licenses>.
 *
 * The contents of this file may alternatively be used under the terms
 * of the Common Development and Distribution License Version 1.0
 * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
 * in the VirtualBox distribution, in which case the provisions of the
 * CDDL are applicable instead of those of the GPL.
 *
 * You may elect to license modified versions of this file under the
 * terms and conditions of either the GPL or the CDDL or both.
 *
 * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
 */

#ifndef VBOX_INCLUDED_SRC_nocrt_vector
#define VBOX_INCLUDED_SRC_nocrt_vector
#ifndef RT_WITHOUT_PRAGMA_ONCE
# pragma once
#endif

#include <iprt/nocrt/memory>

namespace std
{
    template<typename a_Type, class a_Container>
    class RTCNoCrtVectorIterator
    {
    public:
        typedef a_Type                                 &reference;
        typedef a_Type                                 *pointer;
        typedef typename a_Container::difference_type   difference_type;

    protected:
            a_Type *m_pItem;

    public:
        RTCNoCrtVectorIterator() RT_NOEXCEPT
            : m_pItem(NULL)
        { }

        RTCNoCrtVectorIterator(a_Type *a_pItem) RT_NOEXCEPT
            : m_pItem(a_pItem)
        { }

        ~RTCNoCrtVectorIterator()
        {
            m_pItem = NULL;
        }

        /** @name Moving the iterator.
         * @{  */

        RTCNoCrtVectorIterator &operator++() RT_NOEXCEPT
        {
            ++m_pItem;
            return *this;
        }

        RTCNoCrtVectorIterator &operator--() RT_NOEXCEPT
        {
            --m_pItem;
            return *this;
        }

        RTCNoCrtVectorIterator operator++(int) RT_NOEXCEPT
        {
            return RTCNoCrtVectorIterator(m_pItem++);
        }

        RTCNoCrtVectorIterator operator--(int) RT_NOEXCEPT
        {
            return RTCNoCrtVectorIterator(m_pItem--);
        }

        RTCNoCrtVectorIterator &operator+=(difference_type cItems) RT_NOEXCEPT
        {
            m_pItem += cItems;
            return *this;
        }

        RTCNoCrtVectorIterator &operator-=(difference_type cItems) RT_NOEXCEPT
        {
            m_pItem -= cItems;
            return *this;
        }

        RTCNoCrtVectorIterator operator+(difference_type cItems) const RT_NOEXCEPT
        {
            return RTCNoCrtVectorIterator(m_pItem + cItems);
        }

        RTCNoCrtVectorIterator operator-(difference_type cItems) const RT_NOEXCEPT
        {
            return RTCNoCrtVectorIterator(m_pItem - cItems);
        }

        /** @} */

        /** @name Item access
         * @{ */
        reference operator*() const RT_NOEXCEPT
        {
            return *m_pItem;
        }

        pointer operator->() const RT_NOEXCEPT
        {
            return m_pItem;
        }

        reference operator[](difference_type iItem) const RT_NOEXCEPT
        {
            return m_pItem[iItem];
        }

        /** @} */

        /** Helper for const/non-const iterator comparisons: */
        inline typename a_Container::const_pointer getConst() const RT_NOEXCEPT
        {
            return m_pItem;
        }
    };

    template<typename a_TypeLeft, typename a_TypeRight, class a_Container>
    inline bool operator==(const RTCNoCrtVectorIterator<a_TypeLeft,  a_Container> &a_rLeft,
                           const RTCNoCrtVectorIterator<a_TypeRight, a_Container> &a_rRight) RT_NOEXCEPT
    {
        return a_rLeft.getConst() == a_rRight.getConst();
    }

    template<typename a_TypeLeft, typename a_TypeRight, class a_Container>
    inline bool operator!=(const RTCNoCrtVectorIterator<a_TypeLeft,  a_Container> &a_rLeft,
                           const RTCNoCrtVectorIterator<a_TypeRight, a_Container> &a_rRight) RT_NOEXCEPT
    {
        return a_rLeft.getConst() != a_rRight.getConst();
    }

    template<typename a_TypeLeft, typename a_TypeRight, class a_Container>
    inline bool operator<(const RTCNoCrtVectorIterator<a_TypeLeft,  a_Container> &a_rLeft,
                          const RTCNoCrtVectorIterator<a_TypeRight, a_Container> &a_rRight) RT_NOEXCEPT
    {
        return (uintptr_t)a_rLeft.getConst() < (uintptr_t)a_rRight.getConst();
    }

    template<typename a_TypeLeft, typename a_TypeRight, class a_Container>
    inline bool operator<=(const RTCNoCrtVectorIterator<a_TypeLeft,  a_Container> &a_rLeft,
                           const RTCNoCrtVectorIterator<a_TypeRight, a_Container> &a_rRight) RT_NOEXCEPT
    {
        return (uintptr_t)a_rLeft.getConst() <= (uintptr_t)a_rRight.getConst();
    }

    template<typename a_TypeLeft, typename a_TypeRight, class a_Container>
    inline bool operator>(const RTCNoCrtVectorIterator<a_TypeLeft,  a_Container> &a_rLeft,
                          const RTCNoCrtVectorIterator<a_TypeRight, a_Container> &a_rRight) RT_NOEXCEPT
    {
        return (uintptr_t)a_rLeft.getConst() > (uintptr_t)a_rRight.getConst();
    }

    template<typename a_TypeLeft, typename a_TypeRight, class a_Container>
    inline bool operator>=(const RTCNoCrtVectorIterator<a_TypeLeft,  a_Container> &a_rLeft,
                           const RTCNoCrtVectorIterator<a_TypeRight, a_Container> &a_rRight) RT_NOEXCEPT
    {
        return (uintptr_t)a_rLeft.getConst() >= (uintptr_t)a_rRight.getConst();
    }



    template<class a_Type, class a_Allocator = std::allocator<a_Type> >
    class vector
    {
    public:
        typedef a_Type                                  value_type;
        typedef a_Type                                 &reference;
        typedef a_Type const                           &const_reference;
        typedef a_Allocator                             allocator_type;
        typedef typename a_Allocator::size_type         size_type;
        typedef typename a_Allocator::difference_type   difference_type;
        typedef typename a_Allocator::pointer           pointer;
        typedef typename a_Allocator::const_pointer     const_pointer;

        typedef RTCNoCrtVectorIterator<a_Type, vector>          iterator;
        typedef RTCNoCrtVectorIterator<const a_Type, vector>    const_iterator;

    protected:
        pointer         m_paItems;
        size_t          m_cItems;
        size_t          m_cAllocated;
        allocator_type  m_Allocator;

    public:
        vector() RT_NOEXCEPT
            : m_paItems(NULL)
            , m_cItems(0)
            , m_cAllocated(0)
        { }

        vector(size_type a_cAllocate)
            : m_paItems(NULL)
            , m_cItems(0)
            , m_cAllocated(0)
        {
            m_paItems = m_Allocator.allocate(a_cAllocate);
            if (m_paItems)
                m_cAllocated = a_cAllocate;
        }

        ~vector()
        {
            clear();
        }

        /** @name Iterators
         * @{ */
        iterator begin() RT_NOEXCEPT
        {
            return iterator(m_paItems);
        }

        const_iterator begin() const RT_NOEXCEPT
        {
            return const_iterator(m_paItems);
        }

        const_iterator cbegin() const RT_NOEXCEPT
        {
            return const_iterator(m_paItems);
        }

        iterator end() RT_NOEXCEPT
        {
            return iterator(m_paItems + m_cItems);
        }

        const_iterator end() const RT_NOEXCEPT
        {
            return const_iterator(m_paItems + m_cItems);
        }

        const_iterator cend() const RT_NOEXCEPT
        {
            return const_iterator(m_paItems + m_cItems);
        }
        /** @} */

        /** @name Element access
         * @{  */
        reference operator[](size_type iItem) RT_NOEXCEPT
        {
            Assert(iItem < m_cAllocated);
            return m_paItems[iItem];
        }

        const_reference operator[](size_type iItem) const RT_NOEXCEPT
        {
            Assert(iItem < m_cAllocated);
            return m_paItems[iItem];
        }

        reference at(size_type iItem) RT_NOEXCEPT
        {
            Assert(iItem < m_cAllocated);
            return m_paItems[iItem];
        }

        const_reference at(size_type iItem) const RT_NOEXCEPT
        {
            Assert(iItem < m_cAllocated);
            return m_paItems[iItem];
        }

        reference front() RT_NOEXCEPT
        {
            return m_paItems[0];
        }

        const_reference front() const RT_NOEXCEPT
        {
            return m_paItems[0];
        }

        reference back() RT_NOEXCEPT
        {
            return m_paItems[m_cItems - 1];
        }

        const_reference back() const RT_NOEXCEPT
        {
            return m_paItems[m_cItems - 1];
        }

        pointer data() RT_NOEXCEPT
        {
            return m_paItems;
        }

        const_pointer data() const RT_NOEXCEPT
        {
            return m_paItems;
        }

        /** @}  */

        /** @name Capacity
         * @{ */
        bool empty() const RT_NOEXCEPT
        {
            return m_cItems == 0;
        }

        size_type size() const RT_NOEXCEPT
        {
            return m_cItems;
        }

        size_type max_size() const RT_NOEXCEPT
        {
            return m_Allocator.max_size();
        }

        void reserve(size_type a_cNewAllocated)
        {
            Assert(a_cNewAllocated <= max_size());

            if (a_cNewAllocated > m_cAllocated)
            {
                vector Temp(a_cNewAllocated);
                if (Temp.m_paItems)
                {
                    /* Copy over the data: */
                    size_type const cItems = m_cItems;
                    const_pointer   paSrc  = m_paItems;
                    pointer         paDst  = Temp.m_paItems;
                    for (size_type i = 0; i < cItems; Temp.m_cItems = ++i)
                        m_Allocator.construct(&paDst[i], paSrc[i]);

                    /* Swap the data. */
                    size_type const cOldAllocated = m_cAllocated;
                    Temp.m_paItems    = m_paItems;
                    m_paItems         = paDst;
                    m_cAllocated      = Temp.m_cAllocated;
                    Temp.m_cAllocated = cOldAllocated;
                }
            }
        }

        /** @} */

        /** @name Modifiers
         * @{ */
        void push_back(const_reference a_rValue)
        {
            if (m_cItems < m_cAllocated)
            { }
            else
            {
                Assert(m_cItems * 2 >= m_cItems);
                reserve(m_cItems < 8 ? 8 : m_cItems * 2); /* This might be non-standard. */
                AssertReturnVoid(m_cItems < m_cAllocated);
            }
            m_paItems[m_cItems] = a_rValue;
            m_cItems++;
        }

        void pop_back() RT_NOEXCEPT
        {
            if (m_cItems > 0)
                m_cItems -= 1;
        }

        void clear() RT_NOEXCEPT
        {
            size_type i = m_cItems;
            while (i-- > 0)
            {
                m_Allocator.destroy(&m_paItems[i]);
                m_cItems = i;
            }
            m_Allocator.deallocate(m_paItems, m_cAllocated);
            m_paItems = NULL;
            m_cAllocated = 0;
        }
        /** @} */
    };

}

#endif /* !VBOX_INCLUDED_SRC_nocrt_vector */