collection.hpp

// SPDX-FileCopyrightText: 2016 - 2025 Kohei Yoshida
//
// SPDX-License-Identifier: MIT

#pragma once

#include "mdds/multi_type_vector/types.hpp"

#include <type_traits>
#include <vector>
#include <memory>

namespace mdds { namespace mtv {

template<typename _MtvT>
class collection;

namespace detail {

template<typename _MtvT>
class side_iterator
{
    typedef _MtvT mtv_type;
    friend collection<mtv_type>;

    typedef typename mtv_type::size_type size_type;
    typedef typename mtv_type::const_iterator const_iterator;
    typedef typename mtv_type::const_position_type const_position_type;

    struct mtv_item
    {
        const mtv_type* vector;
        const_iterator block_pos;
        const_iterator block_end;

        mtv_item(const mtv_type* v, const const_iterator& bp, const const_iterator& be)
            : vector(v), block_pos(bp), block_end(be)
        {}
    };

    struct node
    {
        friend class side_iterator;

        mdds::mtv::element_t type;

        size_type index;

        size_type position;

        template<typename _Blk>
        typename _Blk::value_type get() const
        {
            return _Blk::get_value(*__position.first->data, __position.second);
        }

    private:
        const_position_type __position;
    };

    enum begin_state_type
    {
        begin_state
    };
    enum end_state_type
    {
        end_state
    };

    std::vector<mtv_item> m_vectors;
    node m_cur_node;
    size_type m_elem_pos;
    size_type m_elem_pos_end;
    size_type m_index_offset;
    uintptr_t m_identity;

    side_iterator(
        std::vector<mtv_item>&& vectors, size_type elem_pos, size_type elem_size, size_type index_offset,
        uintptr_t identity, begin_state_type);

    side_iterator(
        std::vector<mtv_item>&& vectors, size_type elem_pos, size_type elem_size, size_type index_offset,
        uintptr_t identity, end_state_type);

public:
    typedef node value_type;

    side_iterator();

    template<typename _T>
    side_iterator(const _T& begin, const _T& end);

    const value_type& operator*() const
    {
        return m_cur_node;
    }

    const value_type* operator->() const
    {
        return &m_cur_node;
    }

    side_iterator& operator++();

    side_iterator operator++(int);

    bool operator==(const side_iterator& other) const;
    bool operator!=(const side_iterator& other) const;
};

} // namespace detail

template<typename _MtvT>
class collection
{
public:
    typedef _MtvT mtv_type;
    typedef typename mtv_type::size_type size_type;

private:
    struct range
    {
        size_type start;
        size_type size;

        range() : start(0), size(0)
        {}
    };

    std::vector<const mtv_type*> m_vectors;
    size_type m_mtv_size;
    uintptr_t m_identity;

    range m_elem_range; 
    range m_col_range; 

public:
    typedef detail::side_iterator<mtv_type> const_iterator;

    collection();

    template<typename _T>
    collection(const _T& begin, const _T& end);

    const_iterator begin() const;

    const_iterator end() const;

    size_type size() const;

    void swap(collection& other);

    void set_collection_range(size_type start, size_type size);

    void set_element_range(size_type start, size_type size);

private:
    void check_collection_range(size_type start, size_type size) const;
    void check_element_range(size_type start, size_type size) const;

    std::vector<typename const_iterator::mtv_item> build_iterator_state() const;

    void init_insert_vector(const std::unique_ptr<mtv_type>& p);

    void init_insert_vector(const std::shared_ptr<mtv_type>& p);

    template<typename _T>
    void init_insert_vector(const _T& t, typename std::enable_if<std::is_pointer<_T>::value>::type* = 0);

    template<typename _T>
    void init_insert_vector(const _T& t, typename std::enable_if<!std::is_pointer<_T>::value>::type* = 0);

    void check_vector_size(const mtv_type& t);
};

}} // namespace mdds::mtv

#include "collection_def.inl"