#ifndef selection_hh_INCLUDED
#define selection_hh_INCLUDED

#include "buffer.hh"

namespace Kakoune
{

// A Selection holds a buffer range
//
// The Selection class manage a (first, last) buffer iterators pair.
// Selections are oriented, first may be > last, and inclusive.
// Selection updates it's iterators according to modifications made
// in the buffer.
struct Selection : public BufferChangeListener
{
    Selection(const BufferIterator& first, const BufferIterator& last);
    Selection(const Selection& other);
    ~Selection();

    Selection& operator=(const Selection& other);

    // returns min(first, last)
    BufferIterator begin() const;
    // returns max(first, last) + 1
    BufferIterator end() const;

    const BufferIterator& first() const { return m_first; }
    const BufferIterator& last()  const { return m_last; }

    BufferIterator& first() { return m_first; }
    BufferIterator& last()  { return m_last; }

    void merge_with(const Selection& selection);
    void avoid_eol();

private:
    void on_insert(const BufferIterator& begin,
                   const BufferIterator& end) override;
    void on_erase(const BufferIterator& begin,
                  const BufferIterator& end) override;

    void check_invariant() const;

    BufferIterator m_first;
    BufferIterator m_last;

    void register_with_buffer();
    void unregister_with_buffer();
};

typedef std::vector<Selection> SelectionList;
typedef std::vector<String> CaptureList;

// Selections are often associated with a capture list
// like when they are created from a regex match with
// capture groups.
struct SelectionAndCaptures
{
    Selection   selection;
    CaptureList captures;

    SelectionAndCaptures(const BufferIterator& first,
                         const BufferIterator& last,
                         CaptureList captures_list = {})
        : selection(first, last), captures(std::move(captures_list)) {}
    SelectionAndCaptures(const Selection& sel,
                         CaptureList captures_list = {})
        : selection(sel), captures(std::move(captures_list)) {}

    // helper to access the selection
    BufferIterator begin() const { return selection.begin(); }
    BufferIterator end() const { return selection.end(); }

    const BufferIterator& first() const { return selection.first(); }
    const BufferIterator& last() const { return selection.last(); }
};

inline bool overlaps(const SelectionAndCaptures& lhs,
                     const SelectionAndCaptures& rhs)
{
    return (lhs.first() <= rhs.first() and lhs.last() >= rhs.first()) or
           (lhs.first() <= rhs.last()  and lhs.last() >= rhs.last());
}


typedef std::vector<SelectionAndCaptures> SelectionAndCapturesList;

}

#endif // selection_hh_INCLUDED