#ifndef display_buffer_hh_INCLUDED
#define display_buffer_hh_INCLUDED

#include "face.hh"
#include "coord.hh"
#include "range.hh"
#include "string.hh"
#include "vector.hh"
#include "hash_map.hh"
#include <functional>

namespace Kakoune
{

class Buffer;
using BufferRange = Range<BufferCoord>;

class BufferIterator;
// Return a buffer iterator to the coord, tolerating one past end of line coords
BufferIterator get_iterator(const Buffer& buffer, BufferCoord coord);

struct DisplayAtom : public UseMemoryDomain<MemoryDomain::Display>
{
public:
    enum Type { Range, ReplacedRange, Text };

    DisplayAtom(const Buffer& buffer, BufferRange range, Face face = {})
        : face(face), m_type(Range), m_buffer(&buffer), m_range{range} {}

    DisplayAtom(const Buffer& buffer, BufferRange range, String str, Face face = {})
        : face(face), m_type(ReplacedRange), m_buffer(&buffer), m_range{range}, m_text{std::move(str)} {}

    DisplayAtom(String str, Face face)
        : face(face), m_type(Text), m_text(std::move(str)) {}

    explicit DisplayAtom(String str)
        : DisplayAtom(std::move(str), Face{}) {}

    StringView content() const;
    ColumnCount length() const;
    bool empty() const;

    const BufferCoord& begin() const
    {
        kak_assert(has_buffer_range());
        return m_range.begin;
    }

    const BufferCoord& end() const
    {
        kak_assert(has_buffer_range());
        return m_range.end;
    }

    void replace(String text)
    {
        if (m_type == Range)
            m_type = ReplacedRange;
        m_text = std::move(text);
    }

    void replace(const BufferRange& range)
    {
        kak_assert(m_type == Text);
        m_type = ReplacedRange;
        m_range = range;
    }

    bool has_buffer_range() const
    {
        return m_type == Range or m_type == ReplacedRange;
    }

    const Buffer& buffer() const { kak_assert(m_buffer); return *m_buffer; }

    Type type() const { return m_type; }

    ColumnCount trim_begin(ColumnCount count);
    ColumnCount trim_end_to_length(ColumnCount count);

    bool operator==(const DisplayAtom& other) const
    {
        return face == other.face and type() == other.type() and
               content() == other.content();
    }

public:
    Face face;

private:
    friend class DisplayLine;

    Type m_type;

    const Buffer* m_buffer = nullptr;
    BufferRange m_range;
    String m_text;
};

using AtomList = Vector<DisplayAtom, MemoryDomain::Display>;

class DisplayLine : public UseMemoryDomain<MemoryDomain::Display>
{
public:
    using iterator = AtomList::iterator;
    using const_iterator = AtomList::const_iterator;
    using value_type = AtomList::value_type;

    DisplayLine() = default;
    DisplayLine(AtomList atoms);
    DisplayLine(String str, Face face)
    { push_back({ std::move(str), face }); }

    iterator begin() { return m_atoms.begin(); }
    iterator end() { return m_atoms.end(); }

    const_iterator begin() const { return m_atoms.begin(); }
    const_iterator end() const { return m_atoms.end(); }

    const AtomList& atoms() const { return m_atoms; }

    ColumnCount length() const;
    const BufferRange& range() const { return m_range; }

    // Split atom pointed by it at buffer coord pos,
    // returns an iterator to the first atom
    iterator split(iterator it, BufferCoord pos);

    // Split atom pointed by it at its pos column,
    // returns an iterator to the first atom
    iterator split(iterator it, ColumnCount pos);

    iterator split(BufferCoord pos);

    iterator insert(iterator it, DisplayAtom atom);

    template<typename It>
    iterator insert(iterator pos, It beg, It end)
    {
        auto has_buffer_range = std::mem_fn(&DisplayAtom::has_buffer_range);
        if (auto first = std::find_if(beg, end, has_buffer_range); first != end)
        {
            auto& last = *std::find_if(std::reverse_iterator(end), std::reverse_iterator(first), has_buffer_range);
            m_range.begin = std::min(m_range.begin, (*first).begin());
            m_range.end = std::max(m_range.end, last.end());
        }
        return m_atoms.insert(pos, beg, end);
    }

    DisplayLine extract(iterator beg, iterator end);
    iterator erase(iterator beg, iterator end);
    DisplayAtom& push_back(DisplayAtom atom);

    // remove front from the begining of the line, and make sure
    // the line is less that col_count character
    bool trim(ColumnCount front, ColumnCount col_count);

    // remove front from the begining of the line + first_col, and make sure
    // the line is less that col_count character
    bool trim_from(ColumnCount first_col, ColumnCount front, ColumnCount col_count);

    // Merge together consecutive atoms sharing the same display attributes
    void optimize();
private:
    void compute_range();
    BufferRange m_range = { { INT_MAX, INT_MAX }, { INT_MIN, INT_MIN } };
    AtomList  m_atoms;
};

using DisplayLineList = Vector<DisplayLine>;
class FaceRegistry;

DisplayLine parse_display_line(StringView line, const FaceRegistry& faces, const HashMap<String, DisplayLine>& builtins = {});
DisplayLineList parse_display_line_list(StringView content, const FaceRegistry& faces, const HashMap<String, DisplayLine>& builtins = {});

class DisplayBuffer : public UseMemoryDomain<MemoryDomain::Display>
{
public:
    DisplayBuffer() {}

    DisplayLineList& lines() { return m_lines; }
    const DisplayLineList& lines() const { return m_lines; }

    // returns the smallest BufferRange which contains every DisplayAtoms
    const BufferRange& range() const { return m_range; }
    void compute_range();

    // Optimize all lines, set DisplayLine::optimize
    void optimize();

    void set_timestamp(size_t timestamp) { m_timestamp = timestamp; }
    size_t timestamp() const { return m_timestamp; }

private:
    DisplayLineList m_lines;
    BufferRange m_range;
    size_t m_timestamp = -1;
};

}

#endif // display_buffer_hh_INCLUDED