#ifndef BUFFERPANE_H
#define BUFFERPANE_H

#include "Buffer.h"
#include "Pane.h"
#include "Font.h"
#include "GL.h"
#include <memory>
#include "Window.h"

class BufferPane : public Pane
{
public:
    BufferPane(Window * window, std::shared_ptr<Buffer> buffer);
    void resize(int width, int height) override;
    void draw();
    void handle_key(uint32_t keyval);

protected:
    enum class CursorMovement : uint8_t
    {
        LEFT,
        RIGHT,
        UP,
        DOWN,
        SOL,
        EOL,
    };

    int effective_scroll_offset()
    {
        return std::min(m_scroll_offset, (m_rows - 1) / 2);
    }
    int draw_buffer_line(int screen_row, const Buffer::Iterator & start_of_line);
    int character_width(uint32_t character);
    void draw_buffer_character(int screen_column, int screen_row, uint32_t character);
    void draw_cursor(int x, int y, bool insert_mode);
    int rows_in_line(const Buffer::Iterator & start_of_line);
    int rows_in_line_with_iterator_offset(const Buffer::Iterator & start_of_line, const Buffer::Iterator & reference, int * iterator_row_offset);
    int screen_rows_below_line(const Buffer::Iterator & line);
    int screen_rows_above_line(const Buffer::Iterator & line, std::list<std::pair<int, Buffer::Iterator>> & backward_lines);
    int update_cursor_row(std::list<std::pair<int, Buffer::Iterator>> & backward_lines);
    void walk_line(const Buffer::Iterator & start_of_line, std::function<void(int, int, int, int, const Buffer::Iterator &)> callback);
    int determine_new_cursor_screen_row();
    int col_x(int col)
    {
        return col * m_window->font()->get_advance();
    }
    int row_y(int row)
    {
        return m_height - (row + 1) * m_window->font()->get_line_height();
    }
    void cursor_move(CursorMovement which);
    void forward_to_column(int column, bool allow_eol);
    size_t display_line() const { return m_iterator->line() + 1u; }
    size_t display_column() const;
    void draw_status_bar();

    Window * m_window;
    std::shared_ptr<Buffer> m_buffer;
    int m_rows;
    int m_columns;
    int m_scroll_offset;
    int m_cursor_screen_row;
    int m_cursor_virtual_column;
    std::shared_ptr<Buffer::Iterator> m_iterator;
    std::list<std::pair<int, Buffer::Iterator>> m_screen_lines;
    int m_target_column;
};

#endif