// Buffer.h

#include <fstream>
#include <iomanip>
#include <iostream>
#include <list>
#include <string>

class Buffer
{
public:
    void display() const;
    void erase();
    const std::string & get_file_name() const { return file_name_; }
    void insert(const std::string & new_line);
    void move_to_next_line();
    void move_to_previous_line();
    bool open(const std::string & new_file_name);
    bool save(const std::string & new_file_name);
    void set_window_height(int h) { window_height_ = h; }

private:
    std::list<std::string> ls_lines_;
    int ix_current_line_ = 0;
    int ix_top_line_ = 0;
//    auto itr_current_line_ = ls_lines_.end();   // error
    std::list<std::string>::iterator itr_current_line_ =
        ls_lines_.end();
    std::list<std::string>::iterator itr_top_line_ =
        ls_lines_.end();
    std::string file_name_;
    int window_height_;
};