// Buffer.cpp

#include "Buffer.h"

#include <fstream>
#include <iomanip>
#include <iostream>
using std::cout;
#include <string>
using std::string;

void Buffer::display() const
{
    int ix_stop_line = ix_top_line + window_height;
    auto itr = itr_top_line;
    for (int i = ix_top_line; i < ix_stop_line; ++i) {
        if (i <= ls_lines.size()) {
            if (i == ix_current_line)
                cout << '>';
            else
                cout << ' ';
            cout << std::setw(5) << i+1;
            if (i < ls_lines.size()) {
                cout << "  " << *itr;
                ++itr;
            }
        }
        cout << '\n';
    }
}

bool Buffer::open(const string & new_file_name)
{
    std::ifstream file(new_file_name);
    if (!file) return false;

    ls_lines.clear();
    // Note: the list is cleared only after we know the file
    // opened successfully.

    string line;
    while (getline(file, line)) ls_lines.push_back(line);

    file_name = new_file_name;
    ix_current_line = ix_top_line = 0;
    itr_current_line = itr_top_line = ls_lines.begin();
    return true;
}

bool Buffer::save(const string & new_file_name)
{
    std::ofstream file(new_file_name);
    if (!file) return false;

    file_name = new_file_name;
    for (const string & s : ls_lines) file << s << '\n';
    return true;
}