use std::env;
use std::fs::File;
use std::io::BufReader;
use std::io::prelude::*;
use std::io;
use nom::bytes::complete::{tag, take_while, take_till};
use nom::character::complete::one_of;
use nom::sequence::Tuple;
use nom::branch::alt;
use nom::error::ErrorKind;
use nom::error::Error;

pub struct Buffer {
    has_changed: bool,
    buffer: Vec<Result<String, io::Error>>,
    current_line: usize,
}

impl Buffer {
    pub fn new(buffer: Vec<Result<String, io::Error>>) -> Self {
        let tmp = buffer.len().saturating_sub(1);
        Self {
            has_changed: false,
            buffer,
            current_line: tmp
        }
    }

    // Return the actual line of the buffer
    pub fn act(&self) -> usize {
        self.current_line
    }

    // change la ligne actuelle
    pub fn change_act(&mut self, new: usize) {
        // TODO check si > len
        self.current_line = new;
    }

    // affiche une ligne
    pub fn print_line(&self, nb: usize, print_numbers: bool) {
        if  nb >= self.buffer.len() {
            println!("?");
        } else if let Ok(line) = &self.buffer[nb] {
            if print_numbers {
                println!("{}\t{}", nb + 1, line);
            } else {
                println!("{}", line);
            }
        } else {
            println!("?");
        }
    }

    // affiche plusieurs lignes
    pub fn print_range(&self, first: usize, last: usize, print_numbers: bool) {
        for i in first..last {
            self.print_line(i, print_numbers);
        }
    }
}