use crate::Machine;

use std::fs;
use std::io;
use std::io::BufRead;
use std::io::Read;



	/// Load a file into a new machine
	/// 
	/// `panic!` when size is not 1, 2, 4 or 8
    /// `panic!` when the text does not represents instructions in hexadecimal
	/// 
	/// ### Parameters
	/// 
	/// - **path** the path of the file to load
	/// - **size** the number of bytes to write (1, 2, 4 or 8)
#[deprecated]
pub fn _load(path : &str, instruction_size: i32) -> Machine {
    let file = fs::File::open(path).expect("Wrong filename");
    let reader = io::BufReader::new(file);
    let mut machine = Machine::init_machine();

    for (i,line) in reader.lines().enumerate() {
        let res = u64::from_str_radix(&line.unwrap(), 16);
        match res {
            Ok(value) => {
                Machine::write_memory(&mut machine, instruction_size, i*instruction_size as usize, value);
            },
            _ => panic!()
        }
    }
    println!("{:x}", Machine::read_memory(& mut machine, 4, 0));
    machine
}

/// load a 32-bits binary file into the machine
/// 
/// ### Parameters
/// 
/// - **path** path of the file to load
/// - **machine** the machine where the bin file will be loaded
/// - **start_index** at which index of machine memory you want to start to load the program
/// 
/// Returns in a Result any io error
pub fn load(path: &str, machine: &mut Machine, start_index: usize) -> Result<(), std::io::Error> {
    let mut file = fs::File::open(path)?;
    let mut instructions: Vec<u32> = Default::default();
    loop {
        let mut buf: [u8; 4] = [0; 4];
        let res = file.read(&mut buf)?;
        if res == 0 {
            break; // eof
        } else {
            instructions.push(u32::from_le_bytes(buf));
        }
    }
    for i in 0..instructions.len() {
        machine.write_memory(4, 4 * i + start_index, instructions[i] as u64);
    }
    #[cfg(debug_assertions)]
    println!("{:04x?}", instructions); // only print loaded program in debug build
    Ok(())
}