// SPDX-License-Identifier: MIT
// Copyright Murad Karammaev, Nikita Kuzmin

use clap::Parser;
use std::{
    error::Error,
    fs::{File, OpenOptions},
    io::{Read, Write},
    path::PathBuf,
};
use toy_cpu_4bit::assembler::Assembler;

/// ToyCPU-4bit Assembler
#[derive(Parser)]
#[clap(version, about, long_about = None)]
struct Args {
    /// Path to input source code
    input: PathBuf,
    /// Path to output machine code
    output: PathBuf,
}

fn read_code(path: PathBuf) -> Result<String, Box<dyn Error>> {
    let mut code = String::new();
    File::open(path)?.read_to_string(&mut code)?;
    Ok(code)
}

fn write_code(path: PathBuf, code: [u8; 256]) -> Result<(), Box<dyn Error>> {
    let mut file = OpenOptions::new()
        .create(true)
        .write(true)
        .truncate(true)
        .open(path)?;
    file.write_all(&code)?;
    Ok(())
}

fn main() -> Result<(), Box<dyn Error>> {
    let args = Args::parse();
    let code = Assembler::new().assemble(&read_code(args.input)?)?;
    write_code(args.output, code)?;
    Ok(())
}