// Standard library
use std::error::Error;
use std::fs::File;
use std::io::BufReader;
use std::path::Path;

// External crates
use clap::Parser;
use log::{info, warn, error, debug, trace};

// Internal modules
mod types;
mod config;
mod simulator;

// Specific uses from modules
use crate::simulator::Simulator;

#[derive(Parser, Debug)]
#[command(
    version, 
    about="Orbital mechanics simulator", 
    long_about = "Given initial conditions you provide to --config, \
this program will numerically integrate and determinate their \
paths based off Newton's law of gravity.")]
struct Args {
    ///Config file for initial conditions
    #[arg(short, long)]
    config: String,

    ///Step size for simulation (seconds)
    #[arg(short, long, default_value_t = 10)]
    step_size: u8,
}

fn read_config<P: AsRef<Path>>(path: P) -> Result<config::ConfigFile, Box<dyn Error>> {
    let file = File::open(path)?;
    let reader = BufReader::new(file);

    let u = serde_json::from_reader(reader)?;

    Ok(u)
}
//fn parse_time(arg: &str) 

fn main() {
    env_logger::init();
    let args = Args::parse();

    info!("Loading initial parameters from {}", args.config);

    let conf = read_config(args.config).unwrap();
    for body in &conf.bodies {
        info!("Loaded {} with mass {:.3e} kg", body.name, body.mass);
        debug!("R_i = {:?}, V_i = {:?}", body.position, body.velocity);
    }


    let mut sim = Simulator::new(conf.bodies, 0.5);
    sim.run(2);
}