mod world;

use std::sync::{Arc, Mutex};
use std::thread;
use std::time::Duration;
use tiny_http::{Header, Response, Server};
use world::World;

const INDEX: &str = include_str!("index.html");

fn main() {
    let seed = std::env::args()
        .nth(1)
        .and_then(|s| s.parse().ok())
        .unwrap_or(42u64);
    let addr = std::env::var("SIM_ADDR").unwrap_or_else(|_| "127.0.0.1:7878".into());
    let world = Arc::new(Mutex::new(World::new(seed)));

    {
        let world = Arc::clone(&world);
        thread::spawn(move || {
            loop {
                world.lock().unwrap().step();
                thread::sleep(Duration::from_millis(100));
            }
        });
    }

    let server = Server::http(&addr).expect("failed to bind");
    println!("Simulation running at http://{addr}");
    for req in server.incoming_requests() {
        let world = Arc::clone(&world);
        thread::spawn(move || {
            let (body, ctype) = match req.url() {
                "/" => (INDEX.to_string(), "text/html; charset=utf-8"),
                "/api/terrain" => (world.lock().unwrap().terrain_json(), "application/json"),
                "/api/state" => (world.lock().unwrap().state_json(), "application/json"),
                _ => {
                    let _ = req.respond(Response::from_string("not found").with_status_code(404));
                    return;
                }
            };
            let header = Header::from_bytes("Content-Type", ctype).unwrap();
            let _ = req.respond(Response::from_string(body).with_header(header));
        });
    }
}