use std::collections::HashMap;
use std::sync::Arc;
use http::code::Code;
use http::header::Header;
use http::request::Request;
use http::response::Response;
use tokio::net::{TcpListener, TcpStream};
use tokio::io::{AsyncReadExt, AsyncWriteExt};

use crate::bash::handle_script;

mod http;
mod bash;

async fn handle_response(mut socket: TcpStream, code: Code, body: String) {
    let mut res = Response::new();
    res.headers.put(Header::new("Content-Type", "text/plain"));
    res.status = code;
    res.body = Some(body);

    let res_str = res.deserialize();
    
    let _ = socket.write(res_str.as_bytes()).await;
}

async fn handle_connection(mut socket: TcpStream, config: Arc<HashMap<String, String>>) {
    
    let mut buf = [0; 1204];

    let n: usize = match socket.read(&mut buf).await {
        Ok(n) if n == 0 => return,
        Ok(n) => n as usize,
        Err(e) => {
            eprintln!("failed to read from socket; err = {:?}", e);
            return
        }
    };
    
    let str = String::from_utf8_lossy(&buf[0..n]);

    let Some(req) = Request::serialize(&str) else {
        return
    };


    let Some(script) = config.get(&req.uri.route) else {
        handle_response(socket, Code::MethodNotAllowed, "Method Not Allowed".to_owned()).await;
        return
    };

    match handle_script(script, req.body.as_ref()) {
        Ok(out) => {
            handle_response(socket, Code::Success, out).await;
        },
        Err(err) => {
            handle_response(socket, Code::MethodNotAllowed, err).await;
        },
    }
}

#[tokio::main]
async fn main() {

    let config = Arc::new(bash::load_config()); 

    let port = std::env::var("PORT")
        .unwrap_or_else(|_| String::from("8080"))
        .parse::<u16>()
        .unwrap_or_else(|_| 8080);

    let addr = format!("127.0.0.1:{port}");

    let Ok(listener) = TcpListener::bind(&addr).await else {
        println!("failed to bind {addr}");
        return
    };

    println!("listening to tcp requests on {addr}");

    loop {
        let Ok((socket, _)) = listener.accept().await else {
            println!("failed to accept new connection");
            continue
        };

        let config = config.clone();

        tokio::spawn(async move {
            handle_connection(socket, config).await;
        });
    }
}