use std::io::{Read, Write};
use std::net::{TcpListener, TcpStream};
use std::sync::{Arc, RwLock};

use anyhow::{bail, Result};

use bank::bank::Bank;

use crate::commands::Commands;
use crate::protocol;
use crate::threadpool::ThreadPool;

pub fn run(host: &str, threads: usize) -> Result<()> {
    let listener = TcpListener::bind(host)?;
    let pool = ThreadPool::new(threads);
    let cmds = Arc::new(Commands::new());

    let bank = Arc::new(RwLock::new(Bank::new()));

    for stream in listener.incoming() {
        let cmds = cmds.clone();
        let bank = bank.clone();

        let stream = stream?;

        pool.execute(move || {
            if let Err(e) = handle_connection(bank, &cmds, stream) {
                error!("{}", e);
            }
        });
    }

    Ok(())
}

fn handle_connection(bank: Arc<RwLock<Bank>>, cmds: &Commands, mut stream: TcpStream) -> Result<()> {
    const BUF_SIZE: usize = 64;

    let mut data: Vec<u8> = vec![];
    let mut buffer = [0; BUF_SIZE];

    let mut read = stream.read(&mut buffer)?;
    while read > 0 {
        data.append(&mut buffer[..read].to_vec());
        read = stream.read(&mut buffer)?;
    }

    if data[..2] != protocol::START {
        bail!("got {:?} as first bytes, not my problem", &data[..2]);
    }

    let cmd: u8 = (data[2] & 0b1111_0000) >> 4;
    trace!("got command {}", cmd);

    cmds.run(bank, cmd, &data[3..], &stream)?;

    stream.flush()?;

    Ok(())
}