use std::{net::{UdpSocket, SocketAddr}, time::Instant};
use anyhow::{Result, bail};
use hashbrown::HashMap;
use nohash_hasher::BuildNoHashHasher;
use crate::{BINCODE_CONFIG, common::{ClientId, MAX_CLIENTS}};

pub struct ConnectedClient {
  id: ClientId,
  addr: SocketAddr,
  timeout: Instant,
}

#[derive(Clone, Copy, Debug)]
pub struct ServerConfig {
  pub max_clients: usize,
}
impl Default for ServerConfig {
  fn default() -> Self {
    Self {
      max_clients: MAX_CLIENTS,
    }
  }
}

pub struct Server {
  socket: UdpSocket,
  clients: HashMap<ClientId, ConnectedClient, BuildNoHashHasher<u8>>,
  config: ServerConfig,
}
impl Server {
  pub fn bind(addr: SocketAddr, config: ServerConfig) -> anyhow::Result<Self> {
    assert!(config.max_clients <= MAX_CLIENTS);
    let socket = UdpSocket::bind(addr)?;
    socket.set_nonblocking(true)?;
    //socket.set_broadcast(true)?;
    Ok(Self { 
      config,
      socket,
      clients: HashMap::with_capacity_and_hasher(MAX_CLIENTS, BuildNoHashHasher::default())
    })
  }
  fn add_client(&mut self, addr: SocketAddr) -> Result<ClientId> {
    let Some(id) = (1..=self.config.max_clients)
      .map(|x| ClientId::new(x as _).unwrap())
      .find(|i| self.clients.contains_key(i)) else {
        bail!("Server full");
      };
    if self.clients.iter().any(|x| x.1.addr == addr) {
      bail!("Already connected from the same address");
    }
    self.clients.insert(id, ConnectedClient {
      id,
      addr,
      timeout: Instant::now(),
    });
    log::info!("Client with id {id} connected");
    Ok(id)
  }
  pub fn update(&mut self) {
    let mut buf = Vec::new();
    loop {
      if self.socket.recv(&mut buf).is_ok() {
        todo!()
      } else {
        break
      }
      buf.clear()
    }
    
  }
}