#![allow(unused_imports)]
mod client;
mod interserver;

use std::collections::HashMap;
use log::{trace, info, warn};
use std::pin::Pin;
use futures::future::{Future, join_all, FutureExt};
use async_std::sync::{Arc, Mutex, RwLock};

use std::fmt::Debug;

use async_std::io::prelude::{ReadExt, WriteExt};
//use crate::common::mainloop::client::client_accept_mainloop;
//use crate::common::mainloop::interserver::{ship_connect_mainloop, login_listen_mainloop};
pub use crate::common::mainloop::client::NetworkError;
use crate::common::mainloop::client::PacketReceiver;

use crate::common::serverstate::ClientId;
use crate::common::serverstate::{RecvServerPacket, SendServerPacket, ServerState, OnConnect};

use crate::common::interserver::{ServerId, InterserverActor};

use crate::patch::patch::PatchServerState;
use crate::login::login::LoginServerState;
use crate::login::character::CharacterServerState;
//use crate::ship::ship::ShipServerState;
use crate::entity::gateway::entitygateway::EntityGateway;

use libpso::crypto::{PSOCipher, NullCipher, CipherError};

use async_std::channel;




/*
pub fn patch_mainloop(patch_state: PatchServerState, patch_port: u16) -> Pin<Box<dyn Future<Output = ()>>> {
    let patch_state = Arc::new(Mutex::new(patch_state));
    let client_mainloop = client_accept_mainloop(patch_state, patch_port);
    Box::pin(client_mainloop)
}

pub fn login_mainloop<EG: EntityGateway + Clone + 'static>(login_state: LoginServerState<EG>, login_port: u16) -> Pin<Box<dyn Future<Output = ()>>> {
    let login_state = Arc::new(Mutex::new(login_state));
    let client_mainloop = client_accept_mainloop(login_state, login_port);
    Box::pin(client_mainloop)
}

pub fn character_mainloop<EG: EntityGateway + Clone + 'static>(character_state: CharacterServerState<EG>, character_port: u16, comm_port: u16) -> Pin<Box<dyn Future<Output = ()>>> {
    let character_state = Arc::new(Mutex::new(character_state));
    let client_mainloop = client_accept_mainloop(character_state.clone(), character_port);
    let ship_communication_mainloop = login_listen_mainloop(character_state, comm_port);
    Box::pin(join_all(vec![client_mainloop, ship_communication_mainloop]).map(|_| ()))
}


pub fn ship_mainloop<EG: EntityGateway + Clone + 'static>(ship_state: ShipServerState<EG>, ship_port: u16, comm_ip: std::net::Ipv4Addr, comm_port: u16) -> Pin<Box<dyn Future<Output = ()>>> {
    let ship_state = Arc::new(Mutex::new(ship_state));
    let client_mainloop = client_accept_mainloop(ship_state.clone(), ship_port);
    let login_communication_mainloop = ship_connect_mainloop(ship_state, comm_ip, comm_port);
    Box::pin(join_all(vec![client_mainloop, login_communication_mainloop]).map(|_| ()))
}
*/


#[derive(Debug)]
enum MessageReceiverError {
    //InvalidSize,
    InvalidPayload,
    //NetworkError(std::io::Error),
    Disconnected,
}

struct MessageReceiver {
    socket: async_std::net::TcpStream,
}

impl MessageReceiver {
    fn new(socket: async_std::net::TcpStream) -> MessageReceiver {
        MessageReceiver {
            socket,
        }
    }

    async fn recv<R: serde::de::DeserializeOwned + std::fmt::Debug>(&mut self) -> Result<R, MessageReceiverError> {
        let mut size_buf = [0u8; 4];
        self.socket.read_exact(&mut size_buf).await.map_err(|_| MessageReceiverError::Disconnected)?;
        let size = u32::from_le_bytes(size_buf) as usize;

        let mut payload = vec![0u8; size];
        self.socket.read_exact(&mut payload).await.map_err(|_| MessageReceiverError::Disconnected)?;
        let payload = String::from_utf8(payload).map_err(|_| MessageReceiverError::InvalidPayload)?;

        let msg = serde_json::from_str(&payload).map_err(|_| MessageReceiverError::InvalidPayload)?;
        Ok(msg)
    }
}


/*
enum ServerAction<S> {
    NewClient(ClientId, channel::Sender<S>),
    Packet(ClientId, S),
    Disconnect(ClientId),
}
*/

async fn recv_loop<STATE, S, R, C, E>(mut state: STATE,
                                      socket: async_std::net::TcpStream,
                                      client_id: ClientId,
                                      cipher: C,
                                      clients: Arc<RwLock<HashMap<ClientId, channel::Sender<S>>>>)
where
    STATE: ServerState<SendPacket=S, RecvPacket=R, Cipher=C, PacketError=E> + Send,
    S: SendServerPacket + Debug + Send,
    R: RecvServerPacket + Debug + Send,
    C: PSOCipher + Send,
    E: std::fmt::Debug + Send,
{
    let mut pkt_receiver = PacketReceiver::new(socket, cipher);
    loop {
        match pkt_receiver.recv_pkts::<R>().await {
            Ok(pkts) => {
                for pkt in pkts {
                    info!("[recv from {:?}] {:#?}", client_id, pkt);
                    match state.handle(client_id, pkt).await {
                        Ok(response) => {
                            for resp in response {
                                clients
                                    .read()
                                    .await
                                    .get(&resp.0)
                                    .unwrap()
                                    .send(resp.1)
                                    .await;
                            }
                        },
                        Err(err) => {
                            warn!("[client recv {:?}] error {:?} ", client_id, err);
                        }
                    }
                }
            },
            Err(err) => {
                match err {
                    NetworkError::ClientDisconnected => {
                        info!("[client recv {:?}] disconnected", client_id);
                        for pkt in state.on_disconnect(client_id).await.unwrap() {
                            clients
                                .read()
                                .await
                                .get(&pkt.0)
                                .unwrap()
                                .send(pkt.1)
                                .await;
                        }
                        clients
                            .write()
                            .await
                            .remove(&client_id);
                        break;
                    }
                    _ => {
                        warn!("[client {:?} recv error] {:?}", client_id, err);
                    }
                }
            }
        }
    }
}


async fn send_pkt<S, C>(socket: &mut async_std::net::TcpStream,
                        cipher: &mut C,
                        pkt: &S)
                        -> Result<(), NetworkError>
where
    S: SendServerPacket + std::fmt::Debug,
    C: PSOCipher,
{
    let buf = pkt.as_bytes();
    trace!("[send buf] {:?}", buf);
    let cbuf = cipher.encrypt(&buf)?;
    socket.write_all(&cbuf).await?;
    Ok(())
}

async fn send_loop<S, C>(mut socket: async_std::net::TcpStream, client_id: ClientId, mut cipher: C,  packet_queue: channel::Receiver<S>)
where
    S: SendServerPacket + std::fmt::Debug,
    C: PSOCipher,
{
    loop {
        let pkt = packet_queue.recv().await.unwrap();
        if let Err(err) = send_pkt(&mut socket, &mut cipher, &pkt).await {
            warn!("error sending pkt {:#?} to {:?} {:?}", pkt, client_id, err);
        }
    }
}

/*
pub async fn server_multiplex<STATE, S, R, E>(state: STATE, packet_queue: channel::Receiver<ServerAction<S>>)
where
    STATE: ServerState<SendPacket=S, RecvPacket=R, PacketError=E>,
    S: SendServerPacket + std::fmt::Debug,
    R: RecvServerPacket + std::fmt::Debug,
    E: std::fmt::Debug,
{
    let mut clients = HashMap::new();
    loop {
        let action = packet_queue.recv().await.unwrap();

        match action {
            ServerAction::NewClient(client_id, sender) => {
                clients.insert(client_id, sender);
            },
            ServerAction::Packet(client_id, pkt) => {
                if let Some(sender) = clients.get(&client_id) {
                    sender.send(pkt).await;
                }
            },
            ServerAction::Disconnect(client_id) => {
                clients.remove(&client_id);
            }
        }
        
    }
}
*/

pub async fn run_server<STATE, S, R, C, E>(mut state: STATE, port: u16)
where
    STATE: ServerState<SendPacket=S, RecvPacket=R, Cipher=C, PacketError=E> + Send + 'static,
    S: SendServerPacket + std::fmt::Debug + Send + 'static,
    R: RecvServerPacket + std::fmt::Debug + Send,
    C: PSOCipher + Send + 'static,
    E: std::fmt::Debug + Send,
{
    let listener = async_std::net::TcpListener::bind(&std::net::SocketAddr::from((std::net::Ipv4Addr::new(0,0,0,0), port))).await.unwrap();
    let mut id = 0;
    //let (packet_sender, packet_receiver) = async_std::channel::unbounded();

    let clients = Arc::new(RwLock::new(HashMap::new()));

    //let cstate = state.clone();
    /*
    async_std::task::spawn(async move {
        server_multiplex(cstate, packet_receiver).await
    });
     */
        
    loop {
        let (mut socket, addr) = listener.accept().await.unwrap();
        id += 1;
        
        let client_id = crate::common::serverstate::ClientId(id);
        info!("new client {:?} {:?} {:?}", client_id, socket, addr);

        let (client_tx, client_rx) = async_std::channel::unbounded();
        //packet_sender.send(ServerAction::NewClient()).await;

        clients
            .write()
            .await
            .insert(client_id, client_tx.clone());
        
        let mut cipher_in: Option<C> = None;
        let mut cipher_out: Option<C> = None;

        for action in state.on_connect(client_id).await.unwrap() {
            match action {
                OnConnect::Cipher(cin, cout) => {
                    cipher_in = Some(cin);
                    cipher_out = Some(cout);
                },
                OnConnect::Packet(pkt) => {
                    send_pkt(&mut socket, &mut NullCipher {}, &pkt).await;
                }
            }
        }

        let rstate = state.clone();
        let rsocket = socket.clone();
        let rclients = clients.clone();
        async_std::task::spawn(async move {
            /*
            rstate;
            rsocket;
            client_id;
            cipher_in.unwrap();
            rclients;
             */
            //client_tx.send(12).await
            recv_loop(rstate, rsocket, client_id, cipher_in.unwrap(), rclients).await
            //recv_loop2(rstate, rsocket, client_id, cipher_in.unwrap()).await
        });

        //let sstate = state.clone();
        async_std::task::spawn(async move {
            send_loop(socket, client_id, cipher_out.unwrap(), client_rx).await
        });
    }
}

/*
pub async fn listen_interserver<STATE, S, R, C, E>(state: STATE,  port: u16)
where
    STATE: InterserverActor<SendMessage=S, RecvMessage=R, Error=E>,
    S: serde::Serialize,
    R: serde::de::DeserializeOwned,
{
    let listener = async_std::net::TcpListener::bind(&std::net::SocketAddr::from((std::net::Ipv4Addr::new(0,0,0,0), port))).await.unwrap();
    let mut id = 0;

    loop {
        let (socket, addr) = listener.accept().await.unwrap();
        info!("new interserver connection: {:?} {:?}", socket, addr);

        id += 1;
        let server_id = crate::common::interserver::ServerId(id);
    }
}


pub async fn run_interserver_receiver<STATE, S, R, E>(state: STATE, ip: std::net::Ipv4Addr, port: u16)
where
    STATE: InterserverActor<SendMessage=S, RecvMessage=R, Error=E>,
    S: serde::Serialize,
    R: serde::de::DeserializeOwned,
{
    loop {
        
    }

    
}

pub async fn run_interserver_sender<STATE, S, R, E>(state: STATE, to_send: channel::Receiver<S>)
where
    STATE: InterserverActor<SendMessage=S, RecvMessage=R, Error=E>,
    S: serde::Serialize,
    R: serde::de::DeserializeOwned,
{
    loop {
        let msg = to_send.recv().await.unwrap();
        
        let response = state.on_action(msg);



        
    }

}
*/

async fn interserver_recv_loop<STATE, S, R, E>(mut state: STATE, server_id: ServerId, socket: async_std::net::TcpStream, ships: Arc<RwLock<HashMap<ServerId, channel::Sender<S>>>>)
where
    STATE: InterserverActor<SendMessage=S, RecvMessage=R, Error=E> + Send,
    S: serde::Serialize + Debug + Send,
    R: serde::de::DeserializeOwned + Debug + Send,
    E: Debug + Send,
{
    let mut msg_receiver = MessageReceiver::new(socket);

    loop {
        match msg_receiver.recv::<R>().await {
            Ok(msg) => {
                info!("[interserver recv {:?}] {:?}", server_id,  msg);
                match state.on_action(server_id, msg).await {
                    Ok(response) => {
                        for resp in response {
                            ships
                                .read()
                                .await
                                .get(&resp.0)
                                .unwrap()
                                .send(resp.1)
                                .await;
                        }
                    },
                    Err(err) => {
                        warn!("[interserver recv {:?}] error {:?}", server_id, err);
                    }
                }
            },
            Err(err) => {
                if let MessageReceiverError::Disconnected = err {
                    info!("[interserver recv {:?}] disconnected", server_id);
                    for (_, sender) in ships.read().await.iter() {
                        for pkt in state.on_disconnect(server_id).await {
                            ships
                                .read()
                                .await
                                .get(&pkt.0)
                                .unwrap()
                                .send(pkt.1)
                                .await;
                        }
                    }
                    ships
                        .write()
                        .await
                        .remove(&server_id);
                    break;
                }
                info!("[interserver recv {:?}] error {:?}", server_id, err);
            }
        }
    }
}

async fn interserver_send_loop<S>(server_id: ServerId, mut socket: async_std::net::TcpStream, to_send: channel::Receiver<S>)
where
    S: serde::Serialize + std::fmt::Debug,
{
    loop {
        let msg = to_send.recv().await.unwrap();
        let payload = serde_json::to_string(&msg);

        if let Ok(payload) = payload {
            let len_bytes = u32::to_le_bytes(payload.len() as u32);
            if let Err(err) = socket.write_all(&len_bytes).await {
                warn!("[interserver send {:?}] failed: {:?}", server_id, err);
                break;
            }
            if let Err(err) = socket.write_all(payload.as_bytes()).await {
                warn!("[interserver send {:?}] failed: {:?}", server_id, err);
                break;
            }
        }
    }
}

pub async fn run_interserver_listen<STATE, S, R, E>(mut state: STATE, port: u16)
where
    STATE: InterserverActor<SendMessage=S, RecvMessage=R, Error=E> + Send + 'static,
    S: serde::Serialize + Debug + Send + 'static,
    R: serde::de::DeserializeOwned + Debug + Send,
    E: Debug + Send,
{
    let listener = async_std::net::TcpListener::bind(&std::net::SocketAddr::from((std::net::Ipv4Addr::new(0,0,0,0), port))).await.unwrap();
    let mut id = 0;
    let ships = Arc::new(RwLock::new(HashMap::new()));

    loop {
        let (socket, addr) = listener.accept().await.unwrap();
        info!("[interserver listen] new server: {:?} {:?}", socket, addr);

        id += 1;
        let server_id = crate::common::interserver::ServerId(id);
        let (client_tx, client_rx) = async_std::channel::unbounded();

        //let sclient_tx = client_tx.clone();
        /*
        state.set_sender(server_id, Arc::new(Box::new(move |msg| {
            let sclient_tx = sclient_tx.clone();
            Box::new(async move {
                sclient_tx.send(msg).await;
            })})));
         */
        state.set_sender(server_id, client_tx.clone());

        ships
            .write()
            .await
            .insert(server_id, client_tx.clone());

        for msg in state.on_connect(server_id).await {
            if let Some(ship_sender) = ships.read().await.get(&msg.0) {
                ship_sender.send(msg.1).await;
            }
        }
        
        let rstate = state.clone();
        let rsocket = socket.clone();
        let rships = ships.clone();
        async_std::task::spawn(async move {
            interserver_recv_loop(rstate, server_id, rsocket, rships).await;
        });
        async_std::task::spawn(async move {
            interserver_send_loop(server_id, socket, client_rx).await;
        });
    }
}

pub async fn run_interserver_connect<STATE, S, R, E>(mut state: STATE, ip: std::net::Ipv4Addr, port: u16)
where
    STATE: InterserverActor<SendMessage=S, RecvMessage=R, Error=E> + Send + 'static,
    S: serde::Serialize + Debug + Send + 'static,
    R: serde::de::DeserializeOwned + Debug + Send,
    E: Debug + Send,
{
    let mut id = 0;
    
    loop {
        info!("[interserver connect] trying to connect to server");
        let socket = match async_std::net::TcpStream::connect((ip, port)).await {
            Ok(socket) => socket,
            Err(err) => {
                info!("err trying to connect to loginserv {:?}", err);
                async_std::task::sleep(std::time::Duration::from_secs(10)).await;
                continue;
            }
        };
        id += 1;
        let server_id = crate::common::interserver::ServerId(id);
        info!("[interserver connect] found loginserv: {:?} {:?}", server_id, socket);

        let (client_tx, client_rx) = async_std::channel::unbounded();

        state.set_sender(server_id, client_tx.clone());
        /*
        let sclient_tx = client_tx.clone();
        state.set_sender(server_id, Arc::new(Box::new(move |msg| {
            let sclient_tx = sclient_tx.clone();
            Box::new(async move {
                sclient_tx.send(msg).await;
            })})));
         */

        let other_server = vec![(server_id, client_tx.clone())].into_iter().collect();
        
        let rstate = state.clone();
        let rsocket = socket.clone();
        async_std::task::spawn(async move {
            interserver_recv_loop(rstate, server_id, rsocket, Arc::new(RwLock::new(other_server))).await;
        });
        let ssocket = socket.clone();
        async_std::task::spawn(async move {
            interserver_send_loop(server_id, ssocket, client_rx).await;
        });

        let mut buf = [0u8; 1];
        loop {
            let peek = socket.peek(&mut buf).await;
            match peek {
                Ok(len) if len == 0 => {
                    break
                },
                _ => {
                }
            }
        }
    }

}