use anyhow::Result;
use craftio_rs::{CraftAsyncReader, CraftAsyncWriter, CraftIo, CraftReader, CraftWriter};
use mcproto_rs::protocol::{HasPacketKind, PacketDirection, State};
use mcproto_rs::v1_19_3::{Packet761, Packet761Kind, RawPacket761};
use tokio::io::{BufReader};
use tokio::net::tcp::OwnedReadHalf;
use tokio::net::TcpStream;
use tokio::sync::mpsc;
use tokio::task::JoinHandle;

#[macro_export]
macro_rules! await_packet {
    ($packet_type:ident, $conn:expr) => {
        assert_packet!(
            $packet_type,
            $conn.wait_for_packet(Packet761Kind::$packet_type).await?
        )
    };
}

#[macro_export]
macro_rules! assert_packet {
    ($packet_type:ident, $obj:expr) => {
        if let Packet761::$packet_type(packet_data) = $obj {
            packet_data
        } else {
            panic!("Expected packet of type {}", stringify!($packet_type))
        }
    };
    ($packet_type:ident, $conn:expr, $errmgs:literal) => {
        assert_packet!(
            $packet_type,
            $conn
                .read_next_packet()
                .await?
                .ok_or(anyhow::anyhow!("Missing packet"))?
        )
    };
}
#[derive(Debug)]
enum WriterAction {
    Send(Packet761),
    SetState(State),
}

pub struct MinecraftClient {
    send_handle: JoinHandle<()>,
    send_tx: mpsc::UnboundedSender<WriterAction>,
    craft_reader: CraftReader<BufReader<OwnedReadHalf>>,
}

impl MinecraftClient {
    pub fn from_stream(stream: TcpStream) -> Self {
        let (read, write) = stream.into_split();
        let bufread = BufReader::new(read);
        let mut craft_writer = CraftWriter::wrap(write, PacketDirection::ClientBound);
        let craft_reader = CraftReader::wrap(bufread, PacketDirection::ServerBound);
        let (send_tx, mut send_recv) = mpsc::unbounded_channel::<WriterAction>();
        let send_handle = tokio::spawn(async move {
            loop {
                match send_recv.recv().await {
                    None => break,
                    Some(WriterAction::Send(packet)) => {
                        if let Err(err) = craft_writer.write_packet_async(packet).await {
                            println!("Failed to send packet {:?}", err);
                        }
                    }
                    Some(WriterAction::SetState(state)) => {
                        craft_writer.set_state(state);
                    }
                }
            }
            ()
        });
        MinecraftClient {
            craft_reader,
            send_tx,
            send_handle,
        }
    }

    pub async fn close_and_join(self) -> Result<()> {
        drop(self.send_tx);
        self.send_handle.await?;
        // The reader is closed when the writer half is dropped by the send task.
        Ok(())
    }

    pub fn set_state(&mut self, state: State) -> Result<()> {
        self.send_tx.send(WriterAction::SetState(state))?;
        self.craft_reader.set_state(state);
        Ok(())
    }

    pub async fn read_next_packet(&mut self) -> Result<Option<Packet761>> {
        if let Some(raw) = self.craft_reader.read_packet_async::<RawPacket761>().await? {
            // println!("Client -> Server: {:?}", raw);
            Ok(Some(raw))
        } else {
            Ok(None)
        }
    }
    pub async fn wait_for_packet(&mut self, packet_kind: Packet761Kind) -> Result<Packet761> {
        loop {
            if let Some(packet) = self.read_next_packet().await? {
                if packet.kind() == packet_kind {
                    return Ok(packet);
                }
                println!("Skipping packet {:?}", packet);
            }
        }
    }

    pub fn send_packet(&self, packet: Packet761) -> Result<()> {
        // println!("Server -> Client: {:?}", packet);
        self.send_tx.send(WriterAction::Send(packet))?;
        Ok(())
    }

    pub fn send_all_packets(&self, packets: Vec<Packet761>) -> Result<()> {
        for x in packets {
            self.send_packet(x)?;
        }
        Ok(())
    }
}