use crate::queue::{Message, MsgType, Queue};
use std::{
    collections::HashMap,
    sync::{
        mpsc::{channel, Receiver, Sender},
        Arc, Mutex,
    },
    thread::spawn,
};
use uuid::Uuid;

const RESPONS_TO: [MsgType; 3] = [MsgType::Document, MsgType::Error, MsgType::SessionValidated];

#[derive(Clone)]
pub struct ClientChannel {
    queue: Queue,
    registry: Arc<Mutex<HashMap<Uuid, Sender<Message>>>>,
}

impl ClientChannel {
    fn new(queue: Queue) -> Self {
        Self {
            queue: queue,
            registry: Arc::new(Mutex::new(HashMap::new())),
        }
    }

    pub fn send(&self, mut msg: Message) -> Receiver<Message> {
        let mut reg = self.registry.lock().unwrap();
        while reg.contains_key(&msg.get_id()) {
            msg.reset_id();
        }
        let (tx, rx) = channel();
        reg.insert(msg.get_id(), tx);
        self.queue.send(msg).unwrap();
        rx
    }

    fn reply(&self, msg: Message) {
        let mut reg = self.registry.lock().unwrap();
        match reg.remove(&msg.get_id()) {
            Some(tx) => tx.send(msg).unwrap(),
            None => {}
        }
    }
}

#[cfg(test)]
mod client_channels {
    use super::*;
    use std::time::Duration;

    static TIMEOUT: Duration = Duration::from_millis(500);

    #[test]
    fn fowards_message() {
        let msg_type = MsgType::Document;
        let reply_type = MsgType::Time;
        let queue = Queue::new();
        let (tx, rx) = channel();
        queue.add(tx, [msg_type.clone()].to_vec());
        let chan = ClientChannel::new(queue);
        let msg = Message::new(msg_type.clone());
        let client_rx = chan.send(msg.clone());
        let reply = rx.recv_timeout(TIMEOUT).unwrap();
        assert_eq!(reply.get_id(), msg.get_id());
        assert_eq!(reply.get_msg_type().clone(), msg_type);
        let client_reply = reply.reply(MsgType::Time);
        chan.reply(client_reply);
        let client_msg = client_rx.recv_timeout(TIMEOUT).unwrap();
        assert_eq!(client_msg.get_id(), msg.get_id());
        assert_eq!(client_msg.get_msg_type().clone(), reply_type);
    }

    #[test]
    fn no_duplicate_ids() {
        let (tx, rx) = channel();
        let queue = Queue::new();
        queue.add(tx, [MsgType::Time].to_vec());
        let chan = ClientChannel::new(queue);
        let msg1 = Message::new(MsgType::Time);
        let msg2 = msg1.reply(MsgType::Time);
        let rx1 = chan.send(msg1);
        let rx2 = chan.send(msg2);
        let queue1 = rx.recv_timeout(TIMEOUT).unwrap();
        let queue2 = rx.recv_timeout(TIMEOUT).unwrap();
        assert_ne!(queue1.get_id(), queue2.get_id());
        chan.reply(queue1.reply(MsgType::Document));
        chan.reply(queue2.reply(MsgType::Document));
        let reply1 = rx1.recv_timeout(TIMEOUT).unwrap();
        let reply2 = rx2.recv_timeout(TIMEOUT).unwrap();
        assert_eq!(reply1.get_id(), queue1.get_id());
        assert_eq!(reply2.get_id(), queue2.get_id());
    }

    #[test]
    fn ignore_unrequested() {
        let queue = Queue::new();
        let chan = ClientChannel::new(queue);
        chan.reply(Message::new(MsgType::Document));
    }
}

pub struct Client {
    channel: ClientChannel,
    rx: Receiver<Message>,
}

impl Client {
    fn new(chan: ClientChannel, rx: Receiver<Message>) -> Self {
        Self {
            channel: chan,
            rx: rx,
        }
    }

    pub fn start(queue: Queue) -> ClientChannel {
        let (tx, rx) = channel();
        queue.add(tx.clone(), RESPONS_TO.to_vec());
        let chan = ClientChannel::new(queue.clone());
        let client = Client::new(chan.clone(), rx);
        spawn(move || {
            client.listen();
        });
        chan
    }

    fn listen(&self) {
        loop {
            let msg = self.rx.recv().unwrap();
            self.channel.reply(msg);
        }
    }
}

#[cfg(test)]
mod clients {
    use super::*;
    use crate::session::sessions::create_validated_reply;
    use std::time::Duration;

    static TIMEOUT: Duration = Duration::from_millis(500);

    #[test]
    fn session_validated() {
        let queue = Queue::new();
        let (queue_tx, queue_rx) = channel();
        queue.add(queue_tx, [MsgType::SessionValidate].to_vec());
        let chan = Client::start(queue.clone());
        let chan_rx = chan.send(Message::new(MsgType::SessionValidate));
        let msg = queue_rx.recv_timeout(TIMEOUT).unwrap();
        let expected = create_validated_reply(msg);
        queue.send(expected.clone()).unwrap();
        let result = chan_rx.recv_timeout(TIMEOUT).unwrap();
        assert_eq!(result.get_id(), expected.get_id());
        assert_eq!(result.get_msg_type(), expected.get_msg_type());
    }

    #[test]
    fn document_return() {
        let queue = Queue::new();
        let (queue_tx, queue_rx) = channel();
        queue.add(queue_tx, [MsgType::DocumentRequest].to_vec());
        let chan = Client::start(queue.clone());
        let chan_rx = chan.send(Message::new(MsgType::DocumentRequest));
        let msg = queue_rx.recv_timeout(TIMEOUT).unwrap();
        let expected = msg.reply(MsgType::Document);
        queue.send(expected.clone()).unwrap();
        let result = chan_rx.recv_timeout(TIMEOUT).unwrap();
        assert_eq!(result.get_id(), expected.get_id());
        assert_eq!(result.get_msg_type(), expected.get_msg_type());
    }
}