use crate::config::save_config;
use crate::ui_code::{AppState, SocketConnectionUpdate};
use crate::JoystickThreadUpdate;

use async_channel::{Receiver, Sender};
use gilrs::{ev::filter::FilterFn, Axis, Button, Event, EventType, Filter, Gilrs, GilrsBuilder};
use std::net::TcpStream;
use std::panic::{self, AssertUnwindSafe};
use std::{
    sync::{atomic::AtomicBool, Arc},
    time::{Duration, Instant},
};
use websocket::client::{sync::Client, ClientBuilder};
use websocket::Message;

static MAX_RETRY_ATTEMPTS: u32 = 10;


struct SocketState {
    pub ip: String,
    pub port: i32,
    pub socket: Option<Client<TcpStream>>,
}

impl SocketState {
    fn is_connected(&self ) -> bool {
        self.socket.is_some()
    }

    fn close_websocket(&mut self) {
        if let Some(ref mut x) = self.socket {
            println!("closing websocket");
            x.send_message(&Message::close()).unwrap();
            x.shutdown().unwrap();
            self.socket = None;
        }
    }

    fn reconnect_websocket(&mut self) -> bool {
        if self.ip.is_empty() {
            self.socket = None;
            return false
        }

        if let Ok(mut val) =
            ClientBuilder::new(format!("ws://{}:{}", &self.ip, self.port).as_str())
        {
            if let Ok(val2) = val.connect_insecure() {
                self.socket = Some(val2);
                true
            } else {
                println!("couldn't connect websocket! : Step 1");
                self.socket = None;
                false
            }
        } else {
            println!("couldn't connect websocket! : Step 2");
            self.socket = None;
            false
        }
    }
}

struct JTState {
    pub socket: SocketState,
    pub try_reconnect: bool,
    pub retry_attempts: u32,

    pub curr_x: i32,
    pub curr_y: i32,

    pub last_update_time: Instant,
}

struct UnknownSlayer;
impl FilterFn for UnknownSlayer {
    fn filter(&self, ev: Option<Event>, _gilrs: &mut Gilrs) -> Option<Event> {
        match ev {
            Some(Event {
                event: EventType::ButtonPressed(Button::Unknown, ..),
                id,
                ..
            })
            | Some(Event {
                event: EventType::ButtonReleased(Button::Unknown, ..),
                id,
                ..
            })
            | Some(Event {
                event: EventType::AxisChanged(Axis::Unknown, ..),
                id,
                ..
            }) => Some(Event::new(id, EventType::Dropped)),
            _ => ev,
        }
    }
}


pub fn joystick_websocket_loop(
    tx: Sender<JoystickThreadUpdate>,
    do_run: Arc<AtomicBool>,
    rx: Receiver<SocketConnectionUpdate>,
) {
    let mut gilrs = GilrsBuilder::new().set_update_state(false).build().unwrap();

    let mut state = JTState {
        socket: SocketState {
            ip: String::new(),
            port: 0,
            socket: None
        },
        try_reconnect: false,
        retry_attempts: 0,
        
        curr_x: 0,
        curr_y: 0,

        last_update_time: Instant::now(),
    };


    loop {
        match rx.try_recv() {
            Ok(msg) => {
                state.socket.ip = msg.ip;
                state.socket.port = msg.port as i32;

                save_config(&AppState {
                    ip: state.socket.ip.clone(),
                    port: state.socket.port as u32,
                });

                println!("ws://{}:{}", state.socket.ip, state.socket.port);

                if msg.start_websocket {
                    if !state.socket.is_connected() {
                        state.socket.reconnect_websocket();
                    }
                } else if state.socket.is_connected() {
                        state.socket.close_websocket();
                }
            }
            Err(async_channel::TryRecvError::Closed) => break,
            Err(async_channel::TryRecvError::Empty) => {}
        }

        if state.try_reconnect {
            if state.retry_attempts > MAX_RETRY_ATTEMPTS { state.try_reconnect = false; }

            if state.socket.is_connected() { 
                state.try_reconnect = false;
            } else if state.socket.reconnect_websocket() {
                state.try_reconnect = false;
                state.retry_attempts = 0;
            }
            else {
                state.retry_attempts += 1;
            }

        }

        // catch unwind because some buttons on the joystick will panic the gilrs object
        match panic::catch_unwind(AssertUnwindSafe(|| {
            // get the next event, and if it is an axis we are interested in, update the
            // corresponding variable
            while let Some(evt) = gilrs.next_event().filter_ev(&UnknownSlayer {}, &mut gilrs) {
                match evt.event {
                    gilrs::EventType::AxisChanged(gilrs::Axis::LeftStickY, val, _) => {
                        state.curr_y = (val * 100.0) as i32;
                        if state.curr_y > -10 && state.curr_y < 10 {
                            state.curr_y = 0;
                        }
                    }
                    gilrs::EventType::AxisChanged(gilrs::Axis::LeftStickX, val, _) => {
                        state.curr_x = (val * 100.0) as i32;
                        if state.curr_x > -10 && state.curr_x < 10 {
                            state.curr_x = 0;
                        }
                    }
                    _ => {}
                }
            }
        })) {
            Ok(_) => { }
            Err(_) => {
                println!("panic-causing event captured in gilrs event handler")
            }
        }

        if state.socket.is_connected() 
            && Instant::now().duration_since(state.last_update_time) >= Duration::from_millis(150)
        {
            let mut message: String;
            if state.curr_y > 0 {
                message = format!("D{}:", state.curr_y);
            } else {
                message = format!("U{}:", state.curr_y.abs());
            }

            if state.curr_x > 0 {
                message.push_str(&format!("R{}", state.curr_x));
            } else {
                message.push_str(&format!("L{}", state.curr_x.abs()));
            }

            if let Some(ref mut websocket_tx) = state.socket.socket {
                if websocket_tx.send_message(&Message::text(message)).is_ok() {
                } else {
                    state.socket.close_websocket();
                }
            }
            state.last_update_time = Instant::now();
            continue;
        }

        match tx.try_send(JoystickThreadUpdate {
            connected: state.socket.is_connected(),
            x_axis: Some(state.curr_x.to_string()),
            y_axis: Some(state.curr_y.to_string()),
        }) {
            Ok(_) => {}
            Err(async_channel::TrySendError::Closed(_)) => break,
            Err(async_channel::TrySendError::Full(_)) => {}
        }

        if !do_run.load(std::sync::atomic::Ordering::SeqCst) {
            println!("Exiting thread");
            break;
        }
        std::thread::sleep(Duration::from_millis(25));
    }
}