use crate::error::DiscordError;
use crate::gateway::{GateMessage, GateUrl, OpCode};
use crate::route::Route;
use crate::{request_url, GATEWAY_VERSION};
use log::info;
use serde_json::Value;
use std::time::Duration;
use tungstenite::connect;
use ureq::{Agent, AgentBuilder};

#[derive(Debug)]
pub struct Client {
    http: Agent,
    secret: String,
}

impl Client {
    pub fn new(secret: impl AsRef<str>) -> Self {
        let http = AgentBuilder::new().build();
        let secret = secret.as_ref().to_string();

        Client { http, secret }
    }

    pub fn run(self) -> Result<(), DiscordError> {
        let url = request_url(Route::Gateway);
        let url = format!("{}?v={}&encoding=json", url, GATEWAY_VERSION);
        let gateurl: GateUrl = self.http.get(&url).call()?.into_json()?;

        info!("Connecting to websocket stream.");
        let (mut socket, _response) = connect(&gateurl.url)?;
        match socket.get_mut() {
            tungstenite::stream::Stream::Plain(s) => {
                s.set_nonblocking(true)?;
            }
            tungstenite::stream::Stream::Tls(s) => {
                s.get_mut().set_nonblocking(true)?;
            }
        };

        info!("Reading hello message.");
        let hello: GateMessage = serde_json::from_str(&socket.read_message()?.into_text()?)?;
        assert_eq!(hello.op, OpCode::Hello as u8);

        let interval = hello.d.get("heartbeat_interval").unwrap().as_u64().unwrap();
        info!("Heartbeat interval is {} ms.", &interval);

        let heartbeat = GateMessage {
            op: OpCode::HeartBeat as u8,
            d: Value::default(),
            s: None,
            t: None,
        };

        let mut delay = 0;
        loop {
            match socket.read_message() {
                Ok(m) => {
                    let message: GateMessage = serde_json::from_str(&m.into_text()?)?;
                    match message.op {
                        1 => {
                            info!("Re-heartbeating.");
                            socket.write_message(serde_json::to_string(&heartbeat)?.into())?;
                        }
                        11 => info!("Heartbeat acknowledged."),
                        _ => info!("Other message: {:?}", &message),
                    }
                }
                Err(tungstenite::Error::Io(e)) if e.kind() == std::io::ErrorKind::WouldBlock => {}
                Err(e) => return Err(e.into()),
            };

            std::thread::sleep(Duration::from_millis(100));
            delay += 100;

            if delay >= interval {
                info!("Heartbeating.");
                socket.write_message(serde_json::to_string(&heartbeat)?.into())?;
                delay = 0;
            }
        }
    }
}