use std::os::windows::io::{AsRawSocket, FromRawSocket, IntoRawSocket, RawSocket};
use std::time::Duration;
use std::{self, io};

use super::super::{co_io_result, EventData};
#[cfg(feature = "io_cancel")]
use crate::coroutine_impl::co_cancel_data;
use crate::coroutine_impl::{is_coroutine, CoroutineImpl, EventSource};
#[cfg(feature = "io_cancel")]
use crate::io::cancel::CancelIoData;
use crate::scheduler::get_scheduler;
use crate::sync::delay_drop::DelayDrop;
use miow::net::TcpStreamExt;
use windows_sys::Win32::Foundation::*;

pub struct SocketRead<'a> {
    io_data: EventData,
    buf: &'a mut [u8],
    socket: RawSocket,
    timeout: Option<Duration>,
    can_drop: DelayDrop,
    pub(crate) is_coroutine: bool,
}

impl<'a> SocketRead<'a> {
    pub fn new<T: AsRawSocket>(s: &T, buf: &'a mut [u8], timeout: Option<Duration>) -> Self {
        let socket = s.as_raw_socket();
        SocketRead {
            io_data: EventData::new(socket as HANDLE),
            buf,
            socket,
            timeout,
            can_drop: DelayDrop::new(),
            is_coroutine: is_coroutine(),
        }
    }

    pub fn done(&mut self) -> io::Result<usize> {
        co_io_result(&self.io_data, self.is_coroutine)
    }
}

impl<'a> EventSource for SocketRead<'a> {
    fn subscribe(&mut self, co: CoroutineImpl) {
        let s = get_scheduler();
        #[cfg(feature = "io_cancel")]
        let cancel = co_cancel_data(&co);
        let _g = self.can_drop.delay_drop();
        // if the event happened before this there would be something wrong
        // that the timer handle can't be removed in time
        // we must prepare the timer before call the API
        if let Some(dur) = self.timeout {
            s.get_selector().add_io_timer(&mut self.io_data, dur);
        }

        // prepare the co first
        self.io_data.co = Some(co);

        // call the overlapped read API
        co_try!(s, self.io_data.co.take().expect("can't get co"), unsafe {
            let socket: std::net::TcpStream = FromRawSocket::from_raw_socket(self.socket);
            let ret = socket.read_overlapped(self.buf, self.io_data.get_overlapped());
            // don't close the socket
            socket.into_raw_socket();
            ret
        });

        #[cfg(feature = "io_cancel")]
        {
            // register the cancel io data
            cancel.set_io(CancelIoData::new(&self.io_data));
            // re-check the cancel status
            if cancel.is_canceled() {
                unsafe { cancel.cancel() };
            }
        }
    }
}
