use crossterm::event::{self, Event as CrosstermEvent};
use std::thread;

#[cfg(test)]
use mockall::automock;

use super::event::{Event, EventError, EventSender};

#[cfg_attr(test, automock)]
pub trait EventListener {
    fn spawn(self) -> thread::JoinHandle<EventError>;
}

pub struct TuiEventListener {
    events: EventSender,
}

// GRCOV_EXCL_START
impl TuiEventListener {
    pub fn new(events: EventSender) -> Self {
        TuiEventListener { events }
    }
}

impl EventListener for TuiEventListener {
    fn spawn(self) -> thread::JoinHandle<EventError> {
        thread::spawn(move || {
            loop {
                // Put this inside an if event::poll {...} if the display needs to be refreshed on a
                // periodic basis. See
                // https://github.com/tui-rs-revival/rust-tui-template/blob/master/src/event.rs.
                match event::read() {
                    Ok(event) => {
                        if let Err(err) = match event {
                            CrosstermEvent::Key(e) => self.events.send(Event::Key(e)),
                            CrosstermEvent::Mouse(e) => self.events.send(Event::Mouse(e)),
                            CrosstermEvent::Resize(w, h) => self.events.send(Event::Resize(w, h)),
                            _ => unimplemented!(),
                        } {
                            return err;
                        }
                    }
                    Err(err) => return EventError::Io(err),
                };
            }
        })
    }
}
// GRCOV_EXCL_STOP