use bevy::prelude::*;
use bevy_serial::{
    DataBits, FlowControl, Parity, SerialConfig, SerialPlugin, SerialReadEvent, SerialWriteEvent,
    StopBits,
};
use std::sync::Arc;
use std::time::Duration;

// to write data to serial port periodically
#[derive(Resource)]
struct SerialWriteTimer(Timer);

const SERIAL_PORT: &str = "/dev/ttyUSB0";
const SERIAL_LABEL: &str = "my_serial";

fn main() {
    App::new()
        .add_plugins(MinimalPlugins)
        // you can specify various configurations for multiple serial ports by this way
        .add_plugins(SerialPlugin::new_with_config(vec![SerialConfig {
            label: Some(SERIAL_LABEL.to_string()),
            port_name: SERIAL_PORT.to_string(),
            baud_rate: 115200,
            data_bits: DataBits::Eight,
            flow_control: FlowControl::None,
            parity: Parity::None,
            stop_bits: StopBits::One,
            timeout: Duration::from_millis(0),
            read_buffer_len: 2048,
            read_result_handler: Some(Arc::new(|label, result| {
                println!("Read result of {label}: {result:?}");
            })),
            write_result_handler: Some(Arc::new(|label, result| {
                println!("Write result of {label}: {result:?}");
            })),
        }]))
        // to write data to serial port periodically (every 1 second)
        .insert_resource(SerialWriteTimer(Timer::from_seconds(
            1.0,
            TimerMode::Repeating,
        )))
        // reading and writing from/to serial port is achieved via bevy's event system
        .add_systems(Update, read_serial)
        .add_systems(Update, write_serial)
        .run();
}

// reading event for serial port
fn read_serial(mut ev_serial: EventReader<SerialReadEvent>) {
    // you can get label of the port and received data buffer from `SerialReadEvent`
    for SerialReadEvent(label, buffer) in ev_serial.read() {
        let s = String::from_utf8(buffer.clone()).unwrap();
        println!("Received packet from {label}: {s}");
    }
}

// writing event for serial port
fn write_serial(
    mut ev_serial: EventWriter<SerialWriteEvent>,
    mut timer: ResMut<SerialWriteTimer>,
    time: Res<Time>,
) {
    // write msg to serial port every 1 second not to flood serial port
    if timer.0.tick(time.delta()).just_finished() {
        // you can write to serial port via `SerialWriteEvent` with label and buffer to write
        let buffer = b"Hello, bevy!";
        ev_serial.send(SerialWriteEvent(SERIAL_LABEL.to_string(), buffer.to_vec()));
    }
}