use futures::executor::LocalPool;
use futures::prelude::*;
use futures::task::LocalSpawnExt;

// try to run like this
// cargo run --example parameters -- --ros-args -p key1:=[hello,world] -p key2:=5.5 -r __ns:=/demo -r __node:=my_node
// then run
// ros2 param get /demo/my_node key2 # (should return 5.5)
// ros2 param set /demo/my_node key2 false
// ros2 param get /demo/my_node key2 # (should return false)

fn main() -> Result<(), Box<dyn std::error::Error>> {
    // set up executor
    let mut pool = LocalPool::new();
    let spawner = pool.spawner();

    // set up ros node
    let ctx = r2r::Context::create()?;
    let mut node = r2r::Node::create(ctx, "to_be_replaced", "to_be_replaced")?;

    // make a parameter handler (once per node).
    // the parameter handler is optional, only spawn one if you need it.
    let (paramater_handler, parameter_events) = node.make_parameter_handler()?;
    // run parameter handler on your executor.
    spawner.spawn_local(paramater_handler)?;

    // parameter event stream. just print them
    spawner.spawn_local(async move {
        parameter_events
            .for_each(|(param_name, param_val)| {
                println!("parameter event: {} is now {:?}", param_name, param_val);
                future::ready(())
            })
            .await
    })?;

    println!("node name: {}", node.name()?);
    println!(
        "node fully qualified name: {}",
        node.fully_qualified_name()?
    );
    println!("node namespace: {}", node.namespace()?);

    // print all params every 5 seconds.
    let mut timer = node.create_wall_timer(std::time::Duration::from_secs(5))?;
    let params = node.params.clone();
    spawner.spawn_local(async move {
        loop {
            println!("node parameters");
            params.lock().unwrap().iter().for_each(|(k, v)| {
                println!("{} - {:?}", k, v);
            });
            let _elapsed = timer.tick().await.expect("could not tick");
        }
    })?;

    loop {
        node.spin_once(std::time::Duration::from_millis(100));
        pool.run_until_stalled();
    }
}