/// ------------Lamellar Example: Hello World-------------------------
/// This example highlights how to create a Lamellar Array
/// as well as use various iterators to print and modifiy its data
/// --------------------------------------------------------------------
use lamellar::array::prelude::*;

fn main() {
    let world = lamellar::LamellarWorldBuilder::new().build();
    let num_pes = world.num_pes();
    let my_pe = world.my_pe();
    let local_length = 10; //if you want to ensure each thread processes data make this >= LAMELLAR_THREADS environment variable
    let global_length = num_pes * local_length;

    let array = AtomicArray::<usize>::new(world.team(), global_length, Distribution::Block).block(); //Compare with Distribution::Cyclic

    //examine array before initialization
    if my_pe == 0 {
        //we only want to print the array on pe 0
        array
            .onesided_iter() // create a one sided iterator (manages data movement)
            .into_iter() // turn into a normal Rust iterator
            .for_each(|elem| print!("{elem} "));
        println!("");
    }
    world.barrier(); //wait for PE 0 to finish printing

    //initialize array, each PE will set its local elements equal to its ID
    array
        .dist_iter_mut() //create a mutable distributed iterator (i.e. data parallel iteration, similar to Rayon par_iter())
        .enumerate() // enumeration with respect to the global array
        .for_each(move |(i, elem)| {
            println!(
                "PE {:?} setting  array[{:?}]={:?} using thread {:?}",
                my_pe,
                i,
                my_pe,
                std::thread::current().id()
            );
            elem.store(my_pe); //"store" because this is an AtomicArray
        })
        .block();

    //wait for all pes to finish
    world.barrier();

    //examine array after initialization
    if my_pe == 0 {
        //we only want to print the array on pe 0
        array
            .onesided_iter() // create a one sided iterator (manages data movement)
            .into_iter() // turn into a normal Rust iterator
            .for_each(|elem| print!("{elem} "));
        println!("");
    }
    world.barrier(); //wait for PE 0 to finish printing
    array.print(); // now print the local data of each PE
}