#[macro_use(shards)]
extern crate reed_solomon_erasure;

use reed_solomon_erasure::galois_8::ReedSolomon;
// or use the following for Galois 2^16 backend
// use reed_solomon_erasure::galois_16::ReedSolomon;

fn main () {
    let r = ReedSolomon::new(3, 2).unwrap(); // 3 data shards, 2 parity shards

    let mut master_copy = shards!(
        [0, 1,  2,  3],
        [4, 5,  6,  7],
        [8, 9, 10, 11],
        [0, 0,  0,  0], // last 2 rows are parity shards
        [0, 0,  0,  0]
    );

    // Construct the parity shards
    r.encode(&mut master_copy).unwrap();

    // Make a copy and transform it into option shards arrangement
    // for feeding into reconstruct_shards
    let mut shards: Vec<_> = master_copy.iter().cloned().map(Some).collect();

    // We can remove up to 2 shards, which may be data or parity shards
    shards[0] = None;
    shards[4] = None;

    // Try to reconstruct missing shards
    r.reconstruct(&mut shards).unwrap();

    // Convert back to normal shard arrangement
    let result: Vec<_> = shards.into_iter().filter_map(|x| x).collect();

    assert!(r.verify(&result).unwrap());
    assert_eq!(master_copy, result);
}