#[path = "../../../os-virtio-features/src/lib.rs"]
mod virtio_features;

use virtio_features::{Error, Negotiator, Phase, VERSION_1};

const OPTIONAL: u64 = 1 << 5;
const EXTRA: u64 = 1 << 28;

#[test]
fn os_virtio_features_positive() {
    let mut model = Negotiator::new();
    let generation = model.observe_reset(0).unwrap();
    model.acknowledge(generation, 1).unwrap();
    model.driver(generation, 3).unwrap();
    let offered = VERSION_1 | OPTIONAL | EXTRA | 1 << 60;
    model.propose(generation, offered, VERSION_1 | OPTIONAL | EXTRA,
        VERSION_1 | OPTIONAL | EXTRA, VERSION_1, &[(EXTRA, OPTIONAL)]).unwrap();
    assert_eq!(model.snapshot().phase, Phase::Proposed);
    model.observe_features_ok(generation, 0xb).unwrap();
    model.observe_driver_ok(generation, 0xf).unwrap();
    assert_eq!(model.snapshot().phase, Phase::DriverOk);
    let later = model.observe_reset(0).unwrap();
    assert!(later.0 > generation.0);
    assert_eq!(model.snapshot().accepted, 0);
    assert_eq!(model.acknowledge(generation, 1), Err(Error::StaleGeneration));
    model.release(later).unwrap();
    assert_eq!(model.snapshot().phase, Phase::Idle);
}

#[test]
fn os_virtio_features_negative() {
    let mut model = Negotiator::new();
    assert_eq!(model.observe_reset(1), Err(Error::ResetNotObserved));
    let generation = model.observe_reset(0).unwrap();
    assert_eq!(model.release(generation), Ok(()));
    let generation = model.observe_reset(0).unwrap();
    assert_eq!(model.driver(generation, 3), Err(Error::WrongPhase));
    assert_eq!(model.acknowledge(generation, 3), Err(Error::DeviceRejected));
    model.acknowledge(generation, 1).unwrap();
    model.driver(generation, 3).unwrap();
    let before = model.snapshot();
    assert_eq!(model.propose(generation, VERSION_1, VERSION_1 | OPTIONAL,
        VERSION_1 | OPTIONAL, VERSION_1, &[]), Err(Error::UnsupportedFeature));
    assert_eq!(model.propose(generation, VERSION_1 | OPTIONAL,
        VERSION_1 | OPTIONAL, VERSION_1, VERSION_1, &[]),
        Err(Error::UnsupportedFeature));
    assert_eq!(model.propose(generation, VERSION_1 | OPTIONAL,
        OPTIONAL, VERSION_1 | OPTIONAL, VERSION_1, &[]),
        Err(Error::MissingRequired));
    assert_eq!(model.propose(generation, VERSION_1 | OPTIONAL | EXTRA,
        VERSION_1 | EXTRA, VERSION_1 | OPTIONAL | EXTRA, VERSION_1,
        &[(EXTRA, OPTIONAL)]), Err(Error::MissingDependency));
    assert_eq!(model.snapshot(), before);
    model.propose(generation, VERSION_1 | OPTIONAL, VERSION_1,
        VERSION_1, VERSION_1, &[]).unwrap();
    let proposed = model.snapshot();
    assert_eq!(model.release(generation), Err(Error::StillActive));
    assert_eq!(model.propose(generation, VERSION_1, VERSION_1,
        VERSION_1, VERSION_1, &[]), Err(Error::WrongPhase));
    assert_eq!(model.snapshot(), proposed);
    assert_eq!(model.observe_features_ok(generation, 3), Err(Error::DeviceRejected));
    assert_eq!(model.snapshot().phase, Phase::Failed);
    assert_eq!(model.release(generation), Err(Error::StillActive));
    let next = model.observe_reset(0).unwrap();
    model.release(next).unwrap();
}