//! Tests for gossip verification of voluntary exits, propser slashings and attester slashings.

#![cfg(not(debug_assertions))]

#[macro_use]
extern crate lazy_static;

use beacon_chain::observed_operations::ObservationOutcome;
use beacon_chain::test_utils::{
    AttestationStrategy, BeaconChainHarness, BlockStrategy, DiskHarnessType,
};
use sloggers::{null::NullLoggerBuilder, Build};
use std::sync::Arc;
use store::{LevelDB, StoreConfig};
use tempfile::{tempdir, TempDir};
use types::test_utils::{
    AttesterSlashingTestTask, ProposerSlashingTestTask, TestingAttesterSlashingBuilder,
    TestingProposerSlashingBuilder, TestingVoluntaryExitBuilder,
};
use types::*;

pub const VALIDATOR_COUNT: usize = 24;

lazy_static! {
    /// A cached set of keys.
    static ref KEYPAIRS: Vec<Keypair> =
        types::test_utils::generate_deterministic_keypairs(VALIDATOR_COUNT);
}

type E = MinimalEthSpec;
type TestHarness = BeaconChainHarness<DiskHarnessType<E>>;
type HotColdDB = store::HotColdDB<E, LevelDB<E>, LevelDB<E>>;

fn get_store(db_path: &TempDir) -> Arc<HotColdDB> {
    let spec = E::default_spec();
    let hot_path = db_path.path().join("hot_db");
    let cold_path = db_path.path().join("cold_db");
    let config = StoreConfig::default();
    let log = NullLoggerBuilder.build().expect("logger should build");
    Arc::new(
        HotColdDB::open(&hot_path, &cold_path, config, spec, log)
            .expect("disk store should initialize"),
    )
}

fn get_harness(store: Arc<HotColdDB>, validator_count: usize) -> TestHarness {
    let harness = BeaconChainHarness::new_with_disk_store(
        MinimalEthSpec,
        store,
        KEYPAIRS[0..validator_count].to_vec(),
    );
    harness.advance_slot();
    harness
}

#[test]
fn voluntary_exit() {
    let db_path = tempdir().unwrap();
    let store = get_store(&db_path);
    let harness = get_harness(store.clone(), VALIDATOR_COUNT);
    let spec = &harness.chain.spec;

    harness.extend_chain(
        (E::slots_per_epoch() * (spec.shard_committee_period + 1)) as usize,
        BlockStrategy::OnCanonicalHead,
        AttestationStrategy::AllValidators,
    );

    let head_info = harness.chain.head_info().unwrap();

    let make_exit = |validator_index: usize, exit_epoch: u64| {
        TestingVoluntaryExitBuilder::new(Epoch::new(exit_epoch), validator_index as u64).build(
            &KEYPAIRS[validator_index].sk,
            &head_info.fork,
            head_info.genesis_validators_root,
            spec,
        )
    };

    let validator_index1 = VALIDATOR_COUNT - 1;
    let validator_index2 = VALIDATOR_COUNT - 2;

    let exit1 = make_exit(validator_index1, spec.shard_committee_period);

    // First verification should show it to be fresh.
    assert!(matches!(
        harness
            .chain
            .verify_voluntary_exit_for_gossip(exit1.clone())
            .unwrap(),
        ObservationOutcome::New(_)
    ));

    // Second should not.
    assert!(matches!(
        harness
            .chain
            .verify_voluntary_exit_for_gossip(exit1.clone()),
        Ok(ObservationOutcome::AlreadyKnown)
    ));

    // A different exit for the same validator should also be detected as a duplicate.
    let exit2 = make_exit(validator_index1, spec.shard_committee_period + 1);
    assert!(matches!(
        harness.chain.verify_voluntary_exit_for_gossip(exit2),
        Ok(ObservationOutcome::AlreadyKnown)
    ));

    // Exit for a different validator should be fine.
    let exit3 = make_exit(validator_index2, spec.shard_committee_period);
    assert!(matches!(
        harness
            .chain
            .verify_voluntary_exit_for_gossip(exit3)
            .unwrap(),
        ObservationOutcome::New(_)
    ));
}

#[test]
fn proposer_slashing() {
    let db_path = tempdir().unwrap();
    let store = get_store(&db_path);
    let harness = get_harness(store.clone(), VALIDATOR_COUNT);
    let spec = &harness.chain.spec;

    let head_info = harness.chain.head_info().unwrap();

    let validator_index1 = VALIDATOR_COUNT - 1;
    let validator_index2 = VALIDATOR_COUNT - 2;

    let make_slashing = |validator_index: usize| {
        TestingProposerSlashingBuilder::double_vote::<E>(
            ProposerSlashingTestTask::Valid,
            validator_index as u64,
            &KEYPAIRS[validator_index].sk,
            &head_info.fork,
            head_info.genesis_validators_root,
            spec,
        )
    };

    let slashing1 = make_slashing(validator_index1);

    // First slashing for this proposer should be allowed.
    assert!(matches!(
        harness
            .chain
            .verify_proposer_slashing_for_gossip(slashing1.clone())
            .unwrap(),
        ObservationOutcome::New(_)
    ));
    // Duplicate slashing should be detected.
    assert!(matches!(
        harness
            .chain
            .verify_proposer_slashing_for_gossip(slashing1.clone())
            .unwrap(),
        ObservationOutcome::AlreadyKnown
    ));

    // Different slashing for the same index should be rejected
    let slashing2 = ProposerSlashing {
        signed_header_1: slashing1.signed_header_2,
        signed_header_2: slashing1.signed_header_1,
    };
    assert!(matches!(
        harness
            .chain
            .verify_proposer_slashing_for_gossip(slashing2)
            .unwrap(),
        ObservationOutcome::AlreadyKnown
    ));

    // Proposer slashing for a different index should be accepted
    let slashing3 = make_slashing(validator_index2);
    assert!(matches!(
        harness
            .chain
            .verify_proposer_slashing_for_gossip(slashing3)
            .unwrap(),
        ObservationOutcome::New(_)
    ));
}

#[test]
fn attester_slashing() {
    let db_path = tempdir().unwrap();
    let store = get_store(&db_path);
    let harness = get_harness(store.clone(), VALIDATOR_COUNT);
    let spec = &harness.chain.spec;

    let head_info = harness.chain.head_info().unwrap();

    // First third of the validators
    let first_third = (0..VALIDATOR_COUNT as u64 / 3).collect::<Vec<_>>();
    // First half of the validators
    let first_half = (0..VALIDATOR_COUNT as u64 / 2).collect::<Vec<_>>();
    // Last third of the validators
    let last_third = (2 * VALIDATOR_COUNT as u64 / 3..VALIDATOR_COUNT as u64).collect::<Vec<_>>();
    // Last half of the validators
    let second_half = (VALIDATOR_COUNT as u64 / 2..VALIDATOR_COUNT as u64).collect::<Vec<_>>();

    let signer = |idx: u64, message: &[u8]| {
        KEYPAIRS[idx as usize]
            .sk
            .sign(Hash256::from_slice(&message))
    };

    let make_slashing = |validators| {
        TestingAttesterSlashingBuilder::double_vote::<_, E>(
            AttesterSlashingTestTask::Valid,
            validators,
            signer,
            &head_info.fork,
            head_info.genesis_validators_root,
            spec,
        )
    };

    // Slashing for first third of validators should be accepted.
    let slashing1 = make_slashing(&first_third);
    assert!(matches!(
        harness
            .chain
            .verify_attester_slashing_for_gossip(slashing1.clone())
            .unwrap(),
        ObservationOutcome::New(_)
    ));

    // Overlapping slashing for first half of validators should also be accepted.
    let slashing2 = make_slashing(&first_half);
    assert!(matches!(
        harness
            .chain
            .verify_attester_slashing_for_gossip(slashing2.clone())
            .unwrap(),
        ObservationOutcome::New(_)
    ));

    // Repeating slashing1 or slashing2 should be rejected
    assert!(matches!(
        harness
            .chain
            .verify_attester_slashing_for_gossip(slashing1.clone())
            .unwrap(),
        ObservationOutcome::AlreadyKnown
    ));
    assert!(matches!(
        harness
            .chain
            .verify_attester_slashing_for_gossip(slashing2.clone())
            .unwrap(),
        ObservationOutcome::AlreadyKnown
    ));

    // Slashing for last half of validators should be accepted (distinct from all existing)
    let slashing3 = make_slashing(&second_half);
    assert!(matches!(
        harness
            .chain
            .verify_attester_slashing_for_gossip(slashing3)
            .unwrap(),
        ObservationOutcome::New(_)
    ));
    // Slashing for last third (contained in last half) should be rejected.
    let slashing4 = make_slashing(&last_third);
    assert!(matches!(
        harness
            .chain
            .verify_attester_slashing_for_gossip(slashing4)
            .unwrap(),
        ObservationOutcome::AlreadyKnown
    ));
}