// Copyright 2015-2018 Parity Technologies (UK) Ltd.
// This file is part of Parity.

// Parity is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// Parity is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with Parity.  If not, see <http://www.gnu.org/licenses/>.

mod helpers;
mod tx_builder;

use self::{
    helpers::{DummyScoring, NonceReady},
    tx_builder::TransactionBuilder,
};

use std::sync::Arc;

use super::*;
use ethereum_types::{Address, H256, U256};

#[derive(Debug, PartialEq)]
pub struct Transaction {
    pub hash: H256,
    pub nonce: U256,
    pub gas_price: U256,
    pub gas: U256,
    pub sender: Address,
    pub mem_usage: usize,
}

impl VerifiedTransaction for Transaction {
    type Hash = H256;
    type Sender = Address;

    fn hash(&self) -> &H256 {
        &self.hash
    }
    fn mem_usage(&self) -> usize {
        self.mem_usage
    }
    fn sender(&self) -> &Address {
        &self.sender
    }
    fn is_service(&self) -> bool {
        false
    }
}

pub type SharedTransaction = Arc<Transaction>;

type TestPool = Pool<Transaction, DummyScoring>;

impl TestPool {
    pub fn with_limit(max_count: usize) -> Self {
        Self::with_options(Options {
            max_count,
            ..Default::default()
        })
    }
}

fn import<S: Scoring<Transaction>, L: Listener<Transaction>>(
    txq: &mut Pool<Transaction, S, L>,
    tx: Transaction,
) -> Result<Arc<Transaction>, Error<<Transaction as VerifiedTransaction>::Hash>> {
    txq.import(tx, &mut DummyScoring::default())
}

#[test]
fn should_clear_queue() {
    // given
    let b = TransactionBuilder::default();
    let mut txq = TestPool::default();
    assert_eq!(
        txq.light_status(),
        LightStatus {
            mem_usage: 0,
            transaction_count: 0,
            senders: 0,
        }
    );
    let tx1 = b.tx().nonce(0).new();
    let tx2 = b.tx().nonce(1).mem_usage(1).new();

    // add
    import(&mut txq, tx1).unwrap();
    import(&mut txq, tx2).unwrap();
    assert_eq!(
        txq.light_status(),
        LightStatus {
            mem_usage: 1,
            transaction_count: 2,
            senders: 1,
        }
    );

    // when
    txq.clear();

    // then
    assert_eq!(
        txq.light_status(),
        LightStatus {
            mem_usage: 0,
            transaction_count: 0,
            senders: 0,
        }
    );
}

#[test]
fn should_not_allow_same_transaction_twice() {
    // given
    let b = TransactionBuilder::default();
    let mut txq = TestPool::default();
    let tx1 = b.tx().nonce(0).new();
    let tx2 = b.tx().nonce(0).new();

    // when
    import(&mut txq, tx1).unwrap();
    import(&mut txq, tx2).unwrap_err();

    // then
    assert_eq!(txq.light_status().transaction_count, 1);
}

#[test]
fn should_replace_transaction() {
    // given
    let b = TransactionBuilder::default();
    let mut txq = TestPool::default();
    let tx1 = b.tx().nonce(0).gas_price(1).new();
    let tx2 = b.tx().nonce(0).gas_price(2).new();

    // when
    import(&mut txq, tx1).unwrap();
    import(&mut txq, tx2).unwrap();

    // then
    assert_eq!(txq.light_status().transaction_count, 1);
}

#[test]
fn should_reject_if_above_count() {
    let b = TransactionBuilder::default();
    let mut txq = TestPool::with_options(Options {
        max_count: 1,
        ..Default::default()
    });

    // Reject second
    let tx1 = b.tx().nonce(0).new();
    let tx2 = b.tx().nonce(1).new();
    let hash = tx2.hash.clone();
    import(&mut txq, tx1).unwrap();
    assert_eq!(
        import(&mut txq, tx2).unwrap_err(),
        error::Error::TooCheapToEnter(hash, "0x0".into())
    );
    assert_eq!(txq.light_status().transaction_count, 1);

    txq.clear();

    // Replace first
    let tx1 = b.tx().nonce(0).new();
    let tx2 = b.tx().nonce(0).sender(1).gas_price(2).new();
    import(&mut txq, tx1).unwrap();
    import(&mut txq, tx2).unwrap();
    assert_eq!(txq.light_status().transaction_count, 1);
}

#[test]
fn should_reject_if_above_mem_usage() {
    let b = TransactionBuilder::default();
    let mut txq = TestPool::with_options(Options {
        max_mem_usage: 1,
        ..Default::default()
    });

    // Reject second
    let tx1 = b.tx().nonce(1).mem_usage(1).new();
    let tx2 = b.tx().nonce(2).mem_usage(2).new();
    let hash = tx2.hash.clone();
    import(&mut txq, tx1).unwrap();
    assert_eq!(
        import(&mut txq, tx2).unwrap_err(),
        error::Error::TooCheapToEnter(hash, "0x0".into())
    );
    assert_eq!(txq.light_status().transaction_count, 1);

    txq.clear();

    // Replace first
    let tx1 = b.tx().nonce(1).mem_usage(1).new();
    let tx2 = b.tx().nonce(1).sender(1).gas_price(2).mem_usage(1).new();
    import(&mut txq, tx1).unwrap();
    import(&mut txq, tx2).unwrap();
    assert_eq!(txq.light_status().transaction_count, 1);
}

#[test]
fn should_reject_if_above_sender_count() {
    let b = TransactionBuilder::default();
    let mut txq = TestPool::with_options(Options {
        max_per_sender: 1,
        ..Default::default()
    });

    // Reject second
    let tx1 = b.tx().nonce(1).new();
    let tx2 = b.tx().nonce(2).new();
    let hash = tx2.hash.clone();
    import(&mut txq, tx1).unwrap();
    assert_eq!(
        import(&mut txq, tx2).unwrap_err(),
        error::Error::TooCheapToEnter(hash, "0x0".into())
    );
    assert_eq!(txq.light_status().transaction_count, 1);

    txq.clear();

    // Replace first
    let tx1 = b.tx().nonce(1).new();
    let tx2 = b.tx().nonce(2).gas_price(2).new();
    let hash = tx2.hash.clone();
    import(&mut txq, tx1).unwrap();
    // This results in error because we also compare nonces
    assert_eq!(
        import(&mut txq, tx2).unwrap_err(),
        error::Error::TooCheapToEnter(hash, "0x0".into())
    );
    assert_eq!(txq.light_status().transaction_count, 1);
}

#[test]
fn should_construct_pending() {
    // given
    let b = TransactionBuilder::default();
    let mut txq = TestPool::default();

    let tx0 = import(&mut txq, b.tx().nonce(0).gas_price(5).new()).unwrap();
    let tx1 = import(&mut txq, b.tx().nonce(1).gas_price(5).new()).unwrap();

    let tx9 = import(&mut txq, b.tx().sender(2).nonce(0).new()).unwrap();

    let tx5 = import(&mut txq, b.tx().sender(1).nonce(0).new()).unwrap();
    let tx6 = import(&mut txq, b.tx().sender(1).nonce(1).new()).unwrap();
    let tx7 = import(&mut txq, b.tx().sender(1).nonce(2).new()).unwrap();
    let tx8 = import(&mut txq, b.tx().sender(1).nonce(3).gas_price(4).new()).unwrap();

    let tx2 = import(&mut txq, b.tx().nonce(2).new()).unwrap();
    // this transaction doesn't get to the block despite high gas price
    // because of block gas limit and simplistic ordering algorithm.
    let tx3 = import(&mut txq, b.tx().nonce(3).gas_price(4).new()).unwrap();
    //gap
    import(&mut txq, b.tx().nonce(5).new()).unwrap();

    // gap
    import(&mut txq, b.tx().sender(1).nonce(5).new()).unwrap();

    assert_eq!(txq.light_status().transaction_count, 11);
    assert_eq!(
        txq.status(NonceReady::default()),
        Status {
            stalled: 0,
            pending: 9,
            future: 2,
        }
    );
    assert_eq!(
        txq.status(NonceReady::new(1)),
        Status {
            stalled: 3,
            pending: 6,
            future: 2,
        }
    );

    // get only includable part of the pending transactions
    let mut includable = txq.pending(NonceReady::default(), U256::from(4));

    assert_eq!(includable.next(), Some(tx0.clone()));
    assert_eq!(includable.next(), Some(tx1.clone()));
    assert_eq!(includable.next(), Some(tx8.clone()));
    assert_eq!(includable.next(), Some(tx3.clone()));
    assert_eq!(includable.next(), None);

    // get all pending transactions
    let mut current_gas = U256::zero();
    let limit = (21_000 * 8).into();
    let mut pending = txq
        .pending(NonceReady::default(), U256::from(0))
        .take_while(|tx| {
            let should_take = tx.gas + current_gas <= limit;
            if should_take {
                current_gas = current_gas + tx.gas
            }
            should_take
        });

    assert_eq!(pending.next(), Some(tx0));
    assert_eq!(pending.next(), Some(tx1));
    assert_eq!(pending.next(), Some(tx9));
    assert_eq!(pending.next(), Some(tx5));
    assert_eq!(pending.next(), Some(tx6));
    assert_eq!(pending.next(), Some(tx7));
    assert_eq!(pending.next(), Some(tx8));
    assert_eq!(pending.next(), Some(tx2));
    assert_eq!(pending.next(), None);
}

#[test]
fn should_skip_staled_pending_transactions() {
    let b = TransactionBuilder::default();
    let mut txq = TestPool::default();

    let _tx0 = import(&mut txq, b.tx().nonce(0).gas_price(5).new()).unwrap();
    let tx2 = import(&mut txq, b.tx().nonce(2).gas_price(5).new()).unwrap();
    let _tx1 = import(&mut txq, b.tx().nonce(1).gas_price(5).new()).unwrap();

    // tx0 and tx1 are Stale, tx2 is Ready
    let mut pending = txq.pending(NonceReady::new(2), Default::default());

    // tx0 and tx1 should be skipped, tx2 should be the next Ready
    assert_eq!(pending.next(), Some(tx2));
    assert_eq!(pending.next(), None);
}

#[test]
fn should_return_unordered_iterator() {
    // given
    let b = TransactionBuilder::default();
    let mut txq = TestPool::default();

    let tx0 = import(&mut txq, b.tx().nonce(0).gas_price(5).new()).unwrap();
    let tx1 = import(&mut txq, b.tx().nonce(1).gas_price(5).new()).unwrap();
    let tx2 = import(&mut txq, b.tx().nonce(2).new()).unwrap();
    let tx3 = import(&mut txq, b.tx().nonce(3).gas_price(4).new()).unwrap();
    //gap
    import(&mut txq, b.tx().nonce(5).new()).unwrap();

    let tx5 = import(&mut txq, b.tx().sender(1).nonce(0).new()).unwrap();
    let tx6 = import(&mut txq, b.tx().sender(1).nonce(1).new()).unwrap();
    let tx7 = import(&mut txq, b.tx().sender(1).nonce(2).new()).unwrap();
    let tx8 = import(&mut txq, b.tx().sender(1).nonce(3).gas_price(4).new()).unwrap();
    // gap
    import(&mut txq, b.tx().sender(1).nonce(5).new()).unwrap();

    let tx9 = import(&mut txq, b.tx().sender(2).nonce(0).new()).unwrap();
    assert_eq!(txq.light_status().transaction_count, 11);
    assert_eq!(
        txq.status(NonceReady::default()),
        Status {
            stalled: 0,
            pending: 9,
            future: 2,
        }
    );
    assert_eq!(
        txq.status(NonceReady::new(1)),
        Status {
            stalled: 3,
            pending: 6,
            future: 2,
        }
    );

    // get all pending transaction in unordered way
    let all: Vec<_> = txq
        .unordered_pending(NonceReady::default(), Default::default())
        .collect();

    let chain1 = vec![tx0, tx1, tx2, tx3];
    let chain2 = vec![tx5, tx6, tx7, tx8];
    let chain3 = vec![tx9];

    assert_eq!(all.len(), chain1.len() + chain2.len() + chain3.len());

    let mut options = vec![
        vec![chain1.clone(), chain2.clone(), chain3.clone()],
        vec![chain2.clone(), chain1.clone(), chain3.clone()],
        vec![chain2.clone(), chain3.clone(), chain1.clone()],
        vec![chain3.clone(), chain2.clone(), chain1.clone()],
        vec![chain3.clone(), chain1.clone(), chain2.clone()],
        vec![chain1.clone(), chain3.clone(), chain2.clone()],
    ]
    .into_iter()
    .map(|mut v| {
        let mut first = v.pop().unwrap();
        for mut x in v {
            first.append(&mut x);
        }
        first
    });

    assert!(options.any(|opt| all == opt));

    // get only includable part of the pending transactions in unordered way
    let includable: Vec<_> = txq
        .unordered_pending(NonceReady::default(), U256::from(3))
        .collect();

    assert_eq!(includable.len(), 4);
}

#[test]
fn should_update_scoring_correctly() {
    // given
    let b = TransactionBuilder::default();
    let mut txq = TestPool::default();

    let tx9 = import(&mut txq, b.tx().sender(2).nonce(0).new()).unwrap();

    let tx5 = import(&mut txq, b.tx().sender(1).nonce(0).new()).unwrap();
    let tx6 = import(&mut txq, b.tx().sender(1).nonce(1).new()).unwrap();
    let tx7 = import(&mut txq, b.tx().sender(1).nonce(2).new()).unwrap();
    let tx8 = import(&mut txq, b.tx().sender(1).nonce(3).gas_price(4).new()).unwrap();

    let tx0 = import(&mut txq, b.tx().nonce(0).gas_price(5).new()).unwrap();
    let tx1 = import(&mut txq, b.tx().nonce(1).gas_price(5).new()).unwrap();
    let tx2 = import(&mut txq, b.tx().nonce(2).new()).unwrap();
    // this transaction doesn't get to the block despite high gas price
    // because of block gas limit and simplistic ordering algorithm.
    import(&mut txq, b.tx().nonce(3).gas_price(4).new()).unwrap();
    //gap
    import(&mut txq, b.tx().nonce(5).new()).unwrap();

    // gap
    import(&mut txq, b.tx().sender(1).nonce(5).new()).unwrap();

    assert_eq!(txq.light_status().transaction_count, 11);
    assert_eq!(
        txq.status(NonceReady::default()),
        Status {
            stalled: 0,
            pending: 9,
            future: 2,
        }
    );
    assert_eq!(
        txq.status(NonceReady::new(1)),
        Status {
            stalled: 3,
            pending: 6,
            future: 2,
        }
    );

    txq.update_scores(&Address::zero(), helpers::DummyScoringEvent::Penalize);

    // when
    let mut current_gas = U256::zero();
    let limit = (21_000 * 8).into();
    let mut pending = txq
        .pending(NonceReady::default(), Default::default())
        .take_while(|tx| {
            let should_take = tx.gas + current_gas <= limit;
            if should_take {
                current_gas = current_gas + tx.gas
            }
            should_take
        });

    assert_eq!(pending.next(), Some(tx9));
    assert_eq!(pending.next(), Some(tx5));
    assert_eq!(pending.next(), Some(tx6));
    assert_eq!(pending.next(), Some(tx7));
    assert_eq!(pending.next(), Some(tx8));
    // penalized transactions
    assert_eq!(pending.next(), Some(tx0.clone()));
    assert_eq!(pending.next(), Some(tx1.clone()));
    assert_eq!(pending.next(), Some(tx2));
    assert_eq!(pending.next(), None);

    // update scores to initial values
    txq.set_scoring(
        DummyScoring::default(),
        helpers::DummyScoringEvent::UpdateScores,
    );

    current_gas = U256::zero();
    let mut includable = txq
        .pending(NonceReady::default(), Default::default())
        .take_while(|tx| {
            let should_take = tx.gas + current_gas <= limit;
            if should_take {
                current_gas = current_gas + tx.gas
            }
            should_take
        });

    assert_eq!(includable.next(), Some(tx0));
    assert_eq!(includable.next(), Some(tx1));
}

#[test]
fn should_remove_transaction() {
    // given
    let b = TransactionBuilder::default();
    let mut txq = TestPool::default();

    let tx1 = import(&mut txq, b.tx().nonce(0).new()).unwrap();
    let tx2 = import(&mut txq, b.tx().nonce(1).new()).unwrap();
    import(&mut txq, b.tx().nonce(2).new()).unwrap();
    assert_eq!(txq.light_status().transaction_count, 3);

    // when
    assert!(txq.remove(&tx2.hash(), false).is_some());

    // then
    assert_eq!(txq.light_status().transaction_count, 2);
    let mut pending = txq.pending(NonceReady::default(), Default::default());
    assert_eq!(pending.next(), Some(tx1));
    assert_eq!(pending.next(), None);
}

#[test]
fn should_cull_stalled_transactions() {
    // given
    let b = TransactionBuilder::default();
    let mut txq = TestPool::default();

    import(&mut txq, b.tx().nonce(0).gas_price(5).new()).unwrap();
    import(&mut txq, b.tx().nonce(1).new()).unwrap();
    import(&mut txq, b.tx().nonce(3).new()).unwrap();

    import(&mut txq, b.tx().sender(1).nonce(0).new()).unwrap();
    import(&mut txq, b.tx().sender(1).nonce(1).new()).unwrap();
    import(&mut txq, b.tx().sender(1).nonce(5).new()).unwrap();

    assert_eq!(
        txq.status(NonceReady::new(1)),
        Status {
            stalled: 2,
            pending: 2,
            future: 2,
        }
    );

    // when
    assert_eq!(txq.cull(None, NonceReady::new(1)), 2);

    // then
    assert_eq!(
        txq.status(NonceReady::new(1)),
        Status {
            stalled: 0,
            pending: 2,
            future: 2,
        }
    );
    assert_eq!(
        txq.light_status(),
        LightStatus {
            transaction_count: 4,
            senders: 2,
            mem_usage: 0,
        }
    );
}

#[test]
fn should_cull_stalled_transactions_from_a_sender() {
    // given
    let b = TransactionBuilder::default();
    let mut txq = TestPool::default();

    import(&mut txq, b.tx().nonce(0).gas_price(5).new()).unwrap();
    import(&mut txq, b.tx().nonce(1).new()).unwrap();

    import(&mut txq, b.tx().sender(1).nonce(0).new()).unwrap();
    import(&mut txq, b.tx().sender(1).nonce(1).new()).unwrap();
    import(&mut txq, b.tx().sender(1).nonce(2).new()).unwrap();

    assert_eq!(
        txq.status(NonceReady::new(2)),
        Status {
            stalled: 4,
            pending: 1,
            future: 0,
        }
    );

    // when
    let sender = Address::zero();
    assert_eq!(txq.cull(Some(&[sender]), NonceReady::new(2)), 2);

    // then
    assert_eq!(
        txq.status(NonceReady::new(2)),
        Status {
            stalled: 2,
            pending: 1,
            future: 0,
        }
    );
    assert_eq!(
        txq.light_status(),
        LightStatus {
            transaction_count: 3,
            senders: 1,
            mem_usage: 0,
        }
    );
}

#[test]
fn should_re_insert_after_cull() {
    // given
    let b = TransactionBuilder::default();
    let mut txq = TestPool::default();

    import(&mut txq, b.tx().nonce(0).gas_price(5).new()).unwrap();
    import(&mut txq, b.tx().nonce(1).new()).unwrap();
    import(&mut txq, b.tx().sender(1).nonce(0).new()).unwrap();
    import(&mut txq, b.tx().sender(1).nonce(1).new()).unwrap();
    assert_eq!(
        txq.status(NonceReady::new(1)),
        Status {
            stalled: 2,
            pending: 2,
            future: 0,
        }
    );

    // when
    assert_eq!(txq.cull(None, NonceReady::new(1)), 2);
    assert_eq!(
        txq.status(NonceReady::new(1)),
        Status {
            stalled: 0,
            pending: 2,
            future: 0,
        }
    );
    import(&mut txq, b.tx().nonce(0).gas_price(5).new()).unwrap();
    import(&mut txq, b.tx().sender(1).nonce(0).new()).unwrap();

    assert_eq!(
        txq.status(NonceReady::new(1)),
        Status {
            stalled: 2,
            pending: 2,
            future: 0,
        }
    );
}

#[test]
fn should_return_worst_transaction() {
    // given
    let b = TransactionBuilder::default();
    let mut txq = TestPool::default();
    assert!(txq.worst_transaction().is_none());

    // when
    import(&mut txq, b.tx().nonce(0).gas_price(5).new()).unwrap();
    import(&mut txq, b.tx().sender(1).nonce(0).gas_price(4).new()).unwrap();

    // then
    assert_eq!(txq.worst_transaction().unwrap().gas_price, 4.into());
}

#[test]
fn should_return_is_full() {
    // given
    let b = TransactionBuilder::default();
    let mut txq = TestPool::with_limit(2);
    assert!(!txq.is_full());

    // when
    import(&mut txq, b.tx().nonce(0).gas_price(110).new()).unwrap();
    assert!(!txq.is_full());

    import(&mut txq, b.tx().sender(1).nonce(0).gas_price(100).new()).unwrap();

    // then
    assert!(txq.is_full());
}

#[test]
fn should_import_even_if_limit_is_reached_and_should_replace_returns_insert_new() {
    // given
    let b = TransactionBuilder::default();
    let mut txq = TestPool::with_scoring(
        DummyScoring::always_insert(),
        Options {
            max_count: 1,
            ..Default::default()
        },
    );
    txq.import(
        b.tx().nonce(0).gas_price(5).new(),
        &mut DummyScoring::always_insert(),
    )
    .unwrap();
    assert_eq!(
        txq.light_status(),
        LightStatus {
            transaction_count: 1,
            senders: 1,
            mem_usage: 0,
        }
    );

    // when
    txq.import(
        b.tx().nonce(1).gas_price(5).new(),
        &mut DummyScoring::always_insert(),
    )
    .unwrap();

    // then
    assert_eq!(
        txq.light_status(),
        LightStatus {
            transaction_count: 2,
            senders: 1,
            mem_usage: 0,
        }
    );
}

#[test]
fn should_not_import_even_if_limit_is_reached_and_should_replace_returns_false() {
    use std::str::FromStr;

    // given
    let b = TransactionBuilder::default();
    let mut txq = TestPool::with_scoring(
        DummyScoring::default(),
        Options {
            max_count: 1,
            ..Default::default()
        },
    );
    import(&mut txq, b.tx().nonce(0).gas_price(5).new()).unwrap();
    assert_eq!(
        txq.light_status(),
        LightStatus {
            transaction_count: 1,
            senders: 1,
            mem_usage: 0,
        }
    );

    // when
    let err = import(&mut txq, b.tx().nonce(1).gas_price(5).new()).unwrap_err();

    // then
    assert_eq!(
        err,
        error::Error::TooCheapToEnter(
            H256::from_str("00000000000000000000000000000000000000000000000000000000000001f5")
                .unwrap(),
            "0x5".into()
        )
    );
    assert_eq!(
        txq.light_status(),
        LightStatus {
            transaction_count: 1,
            senders: 1,
            mem_usage: 0,
        }
    );
}

#[test]
fn should_import_even_if_sender_limit_is_reached() {
    // given
    let b = TransactionBuilder::default();
    let mut txq = TestPool::with_scoring(
        DummyScoring::always_insert(),
        Options {
            max_count: 1,
            max_per_sender: 1,
            ..Default::default()
        },
    );
    txq.import(
        b.tx().nonce(0).gas_price(5).new(),
        &mut DummyScoring::always_insert(),
    )
    .unwrap();
    assert_eq!(
        txq.light_status(),
        LightStatus {
            transaction_count: 1,
            senders: 1,
            mem_usage: 0,
        }
    );

    // when
    txq.import(
        b.tx().nonce(1).gas_price(5).new(),
        &mut DummyScoring::always_insert(),
    )
    .unwrap();

    // then
    assert_eq!(
        txq.light_status(),
        LightStatus {
            transaction_count: 2,
            senders: 1,
            mem_usage: 0,
        }
    );
}

mod listener {
    use std::{cell::RefCell, fmt, rc::Rc};

    use super::*;

    #[derive(Default)]
    struct MyListener(pub Rc<RefCell<Vec<&'static str>>>);

    impl Listener<Transaction> for MyListener {
        fn added(&mut self, _tx: &SharedTransaction, old: Option<&SharedTransaction>) {
            self.0
                .borrow_mut()
                .push(if old.is_some() { "replaced" } else { "added" });
        }

        fn rejected<H: fmt::Debug + fmt::LowerHex>(
            &mut self,
            _tx: &SharedTransaction,
            _reason: &error::Error<H>,
        ) {
            self.0.borrow_mut().push("rejected".into());
        }

        fn dropped(&mut self, _tx: &SharedTransaction, _new: Option<&Transaction>) {
            self.0.borrow_mut().push("dropped".into());
        }

        fn invalid(&mut self, _tx: &SharedTransaction) {
            self.0.borrow_mut().push("invalid".into());
        }

        fn canceled(&mut self, _tx: &SharedTransaction) {
            self.0.borrow_mut().push("canceled".into());
        }

        fn culled(&mut self, _tx: &SharedTransaction) {
            self.0.borrow_mut().push("culled".into());
        }
    }

    #[test]
    fn insert_transaction() {
        let b = TransactionBuilder::default();
        let listener = MyListener::default();
        let results = listener.0.clone();
        let mut txq = Pool::new(
            listener,
            DummyScoring::default(),
            Options {
                max_per_sender: 1,
                max_count: 2,
                ..Default::default()
            },
        );
        assert!(results.borrow().is_empty());

        // Regular import
        import(&mut txq, b.tx().nonce(1).new()).unwrap();
        assert_eq!(*results.borrow(), &["added"]);
        // Already present (no notification)
        import(&mut txq, b.tx().nonce(1).new()).unwrap_err();
        assert_eq!(*results.borrow(), &["added"]);
        // Push out the first one
        import(&mut txq, b.tx().nonce(1).gas_price(1).new()).unwrap();
        assert_eq!(*results.borrow(), &["added", "replaced"]);
        // Reject
        import(&mut txq, b.tx().nonce(1).new()).unwrap_err();
        assert_eq!(*results.borrow(), &["added", "replaced", "rejected"]);
        results.borrow_mut().clear();
        // Different sender (accept)
        import(&mut txq, b.tx().sender(1).nonce(1).gas_price(2).new()).unwrap();
        assert_eq!(*results.borrow(), &["added"]);
        // Third sender push out low gas price
        import(&mut txq, b.tx().sender(2).nonce(1).gas_price(4).new()).unwrap();
        assert_eq!(*results.borrow(), &["added", "dropped", "added"]);
        // Reject (too cheap)
        import(&mut txq, b.tx().sender(2).nonce(1).gas_price(2).new()).unwrap_err();
        assert_eq!(
            *results.borrow(),
            &["added", "dropped", "added", "rejected"]
        );

        assert_eq!(txq.light_status().transaction_count, 2);
    }

    #[test]
    fn remove_transaction() {
        let b = TransactionBuilder::default();
        let listener = MyListener::default();
        let results = listener.0.clone();
        let mut txq = Pool::new(listener, DummyScoring::default(), Options::default());

        // insert
        let tx1 = import(&mut txq, b.tx().nonce(1).new()).unwrap();
        let tx2 = import(&mut txq, b.tx().nonce(2).new()).unwrap();

        // then
        txq.remove(&tx1.hash(), false);
        assert_eq!(*results.borrow(), &["added", "added", "canceled"]);
        txq.remove(&tx2.hash(), true);
        assert_eq!(
            *results.borrow(),
            &["added", "added", "canceled", "invalid"]
        );
        assert_eq!(txq.light_status().transaction_count, 0);
    }

    #[test]
    fn clear_queue() {
        let b = TransactionBuilder::default();
        let listener = MyListener::default();
        let results = listener.0.clone();
        let mut txq = Pool::new(listener, DummyScoring::default(), Options::default());

        // insert
        import(&mut txq, b.tx().nonce(1).new()).unwrap();
        import(&mut txq, b.tx().nonce(2).new()).unwrap();

        // when
        txq.clear();

        // then
        assert_eq!(*results.borrow(), &["added", "added", "dropped", "dropped"]);
    }

    #[test]
    fn cull_stalled() {
        let b = TransactionBuilder::default();
        let listener = MyListener::default();
        let results = listener.0.clone();
        let mut txq = Pool::new(listener, DummyScoring::default(), Options::default());

        // insert
        import(&mut txq, b.tx().nonce(1).new()).unwrap();
        import(&mut txq, b.tx().nonce(2).new()).unwrap();

        // when
        txq.cull(None, NonceReady::new(3));

        // then
        assert_eq!(*results.borrow(), &["added", "added", "culled", "culled"]);
    }
}