use assert_matches::assert_matches;
use solana_runtime::{
    bank::Bank,
    bank_client::BankClient,
    genesis_utils::{create_genesis_block_with_leader, GenesisBlockInfo},
};
use solana_sdk::{
    account::Account,
    account_utils::State,
    client::SyncClient,
    message::Message,
    pubkey::Pubkey,
    signature::{Keypair, KeypairUtil},
    sysvar::{self, rewards::Rewards},
};
use solana_stake_api::{
    id,
    stake_instruction::{self, process_instruction},
    stake_state::{self, Stake, StakeState},
};
use solana_vote_api::{
    vote_instruction,
    vote_state::{Vote, VoteInit, VoteState},
};
use std::sync::Arc;

fn fill_epoch_with_votes(
    bank: &Arc<Bank>,
    vote_keypair: &Keypair,
    mint_keypair: &Keypair,
) -> Arc<Bank> {
    let mint_pubkey = mint_keypair.pubkey();
    let vote_pubkey = vote_keypair.pubkey();
    let old_epoch = bank.epoch();
    let mut bank = bank.clone();
    while bank.epoch() != old_epoch + 1 {
        bank = Arc::new(Bank::new_from_parent(
            &bank,
            &Pubkey::default(),
            1 + bank.slot(),
        ));

        let bank_client = BankClient::new_shared(&bank);
        let parent = bank.parent().unwrap();

        let message = Message::new_with_payer(
            vec![vote_instruction::vote(
                &vote_pubkey,
                &vote_pubkey,
                Vote::new(vec![parent.slot() as u64], parent.hash()),
            )],
            Some(&mint_pubkey),
        );
        assert!(bank_client
            .send_message(&[&mint_keypair, &vote_keypair], message)
            .is_ok());
    }
    bank
}

#[test]
fn test_stake_account_delegate() {
    let staker_keypair = Keypair::new();
    let staker_pubkey = staker_keypair.pubkey();
    let vote_keypair = Keypair::new();
    let vote_pubkey = vote_keypair.pubkey();
    let node_pubkey = Pubkey::new_rand();

    let GenesisBlockInfo {
        mut genesis_block,
        mint_keypair,
        ..
    } = create_genesis_block_with_leader(100_000_000_000, &Pubkey::new_rand(), 1_000_000);
    genesis_block
        .native_instruction_processors
        .push(solana_stake_program::solana_stake_program!());
    let bank = Bank::new(&genesis_block);
    let mint_pubkey = mint_keypair.pubkey();
    let mut bank = Arc::new(bank);
    let bank_client = BankClient::new_shared(&bank);

    // Create Vote Account
    let message = Message::new(vote_instruction::create_account(
        &mint_pubkey,
        &vote_pubkey,
        &VoteInit {
            node_pubkey,
            authorized_voter: vote_pubkey,
            authorized_withdrawer: vote_pubkey,
            commission: std::u8::MAX / 2,
        },
        10,
    ));
    bank_client
        .send_message(&[&mint_keypair], message)
        .expect("failed to create vote account");

    let authorized = stake_state::Authorized::auto(&staker_pubkey);
    // Create stake account and delegate to vote account
    let message = Message::new(stake_instruction::create_stake_account_and_delegate_stake(
        &mint_pubkey,
        &staker_pubkey,
        &vote_pubkey,
        &authorized,
        1_000_000,
    ));
    bank_client
        .send_message(&[&mint_keypair, &staker_keypair], message)
        .expect("failed to create and delegate stake account");

    // Test that correct lamports are staked
    let account = bank.get_account(&staker_pubkey).expect("account not found");
    let stake_state = account.state().expect("couldn't unpack account data");
    if let StakeState::Stake(_authorized, _lockup, stake) = stake_state {
        assert_eq!(stake.stake, 1_000_000);
    } else {
        assert!(false, "wrong account type found")
    }

    // Test that we cannot withdraw staked lamports
    let message = Message::new_with_payer(
        vec![stake_instruction::withdraw(
            &staker_pubkey,
            &staker_pubkey,
            &Pubkey::new_rand(),
            1_000_000,
        )],
        Some(&mint_pubkey),
    );
    assert!(bank_client
        .send_message(&[&mint_keypair, &staker_keypair], message)
        .is_err());

    // Test that lamports are still staked
    let account = bank.get_account(&staker_pubkey).expect("account not found");
    let stake_state = account.state().expect("couldn't unpack account data");
    if let StakeState::Stake(_authorized, _lockup, stake) = stake_state {
        assert_eq!(stake.stake, 1_000_000);
    } else {
        assert!(false, "wrong account type found")
    }

    // Reward redemption
    // Submit enough votes to generate rewards
    let old_epoch = bank.epoch();
    bank = fill_epoch_with_votes(&bank, &vote_keypair, &mint_keypair);

    // Test that votes and credits are there
    let account = bank.get_account(&vote_pubkey).expect("account not found");
    let vote_state: VoteState = account.state().expect("couldn't unpack account data");

    // 1 less vote, as the first vote should have cleared the lockout
    assert_eq!(vote_state.votes.len(), 31);
    assert_eq!(vote_state.credits(), 1);
    assert_ne!(old_epoch, bank.epoch());

    // Cycle thru banks until we reach next epoch
    bank = fill_epoch_with_votes(&bank, &vote_keypair, &mint_keypair);

    // Test that rewards are there
    let rewards_account = bank
        .get_account(&sysvar::rewards::id())
        .expect("account not found");
    assert_matches!(Rewards::from_account(&rewards_account), Some(_));

    // Redeem the credit
    let bank_client = BankClient::new_shared(&bank);
    let message = Message::new_with_payer(
        vec![stake_instruction::redeem_vote_credits(
            &staker_pubkey,
            &vote_pubkey,
        )],
        Some(&mint_pubkey),
    );
    assert_matches!(bank_client.send_message(&[&mint_keypair], message), Ok(_));

    fn get_stake(bank: &Bank, staker_pubkey: &Pubkey) -> (Stake, Account) {
        let account = bank.get_account(staker_pubkey).unwrap();
        (StakeState::stake_from(&account).unwrap(), account)
    }

    // Test that balance increased, and calculate the rewards
    let (stake, account) = get_stake(&bank, &staker_pubkey);
    assert!(account.lamports > 1_000_000);
    assert!(stake.stake > 1_000_000);
    let rewards = account.lamports - 1_000_000;

    // Deactivate the stake
    let message = Message::new_with_payer(
        vec![stake_instruction::deactivate_stake(
            &staker_pubkey,
            &staker_pubkey,
        )],
        Some(&mint_pubkey),
    );
    assert!(bank_client
        .send_message(&[&mint_keypair, &staker_keypair], message)
        .is_ok());

    // Test that we cannot withdraw staked lamports due to cooldown period
    let message = Message::new_with_payer(
        vec![stake_instruction::withdraw(
            &staker_pubkey,
            &staker_pubkey,
            &Pubkey::new_rand(),
            1_000_000,
        )],
        Some(&mint_pubkey),
    );
    assert!(bank_client
        .send_message(&[&mint_keypair, &staker_keypair], message)
        .is_err());

    let old_epoch = bank.epoch();
    let slots = bank.get_slots_in_epoch(old_epoch);

    // Create a new bank at later epoch (within cooldown period)
    let bank = Bank::new_from_parent(&bank, &Pubkey::default(), slots + bank.slot());
    assert_ne!(old_epoch, bank.epoch());
    let bank = Arc::new(bank);
    let bank_client = BankClient::new_shared(&bank);

    let message = Message::new_with_payer(
        vec![stake_instruction::withdraw(
            &staker_pubkey,
            &staker_pubkey,
            &Pubkey::new_rand(),
            1_000_000,
        )],
        Some(&mint_pubkey),
    );

    assert!(bank_client
        .send_message(&[&mint_keypair, &staker_keypair], message)
        .is_err());

    let message = Message::new_with_payer(
        vec![stake_instruction::withdraw(
            &staker_pubkey,
            &staker_pubkey,
            &Pubkey::new_rand(),
            250_000,
        )],
        Some(&mint_pubkey),
    );
    // assert we can withdraw some smaller amount, more than rewards
    assert!(bank_client
        .send_message(&[&mint_keypair, &staker_keypair], message)
        .is_ok());

    // Create a new bank at a much later epoch (to account for cooldown of stake)
    let mut bank = Bank::new_from_parent(
        &bank,
        &Pubkey::default(),
        genesis_block.epoch_schedule.slots_per_epoch * 10 + bank.slot(),
    );
    bank.add_instruction_processor(id(), process_instruction);
    let bank = Arc::new(bank);
    let bank_client = BankClient::new_shared(&bank);

    // Test that we can withdraw now
    let message = Message::new_with_payer(
        vec![stake_instruction::withdraw(
            &staker_pubkey,
            &staker_pubkey,
            &Pubkey::new_rand(),
            750_000,
        )],
        Some(&mint_pubkey),
    );
    assert!(bank_client
        .send_message(&[&mint_keypair, &staker_keypair], message)
        .is_ok());

    // Test that balance and stake is updated correctly (we have withdrawn all lamports except rewards)
    let (_stake, account) = get_stake(&bank, &staker_pubkey);
    assert_eq!(account.lamports, rewards);
}