// Copyright 2015-2020 Parity Technologies (UK) Ltd.
// This file is part of OpenEthereum.

// OpenEthereum 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.

// OpenEthereum 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 OpenEthereum.  If not, see <http://www.gnu.org/licenses/>.

//! Set of different helpers for client tests

use std::{fs, io, path::Path, sync::Arc};

use blockchain::{
    BlockChain, BlockChainDB, BlockChainDBHandler, Config as BlockChainConfig, ExtrasInsert,
};
use blooms_db;
use bytes::Bytes;
use ethereum_types::{Address, H256, U256};
use ethkey::KeyPair;
use evm::Factory as EvmFactory;
use hash::keccak;
use io::IoChannel;
use kvdb::KeyValueDB;
use kvdb_rocksdb::{self, Database, DatabaseConfig};
use parking_lot::RwLock;
use rlp::{self, RlpStream};
use tempdir::TempDir;
use types::{
    encoded,
    header::Header,
    transaction::{Action, SignedTransaction, Transaction, TypedTransaction},
    view,
    views::BlockView,
};

use block::{Drain, OpenBlock};
use client::{
    ChainInfo, ChainMessageType, ChainNotify, Client, ClientConfig, ImportBlock, PrepareOpenBlock,
};
use factory::Factories;
use miner::Miner;
use spec::Spec;
use state::*;
use state_db::StateDB;
use verification::queue::kind::blocks::Unverified;

/// Creates test block with corresponding header
pub fn create_test_block(header: &Header) -> Bytes {
    let mut rlp = RlpStream::new_list(3);
    rlp.append(header);
    rlp.append_raw(&rlp::EMPTY_LIST_RLP, 1);
    rlp.append_raw(&rlp::EMPTY_LIST_RLP, 1);
    rlp.out()
}

fn create_unverifiable_block_header(order: u32, parent_hash: H256) -> Header {
    let mut header = Header::new();
    header.set_gas_limit(0.into());
    header.set_difficulty((order * 100).into());
    header.set_timestamp((order * 10) as u64);
    header.set_number(order as u64);
    header.set_parent_hash(parent_hash);
    header.set_state_root(H256::zero());

    header
}

fn create_unverifiable_block_with_extra(
    order: u32,
    parent_hash: H256,
    extra: Option<Bytes>,
) -> Bytes {
    let mut header = create_unverifiable_block_header(order, parent_hash);
    header.set_extra_data(match extra {
        Some(extra_data) => extra_data,
        None => {
            let base = (order & 0x000000ff) as u8;
            let generated: Vec<u8> = vec![base + 1, base + 2, base + 3];
            generated
        }
    });
    create_test_block(&header)
}

fn create_unverifiable_block(order: u32, parent_hash: H256) -> Bytes {
    create_test_block(&create_unverifiable_block_header(order, parent_hash))
}

/// Creates test block with corresponding header and data
pub fn create_test_block_with_data(
    header: &Header,
    transactions: &[SignedTransaction],
    uncles: &[Header],
) -> Bytes {
    let mut rlp = RlpStream::new_list(3);
    rlp.append(header);
    rlp.begin_list(transactions.len());
    for t in transactions {
        t.rlp_append(&mut rlp);
    }
    rlp.append_list(&uncles);
    rlp.out()
}

/// Generates dummy client (not test client) with corresponding amount of blocks
pub fn generate_dummy_client(block_number: u32) -> Arc<Client> {
    generate_dummy_client_with_spec_and_data(Spec::new_test, block_number, 0, &[])
}

/// Generates dummy client (not test client) with corresponding amount of blocks and txs per every block
pub fn generate_dummy_client_with_data(
    block_number: u32,
    txs_per_block: usize,
    tx_gas_prices: &[U256],
) -> Arc<Client> {
    generate_dummy_client_with_spec_and_data(
        Spec::new_null,
        block_number,
        txs_per_block,
        tx_gas_prices,
    )
}

/// Generates dummy client (not test client) with corresponding spec and accounts
pub fn generate_dummy_client_with_spec<F>(test_spec: F) -> Arc<Client>
where
    F: Fn() -> Spec,
{
    generate_dummy_client_with_spec_and_data(test_spec, 0, 0, &[])
}

/// Generates dummy client (not test client) with corresponding amount of blocks, txs per block and spec
pub fn generate_dummy_client_with_spec_and_data<F>(
    test_spec: F,
    block_number: u32,
    txs_per_block: usize,
    tx_gas_prices: &[U256],
) -> Arc<Client>
where
    F: Fn() -> Spec,
{
    let test_spec = test_spec();
    let client_db = new_db();

    let client = Client::new(
        ClientConfig::default(),
        &test_spec,
        client_db,
        Arc::new(Miner::new_for_tests(&test_spec, None)),
        IoChannel::disconnected(),
    )
    .unwrap();
    let test_engine = &*test_spec.engine;

    let mut db = test_spec
        .ensure_db_good(get_temp_state_db(), &Default::default())
        .unwrap();
    let genesis_header = test_spec.genesis_header();

    let mut rolling_timestamp = 40;
    let mut last_hashes = vec![];
    let mut last_header = genesis_header.clone();

    let kp = KeyPair::from_secret_slice(&keccak("")).unwrap();
    let author = kp.address();

    let mut n = 0;
    for _ in 0..block_number {
        last_hashes.push(last_header.hash());

        // forge block.
        let mut b = OpenBlock::new(
            test_engine,
            Default::default(),
            false,
            db,
            &last_header,
            Arc::new(last_hashes.clone()),
            author.clone(),
            (3141562.into(), 31415620.into()),
            vec![],
            false,
            None,
        )
        .unwrap();
        rolling_timestamp += 10;
        b.set_timestamp(rolling_timestamp);

        // first block we don't have any balance, so can't send any transactions.
        for _ in 0..txs_per_block {
            b.push_transaction(
                TypedTransaction::Legacy(Transaction {
                    nonce: n.into(),
                    gas_price: tx_gas_prices[n % tx_gas_prices.len()],
                    gas: 100000.into(),
                    action: Action::Create,
                    data: vec![],
                    value: U256::zero(),
                })
                .sign(kp.secret(), Some(test_spec.chain_id())),
                None,
            )
            .unwrap();
            n += 1;
        }

        let b = b
            .close_and_lock()
            .unwrap()
            .seal(test_engine, vec![])
            .unwrap();

        if let Err(e) = client.import_block(Unverified::from_rlp(b.rlp_bytes()).unwrap()) {
            panic!(
                "error importing block which is valid by definition: {:?}",
                e
            );
        }

        last_header = view!(BlockView, &b.rlp_bytes()).header();
        db = b.drain().state.drop().1;
    }
    client.flush_queue();
    client.import_verified_blocks();
    client
}

/// Adds blocks to the client
pub fn push_blocks_to_client(
    client: &Arc<Client>,
    timestamp_salt: u64,
    starting_number: usize,
    block_number: usize,
) {
    let test_spec = Spec::new_test();
    let state_root = test_spec.genesis_header().state_root().clone();
    let genesis_gas = test_spec.genesis_header().gas_limit().clone();

    let mut rolling_hash = client.chain_info().best_block_hash;
    let mut rolling_block_number = starting_number as u64;
    let mut rolling_timestamp = timestamp_salt + starting_number as u64 * 10;

    for _ in 0..block_number {
        let mut header = Header::new();

        header.set_gas_limit(genesis_gas);
        header.set_difficulty(U256::from(0x20000));
        header.set_timestamp(rolling_timestamp);
        header.set_number(rolling_block_number);
        header.set_parent_hash(rolling_hash);
        header.set_state_root(state_root);

        rolling_hash = header.hash();
        rolling_block_number = rolling_block_number + 1;
        rolling_timestamp = rolling_timestamp + 10;

        if let Err(e) =
            client.import_block(Unverified::from_rlp(create_test_block(&header)).unwrap())
        {
            panic!(
                "error importing block which is valid by definition: {:?}",
                e
            );
        }
    }
}

/// Adds one block with transactions
pub fn push_block_with_transactions(client: &Arc<Client>, transactions: &[SignedTransaction]) {
    let test_spec = Spec::new_test();
    let test_engine = &*test_spec.engine;
    let block_number = client.chain_info().best_block_number as u64 + 1;

    let mut b = client
        .prepare_open_block(Address::default(), (0.into(), 5000000.into()), Bytes::new())
        .unwrap();
    b.set_timestamp(block_number * 10);

    for t in transactions {
        b.push_transaction(t.clone(), None).unwrap();
    }
    let b = b
        .close_and_lock()
        .unwrap()
        .seal(test_engine, vec![])
        .unwrap();

    if let Err(e) = client.import_block(Unverified::from_rlp(b.rlp_bytes()).unwrap()) {
        panic!(
            "error importing block which is valid by definition: {:?}",
            e
        );
    }

    client.flush_queue();
    client.import_verified_blocks();
}

/// Creates dummy client (not test client) with corresponding blocks
pub fn get_test_client_with_blocks(blocks: Vec<Bytes>) -> Arc<Client> {
    let test_spec = Spec::new_test();
    let client_db = new_db();

    let client = Client::new(
        ClientConfig::default(),
        &test_spec,
        client_db,
        Arc::new(Miner::new_for_tests(&test_spec, None)),
        IoChannel::disconnected(),
    )
    .unwrap();

    for block in blocks {
        if let Err(e) = client.import_block(Unverified::from_rlp(block).unwrap()) {
            panic!("error importing block which is well-formed: {:?}", e);
        }
    }
    client.flush_queue();
    client.import_verified_blocks();
    client
}

struct TestBlockChainDB {
    _blooms_dir: TempDir,
    _trace_blooms_dir: TempDir,
    blooms: blooms_db::Database,
    trace_blooms: blooms_db::Database,
    key_value: Arc<dyn KeyValueDB>,
}

impl BlockChainDB for TestBlockChainDB {
    fn key_value(&self) -> &Arc<dyn KeyValueDB> {
        &self.key_value
    }

    fn blooms(&self) -> &blooms_db::Database {
        &self.blooms
    }

    fn trace_blooms(&self) -> &blooms_db::Database {
        &self.trace_blooms
    }
}

/// Creates new test instance of `BlockChainDB`
pub fn new_db() -> Arc<dyn BlockChainDB> {
    let blooms_dir = TempDir::new("").unwrap();
    let trace_blooms_dir = TempDir::new("").unwrap();

    let db = TestBlockChainDB {
        blooms: blooms_db::Database::open(blooms_dir.path()).unwrap(),
        trace_blooms: blooms_db::Database::open(trace_blooms_dir.path()).unwrap(),
        _blooms_dir: blooms_dir,
        _trace_blooms_dir: trace_blooms_dir,
        key_value: Arc::new(::kvdb_memorydb::create(::db::NUM_COLUMNS.unwrap())),
    };

    Arc::new(db)
}

/// Creates a new temporary `BlockChainDB` on FS
pub fn new_temp_db(tempdir: &Path) -> Arc<dyn BlockChainDB> {
    let blooms_dir = TempDir::new("").unwrap();
    let trace_blooms_dir = TempDir::new("").unwrap();
    let key_value_dir = tempdir.join("key_value");

    let db_config = DatabaseConfig::with_columns(::db::NUM_COLUMNS);
    let key_value_db = Database::open(&db_config, key_value_dir.to_str().unwrap()).unwrap();

    let db = TestBlockChainDB {
        blooms: blooms_db::Database::open(blooms_dir.path()).unwrap(),
        trace_blooms: blooms_db::Database::open(trace_blooms_dir.path()).unwrap(),
        _blooms_dir: blooms_dir,
        _trace_blooms_dir: trace_blooms_dir,
        key_value: Arc::new(key_value_db),
    };

    Arc::new(db)
}

/// Creates new instance of KeyValueDBHandler
pub fn restoration_db_handler(
    config: kvdb_rocksdb::DatabaseConfig,
) -> Box<dyn BlockChainDBHandler> {
    struct RestorationDBHandler {
        config: kvdb_rocksdb::DatabaseConfig,
    }

    struct RestorationDB {
        blooms: blooms_db::Database,
        trace_blooms: blooms_db::Database,
        key_value: Arc<dyn KeyValueDB>,
    }

    impl BlockChainDB for RestorationDB {
        fn key_value(&self) -> &Arc<dyn KeyValueDB> {
            &self.key_value
        }

        fn blooms(&self) -> &blooms_db::Database {
            &self.blooms
        }

        fn trace_blooms(&self) -> &blooms_db::Database {
            &self.trace_blooms
        }
    }

    impl BlockChainDBHandler for RestorationDBHandler {
        fn open(&self, db_path: &Path) -> io::Result<Arc<dyn BlockChainDB>> {
            let key_value = Arc::new(kvdb_rocksdb::Database::open(
                &self.config,
                &db_path.to_string_lossy(),
            )?);
            let blooms_path = db_path.join("blooms");
            let trace_blooms_path = db_path.join("trace_blooms");
            fs::create_dir_all(&blooms_path)?;
            fs::create_dir_all(&trace_blooms_path)?;
            let blooms = blooms_db::Database::open(blooms_path).unwrap();
            let trace_blooms = blooms_db::Database::open(trace_blooms_path).unwrap();
            let db = RestorationDB {
                blooms,
                trace_blooms,
                key_value,
            };
            Ok(Arc::new(db))
        }
    }

    Box::new(RestorationDBHandler { config })
}

/// Generates dummy blockchain with corresponding amount of blocks
pub fn generate_dummy_blockchain(block_number: u32) -> BlockChain {
    let db = new_db();
    let bc = BlockChain::new(
        BlockChainConfig::default(),
        &create_unverifiable_block(0, H256::zero()),
        db.clone(),
    );

    let mut batch = db.key_value().transaction();
    for block_order in 1..block_number {
        // Total difficulty is always 0 here.
        bc.insert_block(
            &mut batch,
            encoded::Block::new(create_unverifiable_block(block_order, bc.best_block_hash())),
            vec![],
            ExtrasInsert {
                fork_choice: ::engines::ForkChoice::New,
                is_finalized: false,
            },
        );
        bc.commit();
    }
    db.key_value().write(batch).unwrap();
    bc
}

/// Generates dummy blockchain with corresponding amount of blocks (using creation with extra method for blocks creation)
pub fn generate_dummy_blockchain_with_extra(block_number: u32) -> BlockChain {
    let db = new_db();
    let bc = BlockChain::new(
        BlockChainConfig::default(),
        &create_unverifiable_block(0, H256::zero()),
        db.clone(),
    );

    let mut batch = db.key_value().transaction();
    for block_order in 1..block_number {
        // Total difficulty is always 0 here.
        bc.insert_block(
            &mut batch,
            encoded::Block::new(create_unverifiable_block_with_extra(
                block_order,
                bc.best_block_hash(),
                None,
            )),
            vec![],
            ExtrasInsert {
                fork_choice: ::engines::ForkChoice::New,
                is_finalized: false,
            },
        );
        bc.commit();
    }
    db.key_value().write(batch).unwrap();
    bc
}

/// Returns empty dummy blockchain
pub fn generate_dummy_empty_blockchain() -> BlockChain {
    let db = new_db();
    let bc = BlockChain::new(
        BlockChainConfig::default(),
        &create_unverifiable_block(0, H256::zero()),
        db.clone(),
    );
    bc
}

/// Returns temp state
pub fn get_temp_state() -> State<::state_db::StateDB> {
    let journal_db = get_temp_state_db();
    State::new(journal_db, U256::from(0), Default::default())
}

/// Returns temp state using coresponding factory
pub fn get_temp_state_with_factory(factory: EvmFactory) -> State<::state_db::StateDB> {
    let journal_db = get_temp_state_db();
    let mut factories = Factories::default();
    factories.vm = factory.into();
    State::new(journal_db, U256::from(0), factories)
}

/// Returns temp state db
pub fn get_temp_state_db() -> StateDB {
    let db = new_db();
    let journal_db = ::journaldb::new(
        db.key_value().clone(),
        ::journaldb::Algorithm::EarlyMerge,
        ::db::COL_STATE,
    );
    StateDB::new(journal_db, 5 * 1024 * 1024)
}

/// Returns sequence of hashes of the dummy blocks
pub fn get_good_dummy_block_seq(count: usize) -> Vec<Bytes> {
    let test_spec = Spec::new_test();
    get_good_dummy_block_fork_seq(1, count, &test_spec.genesis_header().hash())
}

/// Returns sequence of hashes of the dummy blocks beginning from corresponding parent
pub fn get_good_dummy_block_fork_seq(
    start_number: usize,
    count: usize,
    parent_hash: &H256,
) -> Vec<Bytes> {
    let test_spec = Spec::new_test();
    let genesis_gas = test_spec.genesis_header().gas_limit().clone();
    let mut rolling_timestamp = start_number as u64 * 10;
    let mut parent = *parent_hash;
    let mut r = Vec::new();
    for i in start_number..start_number + count + 1 {
        let mut block_header = Header::new();
        block_header.set_gas_limit(genesis_gas);
        block_header.set_difficulty(U256::from(i) * U256([0, 1, 0, 0]));
        block_header.set_timestamp(rolling_timestamp);
        block_header.set_number(i as u64);
        block_header.set_parent_hash(parent);
        block_header.set_state_root(test_spec.genesis_header().state_root().clone());

        parent = block_header.hash();
        rolling_timestamp = rolling_timestamp + 10;

        r.push(create_test_block(&block_header));
    }
    r
}

/// Returns hash and header of the correct dummy block
pub fn get_good_dummy_block_hash() -> (H256, Bytes) {
    let mut block_header = Header::new();
    let test_spec = Spec::new_test();
    let genesis_gas = test_spec.genesis_header().gas_limit().clone();
    block_header.set_gas_limit(genesis_gas);
    block_header.set_difficulty(U256::from(0x20000));
    block_header.set_timestamp(40);
    block_header.set_number(1);
    block_header.set_parent_hash(test_spec.genesis_header().hash());
    block_header.set_state_root(test_spec.genesis_header().state_root().clone());

    (block_header.hash(), create_test_block(&block_header))
}

/// Returns hash of the correct dummy block
pub fn get_good_dummy_block() -> Bytes {
    let (_, bytes) = get_good_dummy_block_hash();
    bytes
}

/// Returns hash of the dummy block with incorrect state root
pub fn get_bad_state_dummy_block() -> Bytes {
    let mut block_header = Header::new();
    let test_spec = Spec::new_test();
    let genesis_gas = test_spec.genesis_header().gas_limit().clone();

    block_header.set_gas_limit(genesis_gas);
    block_header.set_difficulty(U256::from(0x20000));
    block_header.set_timestamp(40);
    block_header.set_number(1);
    block_header.set_parent_hash(test_spec.genesis_header().hash());
    block_header.set_state_root(0xbad.into());

    create_test_block(&block_header)
}

/// Test actor for chain events
#[derive(Default)]
pub struct TestNotify {
    /// Messages store
    pub messages: RwLock<Vec<Bytes>>,
}

impl ChainNotify for TestNotify {
    fn broadcast(&self, message: ChainMessageType) {
        let data = match message {
            ChainMessageType::Consensus(data) => data,
        };
        self.messages.write().push(data);
    }
}