// Copyright 2015-2017 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/>.

#![warn(missing_docs)]

//! Miner module
//! Keeps track of transactions and currently sealed pending block.

mod miner;
mod service_transaction_checker;

pub mod pool_client;
pub mod stratum;

pub use self::miner::{Miner, MinerOptions, Penalization, PendingSet, AuthoringParams};

use std::sync::Arc;
use std::collections::BTreeMap;

use bytes::Bytes;
use ethereum_types::{H256, U256, Address};
use ethcore_miner::pool::{VerifiedTransaction, QueueStatus, local_transactions};

use block::{Block, SealedBlock};
use client::{
	CallContract, RegistryInfo, ScheduleInfo,
	BlockChain, BlockProducer, SealedBlockImporter, ChainInfo,
	AccountData, Nonce,
};
use error::Error;
use header::{BlockNumber, Header};
use receipt::{RichReceipt, Receipt};
use transaction::{self, UnverifiedTransaction, SignedTransaction, PendingTransaction};
use state::StateInfo;

/// Provides methods to verify incoming external transactions
pub trait TransactionVerifierClient: Send + Sync
	// Required for ServiceTransactionChecker
	+ CallContract + RegistryInfo
	// Required for verifiying transactions
	+ BlockChain + ScheduleInfo + AccountData
{}

/// Extended client interface used for mining
pub trait BlockChainClient: TransactionVerifierClient + BlockProducer + SealedBlockImporter {}

/// Miner client API
pub trait MinerService : Send + Sync {
	/// Type representing chain state
	type State: StateInfo + 'static;

	// Sealing

	/// Submit `seal` as a valid solution for the header of `pow_hash`.
	/// Will check the seal, but not actually insert the block into the chain.
	fn submit_seal(&self, pow_hash: H256, seal: Vec<Bytes>) -> Result<SealedBlock, Error>;

	/// Is it currently sealing?
	fn is_currently_sealing(&self) -> bool;

	/// Get the sealing work package preparing it if doesn't exist yet.
	///
	/// Returns `None` if engine seals internally.
	fn work_package<C>(&self, chain: &C) -> Option<(H256, BlockNumber, u64, U256)>
		where C: BlockChain + CallContract + BlockProducer + SealedBlockImporter + Nonce + Sync;

	/// Update current pending block
	fn update_sealing<C>(&self, chain: &C)
		where C: BlockChain + CallContract + BlockProducer + SealedBlockImporter + Nonce + Sync;


	// Notifications

	/// Called when blocks are imported to chain, updates transactions queue.
	/// `is_internal_import` indicates that the block has just been created in miner and internally sealed by the engine,
	/// so we shouldn't attempt creating new block again.
	fn chain_new_blocks<C>(&self, chain: &C, imported: &[H256], invalid: &[H256], enacted: &[H256], retracted: &[H256], is_internal_import: bool)
		where C: BlockChainClient;


	// Pending block

	/// Get a list of all pending receipts from pending block.
	fn pending_receipts(&self, best_block: BlockNumber) -> Option<BTreeMap<H256, Receipt>>;

	/// Get a particular receipt from pending block.
	fn pending_receipt(&self, best_block: BlockNumber, hash: &H256) -> Option<RichReceipt>;

	/// Get `Some` `clone()` of the current pending block's state or `None` if we're not sealing.
	fn pending_state(&self, latest_block_number: BlockNumber) -> Option<Self::State>;

	/// Get `Some` `clone()` of the current pending block header or `None` if we're not sealing.
	fn pending_block_header(&self, latest_block_number: BlockNumber) -> Option<Header>;

	/// Get `Some` `clone()` of the current pending block or `None` if we're not sealing.
	fn pending_block(&self, latest_block_number: BlockNumber) -> Option<Block>;

	/// Get `Some` `clone()` of the current pending block transactions or `None` if we're not sealing.
	fn pending_transactions(&self, latest_block_number: BlockNumber) -> Option<Vec<SignedTransaction>>;

	// Block authoring

	/// Get current authoring parameters.
	fn authoring_params(&self) -> AuthoringParams;

	/// Set the lower and upper bound of gas limit we wish to target when sealing a new block.
	fn set_gas_range_target(&self, gas_range_target: (U256, U256));

	/// Set the extra_data that we will seal blocks with.
	fn set_extra_data(&self, extra_data: Bytes);

	/// Set info necessary to sign consensus messages and block authoring.
	///
	/// On PoW password is optional.
	fn set_author(&self, address: Address, password: Option<String>) -> Result<(), ::account_provider::SignError>;

	// Transaction Pool

	/// Imports transactions to transaction queue.
	fn import_external_transactions<C>(&self, client: &C, transactions: Vec<UnverifiedTransaction>)
		-> Vec<Result<(), transaction::Error>>
		where C: BlockChainClient;

	/// Imports own (node owner) transaction to queue.
	fn import_own_transaction<C>(&self, chain: &C, transaction: PendingTransaction)
		-> Result<(), transaction::Error>
		where C: BlockChainClient;

	/// Removes transaction from the pool.
	///
	/// Attempts to "cancel" a transaction. If it was not propagated yet (or not accepted by other peers)
	/// there is a good chance that the transaction will actually be removed.
	/// NOTE: The transaction is not removed from pending block if there is one.
	fn remove_transaction(&self, hash: &H256) -> Option<Arc<VerifiedTransaction>>;

	/// Query transaction from the pool given it's hash.
	fn transaction(&self, hash: &H256) -> Option<Arc<VerifiedTransaction>>;

	/// Returns next valid nonce for given address.
	///
	/// This includes nonces of all transactions from this address in the pending queue
	/// if they are consecutive.
	/// NOTE: pool may contain some future transactions that will become pending after
	/// transaction with nonce returned from this function is signed on.
	fn next_nonce<C>(&self, chain: &C, address: &Address) -> U256
		where C: Nonce + Sync;

	/// Get a list of all ready transactions.
	///
	/// Depending on the settings may look in transaction pool or only in pending block.
	fn ready_transactions<C>(&self, chain: &C) -> Vec<Arc<VerifiedTransaction>>
		where C: ChainInfo + Nonce + Sync;

	/// Get a list of all transactions in the pool (some of them might not be ready for inclusion yet).
	fn queued_transactions(&self) -> Vec<Arc<VerifiedTransaction>>;

	/// Get a list of local transactions with statuses.
	fn local_transactions(&self) -> BTreeMap<H256, local_transactions::Status>;

	/// Get current queue status.
	///
	/// Status includes verification thresholds and current pool utilization and limits.
	fn queue_status(&self) -> QueueStatus;

	// Misc

	/// Suggested gas price.
	fn sensible_gas_price(&self) -> U256;

	/// Suggested gas limit.
	fn sensible_gas_limit(&self) -> U256;
}
