/*
	This file is part of cpp-ethereum.

	cpp-ethereum 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.

	cpp-ethereum 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 cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
*/
/** @file Client.h
 * @author Gav Wood <i@gavwood.com>
 * @date 2014
 */

#pragma once

#include <thread>
#include <mutex>
#include <atomic>
#include "Common.h"
#include "BlockChain.h"
#include "TransactionQueue.h"
#include "State.h"
#include "Dagger.h"
#include "PeerNetwork.h"

namespace eth
{

struct MineProgress
{
	uint requirement;
	uint best;
	uint current;
};

class Client;

class ClientGuard
{
public:
	inline ClientGuard(Client* _c);
	inline ~ClientGuard();

private:
	Client* m_client;
};

enum ClientWorkState
{
	Active = 0,
	Deleting,
	Deleted
};

class VersionChecker
{
public:
	VersionChecker(std::string const& _dbPath, unsigned _protocolVersion);

	void setOk();
	bool ok() const { return m_ok; }

private:
	bool m_ok;
	std::string m_path;
	unsigned m_protocolVersion;
};

class Client
{
public:
	/// Constructor.
	explicit Client(std::string const& _clientVersion, Address _us = Address(), std::string const& _dbPath = std::string());

	/// Destructor.
	~Client();

	/// Submits the given transaction.
	void transact(Secret _secret, u256 _value, u256 _gasPrice, u256 _gas, Address _dest, bytes const& _data);

	/// Submits a new contract.
	void transact(Secret _secret, u256 _endowment, u256 _gasPrice, u256 _gas, bytes const& _code, bytes const& _init);

	/// Makes the given call. Nothing is recorded into the state. TODO
//	bytes call(Secret _secret, u256 _amount, u256 _gasPrice, Address _dest, u256 _gas, bytes _data = bytes());

	/// Requires transactions involving this address be queued for inspection.
	void setInterest(Address _dest);

	/// @returns incoming minable transactions that we wanted to be notified of. Clears the queue.
	Transactions pendingQueue() { ClientGuard g(this); return m_tq.interestQueue(); }

	/// @returns alterations in state of a mined block that we wanted to be notified of. Clears the queue.
	std::vector<std::pair<Address, AddressState>> minedQueue() { ClientGuard g(this); return m_bc.interestQueue(); }

	// Not yet - probably best as using some sort of signals implementation.
	/// Calls @a _f when a valid transaction is received that involves @a _dest and once per such transaction.
//	void onPending(Address _dest, function<void(Transaction)> const& _f);

	/// Calls @a _f when a transaction is mined that involves @a _dest and once per change.
//	void onConfirmed(Address _dest, function<void(Transaction, AddressState)> const& _f);

	// Informational stuff:

	/// Locks/unlocks the state/blockChain/transactionQueue for access.
	void lock();
	void unlock();

	/// Determines whether at least one of the state/blockChain/transactionQueue has changed since the last call to changed().
	bool changed() const { auto ret = m_changed; m_changed = false; return ret; }

	/// Get the object representing the current state of Ethereum.
	State const& state() const { return m_preMine; }
	/// Get the object representing the current state of Ethereum.
	State const& postState() const { return m_postMine; }
	/// Get the object representing the current canonical blockchain.
	BlockChain const& blockChain() const { return m_bc; }
	/// Get a map containing each of the pending transactions.
	Transactions const& pending() const { return m_postMine.pending(); }

	void setClientVersion(std::string const& _name) { m_clientVersion = _name; }

	// Network stuff:

	/// Get information on the current peer set.
	std::vector<PeerInfo> peers();
	/// Same as peers().size(), but more efficient.
	size_t peerCount() const;

	/// Start the network subsystem.
	void startNetwork(unsigned short _listenPort = 30303, std::string const& _remoteHost = std::string(), unsigned short _remotePort = 30303, NodeMode _mode = NodeMode::Full, unsigned _peers = 5, std::string const& _publicIP = std::string(), bool _upnp = true);
	/// Connect to a particular peer.
	void connect(std::string const& _seedHost, unsigned short _port = 30303);
	/// Stop the network subsystem.
	void stopNetwork();
	/// Is the network subsystem up?
	bool haveNetwork() { return !!m_net; }
	/// Get access to the peer server object. This will be null if the network isn't online.
	PeerServer* peerServer() const { return m_net.get(); }

	// Mining stuff:

	/// Set the coinbase address.
	void setAddress(Address _us) { m_preMine.setAddress(_us); }
	/// Get the coinbase address.
	Address address() const { return m_preMine.address(); }
	/// Start mining.
	void startMining();
	/// Stop mining.
	void stopMining();
	/// Are we mining now?
	bool isMining() { return m_doMine; }
	/// Check the progress of the mining.
	MineProgress miningProgress() const { return m_mineProgress; }

private:
	void work();

	std::string m_clientVersion;		///< Our end-application client's name/version.
	VersionChecker m_vc;				///< Dummy object to check & update the protocol version.
	BlockChain m_bc;					///< Maintains block database.
	TransactionQueue m_tq;				///< Maintains list of incoming transactions not yet on the block chain.
	Overlay m_stateDB;					///< Acts as the central point for the state database, so multiple States can share it.
	State m_preMine;					///< The present state of the client.
	State m_postMine;					///< The state of the client which we're mining (i.e. it'll have all the rewards added).
	std::unique_ptr<PeerServer> m_net;	///< Should run in background and send us events when blocks found and allow us to send blocks as required.
	
	std::unique_ptr<std::thread> m_work;///< The work thread.
	
	std::recursive_mutex m_lock;
	std::atomic<ClientWorkState> m_workState;
	bool m_doMine = false;				///< Are we supposed to be mining?
	MineProgress m_mineProgress;
	mutable bool m_restartMining = false;

	mutable bool m_changed;
};

inline ClientGuard::ClientGuard(Client* _c): m_client(_c)
{
	m_client->lock();
}

inline ClientGuard::~ClientGuard()
{
	m_client->unlock();
}

}