/*
	Copyright (c) 2009-2010 Christopher A. Taylor.  All rights reserved.

	Redistribution and use in source and binary forms, with or without
	modification, are permitted provided that the following conditions are met:

	* Redistributions of source code must retain the above copyright notice,
	  this list of conditions and the following disclaimer.
	* Redistributions in binary form must reproduce the above copyright notice,
	  this list of conditions and the following disclaimer in the documentation
	  and/or other materials provided with the distribution.
	* Neither the name of LibCat nor the names of its contributors may be used
	  to endorse or promote products derived from this software without
	  specific prior written permission.

	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
	AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
	LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	POSSIBILITY OF SUCH DAMAGE.
*/

#ifndef CAT_SPHYNX_CLIENT_HPP
#define CAT_SPHYNX_CLIENT_HPP

#include <cat/net/SphynxTransport.hpp>
#include <cat/crypt/tunnel/KeyAgreementInitiator.hpp>
#include <cat/threads/Thread.hpp>
#include <cat/threads/WaitableFlag.hpp>

namespace cat {


namespace sphynx {


//// sphynx::Client

class Client : Thread, public UDPEndpoint, public Transport
{
	static const int HANDSHAKE_TICK_RATE = 100; // milliseconds
	static const int INITIAL_HELLO_POST_INTERVAL = 200; // milliseconds
	static const int CONNECT_TIMEOUT = 6000; // milliseconds
	static const u32 MTU_PROBE_INTERVAL = 8000; // 8 seconds
	static const int CLIENT_THREAD_KILL_TIMEOUT = 10000; // 10 seconds

	static const int SESSION_KEY_BYTES = 32;
	char _session_key[SESSION_KEY_BYTES];

	KeyAgreementInitiator _key_agreement_initiator;
	u8 _server_public_key[PUBLIC_KEY_BYTES];
	u8 _cached_challenge[CHALLENGE_BYTES];

	WaitableFlag _kill_flag;

protected:
	u32 _last_send_mstsc;
	NetAddr _server_addr;
	bool _connected;
	AuthenticatedEncryption _auth_enc;

	// Last time a packet was received from the server -- for disconnect timeouts
	u32 _last_recv_tsc;

public:
	Client();
	virtual ~Client();

	bool SetServerKey(ThreadPoolLocalStorage *tls, const void *server_key, int key_bytes, const char *session_key);

	bool Connect(const char *hostname, Port port);
	bool Connect(const NetAddr &addr);

	void Disconnect();

protected:
	bool IsConnected() { return _connected; }

	virtual void OnClose() = 0;
	virtual void OnConnectFail() = 0;
	virtual void OnConnect(ThreadPoolLocalStorage *tls) = 0;
	virtual void OnTimestampDeltaUpdate(u32 rtt, s32 delta) {}
	virtual void OnMessage(ThreadPoolLocalStorage *tls, BufferStream msg, u32 bytes) = 0;
	virtual void OnDisconnect() = 0;
	virtual void OnTick(ThreadPoolLocalStorage *tls, u32 now) = 0;

private:
	virtual void OnRead(ThreadPoolLocalStorage *tls, const NetAddr &src, u8 *data, u32 bytes);
	virtual void OnWrite(u32 bytes);

private:
	bool PostHello();
	void OnUnreachable(const NetAddr &src);

	// Return false to remove resolve from cache
	bool OnResolve(const char *hostname, const NetAddr *array, int array_length);

	virtual bool PostPacket(u8 *buffer, u32 buf_bytes, u32 msg_bytes, u32 skip_bytes);

private:
	bool ThreadFunction(void *param);
};


} // namespace sphynx


} // namespace cat

#endif // CAT_SPHYNX_CLIENT_HPP