/* $Id$ */

/*
 * This file is part of OpenTTD.
 * OpenTTD 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, version 2.
 * OpenTTD 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 OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file network_admin.cpp Server part of the admin network protocol. */

#ifdef ENABLE_NETWORK

#include "../stdafx.h"
#include "../debug.h"
#include "../strings_func.h"
#include "../date_func.h"
#include "network_admin.h"
#include "network.h"
#include "network_base.h"
#include "../company_base.h"
#include "../console_func.h"
#include "../core/pool_func.hpp"
#include "../map_func.h"
#include "../rev.h"

#include "table/strings.h"

/* This file handles all the admin network commands. */

/** The amount of admins connected. */
byte _network_admins_connected = 0;

NetworkAdminSocketPool _networkadminsocket_pool("NetworkAdminSocket");
INSTANTIATE_POOL_METHODS(NetworkAdminSocket)

/** The timeout for authorisation of the client. */
static const int ADMIN_AUTHORISATION_TIMEOUT = 10000;


/** Frequencies, which may be registered for a certain update type. */
static const AdminUpdateFrequency _admin_update_type_frequencies[] = {
	ADMIN_FREQUENCY_POLL | ADMIN_FREQUENCY_DAILY | ADMIN_FREQUENCY_WEEKLY | ADMIN_FREQUENCY_MONTHLY | ADMIN_FREQUENCY_QUARTERLY | ADMIN_FREQUENCY_ANUALLY, ///< ADMIN_UPDATE_DATE
};
assert_compile(lengthof(_admin_update_type_frequencies) == ADMIN_UPDATE_END);

/**
 * Create a new socket for the server side of the admin network.
 * @param s The socket to connect with.
 */
ServerNetworkAdminSocketHandler::ServerNetworkAdminSocketHandler(SOCKET s) : NetworkAdminSocketHandler(s)
{
	_network_admins_connected++;
	this->status = ADMIN_STATUS_INACTIVE;
	this->realtime_connect = _realtime_tick;
}

/**
 * Clear everything related to this admin.
 */
ServerNetworkAdminSocketHandler::~ServerNetworkAdminSocketHandler()
{
	_network_admins_connected--;
	DEBUG(net, 1, "[admin] '%s' (%s) has disconnected", this->admin_name, this->admin_version);
}

/**
 * Whether a connection is allowed or not at this moment.
 * @return Whether the connection is allowed.
 */
/* static */ bool ServerNetworkAdminSocketHandler::AllowConnection()
{
	return !StrEmpty(_settings_client.network.admin_password) && _network_admins_connected < MAX_ADMINS;
}

/** Send the packets for the server sockets. */
/* static */ void ServerNetworkAdminSocketHandler::Send()
{
	ServerNetworkAdminSocketHandler *as;
	FOR_ALL_ADMIN_SOCKETS(as) {
		if (as->status == ADMIN_STATUS_INACTIVE && as->realtime_connect + ADMIN_AUTHORISATION_TIMEOUT < _realtime_tick) {
			DEBUG(net, 1, "[admin] Admin did not send its authorisation within %d seconds", ADMIN_AUTHORISATION_TIMEOUT / 1000);
			as->CloseConnection(true);
			continue;
		}
		if (as->writable) {
			as->Send_Packets();
		}
	}
}

/* static */ void ServerNetworkAdminSocketHandler::AcceptConnection(SOCKET s, const NetworkAddress &address)
{
	ServerNetworkAdminSocketHandler *as = new ServerNetworkAdminSocketHandler(s);
	as->address = address; // Save the IP of the client
}

/***********
 * Sending functions for admin network
 ************/

NetworkRecvStatus ServerNetworkAdminSocketHandler::SendError(NetworkErrorCode error)
{
	Packet *p = new Packet(ADMIN_PACKET_SERVER_ERROR);

	p->Send_uint8(error);
	this->Send_Packet(p);

	char str[100];
	StringID strid = GetNetworkErrorMsg(error);
	GetString(str, strid, lastof(str));

	DEBUG(net, 1, "[admin] the admin '%s' (%s) made an error and has been disconnected. Reason: '%s'", this->admin_name, this->admin_version, str);

	return this->CloseConnection(true);
}

NetworkRecvStatus ServerNetworkAdminSocketHandler::SendProtocol()
{
	Packet *p = new Packet(ADMIN_PACKET_SERVER_PROTOCOL);

	/* announce the protocol version */
	p->Send_uint8(NETWORK_GAME_ADMIN_VERSION);

	for (int i = 0; i < ADMIN_UPDATE_END; i++) {
		p->Send_bool  (true);
		p->Send_uint16(i);
		p->Send_uint16(_admin_update_type_frequencies[i]);
	}

	p->Send_bool(false);
	this->Send_Packet(p);

	return this->SendWelcome();
}

NetworkRecvStatus ServerNetworkAdminSocketHandler::SendWelcome()
{
	this->status = ADMIN_STATUS_ACTIVE;

	Packet *p = new Packet(ADMIN_PACKET_SERVER_WELCOME);

	p->Send_string(_settings_client.network.server_name);
	p->Send_string(_openttd_revision);
	p->Send_bool  (_network_dedicated);

	p->Send_string(_network_game_info.map_name);
	p->Send_uint32(_settings_game.game_creation.generation_seed);
	p->Send_uint8 (_settings_game.game_creation.landscape);
	p->Send_uint32(ConvertYMDToDate(_settings_game.game_creation.starting_year, 0, 1));
	p->Send_uint16(MapSizeX());
	p->Send_uint16(MapSizeY());

	this->Send_Packet(p);

	return NETWORK_RECV_STATUS_OKAY;
}

NetworkRecvStatus ServerNetworkAdminSocketHandler::SendNewGame()
{
	Packet *p = new Packet(ADMIN_PACKET_SERVER_NEWGAME);
	this->Send_Packet(p);
	return NETWORK_RECV_STATUS_OKAY;
}

NetworkRecvStatus ServerNetworkAdminSocketHandler::SendShutdown()
{
	Packet *p = new Packet(ADMIN_PACKET_SERVER_SHUTDOWN);
	this->Send_Packet(p);
	return NETWORK_RECV_STATUS_OKAY;
}

NetworkRecvStatus ServerNetworkAdminSocketHandler::SendDate()
{
	Packet *p = new Packet(ADMIN_PACKET_SERVER_DATE);

	p->Send_uint32(_date);
	this->Send_Packet(p);

	return NETWORK_RECV_STATUS_OKAY;
}

/***********
 * Receiving functions
 ************/

DEF_ADMIN_RECEIVE_COMMAND(Server, ADMIN_PACKET_ADMIN_JOIN)
{
	if (this->status != ADMIN_STATUS_INACTIVE) return this->SendError(NETWORK_ERROR_NOT_EXPECTED);

	char password[NETWORK_PASSWORD_LENGTH];
	p->Recv_string(password, sizeof(password));

	if (StrEmpty(_settings_client.network.admin_password) ||
			strcmp(password, _settings_client.network.admin_password) != 0) {
		/* Password is invalid */
		return this->SendError(NETWORK_ERROR_WRONG_PASSWORD);
	}

	p->Recv_string(this->admin_name, sizeof(this->admin_name));
	p->Recv_string(this->admin_version, sizeof(this->admin_version));

	if (StrEmpty(this->admin_name) || StrEmpty(this->admin_version)) {
		/* no name or version supplied */
		return this->SendError(NETWORK_ERROR_ILLEGAL_PACKET);
	}

	DEBUG(net, 1, "[admin] '%s' (%s) has connected", this->admin_name, this->admin_version);

	return this->SendProtocol();
}

DEF_ADMIN_RECEIVE_COMMAND(Server, ADMIN_PACKET_ADMIN_QUIT)
{
	/* The admin is leaving nothing else to do */
	return this->CloseConnection();
}

DEF_ADMIN_RECEIVE_COMMAND(Server, ADMIN_PACKET_ADMIN_UPDATE_FREQUENCY)
{
	if (this->status == ADMIN_STATUS_INACTIVE) return this->SendError(NETWORK_ERROR_NOT_EXPECTED);

	AdminUpdateType type = (AdminUpdateType)p->Recv_uint16();
	AdminUpdateFrequency freq = (AdminUpdateFrequency)p->Recv_uint16();

	if (type >= ADMIN_UPDATE_END || (_admin_update_type_frequencies[type] & freq) != freq) {
		/* The server does not know of this UpdateType. */
		DEBUG(net, 3, "[admin] Not supported update frequency %d (%d) from '%s' (%s).", type, freq, this->admin_name, this->admin_version);
		return this->SendError(NETWORK_ERROR_ILLEGAL_PACKET);
	}

	this->update_frequency[type] = freq;

	return NETWORK_RECV_STATUS_OKAY;
}

DEF_ADMIN_RECEIVE_COMMAND(Server, ADMIN_PACKET_ADMIN_POLL)
{
	if (this->status == ADMIN_STATUS_INACTIVE) return this->SendError(NETWORK_ERROR_NOT_EXPECTED);

	AdminUpdateType type = (AdminUpdateType)p->Recv_uint8();
	uint32 d1 = p->Recv_uint32();

	switch (type) {
		case ADMIN_UPDATE_DATE:
			/* The admin is requesting the current date. */
			this->SendDate();
			break;

		default:
			/* An unsupported "poll" update type. */
			DEBUG(net, 3, "[admin] Not supported poll %d (%d) from '%s' (%s).", type, d1, this->admin_name, this->admin_version);
			return this->SendError(NETWORK_ERROR_ILLEGAL_PACKET);
	}

	return NETWORK_RECV_STATUS_OKAY;
}

/*
 * Useful wrapper functions
 */

/**
 * Send a Welcome packet to all connected admins
 */
void ServerNetworkAdminSocketHandler::WelcomeAll()
{
	ServerNetworkAdminSocketHandler *as;
	FOR_ALL_ADMIN_SOCKETS(as) {
		as->SendWelcome();
	}
}

/**
 * Send (push) updates to the admin network as they have registered for these updates.
 * @param freq the frequency to be processd.
 */
void NetworkAdminUpdate(AdminUpdateFrequency freq)
{
	ServerNetworkAdminSocketHandler *as;
	FOR_ALL_ADMIN_SOCKETS(as) {
		for (int i = 0; i < ADMIN_UPDATE_END; i++) {
			if (as->update_frequency[i] & freq) {
				/* Update the admin for the required details */
				switch (i) {
					case ADMIN_UPDATE_DATE:
						as->SendDate();
						break;

					default: NOT_REACHED();
				}
			}
		}
	}
}

#endif /* ENABLE_NETWORK */