/*       +------------------------------------+
 *       | Inspire Internet Relay Chat Daemon |
 *       +------------------------------------+
 *
 *  Inspire is copyright (C) 2002-2004 ChatSpike-Dev.
 *                       E-mail:
 *                <brain@chatspike.net>
 *           	  <Craig@chatspike.net>
 *     
 * Written by Craig Edwards, Craig McLure, and others.
 * This program is free but copyrighted software; see
 *            the file COPYING for details.
 *
 * ---------------------------------------------------
 */

using namespace std;

#include "inspircd_config.h" 
#include "channels.h"
#include "connection.h"
#include "users.h"
#include "inspircd.h"
#include <stdio.h>
#ifdef THREADED_DNS
#include <pthread.h>
#include <signal.h>
#endif
#include "inspstring.h"
#include "commands.h"
#include "helperfuncs.h"
#include "typedefs.h"
#include "socketengine.h"
#include "hashcomp.h"
#include "message.h"
#include "wildcard.h"
#include "xline.h"

extern InspIRCd* ServerInstance;
extern int WHOWAS_STALE;
extern int WHOWAS_MAX;
extern std::vector<Module*> modules;
extern std::vector<ircd_module*> factory;
extern std::vector<InspSocket*> module_sockets;
extern int MODCOUNT;
extern InspSocket* socket_ref[65535];
extern time_t TIME;
extern userrec* fd_ref_table[65536];
extern serverstats* stats;
extern ServerConfig *Config;
extern user_hash clientlist;
extern whowas_hash whowas;
extern Module* IOHookModule;
std::vector<userrec*> local_users;

std::vector<userrec*> all_opers;

template<typename T> inline string ConvToStr(const T &in)
{
        stringstream tmp;
        if (!(tmp << in)) return string();
        return tmp.str();
}

userrec::userrec()
{
	// the PROPER way to do it, AVOID bzero at *ALL* costs
	strcpy(nick,"");
	strcpy(ip,"127.0.0.1");
	timeout = 0;
	strcpy(ident,"");
	strcpy(host,"");
	strcpy(dhost,"");
	strcpy(fullname,"");
	strcpy(modes,"");
	server = (char*)FindServerNamePtr(Config->ServerName);
	strcpy(awaymsg,"");
	strcpy(oper,"");
	reset_due = TIME;
	lines_in = 0;
	fd = lastping = signon = idle_lastmsg = nping = registered = 0;
	flood = port = bytes_in = bytes_out = cmds_in = cmds_out = 0;
	haspassed = false;
	dns_done = false;
	recvq = "";
	sendq = "";
	chans.clear();
	invites.clear();
}

userrec::~userrec()
{
}

void userrec::CloseSocket()
{
	shutdown(this->fd,2);
	close(this->fd);
}
 
char* userrec::GetFullHost()
{
	static char result[MAXBUF];
	snprintf(result,MAXBUF,"%s!%s@%s",nick,ident,dhost);
	return result;
}

int userrec::ReadData(void* buffer, size_t size)
{
	if (this->fd > -1)
	{
		return read(this->fd, buffer, size);
	}
	else return 0;
}


char* userrec::GetFullRealHost()
{
	static char fresult[MAXBUF];
	snprintf(fresult,MAXBUF,"%s!%s@%s",nick,ident,host);
	return fresult;
}

bool userrec::IsInvited(irc::string &channel)
{
	for (InvitedList::iterator i = invites.begin(); i != invites.end(); i++)
	{
		irc::string compare = i->channel;
		if (compare == channel)
		{
			return true;
		}
	}
	return false;
}

InvitedList* userrec::GetInviteList()
{
	return &invites;
}

void userrec::InviteTo(irc::string &channel)
{
	Invited i;
	i.channel = channel;
	invites.push_back(i);
}

void userrec::RemoveInvite(irc::string &channel)
{
	log(DEBUG,"Removing invites");
	if (invites.size())
	{
		for (InvitedList::iterator i = invites.begin(); i != invites.end(); i++)
		{
			irc::string compare = i->channel;
			if (compare == channel)
			{
				invites.erase(i);
				return;
       	         	}
       		}
       	}
}

bool userrec::HasPermission(std::string &command)
{
	char TypeName[MAXBUF],Classes[MAXBUF],ClassName[MAXBUF],CommandList[MAXBUF];
	char* mycmd;
	char* savept;
	char* savept2;
	
	// users on u-lined servers can completely bypass
	// all permissions based checks.
	//
	// of course, if this is sent to a remote server and this
	// server is not ulined there, then that other server
	// silently drops the command.
	if (is_uline(this->server))
		return true;
	
	// are they even an oper at all?
	if (strchr(this->modes,'o'))
	{
		for (int j =0; j < Config->ConfValueEnum("type",&Config->config_f); j++)
		{
			Config->ConfValue("type","name",j,TypeName,&Config->config_f);
			if (!strcmp(TypeName,this->oper))
			{
				Config->ConfValue("type","classes",j,Classes,&Config->config_f);
				char* myclass = strtok_r(Classes," ",&savept);
				while (myclass)
				{
					for (int k =0; k < Config->ConfValueEnum("class",&Config->config_f); k++)
					{
						Config->ConfValue("class","name",k,ClassName,&Config->config_f);
						if (!strcmp(ClassName,myclass))
						{
							Config->ConfValue("class","commands",k,CommandList,&Config->config_f);
							mycmd = strtok_r(CommandList," ",&savept2);
							while (mycmd)
							{
								if ((!strcasecmp(mycmd,command.c_str())) || (*mycmd == '*'))
								{
									return true;
								}
								mycmd = strtok_r(NULL," ",&savept2);
							}
						}
					}
					myclass = strtok_r(NULL," ",&savept);
				}
			}
		}
	}
	return false;
}


bool userrec::AddBuffer(std::string a)
{
        std::string b = "";
        for (unsigned int i = 0; i < a.length(); i++)
                if ((a[i] != '\r') && (a[i] != '\0') && (a[i] != 7))
                        b = b + a[i];
        std::stringstream stream(recvq);
        stream << b;
        recvq = stream.str();
	unsigned int i = 0;
	// count the size of the first line in the buffer.
	while (i < recvq.length())
	{
		if (recvq[i++] == '\n')
			break;
	}
	if (recvq.length() > (unsigned)this->recvqmax)
	{
		this->SetWriteError("RecvQ exceeded");
		WriteOpers("*** User %s RecvQ of %d exceeds connect class maximum of %d",this->nick,recvq.length(),this->recvqmax);
	}
	// return false if we've had more than 600 characters WITHOUT
	// a carriage return (this is BAD, drop the socket)
	return (i < 600);
}

bool userrec::BufferIsReady()
{
        for (unsigned int i = 0; i < recvq.length(); i++)
		if (recvq[i] == '\n')
			return true;
        return false;
}

void userrec::ClearBuffer()
{
        recvq = "";
}

std::string userrec::GetBuffer()
{
	if (recvq == "")
		return "";
        char* line = (char*)recvq.c_str();
        std::string ret = "";
        while ((*line != '\n') && (strlen(line)))
        {
                ret = ret + *line;
                line++;
        }
        if ((*line == '\n') || (*line == '\r'))
                line++;
        recvq = line;
        return ret;
}

void userrec::AddWriteBuf(std::string data)
{
	if (this->GetWriteError() != "")
		return;
	if (sendq.length() + data.length() > (unsigned)this->sendqmax)
	{
		/* Fix by brain - Set the error text BEFORE calling writeopers, because
		 * if we dont it'll recursively  call here over and over again trying
		 * to repeatedly add the text to the sendq!
		 */
		this->SetWriteError("SendQ exceeded");
		WriteOpers("*** User %s SendQ of %d exceeds connect class maximum of %d",this->nick,sendq.length() + data.length(),this->sendqmax);
		return;
	}
        std::stringstream stream;
        stream << sendq << data;
        sendq = stream.str();
}

// send AS MUCH OF THE USERS SENDQ as we are able to (might not be all of it)
void userrec::FlushWriteBuf()
{
	if (sendq.length())
	{
		char* tb = (char*)this->sendq.c_str();
		int n_sent = write(this->fd,tb,this->sendq.length());
		if (n_sent == -1)
		{
			this->SetWriteError(strerror(errno));
		}
		else
		{
			// advance the queue
			tb += n_sent;
			this->sendq = tb;
			// update the user's stats counters
			this->bytes_out += n_sent;
			this->cmds_out++;
		}
	}
}

void userrec::SetWriteError(std::string error)
{
	log(DEBUG,"Setting error string for %s to '%s'",this->nick,error.c_str());
	// don't try to set the error twice, its already set take the first string.
	if (this->WriteError == "")
		this->WriteError = error;
}

std::string userrec::GetWriteError()
{
	return this->WriteError;
}

void AddOper(userrec* user)
{
        log(DEBUG,"Oper added to optimization list");
        all_opers.push_back(user);
}

void DeleteOper(userrec* user)
{
        for (std::vector<userrec*>::iterator a = all_opers.begin(); a < all_opers.end(); a++)
        {
                if (*a == user)
                {
                        log(DEBUG,"Oper removed from optimization list");
                        all_opers.erase(a);
                        return;
                }
        }
}

void kill_link(userrec *user,const char* r)
{
        user_hash::iterator iter = clientlist.find(user->nick);

        char reason[MAXBUF];

        strncpy(reason,r,MAXBUF);

        if (strlen(reason)>MAXQUIT)
        {
                reason[MAXQUIT-1] = '\0';
        }

        log(DEBUG,"kill_link: %s '%s'",user->nick,reason);
        Write(user->fd,"ERROR :Closing link (%s@%s) [%s]",user->ident,user->host,reason);
        log(DEBUG,"closing fd %lu",(unsigned long)user->fd);

        if (user->registered == 7) {
                FOREACH_MOD OnUserQuit(user,reason);
                WriteCommonExcept(user,"QUIT :%s",reason);
        }

        user->FlushWriteBuf();

        FOREACH_MOD OnUserDisconnect(user);

        if (user->fd > -1)
        {
		if (IOHookModule)
		{
                	IOHookModule->OnRawSocketClose(user->fd);
		}
                ServerInstance->SE->DelFd(user->fd);
                user->CloseSocket();
        }

        // this must come before the WriteOpers so that it doesnt try to fill their buffer with anything
        // if they were an oper with +s.
        if (user->registered == 7) {
                purge_empty_chans(user);
                // fix by brain: only show local quits because we only show local connects (it just makes SENSE)
                if (user->fd > -1)
                        WriteOpers("*** Client exiting: %s!%s@%s [%s]",user->nick,user->ident,user->host,reason);
                AddWhoWas(user);
        }

        if (iter != clientlist.end())
        {
                log(DEBUG,"deleting user hash value %lu",(unsigned long)user);
                if (user->fd > -1)
		{
                        fd_ref_table[user->fd] = NULL;
			if (find(local_users.begin(),local_users.end(),user) != local_users.end())
			{
				local_users.erase(find(local_users.begin(),local_users.end(),user));
				log(DEBUG,"Delete local user");
			}
		}
                clientlist.erase(iter);
        }
        delete user;
}

void kill_link_silent(userrec *user,const char* r)
{
        user_hash::iterator iter = clientlist.find(user->nick);

        char reason[MAXBUF];

        strncpy(reason,r,MAXBUF);

        if (strlen(reason)>MAXQUIT)
        {
                reason[MAXQUIT-1] = '\0';
        }

        log(DEBUG,"kill_link: %s '%s'",user->nick,reason);
        Write(user->fd,"ERROR :Closing link (%s@%s) [%s]",user->ident,user->host,reason);
        log(DEBUG,"closing fd %lu",(unsigned long)user->fd);

        user->FlushWriteBuf();

        if (user->registered == 7) {
                FOREACH_MOD OnUserQuit(user,reason);
                WriteCommonExcept(user,"QUIT :%s",reason);
        }

        FOREACH_MOD OnUserDisconnect(user);

        if (user->fd > -1)
        {
		if (IOHookModule)
		{
                	IOHookModule->OnRawSocketClose(user->fd);
		}
                ServerInstance->SE->DelFd(user->fd);
                user->CloseSocket();
        }

        if (user->registered == 7) {
                purge_empty_chans(user);
        }

        if (iter != clientlist.end())
        {
                log(DEBUG,"deleting user hash value %lu",(unsigned long)user);
                if (user->fd > -1)
		{
                        fd_ref_table[user->fd] = NULL;
			if (find(local_users.begin(),local_users.end(),user) != local_users.end())
			{
				log(DEBUG,"Delete local user");
	                        local_users.erase(find(local_users.begin(),local_users.end(),user));
			}
		}
                clientlist.erase(iter);
        }
        delete user;
}


/* adds or updates an entry in the whowas list */
void AddWhoWas(userrec* u)
{
        whowas_hash::iterator iter = whowas.find(u->nick);
        WhoWasUser *a = new WhoWasUser();
        strlcpy(a->nick,u->nick,NICKMAX);
        strlcpy(a->ident,u->ident,IDENTMAX);
        strlcpy(a->dhost,u->dhost,160);
        strlcpy(a->host,u->host,160);
        strlcpy(a->fullname,u->fullname,MAXGECOS);
        strlcpy(a->server,u->server,256);
        a->signon = u->signon;

        /* MAX_WHOWAS:   max number of /WHOWAS items
         * WHOWAS_STALE: number of hours before a WHOWAS item is marked as stale and
         *               can be replaced by a newer one
         */

        if (iter == whowas.end())
        {
                if (whowas.size() >= (unsigned)WHOWAS_MAX)
                {
                        for (whowas_hash::iterator i = whowas.begin(); i != whowas.end(); i++)
                        {
                                // 3600 seconds in an hour ;)
                                if ((i->second->signon)<(TIME-(WHOWAS_STALE*3600)))
                                {
                                        // delete the old one
                                        if (i->second) delete i->second;
                                        // replace with new one
                                        i->second = a;
                                        log(DEBUG,"added WHOWAS entry, purged an old record");
                                        return;
                                }
                        }
                        // no space left and user doesnt exist. Don't leave ram in use!
                        log(DEBUG,"Not able to update whowas (list at WHOWAS_MAX entries and trying to add new?), freeing excess ram");
                        delete a;
                }
                else
                {
                        log(DEBUG,"added fresh WHOWAS entry");
                        whowas[a->nick] = a;
                }
        }
        else
        {
                log(DEBUG,"updated WHOWAS entry");
                if (iter->second) delete iter->second;
                iter->second = a;
        }
}

/* add a client connection to the sockets list */
void AddClient(int socket, char* host, int port, bool iscached, char* ip)
{
        string tempnick;
        char tn2[MAXBUF];
        user_hash::iterator iter;

        tempnick = ConvToStr(socket) + "-unknown";
        sprintf(tn2,"%lu-unknown",(unsigned long)socket);

        iter = clientlist.find(tempnick);

        // fix by brain.
        // as these nicknames are 'RFC impossible', we can be sure nobody is going to be
        // using one as a registered connection. As theyre per fd, we can also safely assume
        // that we wont have collisions. Therefore, if the nick exists in the list, its only
        // used by a dead socket, erase the iterator so that the new client may reclaim it.
        // this was probably the cause of 'server ignores me when i hammer it with reconnects'
        // issue in earlier alphas/betas
        if (iter != clientlist.end())
        {
                userrec* goner = iter->second;
                delete goner;
                clientlist.erase(iter);
        }

        /*
         * It is OK to access the value here this way since we know
         * it exists, we just created it above.
         *
         * At NO other time should you access a value in a map or a
         * hash_map this way.
         */
        clientlist[tempnick] = new userrec();

        NonBlocking(socket);
        log(DEBUG,"AddClient: %lu %s %d %s",(unsigned long)socket,host,port,ip);

        clientlist[tempnick]->fd = socket;
        strlcpy(clientlist[tempnick]->nick, tn2,NICKMAX);
        strlcpy(clientlist[tempnick]->host, host,160);
        strlcpy(clientlist[tempnick]->dhost, host,160);
        clientlist[tempnick]->server = (char*)FindServerNamePtr(Config->ServerName);
        strlcpy(clientlist[tempnick]->ident, "unknown",IDENTMAX);
        clientlist[tempnick]->registered = 0;
        clientlist[tempnick]->signon = TIME + Config->dns_timeout;
        clientlist[tempnick]->lastping = 1;
        clientlist[tempnick]->port = port;
        strlcpy(clientlist[tempnick]->ip,ip,16);

        // set the registration timeout for this user
        unsigned long class_regtimeout = 90;
        int class_flood = 0;
        long class_threshold = 5;
        long class_sqmax = 262144;      // 256kb
        long class_rqmax = 4096;        // 4k

        for (ClassVector::iterator i = Config->Classes.begin(); i != Config->Classes.end(); i++)
        {
                if (match(clientlist[tempnick]->host,i->host) && (i->type == CC_ALLOW))
                {
                        class_regtimeout = (unsigned long)i->registration_timeout;
                        class_flood = i->flood;
                        clientlist[tempnick]->pingmax = i->pingtime;
                        class_threshold = i->threshold;
                        class_sqmax = i->sendqmax;
                        class_rqmax = i->recvqmax;
                        break;
                }
        }

        clientlist[tempnick]->nping = TIME+clientlist[tempnick]->pingmax + Config->dns_timeout;
        clientlist[tempnick]->timeout = TIME+class_regtimeout;
        clientlist[tempnick]->flood = class_flood;
        clientlist[tempnick]->threshold = class_threshold;
        clientlist[tempnick]->sendqmax = class_sqmax;
        clientlist[tempnick]->recvqmax = class_rqmax;

        ucrec a;
        a.channel = NULL;
        a.uc_modes = 0;
        for (int i = 0; i < MAXCHANS; i++)
                clientlist[tempnick]->chans.push_back(a);

        if (clientlist.size() > Config->SoftLimit)
        {
                kill_link(clientlist[tempnick],"No more connections allowed");
                return;
        }

        if (clientlist.size() >= MAXCLIENTS)
        {
                kill_link(clientlist[tempnick],"No more connections allowed");
                return;
        }

        // this is done as a safety check to keep the file descriptors within range of fd_ref_table.
        // its a pretty big but for the moment valid assumption:
        // file descriptors are handed out starting at 0, and are recycled as theyre freed.
        // therefore if there is ever an fd over 65535, 65536 clients must be connected to the
        // irc server at once (or the irc server otherwise initiating this many connections, files etc)
        // which for the time being is a physical impossibility (even the largest networks dont have more
        // than about 10,000 users on ONE server!)
        if ((unsigned)socket > 65534)
        {
                kill_link(clientlist[tempnick],"Server is full");
                return;
        }
        char* e = matches_exception(ip);
        if (!e)
        {
                char* r = matches_zline(ip);
                if (r)
                {
                        char reason[MAXBUF];
                        snprintf(reason,MAXBUF,"Z-Lined: %s",r);
                        kill_link(clientlist[tempnick],reason);
                        return;
                }
        }
        fd_ref_table[socket] = clientlist[tempnick];
	local_users.push_back(clientlist[tempnick]);
        ServerInstance->SE->AddFd(socket,true,X_ESTAB_CLIENT);
}

void FullConnectUser(userrec* user)
{
        stats->statsConnects++;
        user->idle_lastmsg = TIME;
        log(DEBUG,"ConnectUser: %s",user->nick);

        if ((strcmp(Passwd(user),"")) && (!user->haspassed))
        {
                kill_link(user,"Invalid password");
                return;
        }
        if (IsDenied(user))
        {
                kill_link(user,"Unauthorised connection");
                return;
        }

        char match_against[MAXBUF];
        snprintf(match_against,MAXBUF,"%s@%s",user->ident,user->host);
        char* e = matches_exception(match_against);
        if (!e)
        {
                char* r = matches_gline(match_against);
                if (r)
                {
                        char reason[MAXBUF];
                        snprintf(reason,MAXBUF,"G-Lined: %s",r);
                        kill_link_silent(user,reason);
                        return;
                }
                r = matches_kline(user->host);
                if (r)
                {
                        char reason[MAXBUF];
                        snprintf(reason,MAXBUF,"K-Lined: %s",r);
                        kill_link_silent(user,reason);
                        return;
                }
        }


        WriteServ(user->fd,"NOTICE Auth :Welcome to \002%s\002!",Config->Network);
        WriteServ(user->fd,"001 %s :Welcome to the %s IRC Network %s!%s@%s",user->nick,Config->Network,user->nick,user->ident,user->host);
        WriteServ(user->fd,"002 %s :Your host is %s, running version %s",user->nick,Config->ServerName,VERSION);
        WriteServ(user->fd,"003 %s :This server was created %s %s",user->nick,__TIME__,__DATE__);
        WriteServ(user->fd,"004 %s %s %s iowghraAsORVSxNCWqBzvdHtGI lvhopsmntikrRcaqOALQbSeKVfHGCuzN",user->nick,Config->ServerName,VERSION);
        // the neatest way to construct the initial 005 numeric, considering the number of configure constants to go in it...
        std::stringstream v;
        v << "WALLCHOPS MODES=13 CHANTYPES=# PREFIX=(ohv)@%+ MAP SAFELIST MAXCHANNELS=" << MAXCHANS;
        v << " MAXBANS=60 NICKLEN=" << NICKMAX;
        v << " TOPICLEN=" << MAXTOPIC << " KICKLEN=" << MAXKICK << " MAXTARGETS=20 AWAYLEN=" << MAXAWAY << " CHANMODES=ohvb,k,l,psmnti NETWORK=";
        v << Config->Network;
        std::string data005 = v.str();
        FOREACH_MOD On005Numeric(data005);
        // anfl @ #ratbox, efnet reminded me that according to the RFC this cant contain more than 13 tokens per line...
        // so i'd better split it :)
        std::stringstream out(data005);
        std::string token = "";
        std::string line5 = "";
        int token_counter = 0;
        while (!out.eof())
        {
                out >> token;
                line5 = line5 + token + " ";
                token_counter++;
                if ((token_counter >= 13) || (out.eof() == true))
                {
                        WriteServ(user->fd,"005 %s %s:are supported by this server",user->nick,line5.c_str());
                        line5 = "";
                        token_counter = 0;
                }
        }
        ShowMOTD(user);

        // fix 3 by brain, move registered = 7 below these so that spurious modes and host changes dont go out
        // onto the network and produce 'fake direction'
        FOREACH_MOD OnUserConnect(user);
        FOREACH_MOD OnGlobalConnect(user);
        user->registered = 7;
        WriteOpers("*** Client connecting on port %lu: %s!%s@%s [%s]",(unsigned long)user->port,user->nick,user->ident,user->host,user->ip);
}


/* shows the message of the day, and any other on-logon stuff */
void ConnectUser(userrec *user)
{
        // dns is already done, things are fast. no need to wait for dns to complete just pass them straight on
        if ((user->dns_done) && (user->registered >= 3) && (AllModulesReportReady(user)))
        {
                FullConnectUser(user);
        }
}

/* re-allocates a nick in the user_hash after they change nicknames,
 * returns a pointer to the new user as it may have moved */

userrec* ReHashNick(char* Old, char* New)
{
        //user_hash::iterator newnick;
        user_hash::iterator oldnick = clientlist.find(Old);

        log(DEBUG,"ReHashNick: %s %s",Old,New);

        if (!strcasecmp(Old,New))
        {
                log(DEBUG,"old nick is new nick, skipping");
                return oldnick->second;
        }

        if (oldnick == clientlist.end()) return NULL; /* doesnt exist */

        log(DEBUG,"ReHashNick: Found hashed nick %s",Old);

        userrec* olduser = oldnick->second;
        clientlist[New] = olduser;
        clientlist.erase(oldnick);

        log(DEBUG,"ReHashNick: Nick rehashed as %s",New);

        return clientlist[New];
}

void force_nickchange(userrec* user,const char* newnick)
{
        char nick[MAXBUF];
        int MOD_RESULT = 0;

        strcpy(nick,"");

        FOREACH_RESULT(OnUserPreNick(user,newnick));
        if (MOD_RESULT) {
                stats->statsCollisions++;
                kill_link(user,"Nickname collision");
                return;
        }
        if (matches_qline(newnick))
        {
                stats->statsCollisions++;
                kill_link(user,"Nickname collision");
                return;
        }

        if (user)
        {
                if (newnick)
                {
                        strncpy(nick,newnick,MAXBUF);
                }
                if (user->registered == 7)
                {
                        char* pars[1];
                        pars[0] = nick;
                        handle_nick(pars,1,user);
                }
        }
}