/*
 * sbsessions.c
 * 
 * SB session (=>IM window) management (but not the protocol nor UI)
 *
 * (c) 2002-2005 Thomas White <taw27@srcf.ucam.org>
 *  Part of TuxMessenger - GTK+-based MSN Messenger client
 *
 * This package 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 dated June, 1991. 
 *
 * This package 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 this package; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA. 
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <gtk/gtk.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h>

#include "debug.h"
#include "messagewindow.h"
#include "sbsessions.h"
#include "sbprotocol.h"
#include "msnprotocol.h"
#include "contactlist.h"
#include "msngenerics.h"
#include "options.h"
#include "msnp2p.h"
#include "error.h"
#include "routines.h"
#include "fonttrans.h"

SbSession *sessions = NULL;

static SbSession *sbsessions_lastsession() {

	SbSession *session = sessions;

	while ( session ) {
	
		assert(session != NULL);

		if ( session->next == NULL ) {
			return session;
		} else {
			session = session->next;
		}
		
	}
	
	return NULL;	/* If there were no sessions at all. */

}

static void sbsessions_inituser(SbUser *new_user) {

}

static int sbsessions_ready_callback(SbSession *session) {

	if ( !session->ready ) {
		debug_print("SS %8p: Not ready after 60 seconds - deleting.\n", session);
		sbsessions_destroy(session);
		return FALSE;
	}	
	session->ready_timeout = 0;
	
	return FALSE;	/* Don't repeat */

}


static SbSession *sbsessions_new(const char *username, SbSessionSource source) {

	SbSession *new_session;
	SbSession *last_session;
		
	new_session = malloc(sizeof(SbSession));
	new_session->users = malloc(sizeof(SbUser));
	assert(new_session->users != NULL);
	
	new_session->messagewindow = NULL;
		
	new_session->users->next = NULL;
	new_session->users->username = strdup(username);
	sbsessions_inituser(new_session->users);
		
	new_session->ready = FALSE;
	new_session->num_users = 1;
	new_session->rbufsize = 0;
	new_session->wbufsize = 0;
	new_session->rbuffer = NULL;
	new_session->wbuffer = NULL;
	new_session->roffset = 0;
	new_session->roffset = 0;
	new_session->am_typing = 0;
	new_session->am_typing_callback = 0;
	new_session->threeway_intent = NULL;
	new_session->multipackets = NULL;
	new_session->trid = 1;	/* Reset in sbprotocol_connect */
	new_session->cached = NULL;

	new_session->source = source;
	new_session->rcallback = 0;
	new_session->wcallback = 0;
	
	/* 60 seconds to get ready. */
	new_session->ready_timeout = gtk_timeout_add(60000, (GtkFunction)sbsessions_ready_callback, new_session);
	
	/* Link it into the list. */
	last_session = sbsessions_lastsession();
	if ( last_session != NULL ) {
		assert(last_session->next == NULL);
		last_session->next = new_session;
	} else {
		sessions = new_session;
	}
	new_session->next = NULL;

	return new_session;

}

SbSession *sbsessions_create_local(const char *username) {

	SbSession *session = sbsessions_new(username, SESSION_SOURCE_LOCAL);
	
	session->neg_trid = msnprotocol_initiatesb();
	debug_print("SS %8p: New local session for user %s.\n", session, username);
	
	return session;

}

/* Called when the user clicks on a name in the contact list. */
SbSession *sbsessions_create_remote(char *username, char *switchboardaddress, char *sessionid, char *authchallenge) {

	SbSession *session = sbsessions_new(username, SESSION_SOURCE_REMOTE);
	
	session->neg_trid = 0;
	sbprotocol_initiate_remote(session, switchboardaddress, sessionid, authchallenge);
	debug_print("SS %8p: New remote session for user %s.\n", session, username);

	return session;

}

/* Create a three-way session in "one go". */
SbSession *sbsessions_create_threeway(char *username1, char *username2) {

	SbSession *session = sbsessions_new(username1, SESSION_SOURCE_LOCAL);

	session->threeway_intent = strdup(username2);
	session->neg_trid = msnprotocol_initiatesb();
	debug_print("SS %8p: New local session for user %s.  Intending to invite %s too.\n", session, username1, username2);

	return session;

}

void sbsessions_plug(SbSession *session, MessageWindow *messagewindow) {
	session->messagewindow = messagewindow;
}

/* Unplug any SB sessions which are plugged into a given IM window */
void sbsessions_unplug(MessageWindow *messagewindow) {

	SbSession *session = sessions;
	
	while ( session != NULL ) {
		if ( session->messagewindow == messagewindow ) {
			session->messagewindow = NULL;
		}
		session = session->next;
	}

}

/* Find a headless session with this username. */
SbSession *sbsessions_find_headless(const char *username) {

	SbSession *session = sessions;
	
	while ( session != NULL ) {
		if ( (session->num_users == 1) && (strcmp(username, session->users->username) == 0) && (session->messagewindow == NULL) ) {
			return session;
		}
		session = session->next;
	}
	
	return NULL;	

}

/* Find a session with just this user in, and noone about to randomly join (hopefully...) */
SbSession *sbsessions_find_single_safe(const char *username) {

	SbSession *session = sessions;
	
	while ( session != NULL ) {
		if ( (session->num_users == 1) && (strcmp(username, session->users->username) == 0) ) {
			if ( session->threeway_intent == NULL ) {
				return session;
			}
		}
		session = session->next;
	}
	
	return NULL;	

}


/* SbUsers are unique to a particular SbSession.  Find the parent SbSession
	given the SbUser. Could just keep a note of the parent record in the
	SbUser record, but sbsessions_stoptyping needs to know if the SbUser
	is still attached to (any) SbSession. */
SbSession *sbsessions_find_user(SbUser *target_user) {

	SbSession *session;

	session = sessions;
	while ( session != NULL ) {	
		SbUser *user = session->users;
		while ( user != NULL ) {		
			if ( user == target_user ) {
				return session;
			}		
			user = user->next;		
		}		
		session = session->next;		
	}
	
	debug_print("SS %8p: Couldn't find user in all sessions.\n", NULL);
	return NULL;

}

/* Return a session's record given "TrID". */
SbSession *sbsessions_find_trid(unsigned int trid) {

	SbSession *session;

	session = sessions;
	while ( session != NULL ) {
	
		assert(session != NULL);
	
		if ( session->neg_trid == trid ) {
			return session;
		} else {
			session = session->next;
		}
		
	}
	
	debug_print("SS %8p: Failed to find session negotiated with TrId %i\n", NULL, trid);
	return NULL;

}

SbUser *sbsessions_find_username(SbSession *session, const char *username) {

	SbUser *user;
	
	assert(session != NULL);
	assert(session->users != NULL);
	
	user = session->users;
	while ( user != NULL ) {
	
		assert(user != NULL);
		
		/* Case-insensitive here.  Username may have different case depending
			on its source, since the servers seem to change usernames to
			lower case but clients might not in (e.g.) TypingUser controls. */
		if ( strcasecmp(user->username, username) == 0 ) {
			return user;
		} else {
			user = user->next;
		}
	
	}
	
	return NULL;

}

/* Locate a user on a given SB session from their DP SHA1D field. */
SbUser *sbsessions_find_dpsha1d(SbSession *session, char *sha1d) {

	SbUser *user;
	
	assert(session != NULL);
	assert(session->users != NULL);
	
	user = session->users;
	while ( user != NULL ) {
	
		assert(user != NULL);
		
		if ( strcmp(user->dpsha1d, sha1d) == 0 ) {
			return user;
		} else {
			user = user->next;
		}
	
	}
	
	return NULL;

}

void sbsessions_destroy(SbSession *session) {

	SbSession *prev_session;
	SbUser *user;
	CachedMsg *cached;
	
	/* Unplug the session and close the socket. */
	messagewindow_unplug(session);
	sbprotocol_close(session);
	
	/* Remove the session from the list. */
	prev_session = sessions;
	if ( prev_session != session ) {
		while ( prev_session != NULL ) {
			assert(prev_session != NULL);
			if ( prev_session->next == session ) {
				break;
			} else {
				prev_session = prev_session->next;
			}
		}
		assert(prev_session->next == session);
		/* Link it out of the list. */
		prev_session->next = session->next;
	} else {
		/* This session was the first on the list. */
		assert(sessions == session);	/* Can't fail... */
		sessions = session->next;	/* Which may be NULL if the list is now empty. */
	}	
	
	/* Drop all MSNP2P sessions in this SB session. */
	msnp2p_abortall(session);
	
	/* Drop any cached messages, and inform the user. */
	cached = session->cached;
	while ( cached != NULL ) {
	
		CachedMsg *next = cached->next;
		if ( !session->messagewindow ) {
			messagewindow_mitigate(session);
		}
		messagewindow_reportdropped(session->messagewindow, cached->message, cached->length);
		free(cached->message);
		free(cached);
		cached = next;
		messagewindow_unplug(session);	/* This session doesn't exist, remember? */
	
	}
	
	/* Remove all the users. */
	user = session->users;
	while ( user != NULL ) {
	
		SbUser *next_user = user->next;
		free(user->username);
		free(user);
		user = next_user;
		
	}
	
	/* Wind up the low-level business. */
	if ( session->rcallback != 0 ) {
		gdk_input_remove(session->rcallback);
	}
	session->rcallback = 0;
	if ( session->wcallback != 0 ) {
		gdk_input_remove(session->wcallback);
	}
	session->wcallback = 0;

	if ( session->ready_timeout != 0 ) {
		gtk_timeout_remove(session->ready_timeout);
	}
	session->ready_timeout = 0;
		
	if ( session->am_typing_callback != 0 ) {
		gtk_timeout_remove(session->am_typing_callback);
		session->am_typing = 0;
		session->am_typing_callback = 0;
	}
	
	if ( session->rbuffer != NULL ) {
		free(session->rbuffer);
	}
	if ( session->wbuffer != NULL ) {
		free(session->wbuffer);
	}
	
	free(session);

}

SbUser *sbsessions_lastuser(SbSession *session) {

	SbUser *user;

	user = session->users;
	while ( user != NULL ) {
	
		assert(user != NULL);
		
		if ( user->next == NULL ) {
			return user;
		} else {
			user = user->next;
		}
	
	}
	
	debug_print("SS %8p: Reached end of sbsessions_lastuser!  This doesn't happen!\n", session);
	return NULL;

}

static SbUser *sbsessions_addnewuser(SbSession *session, char *username) {

	SbUser *new_user;
	SbUser *previous_user;

	new_user = malloc(sizeof(SbUser));
	assert(new_user != NULL);
	new_user->next = NULL;
	new_user->username = strdup(username);
	sbsessions_inituser(new_user);

	previous_user = sbsessions_lastuser(session);
	assert(previous_user->next == NULL);
	previous_user->next = new_user;
	
	session->num_users++;
	
	return new_user;

}

/* Deal with any user joining a session (whether by JOI or IRO). */
void sbsessions_joined(SbSession *session, char *username, char *friendlyname) {

	SbUser *user;

	/* "friendlyname" is from the JOI message.  This user might not be in any of the
		contact lists.  Now would be a good time to check, and if not, create a
		temporary record for them. */
	if ( contactlist_friendlyname(username) == NULL ) {	
		debug_print("SS %8p: Creating temporary user record for '%s'/'%s'\n", session, username, friendlyname);
		contactlist_tldetails(CONTACT_SOURCE_RNG, username, friendlyname, ONLINE_NLN);
	}
	
	user = sbsessions_find_username(session, username);
	if ( user == NULL ) {
	
		/* User is new - probably got invited by someone else */
		debug_print("SS %8p: Couldn't find user %s in SB record - adding them.\n", session, username);
		
		user = sbsessions_addnewuser(session, username);
				
	}
	
	if ( session->messagewindow != NULL ) {
		messagewindow_joined(session->messagewindow, username);
	}

}

/* Deal with any user leaving a session. */
void sbsessions_left(SbSession *session, char *username) {

	SbUser *user;
	
	user = sbsessions_find_username(session, username);
	if ( user == NULL ) {
		debug_print("SS %8p: Couldn't find leaving user %s in SB record!\n", session, username);
		return;
	}
	
	if ( session->num_users == 1 ) {
		sbprotocol_leavesession(session);
	} else {

		/* "Normal" situation.  Remove user record, their DP and status bar. */

		SbUser *find_user;

		session->num_users--;
		if ( session->messagewindow != NULL ) {
			messagewindow_removeuser(session->messagewindow, username);
		}
		
		/* Find the preceding user in the session and link this user out. */
		find_user = session->users;
		if ( find_user == user ) {
			/* User was the first in the list. */
			session->users = user->next;
		} else {
		
			while ( find_user != NULL ) {
		
				assert(find_user != NULL);
			
				if ( find_user->next == user ) {
					find_user->next = user->next;
					break;
				} else {
					find_user = find_user->next;
				}
		
			}

		}
		free(user->username);
		free(user);

	}

}

static int sbsessions_amtyping_callback(SbSession *session) {

	session->am_typing = 0;
	session->am_typing_callback = 0;
	
	return FALSE;	/* Don't repeat */

}

void sbsessions_am_typing(SbSession *session) {

	if ( !session->ready ) {
		debug_print("SS %8p: Not ready - not sending TypingUser.\n", session);
		return;
	}

	/* Calculate timeout then send TypingUser control. */
	if ( session->am_typing == 0 ) {

		sbprotocol_sendtypingcontrol(session);
		session->am_typing = 1;
		session->am_typing_callback = gtk_timeout_add(5000, (GtkFunction)sbsessions_amtyping_callback, session);
	
	}

}

/* Check a session is ready for I/O. */
int sbsessions_sessionready(SbSession *session) {

	if ( session == NULL ) {
		return FALSE;
	}

	return session->ready;

}

/* Delete all sessions. */
void sbsessions_destroy_all() {

	SbSession *session;
	SbSession *next;

	debug_print("SB %8p: destroying all sessions.\n", NULL);

	session = sessions;
	while ( session != NULL ) {
		next = session->next;
		sbsessions_destroy(session);
		session = next;
	}

}