/**
 * GMyth Library
 *
 * @file gmyth/gmyth_socket.c
 * 
 * @brief <p> MythTV socket implementation, according to the MythTV Project
 * (www.mythtv.org). 
 * 
 * This component provides basic socket functionalities to interact with
 * the Mythtv backend.
 * <p>
 *
 * Copyright (C) 2006 INdT - Instituto Nokia de Tecnologia.
 * @author Rosfran Lins Borges <rosfran.borges@indt.org.br> 
 *
 *//*
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 Lesser General Public License
 * along with this program; 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 "gmyth_socket.h"

#include <glib.h> 
#include <glib/gprintf.h>

#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/param.h>
#include <netdb.h>
#include <net/if.h>
#include <errno.h>
#include <stdlib.h>

#include <unistd.h>
#include <netinet/in.h>
#include <fcntl.h>
#include <signal.h>

#include <sys/ioctl.h>

#include "gmyth_stringlist.h"
#include "gmyth_uri.h"
#include "gmyth_debug.h"

#define BUFLEN 				   	512
#define MYTH_SEPARATOR 			    	"[]:[]"
#define MYTH_PROTOCOL_FIELD_SIZE		8

/* max number of iterations */
#define MYTHTV_MAX_VERSION_CHECKS		40

// FIXME: put this in the right place
#define  MYTHTV_VERSION_DEFAULT			30

static GStaticMutex mutex = G_STATIC_MUTEX_INIT;

static gchar* local_hostname = NULL;

static void gmyth_socket_class_init          (GMythSocketClass *klass);
static void gmyth_socket_init                (GMythSocket *object);

static void gmyth_socket_dispose  (GObject *object);
static void gmyth_socket_finalize (GObject *object);

G_DEFINE_TYPE(GMythSocket, gmyth_socket, G_TYPE_OBJECT)

static void
gmyth_socket_class_init (GMythSocketClass *klass)
{
    GObjectClass *gobject_class;

    gobject_class = (GObjectClass *) klass;

    gobject_class->dispose  = gmyth_socket_dispose;
    gobject_class->finalize = gmyth_socket_finalize;	
}

static void
gmyth_socket_init (GMythSocket *gmyth_socket)
{
	
	/* gmyth_socket->local_hostname = NULL; */
	
}

/** Gets the some important address translation info, from the client socket
 * that will open a connection.
 * 
 * @return gint that represents the error number from getaddrinfo(). 
 */
static gint
gmyth_socket_toaddrinfo (const gchar *addr, gint port, struct addrinfo **addrInfo )
{
    struct addrinfo hints;
    gchar *portStr = NULL;
    gint errorn = EADDRNOTAVAIL;
 
    g_return_val_if_fail ( addr != NULL, -1 );
    g_debug ("Calling %s\n", __FUNCTION__);

    /* hints = g_malloc0 ( sizeof(struct addrinfo) ); */
    memset ( &hints, 0, sizeof(struct addrinfo) );
    hints.ai_family = AF_INET;
    hints.ai_socktype = SOCK_STREAM;
    /* hints.ai_flags = AI_NUMERICHOST; */
    
    if ( port != -1 )	
        portStr = g_strdup_printf ( "%d", port );
    else
	portStr = NULL;

    gmyth_debug ("Getting name resolution for: %s, %d\n", addr, port);

    if ( ( errorn = getaddrinfo(addr, portStr, &hints, addrInfo) ) != 0 ) {
		g_printerr( "[%s] Socket ERROR: %s\n", __FUNCTION__, gai_strerror(errorn) );
    }
    g_free (portStr);
    /* g_free (hints); */
    return errorn;
}

static gint
gmyth_socket_find_match_address_uri( GMythURI* uri, gchar *address ) {

        if ( g_ascii_strcasecmp( gmyth_uri_get_host( uri ), address ) == 0 ) {
                //g_printerr( "Found URI: %s !!!\n", rui_uri_getvalue(uri) );
                return 0;
        } else {
                return -1;
        }

}

static const gchar *PATH_PROC_NET_DEV = "/proc/net/dev";

/** Gets the list of all local network interfaces (using the /proc/net/dev directory).
 * 
 * @param current_connections	A list with all the network interfaces are valid, 
 * 		to be applied just like a filter.
 * @return List with all the local net interfaces. 
 */
static GList *
gmyth_socket_get_local_addrs( GList *current_connections )
{

	GList *local_addrs = NULL;
	FILE *fd;
	gint s;
	gchar buffer[256+1];
	gchar ifaddr[20+1];
	gchar *ifname;
	gchar *sep;
	
	s = socket(AF_INET, SOCK_DGRAM, 0);
	if (s < 0)
		return 0;
	fd = fopen(PATH_PROC_NET_DEV, "r");
	fgets(buffer, sizeof(buffer)-1, fd);
	fgets(buffer, sizeof(buffer)-1, fd);
	while (!feof(fd)) {
		ifname = buffer;
		sep;
		if (fgets(buffer, sizeof(buffer)-1, fd) == NULL)
			break;
		sep = strrchr(buffer, ':');
		if (sep)
			*sep = 0;
		while (*ifname == ' ')
			ifname++;
		struct ifreq req;
		strcpy(req.ifr_name, ifname);
		if (ioctl(s, SIOCGIFFLAGS, &req) < 0)
			continue;
		if (!(req.ifr_flags & IFF_UP))
			continue;
		if (req.ifr_flags & IFF_LOOPBACK)
			continue;
		if (ioctl(s, SIOCGIFADDR, &req) < 0)
			continue;
		g_strlcpy( ifaddr, inet_ntoa(((struct sockaddr_in*)&req.ifr_addr)->sin_addr), sizeof(struct ifaddr)-1 );
		local_addrs = g_list_append( local_addrs, g_strdup( ifaddr ) );

		gmyth_debug( "( from the /proc/net/dev) Interface name: %s, address: %s\n", 
								ifname, ifaddr );
	}
	fclose(fd);
	close(s);
	return local_addrs;

}


/**
 * Get only the local addresses from the primary interface
 */
static gchar *
gmyth_socket_get_primary_addr()
{
	
	gchar *if_eth0 = g_new0( gchar, sizeof(struct ifaddr)-1 );
	GList *if_tmp = NULL;
	
	GList *interfs = gmyth_socket_get_local_addrs( NULL );
	
	if ( interfs != NULL && ( g_list_length( interfs ) > 0 ) ) 
	{
		/* get the first occurrence (primary interface) */
		if_tmp = g_list_first( interfs );
		
		if ( if_tmp != NULL )
			g_strlcpy (if_eth0, (gchar *)if_tmp->data, sizeof(struct ifaddr)-1 );

	}
	
	if ( interfs != NULL )
		g_list_free( interfs );
	
	return if_eth0;
}

/** This function retrieves the local hostname of the 
 * client machine.
 *
 * @return GString* get local hostname.
 */
GString *
gmyth_socket_get_local_hostname  ()
{

    char hname[50];
    gint res = gethostname (hname, 50);

    if (res == -1) {
	g_debug ("Error while getting hostname");
	return NULL;
    }

    return g_string_new (hname);
    
#if 0	
    GString *str = NULL;
    
    if ( local_hostname != NULL && strlen(local_hostname) > 0 )
    	return g_string_new( local_hostname );

    gchar *localaddr = NULL; 
    gboolean found_addr = FALSE;
    struct addrinfo* addr_info_data = NULL, *addr_info0 = NULL;
    struct sockaddr_in* sa = NULL;
    gchar localhostname[MAXHOSTNAMELEN];


    if (gethostname (localhostname, MAXHOSTNAMELEN) != 0 ) {
    	gmyth_debug ( "Error on gethostname" );
    }
    localhostname[MAXHOSTNAMELEN-1] = 0;

    gint err = gmyth_socket_toaddrinfo (localhostname, -1,  &addr_info_data );
    
    if ( err == EADDRNOTAVAIL )
    {
    	g_warning( "[%s] Address (%s) not available. (reason = %d)\n", __FUNCTION__, localhostname, err );
    	return str;
    }
    
    g_static_mutex_lock( &mutex );    	

    addr_info0 = addr_info_data;

    while( addr_info0 != NULL && addr_info0->ai_addr != NULL && 
	    ( sa = (struct sockaddr_in*)addr_info0->ai_addr ) != NULL && !found_addr ) {
    	localaddr = inet_ntoa( sa->sin_addr );

	    if ( localaddr != NULL && ( g_strrstr( localaddr, "127" ) == NULL ) ) {
	        str = g_string_new (localaddr);
	        found_addr = TRUE;
		g_free (localaddr);
	        break;
	    }
/*
	    if (localaddr != NULL) {
		g_free (localaddr);
		localaddr = NULL;
	    }
	    */

	    addr_info0 = addr_info0->ai_next;
    };
    
    freeaddrinfo (addr_info_data);
    addr_info_data = NULL;
    
    if ( found_addr == FALSE ) {
        gchar *prim_addr = gmyth_socket_get_primary_addr();

    	if ( prim_addr != NULL ) {
		g_warning("[%s] Could not determine the local alphanumerical hostname. Setting to %s\n",
    	        __FUNCTION__, prim_addr );
      
	        str = g_string_new (prim_addr);
	        g_free (prim_addr);
    	} else {
        	str = g_string_new (localhostname);
    	}
    }

    g_static_mutex_unlock (&mutex);
    
    if ( str != NULL && str->str != NULL )
    	local_hostname = g_strdup( str->str );

    return str;
#endif    
}

static void
gmyth_socket_dispose  (GObject *object)
{
    GMythSocket *gmyth_socket = GMYTH_SOCKET(object);

    /* disconnect socket */
    gmyth_socket_close_connection (gmyth_socket);

    g_free (gmyth_socket->hostname);
    gmyth_socket->hostname = NULL;
    
    g_free (local_hostname);
    
    local_hostname = NULL;

    G_OBJECT_CLASS (gmyth_socket_parent_class)->dispose (object);
}

static void
gmyth_socket_finalize (GObject *object)
{
    g_signal_handlers_destroy (object);

    G_OBJECT_CLASS (gmyth_socket_parent_class)->finalize (object);
}

/** Creates a new instance of GMythSocket.
 * 
 * @return a new instance of GMythSocket.
 */
GMythSocket*
gmyth_socket_new ()
{
    GMythSocket *gmyth_socket = GMYTH_SOCKET (g_object_new(GMYTH_SOCKET_TYPE, NULL));

    gmyth_socket->mythtv_version = MYTHTV_VERSION_DEFAULT;

    return gmyth_socket;
}

/** Try to open an asynchronous connection to the MythTV backend.
 * 
 * @param fd 			Socket descriptor.
 * @param remote 	Remote address.
 * @param len 		Newly created socket length field.
 * @param timeout	Timeval argument with the time interval to timeout before closing.
 * @param err			Error message number.
 * @return Any numerical value below 0, if an error had been found.
 */
static gint 
gmyth_socket_try_connect ( gint fd, struct sockaddr *remote, gint len,
               struct timeval *timeout, gint *err)
{
	  /*g_return_val_if_fail( timeout != NULL, 0 );*/	  
	  gint saveflags, ret, back_err;
	  
	  fd_set fd_w;
	
	  saveflags = fcntl( fd, F_GETFL, 0 );
	  if( saveflags < 0 ) {
	    g_warning( "[%s] Problems when getting socket flags on fcntl.\n", __FUNCTION__ );
	    *err=errno;
	    return -1;
	  }
	
	  /* Set non blocking */
	  if( fcntl( fd, F_SETFL, saveflags | O_NONBLOCK ) < 0) {
	  	g_warning( "[%s] Problems when setting non-blocking using fcntl.\n", __FUNCTION__ );
	    *err=errno;
	    return -1;
	  }
	
	  /* This will return immediately */
	  *err= connect ( fd, remote, len );
		back_err=errno;
	
		/* restore flags */
	  if( fcntl( fd, F_SETFL, saveflags ) < 0) {
	    g_warning( "[%s] Problems when trying to restore flags with fcntl.\n", __FUNCTION__ );
	    *err=errno;
	    return -1;
	  }
	
	  /* return unless the connection was successful or the connect is
	     still in progress. */
	  if( *err < 0 && back_err != EINPROGRESS) {
	    g_warning( "[%s] Connection unsucessfully (it is not in progress).\n", __FUNCTION__ );
	    *err = errno;
	    return -1;
	  }
	
	  FD_ZERO( &fd_w );
	  FD_SET( fd, &fd_w );
	
	  *err = select( FD_SETSIZE, NULL, &fd_w, NULL, timeout);
	  if ( *err < 0 ) {
	    g_warning( "[%s] Connection unsucessfull (timed out).\n", __FUNCTION__ );
	    *err=errno;
	    return -1;
	  }
	
	  /* 0 means it timeout out & no fds changed */
	  if(*err==0) {
	    close(fd);
	    *err=ETIMEDOUT;
	    return -1;
	  }
	
	  /* Get the return code from the connect */
	  len = sizeof( ret );
	  *err=getsockopt( fd, SOL_SOCKET, SO_ERROR, &ret, (socklen_t *) &len);
	  
	  if( *err < 0 ) {
	    g_warning( "[%s] Connection usnsucessfull.\n", __FUNCTION__ );
	    *err=errno;
	    return -1;
	  }
	
	  /* ret=0 means success, otherwise it contains the errno */
	  if (ret) {
	    *err=ret;
	    return -1;
	  }
	
	  *err=0;
	  return 0;
}

/** Connects to the backend.
 * 
 * @param gmyth_socket The GMythSocket instance.
 * @param hostname The backend hostname or IP address.
 * @param port The backend port.
 * @return TRUE if success, FALSE if error.
 */


gboolean
gmyth_socket_connect (GMythSocket *gmyth_socket,
	const gchar *hostname, gint port)
{
    return gmyth_socket_connect_with_timeout (gmyth_socket,
		    hostname, port, 0);
}

gboolean
gmyth_socket_connect_with_timeout (GMythSocket *gmyth_socket,
	const gchar *hostname, gint port, guint timeout)
{
    struct addrinfo *addr_info_data = NULL, *addr_info0 = NULL;
    gint ret_code = -1;
    gint errno;
    gboolean ret = TRUE;

    gmyth_debug ("CONNECTING %s:%d", hostname, port);

    if ( hostname == NULL )
        gmyth_debug ( "Invalid hostname parameter!\n");

    /* store hostname and port number */
    if (gmyth_socket->hostname != NULL) {
        //g_free (gmyth_socket->hostname);
        gmyth_socket->hostname = NULL;
    }

    errno = gmyth_socket_toaddrinfo ( hostname, port, &addr_info_data );

    g_return_val_if_fail( addr_info_data != NULL && hostname != NULL, FALSE );

    gmyth_socket->hostname = g_strdup( hostname );
    gmyth_socket->port = port;

    for ( addr_info0 = addr_info_data; addr_info0; addr_info0 = addr_info_data->ai_next ) {
        /* init socket descriptor */
        gmyth_socket->sd = socket( addr_info0->ai_family, addr_info0->ai_socktype,
                         addr_info0->ai_protocol );

        if ( gmyth_socket->sd < 0 )
            continue;

        struct timeval *timeout_val = g_new0 (struct timeval, 1);
	if (timeout != 0) {
	    /*timeout_val = g_new0 (struct timeval, 1);*/
	    
            timeout_val->tv_sec = timeout;
            timeout_val->tv_usec = 0;
	} else {
            timeout_val->tv_sec = 5;
            timeout_val->tv_usec = 100;
	}
        
        if (gmyth_socket_try_connect (gmyth_socket->sd, (struct sockaddr *)addr_info0->ai_addr,
                addr_info0->ai_addrlen, timeout_val, &ret_code ) < 0 )
        {
            g_printerr( "[%s] Error connecting to backend!\n", __FUNCTION__ );
            if (ret_code == ETIMEDOUT)
                g_printerr( "[%s]\tBackend host unreachable!\n", __FUNCTION__ );

            close (gmyth_socket->sd);
            gmyth_socket->sd = -1;
            g_printerr ("ERROR: %s\n", gai_strerror(ret_code));
	    g_free (timeout_val);
            continue;
        }

	g_free (timeout_val);

        /* only will be reached if none of the error above occurred */
        break;
    }

    freeaddrinfo (addr_info_data);
    addr_info_data = NULL;

    if (gmyth_socket->sd_io_ch != NULL) {
        g_io_channel_unref (gmyth_socket->sd_io_ch);
        gmyth_socket->sd_io_ch = NULL;
    }

    gmyth_socket->sd_io_ch = g_io_channel_unix_new (gmyth_socket->sd);
    
    //GIOFlags flags = g_io_channel_get_flags (gmyth_socket->sd_io_ch);
		/* unset the nonblock flag */
		//flags &= ~G_IO_FLAG_NONBLOCK;
		/* unset the nonblocking stuff for some time, because GNUTLS doesn't like
		 * that */
		//g_io_channel_set_flags (gmyth_socket->sd_io_ch, flags, NULL);

    ret = ( ret_code == 0 ) ? TRUE : FALSE ;
    return ret;
}

/** Gets the GIOChannel associated to the given GMythSocket.
 * 
 * @param gmyth_socket The GMythSocket instance.
 */
GIOChannel *
gmyth_socket_get_io_channel( GMythSocket *gmyth_socket )
{
    g_return_val_if_fail( gmyth_socket != NULL, NULL );

    return gmyth_socket->sd_io_ch;
}

/** Verifies if the socket is able to read.
 * 
 * @param gmyth_socket The GMythSocket instance.
 * @return TRUE if the socket is able to read, FALSE if not.
 */
gboolean
gmyth_socket_is_able_to_read( GMythSocket *gmyth_socket )
{
    gboolean ret = TRUE;

    /* verify if the input (read) buffer is ready to receive data */
    GIOCondition io_cond = g_io_channel_get_buffer_condition( gmyth_socket->sd_io_ch );

    if ( ( io_cond & G_IO_IN ) == 0 ) {
	g_warning ("[%s] IO channel is not able to send data!\n", __FUNCTION__);
	ret = FALSE;
    }

    return ret;

}

/** Verifies if the socket is able to write.
 * 
 * @param gmyth_socket The GMythSocket instance.
 * @return TRUE if the socket is able to write, FALSE if not.
 */
gboolean
gmyth_socket_is_able_to_write( GMythSocket *gmyth_socket )
{
    gboolean ret = TRUE;

    /* verify if the input (read) buffer is ready to receive data */
    GIOCondition io_cond = g_io_channel_get_buffer_condition( gmyth_socket->sd_io_ch );

    if ( ( ( io_cond & G_IO_OUT ) == 0 ) || ( ( io_cond & G_IO_HUP ) == 0 ) ) {
	g_warning ("[%s] IO channel is not able to send data!\n", __FUNCTION__);
	ret = FALSE;
    }

    return ret;

}

/** Sends a command to the backend.
 * 
 * @param gmyth_socket the GMythSocket instance.
 * @param command The string command to be sent.
 */
gboolean
gmyth_socket_send_command(GMythSocket *gmyth_socket, GString *command) 
{
    gboolean ret = TRUE;

    GIOStatus io_status = G_IO_STATUS_NORMAL;
    //GIOCondition io_cond;
    GError* error = NULL;
   
    
    gchar *buffer = NULL;

    gsize bytes_written = 0;

    if( command == NULL || ( command->len <= 0 ) || command->str == NULL ) {
		g_warning ("[%s] Invalid NULL command parameter!\n", __FUNCTION__);
		ret = FALSE;
		goto done;
    }

    //g_static_mutex_lock( &mutex );
    gmyth_debug ("Sending command to backend: %s\n", command->str);

    buffer = g_strnfill( BUFLEN, ' ' );
    g_snprintf( buffer, MYTH_PROTOCOL_FIELD_SIZE+1, "%-8d", command->len);

    command = g_string_prepend(command, buffer);

    /* write bytes to socket */    
    io_status = g_io_channel_write_chars( gmyth_socket->sd_io_ch, command->str, 
	    command->len, &bytes_written, &error );


    if( (io_status == G_IO_STATUS_ERROR) || ( bytes_written <= 0 ) ) {
		g_warning ("[%s] Error while writing to socket", __FUNCTION__);
		ret = FALSE;
    } else if ( bytes_written < command->len ) {
		g_warning ("[%s] Not all data was written socket", __FUNCTION__);
		ret = FALSE;
    }

    io_status = g_io_channel_flush( gmyth_socket->sd_io_ch, &error );

    if ( ( bytes_written != command->len ) || ( io_status == G_IO_STATUS_ERROR ) )
    {
		g_warning ("[%s] Some problem occurred when sending data to the socket\n", __FUNCTION__);
	
		ret = TRUE;
    }

    //g_static_mutex_unlock( &mutex );
done:
    if ( error != NULL ) {
		g_printerr( "[%s] Error found reading data from IO channel: (%d, %s)\n", __FUNCTION__, error->code, error->message );
		ret = FALSE;
		g_error_free( error );
    }

    if ( buffer!= NULL )
		g_free( buffer );

    return ret;
}

/** Starts Mythtv protocol level connection. Checks Mythtv protocol version
 * supported by the backend and send the "ANN" command.
 * 
 * @param gmyth_socket the GMythSocket instance.
 * @param hostname_backend The backend hostname or IP address.
 * @param port The backend port to connect.
 * @param blocking_client A flag to choose between blocking and non-blocking
 * @param with_events	Sets the connection flag to receive events.
 * 										backend connection. 
 */
static gboolean
gmyth_socket_connect_to_backend_and_events (GMythSocket *gmyth_socket, 
	const gchar *hostname_backend, gint port, gboolean blocking_client,
	gboolean with_events)
{
    if (!gmyth_socket_connect (gmyth_socket, hostname_backend, port)) {
		g_warning ("[%s] Could not open socket to backend machine [%s]\n", __FUNCTION__,
					hostname_backend );
		return FALSE;
    }

    if ( gmyth_socket_check_protocol_version (gmyth_socket) ) {

	GString *result;
	GString *base_str = g_string_new("");
	GString *hostname = NULL;

	hostname = gmyth_socket_get_local_hostname();
	if (hostname == NULL) {
	    g_debug ("Hostname not available, setting to n800frontend\n");
	    hostname = g_strdup ("n800frontend");
	}

	g_string_printf(base_str, "ANN %s %s %u", 
		(blocking_client ? "Playback" : "Monitor"),
		hostname->str, with_events);

	gmyth_socket_send_command (gmyth_socket, base_str);
	result = gmyth_socket_receive_response (gmyth_socket);

	if (result != NULL) {
	    gmyth_debug ("Response received from backend: %s", result->str);
	    g_string_free (result, TRUE);
	}

	g_string_free (hostname, TRUE);
	g_string_free (base_str, TRUE);

	return TRUE;
    } else {
	g_warning ("[%s] GMythSocket could not connect to the backend", __FUNCTION__);	
	return FALSE;
    }
}

/** Starts Mythtv protocol level connection. Checks Mythtv protocol version
 * supported by the backend and send the "ANN" command.
 * 
 * @param gmyth_socket the GMythSocket instance.
 * @param hostname_backend The backend hostname or IP address.
 * @param port The backend port to connect.
 * @param blocking_client A flag to choose between blocking and non-blocking 
 */
gboolean
gmyth_socket_connect_to_backend (GMythSocket *gmyth_socket, 
	const gchar *hostname_backend, gint port, gboolean blocking_client)
{
    if (!gmyth_socket_connect_to_backend_and_events ( gmyth_socket, hostname_backend, port,
    		blocking_client, FALSE) ) {
		gmyth_debug ("Could not open socket to backend machine [%s]\n",
					hostname_backend );
		return FALSE;
    }
    
    return TRUE;

}

/** Starts Mythtv protocol level connection. Checks Mythtv protocol version
 * supported by the backend and send the "ANN" command.
 * 
 * @param gmyth_socket the GMythSocket instance.
 * @param hostname_backend The backend hostname or IP address.
 * @param port The backend port to connect.
 * @param blocking_client A flag to choose between blocking and non-blocking 
 */
gboolean
gmyth_socket_connect_to_backend_events (GMythSocket *gmyth_socket, 
	const gchar *hostname_backend, gint port, gboolean blocking_client)
{
    if (!gmyth_socket_connect_to_backend_and_events ( gmyth_socket, hostname_backend, port,
    		blocking_client, TRUE) ) {
		gmyth_debug ("Could not open socket to backend machine in order to receive events [%s]\n",
					hostname_backend );
		return FALSE;
    }
    
    return TRUE;
}

/** Closes the socket connection to the backend.
 * 
 * @param gmyth_socket The GMythSocket instance.
 */
void
gmyth_socket_close_connection (GMythSocket *gmyth_socket)
{
    close (gmyth_socket->sd);	
    gmyth_socket->sd = -1;

    if (gmyth_socket->sd_io_ch != NULL) {
        g_io_channel_unref (gmyth_socket->sd_io_ch);
        gmyth_socket->sd_io_ch = NULL;
    }
}


/** Try the MythTV version numbers, and get the version returned by
 * the possible REJECT message, in order to contruct a new
 * MythTV version request.
 * 
 * @param gmyth_socket The GMythSocket instance.
 * @param mythtv_version The Mythtv protocol version to be tested
 * 
 * @return The actual MythTV the client is connected to.
 */
gint
gmyth_socket_check_protocol_version_number (GMythSocket *gmyth_socket, gint mythtv_version)
{
    GString *response = NULL;
    GString *payload = NULL;
    gboolean res = TRUE;
    gint mythtv_new_version = MYTHTV_CANNOT_NEGOTIATE_VERSION;
    guint max_iterations = MYTHTV_MAX_VERSION_CHECKS;

try_new_version:
    payload = g_string_new ("MYTH_PROTO_VERSION");
    g_string_append_printf( payload, " %d", mythtv_version );

    gmyth_socket_send_command(gmyth_socket, payload);
    response = gmyth_socket_receive_response(gmyth_socket);

    if (response == NULL) {
		g_warning ("[%s] Check protocol version error! Not answered!", __FUNCTION__);
		res = FALSE;	
		goto done;
    }

    res = g_str_has_prefix (response->str, "ACCEPT");
    if (!res) {
		g_warning ("[%s] Protocol version request error: %s", __FUNCTION__, response->str);
	/* get the version number returned by the REJECT message */
	if ( ( res = g_str_has_prefix (response->str, "REJECT") ) == TRUE ) {
        gchar *new_version = NULL;
	    new_version = g_strrstr( response->str, "]" );
	    if (new_version!=NULL) {
		++new_version; /* skip ']' character */
		if ( new_version != NULL ) {
		    gmyth_debug ( "[%s] got MythTV version = %s.\n", __FUNCTION__, new_version );
		    mythtv_version = (gint)g_ascii_strtoull (new_version, NULL, 10 );
		    /* do reconnection to the socket (socket is closed if the MythTV version was wrong) */
		    gmyth_socket_connect( gmyth_socket, gmyth_socket->hostname, gmyth_socket->port );
            new_version =NULL;
		    if ( --max_iterations > 0 ) 
		    	goto try_new_version;
		    else
		    	goto done;
		}
	    }
	}
    }
    
    /* change the return value to a valid one */
    if ( res ) {
    	mythtv_new_version = mythtv_version;
    	gmyth_socket->mythtv_version = mythtv_new_version;
    }

done:
    if ( payload != NULL )
		g_string_free (payload, TRUE);
    if ( response != NULL )
		g_string_free (response, TRUE);

    return mythtv_new_version;
}

/** Verifies if the Mythtv backend supported the GMyth supported version.
 * 
 * @param gmyth_socket The GMythSocket instance.
 * @return TRUE if supports, FALSE if not.
 */
gboolean
gmyth_socket_check_protocol_version (GMythSocket *gmyth_socket)
{
    return ( ( gmyth_socket->mythtv_version = 
    		gmyth_socket_check_protocol_version_number ( gmyth_socket, 
    							MYTHTV_VERSION_DEFAULT ) ) != MYTHTV_CANNOT_NEGOTIATE_VERSION );
}

/** Returns the Mythtv backend supported version.
 * 
 * @param gmyth_socket The GMythSocket instance.
 * @return The actual MythTV version number.
 */
gint
gmyth_socket_get_protocol_version (GMythSocket *gmyth_socket) 
{
	return gmyth_socket->mythtv_version;
}

/** Receives a backend answer after a gmyth_socket_send_command_call ().
 * 
 * @param gmyth_socket The GMythSocket instance.
 * @return The response received, or NULL if error or nothing was received.
 */
GString*
gmyth_socket_receive_response(GMythSocket *gmyth_socket)
{
    GIOStatus io_status = G_IO_STATUS_NORMAL;
    GError* error = NULL;
    gchar *buffer;

    GString *str = NULL;

    gsize bytes_read = 0;
    gint  len = 0;
    GIOCondition io_cond = g_io_channel_get_buffer_condition (gmyth_socket->sd_io_ch);

    g_return_val_if_fail( gmyth_socket != NULL, NULL );

    /* verify if the input (read) buffer is ready to receive data */

    //g_static_mutex_lock( &mutex );

    //buffer = g_new0 (gchar, MYTH_PROTOCOL_FIELD_SIZE);
    buffer = g_strnfill (MYTH_PROTOCOL_FIELD_SIZE, ' ');
    io_status = g_io_channel_read_chars (gmyth_socket->sd_io_ch, buffer, MYTH_PROTOCOL_FIELD_SIZE, &bytes_read, &error);

    /* verify if the input (read) buffer is ready to receive data */
    io_cond = g_io_channel_get_buffer_condition (gmyth_socket->sd_io_ch);

    gmyth_debug ( "[%s] Bytes read = %d\n", __FUNCTION__, bytes_read );

    if( (io_status == G_IO_STATUS_ERROR) || (bytes_read <= 0) ) {
		g_warning ("[%s] Error in mythprotocol response from backend\n", __FUNCTION__);
		str = NULL;
		//return NULL;
    } else {

		io_status = g_io_channel_flush( gmyth_socket->sd_io_ch, &error );
		/* verify if the input (read) buffer is ready to receive data */
		io_cond = g_io_channel_get_buffer_condition( gmyth_socket->sd_io_ch );
	
		//if ( ( io_cond & G_IO_IN ) != 0 ) {
            //gchar *buffer_aux = NULL;

		    /* removes trailing whitespace */
		    //buffer_aux = g_strstrip (buffer);
		    len = (gint)g_ascii_strtoull ( g_strstrip (buffer), NULL, 10 );

            if (buffer != NULL) {
                g_free (buffer);
                buffer = NULL;
            }
            
            /*            
            if (buffer_aux != NULL) {
                g_free (buffer_aux);
                buffer_aux = NULL;
            }
            */

            buffer = g_new0 (gchar, len+1);
	
		    bytes_read = 0;
		    io_status = g_io_channel_read_chars( gmyth_socket->sd_io_ch, buffer, len, &bytes_read, &error);
		    buffer[bytes_read] = '\0';
		//}
    }  

    //g_static_mutex_unlock( &mutex );

    gmyth_debug ("Response received from backend: {%s}\n", buffer);

    if ( ( bytes_read != len ) || ( io_status == G_IO_STATUS_ERROR ) )
		str = NULL;
    else
		str = g_string_new (buffer);

    if ( error != NULL ) {
		g_printerr( "[%s] Error found receiving response from the IO channel: (%d, %s)\n", __FUNCTION__, error->code, error->message );
		str = NULL;
		g_error_free (error);
    }

    g_free (buffer);
    return str;
}

/** Format a Mythtv command from the str_list entries and send it to backend.
 * 
 * @param gmyth_socket The GMythSocket instance.
 * @param str_list The string list to form the command
 * @return TRUE if command was sent, FALSE if any error happens.
 */
gboolean
gmyth_socket_write_stringlist(GMythSocket *gmyth_socket, GMythStringList* str_list)
{

    GList *tmp_list = NULL;
    GPtrArray *ptr_array = NULL;
    gchar *str_array = NULL;

    g_static_mutex_lock( &mutex );

    ptr_array = g_ptr_array_sized_new (g_list_length(str_list->glist));

    // FIXME: change this implementation!
    tmp_list = str_list->glist;
    for(; tmp_list; tmp_list = tmp_list->next) {
	if ( tmp_list->data != NULL ) {
	    g_ptr_array_add(ptr_array, ((GString*)tmp_list->data)->str);
	} else {
	    g_ptr_array_add (ptr_array, "");
	}
    }
    g_ptr_array_add(ptr_array, NULL); // g_str_joinv() needs a NULL terminated string

    str_array = g_strjoinv (MYTH_SEPARATOR, (gchar **) (ptr_array->pdata));

    g_static_mutex_unlock( &mutex );

    gmyth_debug ( "[%s] Sending socket request: %s\n", __FUNCTION__, str_array );

    // Sends message to backend	
    // TODO: implement looping to send remaining data, and add timeout testing!    
    GString *command = g_string_new(str_array);
    gmyth_socket_send_command(gmyth_socket, command);
    g_string_free (command, TRUE);

    g_free (str_array);
    g_ptr_array_free (ptr_array, TRUE);

    return TRUE;
}

/* Receives a backend command response and split it into the given string list.
 * 
 * @param gmyth_socket The GMythSocket instance.
 * @param str_list the string list to be filled.
 * @return The number of received strings.
 */
gint
gmyth_socket_read_stringlist (GMythSocket *gmyth_socket, GMythStringList* str_list)
{
    GString *response;
    gchar **str_array;
    gint i;

    response = gmyth_socket_receive_response(gmyth_socket);
    g_static_mutex_lock( &mutex );

    gmyth_string_list_clear_all (str_list);	
    str_array = g_strsplit (response->str, MYTH_SEPARATOR, -1);

    for (i=0; i< g_strv_length (str_array); i++) {
	gmyth_string_list_append_char_array (str_list, str_array[i] );
    }
    g_static_mutex_unlock( &mutex );

    g_string_free (response, TRUE);
    g_strfreev (str_array);

    return gmyth_string_list_length (str_list);
}

/** Formats a Mythtv protocol command based on str_list and sends it to
 * the connected backend. The backend response is overwritten into str_list.
 *
 * @param gmyth_socket The GMythSocket instance.
 * @param str_list The string list to be sent, and on which the answer 
 * will be written.
 * @return TRUE if command was sent and an answer was received, FALSE if any
 * error happens.
 */
gint
gmyth_socket_sendreceive_stringlist (GMythSocket *gmyth_socket, GMythStringList *str_list)
{
    gmyth_socket_write_stringlist (gmyth_socket, str_list);

    return gmyth_socket_read_stringlist (gmyth_socket, str_list);
}