/*
 * Copyright (C) 2005-2009 Alex Murray <murray.alex@gmail.com>
 *
 * This program 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; 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 General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif /* HAVE_CONFIG_H */

#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif

#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif

#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif

#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif

#include <unistd.h>
#include <glib.h>
#include "hddtemp-plugin.h"

const gchar *plugin_name = "hddtemp";

#define HDDTEMP_SERVER_IP_ADDRESS "127.0.0.1"
#define HDDTEMP_PORT_NUMBER 7634
#define HDDTEMP_OUTPUT_BUFFER_LENGTH 1024

enum {
	HDDTEMP_SOCKET_OPEN_ERROR,
	HDDTEMP_SOCKET_CONNECT_ERROR,
	HDDTEMP_GIOCHANNEL_ERROR,
	HDDTEMP_GIOCHANNEL_READ_ERROR
	
};

static const gchar *hddtemp_plugin_query_hddtemp_daemon(GError **error) {
	int sockfd;
	ssize_t n = 1;
	gboolean first_run = FALSE;
	gint output_length = 0;
	gchar *pc;

	struct sockaddr_in address;
	static GTimeVal previous_query_time;
	GTimeVal current_query_time;

	if (NULL == buffer) {
		// initialise buffer and current time
		buffer = g_new0(char, HDDTEMP_OUTPUT_BUFFER_LENGTH);
		g_get_current_time(&previous_query_time);
		first_run = TRUE;
	}
	g_get_current_time(&current_query_time);

	/* only actually query if more than 60 seconds has elapsed as
	hddtemp daemon will only actually send a new value if is > 60
	seconds */
	if (first_run || current_query_time.tv_sec - previous_query_time.tv_sec > 60) {
		previous_query_time = current_query_time;

		if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
			// couldn't open socket
			g_set_error(error, SENSORS_APPLET_PLUGIN_ERROR, HDDTEMP_SOCKET_OPEN_ERROR, "Error opening socket for hddtemp");
			return NULL;
		}
		
		address.sin_family = AF_INET;
		address.sin_addr.s_addr = inet_addr(HDDTEMP_SERVER_IP_ADDRESS);
		address.sin_port = htons(HDDTEMP_PORT_NUMBER);

		if (connect(sockfd, (struct sockaddr *)&address, (socklen_t)sizeof(address)) == -1) {
			g_set_error(error, SENSORS_APPLET_PLUGIN_ERROR, HDDTEMP_SOCKET_CONNECT_ERROR, "Error connecting to hddtemp daemon on port %i on %s", htons(HDDTEMP_PORT_NUMBER), HDDTEMP_SERVER_IP_ADDRESS);
			return NULL;
		}

		pc = buffer;
		while ((n = read(sockfd, pc, HDDTEMP_OUTPUT_BUFFER_LENGTH - output_length)) > 0) {
			output_length += n;
			pc = &pc[n];
		}
		/* terminate with pipe if not already terminated */
		if (buffer[n - 1] != '|') {
			buffer[n++] = '|';
		} 
		/* always null terminate the end of the buffer
		 * regardless of how much stuff is in it already */
		buffer[output_length] = '\0';  
		close(sockfd);
	}

	return buffer;
}
	
static void hddtemp_plugin_get_sensors(GList **sensors) {
	GError *error = NULL;
	const gchar *hddtemp_output;
	gchar **output_vector = NULL, **pv;
	
	hddtemp_output = hddtemp_plugin_query_hddtemp_daemon(&error);
	
	if (error) {
		g_error_free(error);
		return;
	}

	if (hddtemp_output[0] != '|') {
		g_debug("Error in format of string returned from hddtemp daemon: char at [0] should be \"|\", instead whole output is: \"%s\"", hddtemp_output);
		return;
	}

	/* for each sensor the output will contain four strings ie 
	   |/dev/hda|WDC WD800JB-00ETA0|32|C||/dev/hdb|???|ERR|*|
	   note the repetition -----^ */

	/*
	  
	  pv[0 + 5*n] empty
	  pv[1 + 5*n] device name
	  pv[2 + 5*n] disk label
	  pv[3 + 5*n] temperature
	  pv[4 + 5*n] unit
	  pv[5 + 5*n] empty

	*/

	pv = output_vector = g_strsplit(hddtemp_output, "|", -1);
	
	while(pv[1] != NULL) {
		if (g_strcmp0(pv[2], "") && g_strcmp0(pv[3], "") && g_strcmp0(pv[4], "") && (!(g_ascii_strcasecmp(pv[2], "???") == 0 || g_ascii_strcasecmp(pv[3], "ERR") == 0 || g_ascii_strcasecmp(pv[4], "*") == 0))) {
                        sensors_applet_plugin_add_sensor(sensors,
                                                        pv[1], // must be dynamically allocated
                                                        pv[1], // must be dynamically allocated
                                                        pv[2], // must be dynamically allocated
                                                        TEMP_SENSOR,
                                                        FALSE,
                                                        HDD_ICON,
                                                        DEFAULT_GRAPH_COLOR);
		}
		pv += 5; 
	}
	g_strfreev(output_vector);
        
}

/* to be called to setup for hddtemp sensors */
static GList *hddtemp_plugin_init(void) {
	GList *sensors = NULL;
	hddtemp_plugin_get_sensors(&sensors);		
        return sensors;
}


/* returns the value of the sensor_list at the given iter, or if an
   error occurs, instatiates error with an error message */
static gdouble hddtemp_plugin_get_sensor_value(const gchar *path, 
						  const gchar *id, 
						  SensorType type,
						  GError **error) {

	const gchar *hddtemp_output;
	gchar **output_vector = NULL, **pv;

	gfloat sensor_value = -1.0f;

	hddtemp_output = hddtemp_plugin_query_hddtemp_daemon(error);

	if (*error) {
		return sensor_value;
	}

	if (hddtemp_output[0] != '|') {
		g_debug("Error in format of string returned from hddtemp daemon: char at [0] should be \"|\", instead whole output is: \"%s\"", hddtemp_output);
		return sensor_value;
	}

	/* for each sensor the output will contain four strings ie 
	   |/dev/hda|WDC WD800JB-00ETA0|32|C||/dev/hdb|???|ERR|*|
	            note the repetition -----^ 

	  pv[0 + 5*n] empty
	  pv[1 + 5*n] device name
	  pv[2 + 5*n] disk label
	  pv[3 + 5*n] temperature
	  pv[4 + 5*n] unit
	  pv[5 + 5*n] empty

	*/

	pv = output_vector = g_strsplit(hddtemp_output, "|", -1);
	
	while(pv[1] != NULL) {
		if (g_ascii_strcasecmp(pv[1], path) == 0) {
			sensor_value = (gfloat)(g_ascii_strtod(pv[3], NULL));
	
			/* always return sensor values in celsius */
			if (pv[4][0] == 'F') {
				sensor_value = (sensor_value - 32.0) * 5.0 / 9.0;
			}
			break;
		}
		pv += 5; 
	}
	g_strfreev(output_vector);
	
	return (gdouble)sensor_value;
}

const gchar *sensors_applet_plugin_name(void) 
{
        return plugin_name;
}

GList *sensors_applet_plugin_init(void) 
{
        return hddtemp_plugin_init();
}

gdouble sensors_applet_plugin_get_sensor_value(const gchar *path, 
                                                const gchar *id, 
                                                SensorType type,
                                                GError **error) {
        return hddtemp_plugin_get_sensor_value(path, id, type, error);
}