/*
 * Copyright (C) 2005 Alex Murray <pragmatine@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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

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

#include "sensors-applet.h"
#include "acpi-sensors-interface.h"

#define ACPI_THERMAL_ZONE_BASE_DIR "/proc/acpi/thermal_zone"
#define ACPI_THERMAL_BASE_DIR "/proc/acpi/thermal"

/* for error handling */
#define ACPI_DEVICE_FILE_ERROR (acpi_sensors_interface_device_file_error_quark())

enum {
	ACPI_DEVICE_FILE_OPEN_ERROR,
	ACPI_DEVICE_FILE_READ_ERROR
};

static void acpi_sensors_interface_add_sensor(SensorsApplet *sensors_applet, const gchar *path) {
	gchar *dirname;
	gchar *id;

	dirname = g_path_get_dirname(path);
	id = g_path_get_basename(dirname);
	g_free(dirname);
		
	sensors_applet_add_sensor(sensors_applet,
				  path,
				  id,
				  _("CPU"),
				  ACPI,
				  TRUE,
				  TEMP_SENSOR,
				  CPU_ICON);
	g_free(id);
}	

/* recursive function to find sensors in a given path - once found
   will call function to add sensor to the sensors_list */
static void acpi_sensors_interface_find_sensors(SensorsApplet *sensors_applet, const gchar *path) {
	GDir *dir;
	FILE *fp;
	const gchar* new_file;
	gchar *new_path, *filename;
	if (g_file_test(path, G_FILE_TEST_IS_REGULAR)) {
		filename = g_path_get_basename(path);
		if (g_strrstr(filename, "temperature") || g_strrstr(filename, "status")) {
			/* also test can actually open file for
			   reading */
			if ((fp = fopen(path, "r")) != NULL) {
				fclose(fp);
				acpi_sensors_interface_add_sensor(sensors_applet, path);

			}
		}
		g_free(filename);
		
	}
	/* if is a directory (but not a symlinked dir as this
	   will lead us in circular loops) descend into it and look
	   for a sensor dir
	*/
	if (g_file_test(path, G_FILE_TEST_IS_DIR) && !g_file_test(path, G_FILE_TEST_IS_SYMLINK)) {
		dir = g_dir_open(path, 0, NULL);
		if (dir != NULL) {
			while(new_file = g_dir_read_name(dir)) {
				new_path = g_strdup_printf("%s/%s", path, new_file);
				acpi_sensors_interface_find_sensors(sensors_applet, new_path);
				g_free(new_path);
			}
			g_dir_close(dir);
		}
	}
}

/* to be called to setup for acpi sensors */
void acpi_sensors_interface_init(SensorsApplet *sensors_applet) {
	sensors_applet_register_sensors_interface(sensors_applet,
						  ACPI,
						  acpi_sensors_interface_get_sensor_value);
		/* call function to recursively look for sensors
		   starting at the defined base directory */
		acpi_sensors_interface_find_sensors(sensors_applet, ACPI_THERMAL_ZONE_BASE_DIR);
		acpi_sensors_interface_find_sensors(sensors_applet, ACPI_THERMAL_BASE_DIR);
		
}


/* for error handling */
static GQuark acpi_sensors_interface_device_file_error_quark(void) {
	static GQuark quark = 0;
	gchar *string;

	if (quark == 0) {
		string = g_strdup_printf("%s-device-file-error", sensor_interface[ACPI]);
		quark = g_quark_from_string(string);
		g_free(string);
	}

	return quark;
}

gdouble acpi_sensors_interface_get_sensor_value(const gchar *path, 
					       const gchar *id, 
					       SensorType type,
					       GError **error) {

	/* to open and access the value of each sensor */
	FILE *fp;
	gfloat sensor_value =-1.0f;
	gchar units[32];

	if (NULL == (fp = fopen(path, "r"))) {
		g_set_error(error, ACPI_DEVICE_FILE_ERROR, ACPI_DEVICE_FILE_OPEN_ERROR, "Error opening sensor device file %s", path);
		return;
	}

	if (fscanf(fp, "temperature: %f %31s", &sensor_value, units) < 1) {
		g_set_error(error, ACPI_DEVICE_FILE_ERROR, ACPI_DEVICE_FILE_READ_ERROR, "Error reading from sensor device file %s", path);
		fclose(fp);
		return;
	}
	fclose(fp);

	/* need to convert if units are deciKelvin */
	if (g_ascii_strcasecmp(units, "dK") == 0) {
		sensor_value = (sensor_value / 10.0) - 273.0;
	}

	return (gdouble)sensor_value;
}