/*
 * 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 "i2c-proc-sensors-interface.h"
#include "sensors-applet.h"

#define I2C_PROC_BASE_DIR "/proc/sys/dev/sensors"

/* for error handling */
#define I2C_PROC_DEVICE_FILE_ERROR (i2c_proc_sensors_interface_device_file_error_quark())

enum {
	I2C_PROC_DEVICE_FILE_OPEN_ERROR,
	I2C_PROC_DEVICE_FILE_READ_ERROR
};


static void i2c_proc_sensors_interface_add_sensor(SensorsApplet *sensors_applet, const gchar *path) {
	gchar *filename;
	gchar *label;
	gboolean enable;
	SensorType sensor_type;
	const gchar *icon_filename = NULL;
	
	filename = g_path_get_basename(path);

	/* setup temp2 as CPU sensor and enable it */
	if (g_ascii_strcasecmp(filename, "temp2") == 0) {
		sensor_type = TEMP_SENSOR;
		label = g_strdup(_("CPU"));
		enable = TRUE;
		icon_filename = CPU_ICON;
	} else {
		label = g_strdup(filename);
		
		switch(filename[0]) {
		case 'c':     /* currents are "curr?" */
			sensor_type = CURRENT_SENSOR;
			break;
		case 'f':     /* fans are "fan?" */
			sensor_type = FAN_SENSOR;
			icon_filename = FAN_ICON;
			break;
		case 'i':     /* voltages are "in?" */
			sensor_type = VOLTAGE_SENSOR;
			icon_filename = VOLTAGE_ICON;
			break;
		case 't':     /* temps are "temp?" */
			sensor_type = TEMP_SENSOR;
			break;
		case 'v':     /* vids are just vid */
			sensor_type = VOLTAGE_SENSOR;
			icon_filename = VOLTAGE_ICON;
			break;
		default:
			/* SHOULDN'T BE ABLE
			 * TO GET HERE!! */
			g_assert_not_reached();
		}
		/* disable all other sensors */
		enable = FALSE;
	}
	sensors_applet_add_sensor(sensors_applet,
				  path,
				  filename,
				  label,
				  I2C_PROC,
				  enable,
				  sensor_type,
				  NULL);


	g_free(filename);
	g_free(label);
}	

/* recursive function to find sensors in a given path - once found
   will call function to add sensor to the sensors_list */
static void i2c_proc_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);
		/* see if filename starts with any of the sensor
		   prefixes */
		if (g_strrstr(filename, "curr") == filename || 
		    (g_strrstr(filename, "fan") == filename && g_strrstr(filename, "fan_div") == NULL) || 
		    g_strrstr(filename, "in") == filename || 
		    g_strrstr(filename, "temp") == filename || 
		    g_strrstr(filename, "vid") == filename) {
			/* also test can actually open file for
			   reading */
			if (fp = fopen(path, "r")) {
				fclose(fp);
				i2c_proc_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);
				i2c_proc_sensors_interface_find_sensors(sensors_applet, new_path);
				g_free(new_path);
			}
			g_dir_close(dir);
		}
	}
}

/* to be called to setup for proc sensors */
void i2c_proc_sensors_interface_init(SensorsApplet *sensors_applet) {
	sensors_applet_register_sensors_interface(sensors_applet,
						  I2C_PROC,
						  i2c_proc_sensors_interface_get_sensor_value);
	/* call function to recursively look for sensors
	   starting at the defined base directory */
	i2c_proc_sensors_interface_find_sensors(sensors_applet, I2C_PROC_BASE_DIR);
	
}

static GQuark i2c_proc_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[I2C_PROC]);
		quark = g_quark_from_string(string);
		g_free(string);
	}

	return quark;
}


gdouble i2c_proc_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 float1, float2, float3;
	gint int1, int2, int3;

	gfloat sensor_value;

	if (NULL == (fp = fopen(path, "r"))) {
		g_set_error(error, I2C_PROC_DEVICE_FILE_ERROR, I2C_PROC_DEVICE_FILE_OPEN_ERROR, "Error opening sensor device file %s", path);
		return;
	}

	switch (type) {
	case CURRENT_SENSOR:

		if (fscanf(fp, "%f %f %f", &float1, &float2, &float3) != 3) {
			g_set_error(error, I2C_PROC_DEVICE_FILE_ERROR, I2C_PROC_DEVICE_FILE_READ_ERROR, "Error reading from sensor device file %s", path);
			fclose(fp);
			return;
		}
		
		sensor_value = float3;
		break;
		
	case FAN_SENSOR:
		if (fscanf(fp, "%d %d", &int1, &int2) != 2) {
			g_set_error(error, I2C_PROC_DEVICE_FILE_ERROR, I2C_PROC_DEVICE_FILE_READ_ERROR, "Error reading from sensor device file %s", path);
			fclose(fp);
			return;
		}

		sensor_value = (gfloat)int2;
		break;
		
	case VOLTAGE_SENSOR:
		/* is it CPU_VID or IN */
		switch(id[0]) {
		case 'i':
			if (fscanf(fp, "%f %f %f", &float1, &float2, &float3) != 3) {
				g_set_error(error, I2C_PROC_DEVICE_FILE_ERROR, I2C_PROC_DEVICE_FILE_READ_ERROR, "Error reading from sensor device file %s", path);
				fclose(fp);
				return;
			}
			sensor_value = float3;
			break;

		case 'v':
			/* want first value in file as float */
			if (fscanf(fp, "%f", &float1) != 1) {
				g_set_error(error, I2C_PROC_DEVICE_FILE_ERROR, I2C_PROC_DEVICE_FILE_READ_ERROR, "Error reading from sensor device file %s", path);
				fclose(fp);
				return;
			}
			sensor_value = float1;
			break;
		default:
			g_assert_not_reached();
		}
		break;
	case TEMP_SENSOR:
		if (fscanf(fp, "%f %f %f", &float1, &float2, &float3) != 3) {
			g_set_error(error, I2C_PROC_DEVICE_FILE_ERROR, I2C_PROC_DEVICE_FILE_READ_ERROR, "Error reading from sensor device file %s", path);
			fclose(fp);
			return;
		}
		sensor_value = float3;		
		break;

	default:
		g_assert_not_reached();
	} /* end switch */
	fclose(fp);

	return (gdouble)sensor_value;
}