/**
 * collectd - src/thermal.c
 * Copyright (C) 2008  Michał Mirosław
 *
 * 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; only version 2 of the License is applicable.
 *
 * 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
 *
 * Authors:
 *   Michał Mirosław <mirq-linux at rere.qmqm.pl>
 **/

#include "collectd.h"
#include "common.h"
#include "plugin.h"
#include "configfile.h"
#include "utils_ignorelist.h"

#if !KERNEL_LINUX
# error "This module is for Linux only."
#endif

static const char *config_keys[] = {
	"Device",
	"IgnoreSelected",
	"ForceUseProcfs"
};

const char *const dirname_sysfs = "/sys/class/thermal";
const char *const dirname_procfs = "/proc/acpi/thermal_zone";

static _Bool force_procfs = 0;
static ignorelist_t *device_list;

enum dev_type {
	TEMP = 0,
	COOLING_DEV
};

static void thermal_submit (const char *plugin_instance, enum dev_type dt,
		gauge_t value)
{
	value_list_t vl = VALUE_LIST_INIT;
	value_t v;

	v.gauge = value;
	vl.values = &v;

	vl.values_len = 1;

	sstrncpy (vl.host, hostname_g, sizeof (vl.host));
	sstrncpy (vl.plugin, "thermal", sizeof(vl.plugin));
	if (plugin_instance != NULL)
		sstrncpy (vl.plugin_instance, plugin_instance,
				sizeof (vl.plugin_instance));
	sstrncpy (vl.type,
			(dt == TEMP) ? "temperature" : "gauge",
			sizeof (vl.type));

	plugin_dispatch_values (&vl);
}

static int thermal_sysfs_device_read (const char __attribute__((unused)) *dir,
		const char *name, void __attribute__((unused)) *user_data)
{
	char filename[256];
	char data[1024];
	int len;
	_Bool success = 0;

	if (device_list && ignorelist_match (device_list, name))
		return -1;

	len = snprintf (filename, sizeof (filename),
			"%s/%s/temp", dirname_sysfs, name);
	if ((len < 0) || ((size_t) len >= sizeof (filename)))
		return -1;

	len = read_file_contents (filename, data, sizeof(data));
	if (len > 1 && data[--len] == '\n') {
		char *endptr = NULL;
		double temp;

		data[len] = 0;
		errno = 0;
		temp = strtod (data, &endptr) / 1000.0;

		if (endptr == data + len && errno == 0) {
			thermal_submit(name, TEMP, temp);
			success = 1;
		}
	}

	len = snprintf (filename, sizeof (filename),
			"%s/%s/cur_state", dirname_sysfs, name);
	if ((len < 0) || ((size_t) len >= sizeof (filename)))
		return -1;

	len = read_file_contents (filename, data, sizeof(data));
	if (len > 1 && data[--len] == '\n') {
		char *endptr = NULL;
		double state;

		data[len] = 0;
		errno = 0;
		state = strtod (data, &endptr);

		if (endptr == data + len && errno == 0) {
			thermal_submit(name, COOLING_DEV, state);
			success = 1;
		}
	}

	return (success ? 0 : -1);
}

static int thermal_procfs_device_read (const char __attribute__((unused)) *dir,
		const char *name, void __attribute__((unused)) *user_data)
{
	const char str_temp[] = "temperature:";
	char filename[256];
	char data[1024];
	int len;

	if (device_list && ignorelist_match (device_list, name))
		return -1;

	/**
	 * rechot ~ # cat /proc/acpi/thermal_zone/THRM/temperature
	 * temperature:             55 C
	 */
	
	len = snprintf (filename, sizeof (filename),
			"%s/%s/temperature", dirname_procfs, name);
	if ((len < 0) || ((size_t) len >= sizeof (filename)))
		return -1;

	len = read_file_contents (filename, data, sizeof(data));
	if ((len > 0) && ((size_t) len > sizeof(str_temp))
			&& (data[--len] == '\n')
			&& (! strncmp(data, str_temp, sizeof(str_temp)-1))) {
		char *endptr = NULL;
		double temp;
		double factor, add;
		
		if (data[--len] == 'C') {
			add = 0;
			factor = 1.0;
		} else if (data[len] == 'F') {
			add = -32;
			factor = 5.0/9.0;
		} else if (data[len] == 'K') {
			add = -273.15;
			factor = 1.0;
		} else
			return -1;

		while (len > 0 && data[--len] == ' ')
			;
		data[len + 1] = 0;

		while (len > 0 && data[--len] != ' ')
			;
		++len;

		errno = 0;
		temp = (strtod (data + len, &endptr) + add) * factor;

		if (endptr != data + len && errno == 0) {
			thermal_submit(name, TEMP, temp);
			return 0;
		}
	}

	return -1;
}

static int thermal_config (const char *key, const char *value)
{
	if (device_list == NULL)
		device_list = ignorelist_create (1);

	if (strcasecmp (key, "Device") == 0)
	{
		if (ignorelist_add (device_list, value))
		{
			ERROR ("thermal plugin: "
					"Cannot add value to ignorelist.");
			return 1;
		}
	}
	else if (strcasecmp (key, "IgnoreSelected") == 0)
	{
		ignorelist_set_invert (device_list, 1);
		if (IS_TRUE (value))
			ignorelist_set_invert (device_list, 0);
	}
	else if (strcasecmp (key, "ForceUseProcfs") == 0)
	{
		force_procfs = 0;
		if (IS_TRUE (value))
			force_procfs = 1;
	}
	else
	{
		return -1;
	}

	return 0;
}

static int thermal_sysfs_read (void)
{
	return walk_directory (dirname_sysfs, thermal_sysfs_device_read,
			/* user_data = */ NULL, /* include hidden */ 0);
}

static int thermal_procfs_read (void)
{
	return walk_directory (dirname_procfs, thermal_procfs_device_read,
			/* user_data = */ NULL, /* include hidden */ 0);
}

static int thermal_init (void)
{
	int ret = -1;

	if (!force_procfs && access (dirname_sysfs, R_OK | X_OK) == 0) {
		ret = plugin_register_read ("thermal", thermal_sysfs_read);
	} else if (access (dirname_procfs, R_OK | X_OK) == 0) {
		ret = plugin_register_read ("thermal", thermal_procfs_read);
	}

	return ret;
}

static int thermal_shutdown (void)
{
	ignorelist_free (device_list);

	return 0;
}

void module_register (void)
{
	plugin_register_config ("thermal", thermal_config,
			config_keys, STATIC_ARRAY_SIZE(config_keys));
	plugin_register_init ("thermal", thermal_init);
	plugin_register_shutdown ("thermal", thermal_shutdown);
}

