/*
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * 
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following disclaimer
 *   in the documentation and/or other materials provided with the
 *   distribution.
 * * Neither the name of the  nor the names of its
 *   contributors may be used to endorse or promote products derived from
 *   this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 */

#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <getopt.h>
#include <string.h>
#include <errno.h>

#define MAX_LABEL_LENGTH 32
#define PARAM_SHORT_VIEW 1
#define PARAM_MAX_ONLY 1 << 2

typedef struct {
	float cpu;
	float cpu_cores[64];
	float acpi_sensors[16];
	unsigned int cpu_cores_count;
	unsigned int acpi_sensors_count;
} thermal_sensors;

static void show_help(void)
{
	puts("parametry:");
	puts("  -m  zobrazi pouze maximalni hodnoty");
	puts("  -s  kratky vypis");
	puts("  -l <nadpis>");
}

static int load_sensors(thermal_sensors *sensors)
{
	memset(sensors, 0, sizeof(thermal_sensors));
	char buffer[1024];
	FILE *p_file = popen("sensors", "r");
	if (NULL == p_file)
		return errno;
	float dval;
	const unsigned int section_cpu = 1;
	const unsigned int section_acpitz = 0;
	unsigned int section = 0;
	size_t index_acpitz = 0;
	size_t index_cpu = 0;
	size_t max_cpu_count = sizeof(sensors->cpu_cores) / sizeof(float);
	size_t max_acpi_count = sizeof(sensors->acpi_sensors) / sizeof(float);
	char pattern[64];
	while (!feof(p_file)) {
		if (index_acpitz >= max_acpi_count)
			break;
		if (index_cpu >= max_cpu_count)
			break;
		if (fgets(buffer, sizeof(buffer), p_file) != NULL) {
			if (*buffer == '\n') {
				section = 0;
				continue;
			}
			if (0 == strncasecmp(buffer, "coretemp", 8)) {
				section = section_cpu;
				continue;
			}
			if (0 == strncasecmp(buffer, "acpitz", 6)) {
				section = section_acpitz;
				continue;
			}
			if (section_cpu == section) {
				if (sscanf(buffer, "Package id 0: %f", &dval) == 1) {
					sensors->cpu = dval;
					continue;
				}
				(void)sprintf(pattern, "Core %d: ", (int)index_cpu);
				(void)strncat(pattern, "%f",
					sizeof(pattern) - strlen(pattern) - 1);
				if (sscanf(buffer, pattern, &dval) == 1) {
					sensors->cpu_cores[index_cpu] = dval;
					index_cpu++;
					continue;
				}
			}
			else if (section_acpitz == section) {
				(void)sprintf(pattern, "temp%d: ", (int)index_acpitz+1);
				(void)strncat(pattern, "%f",
					sizeof(pattern) - strlen(pattern) - 1);
				if (sscanf(buffer, pattern, &dval) == 1) {
					sensors->acpi_sensors[index_acpitz] = dval;
					++index_acpitz;
					continue;
				}
			}
		}
		else
			break;
	}
	sensors->cpu_cores_count = index_cpu;
	sensors->acpi_sensors_count = index_acpitz;
	(void)pclose(p_file);
	return (index_cpu > 0 || index_acpitz > 0) ? 1 : -1;
}

static void print_sensors_info_line(thermal_sensors *sensors,
	const char *szlabel, uint_fast32_t params) {
	if (szlabel && (*szlabel != 0)) {
		printf(szlabel);
		printf(" ");
	}
	float max_core = 0;
	for (size_t i = 0; i < sensors->cpu_cores_count; ++i) {
		if (sensors->cpu_cores[i] > max_core)
			max_core = sensors->cpu_cores[i];
	}
	if (params & PARAM_MAX_ONLY) {
		if (params & PARAM_SHORT_VIEW)
			(void)printf("%.0f°",
				sensors->cpu > max_core ? sensors->cpu : max_core);
		else
			(void)printf("cpu: %.0f°C acpi:",
				sensors->cpu > max_core ? sensors->cpu : max_core);
		float max_acpi = 0.0;
		for (size_t i = 0; i < sensors->acpi_sensors_count; ++i) {
			if (sensors->acpi_sensors[i] > max_acpi)
				max_acpi = sensors->acpi_sensors[i];
		}
		if (params & PARAM_SHORT_VIEW)
			(void)printf(" %.0f°", max_acpi);
		else
			(void)printf(" %.0f°C", max_acpi);
	}
	else {
		if (params & PARAM_SHORT_VIEW)
			(void)printf("%.0f° %.0f°, ", sensors->cpu, max_core);
		else
			(void)printf("cpu: %.0f°C %.0f°C acpi:", sensors->cpu, max_core);
		for (size_t i = 0; i < sensors->acpi_sensors_count; ++i) {
			if (params & PARAM_SHORT_VIEW)
				(void)printf(" %.0f°", sensors->acpi_sensors[i]);
			else
				(void)printf(" %.0f°C", sensors->acpi_sensors[i]);
		}
	}
	(void)printf("\n");
}

int main(int argc, char **argv)
{
	int opt;
	uint_fast32_t params = 0;
	char szlabel[MAX_LABEL_LENGTH];
	*szlabel = 0;
	if (argc > 1) {
		while ((opt = getopt(argc, argv, "mshl:")) != -1) {
			switch (opt) {
			case 'l':
				if (strlen(optarg) <= sizeof(szlabel) - 1)
					strcpy(szlabel, optarg);
				break;
			case 'm':
				params |= PARAM_MAX_ONLY;
				break;
			case 's':
				params |= PARAM_SHORT_VIEW;
				break;
			case 'h':
				show_help();
				return EXIT_SUCCESS;
				break;
			}
		}
	}
	thermal_sensors sensors;
	int retval = load_sensors(&sensors);
	if (-1 == retval)
		return EXIT_FAILURE;
	print_sensors_info_line(&sensors, szlabel, params);
	return EXIT_SUCCESS;
}