#include <cstddef>
#include <cstdint>
#include <freeipmi/api/ipmi-api.h>
#include <vector>
#include <string>
#include <iostream>
#include <algorithm>
#include <unistd.h>
#include <sensors/sensors.h>
#include <sensors/error.h>
#include <signal.h>
#include <limits>
#include <freeipmi/freeipmi.h>

#include "ipmi.h"
#include "lm.h"

static constexpr size_t IPMI_RAW_MAX_ARGS = 65536*2;

sig_atomic_t running = true;

void sig_handler(int sig)
{
	(void)sig;
	running = false;
}

std::vector<Sensor> gather_sensors(std::vector<Sensor>& ipmi_sensors, ipmi_monitoring_ctx_t ctx, std::vector<const sensors_chip_name*>& lm_chips)
{
	std::vector<Sensor> out;
	struct ipmi_monitoring_ipmi_config ipmi_config = {};
	ipmi_config.driver_type = IPMI_MONITORING_DRIVER_TYPE_OPENIPMI;

	bool grabids = false;
	for(Sensor& sensor : ipmi_sensors)
	{
		if(sensor.id <= 0)
		{
			grabids = true;
			break;
		}
	}

	if(grabids)
	{
		if(!ipmi_fill_sensor_ids(ipmi_sensors, ctx, &ipmi_config))
		{
			std::cout<<"could not get ids for all the required sensors\n";
			return out;
		}
	}
	else
	{
		ipmi_update_sensors(ipmi_sensors, ctx, &ipmi_config);
	}

	out.insert(out.end(), ipmi_sensors.begin(), ipmi_sensors.end());
	std::vector<Sensor> lm_sensors = lm_get_temperatures(lm_chips);
	out.insert(out.end(), lm_sensors.begin(), lm_sensors.end());

	return out;
}

double fan_curve(double temperature, double min_fan, double max_fan, double low_temperature, double high_temperature)
{
	double slope = (max_fan-min_fan)/(high_temperature-low_temperature);
	return std::max(std::min(max_fan, min_fan+slope*(temperature-low_temperature)), min_fan);
}

double gpu_fan_zone(const std::vector<Sensor>& sensors)
{
	const char mi50Chip[] = "amdgpu-pci-2300";
	const char mi25Chip[] = "amdgpu-pci-4300";
	const char monitored_sensor_name[] = "edge";

	double max_temp = std::numeric_limits<double>::min();
	for(const Sensor& sensor : sensors)
	{
		if((sensor.chip == mi50Chip || sensor.chip == mi25Chip) && sensor.name == monitored_sensor_name)
		{
			if(max_temp < sensor.reading)
				max_temp = sensor.reading;
		}
	}

	return fan_curve(max_temp, 0.2, 1.0, 40, 75);
}

double system_fan_zone(const std::vector<Sensor>& sensors)
{
	Sensor cpu("IPMI", "CPU Temp");
	Sensor system("IPMI", "System Temp");
	std::vector<double> out;

	for(const Sensor& sensor : sensors)
	{
		if(cpu == sensor)
			cpu = sensor;
		else if(sensor == system)
			system = sensor;
	}

	double fanSystem = fan_curve(system.reading, 0.2, 1.0, 35, 45);
	double fanCpu = fan_curve(cpu.reading, 0.2, 1.0, 40, 70);

	return std::max(fanSystem, fanCpu);
}

std::vector<double> get_fan_zones(const std::vector<Sensor>& sensors)
{
	std::vector<double> out;
	out.push_back(system_fan_zone(sensors));
	out.push_back(gpu_fan_zone(sensors));
	return out;
}

ipmi_ctx_t ipmi_open()
{
	ipmi_ctx_t ctx = nullptr;

	ipmi_driver_type_t driver = IPMI_DEVICE_OPENIPMI;
	int ret = ipmi_ctx_find_inband(ctx, &driver, false, 0, 0, nullptr, 0, 0);
	if(ret < 0)
	{
		std::cerr<<"Could not create raw context "<<ipmi_ctx_errormsg(ctx)<<'\n';
		return nullptr;
	}
	return ctx;
}

bool ipmi_set_fan_group(ipmi_ctx_t raw_ctx, uint8_t group, double speed)
{
	char converted_speed = std::min(std::max(static_cast<char>(64), static_cast<char>(speed*64)), static_cast<char>(0));

	char command[] = {0x70, 0x66, 0x01, static_cast<char>(group), converted_speed};
	char bytesrx[IPMI_RAW_MAX_ARGS] = {0};
	int rxlen = ipmi_cmd_raw(raw_ctx, 0, 0x30, command, sizeof(command), bytesrx, IPMI_RAW_MAX_ARGS);
	if(rxlen < 0)
	{
		std::cerr<<"Raw write to ipmi failed with: "<<ipmi_ctx_errormsg(raw_ctx);
		return false;
	}
	return true;
}

int main (int argc, char **argv)
{
	signal(SIGABRT, sig_handler);
	signal(SIGTERM, sig_handler);
	signal(SIGHUP, sig_handler);
	signal(SIGINT, sig_handler);

	int ret = sensors_init(nullptr);
	if(ret < 0)
	{
		std::cerr<<"Could not init lm_sensors\n";
	}

	std::vector<const sensors_chip_name*> lm_chips = lm_get_chips("amdgpu-*");
	std::vector<Sensor> ipmi_sensors;
	ipmi_sensors.push_back(Sensor("IPMI", "CPU Temp"));
	ipmi_sensors.push_back(Sensor("IPMI", "System Temp"));

	ipmi_monitoring_ctx_t monitoring_ctx = init_ipmi_monitoring();
	if(!monitoring_ctx)
		return 1;

	ipmi_ctx_t raw_ctx = ipmi_open();
	if(!raw_ctx)
		return 1;



	while(running)
	{
		std::vector<Sensor> sensors = gather_sensors(ipmi_sensors, monitoring_ctx, lm_chips);
		std::vector<double> fanzones = get_fan_zones(sensors);
		for(const double fanzone : fanzones)
			std::cout<<fanzone<<'\n';
		sleep(1);
	}

	ipmi_ctx_close(raw_ctx);
	ipmi_ctx_destroy(raw_ctx);
	ipmi_monitoring_ctx_destroy(monitoring_ctx);
	sensors_cleanup();
	return 0;
}