#include "sensors.hpp"

#include <CoreFoundation/CoreFoundation.h>
#include <IOKit/hidsystem/IOHIDEventSystemClient.h>

#include <string>
#include <numeric>
#include <vector>

extern "C" {
typedef struct __IOHIDEvent *IOHIDEventRef;
typedef struct __IOHIDServiceClient *IOHIDServiceClientRef;
#ifdef __LP64__
typedef double IOHIDFloat;
#else
typedef float IOHIDFloat;
#endif

#define IOHIDEventFieldBase(type) (type << 16)
#define kIOHIDEventTypeTemperature 15

IOHIDEventSystemClientRef IOHIDEventSystemClientCreate(CFAllocatorRef allocator);
int IOHIDEventSystemClientSetMatching(IOHIDEventSystemClientRef client, CFDictionaryRef match);
int IOHIDEventSystemClientSetMatchingMultiple(IOHIDEventSystemClientRef client, CFArrayRef match);
IOHIDEventRef IOHIDServiceClientCopyEvent(IOHIDServiceClientRef, int64_t, int32_t, int64_t);
CFStringRef IOHIDServiceClientCopyProperty(IOHIDServiceClientRef service, CFStringRef property);
IOHIDFloat IOHIDEventGetFloatValue(IOHIDEventRef event, int32_t field);

// create a dict ref, like for temperature sensor {"PrimaryUsagePage":0xff00, "PrimaryUsage":0x5}
CFDictionaryRef matching(int page, int usage) {
	CFNumberRef nums[2];
	CFStringRef keys[2];

	keys[0] = CFStringCreateWithCString(0, "PrimaryUsagePage", 0);
	keys[1] = CFStringCreateWithCString(0, "PrimaryUsage", 0);
	nums[0] = CFNumberCreate(0, kCFNumberSInt32Type, &page);
	nums[1] = CFNumberCreate(0, kCFNumberSInt32Type, &usage);

	CFDictionaryRef dict = CFDictionaryCreate(0, (const void **)keys, (const void **)nums, 2, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
	CFRelease(keys);
	return dict;
}

double getValue(IOHIDServiceClientRef sc) {
	IOHIDEventRef event = IOHIDServiceClientCopyEvent(sc, kIOHIDEventTypeTemperature, 0, 0);  // here we use ...CopyEvent
	IOHIDFloat temp = 0.0;
	if (event != 0) {
		temp = IOHIDEventGetFloatValue(event, IOHIDEventFieldBase(kIOHIDEventTypeTemperature));
		CFRelease(event);
	}
	return temp;
}

}  // extern C

long long Cpu::ThermalSensors::getSensors() {
	CFDictionaryRef thermalSensors = matching(0xff00, 5);  // 65280_10 = FF00_16
	                                                       // thermalSensors's PrimaryUsagePage should be 0xff00 for M1 chip, instead of 0xff05
	                                                       // can be checked by ioreg -lfx
	IOHIDEventSystemClientRef system = IOHIDEventSystemClientCreate(kCFAllocatorDefault);
	IOHIDEventSystemClientSetMatching(system, thermalSensors);
	CFArrayRef matchingsrvs = IOHIDEventSystemClientCopyServices(system);
	std::vector<double> temps;
	if (matchingsrvs) {
		long count = CFArrayGetCount(matchingsrvs);
		for (int i = 0; i < count; i++) {
			IOHIDServiceClientRef sc = (IOHIDServiceClientRef)CFArrayGetValueAtIndex(matchingsrvs, i);
			if (sc) {
				CFStringRef name = IOHIDServiceClientCopyProperty(sc, CFSTR("Product"));  // here we use ...CopyProperty
				if (name) {
					char buf[200];
					CFStringGetCString(name, buf, 200, kCFStringEncodingASCII);
					std::string n(buf);
					// this is just a guess, nobody knows which sensors mean what
					// on my system PMU tdie 3 and 9 are missing...
					// there is also PMU tdev1-8 but it has negative values??
					// there is also eACC for efficiency package but it only has 2 entries
					// and pACC for performance but it has 7 entries (2 - 9) WTF
					if (n.starts_with("eACC") or n.starts_with("pACC")) {
						temps.push_back(getValue(sc));
					}
					CFRelease(name);
				}
			}
		}
		CFRelease(matchingsrvs);
	}
	CFRelease(system);
	CFRelease(thermalSensors);
	if (temps.empty()) return 0ll;
	return round(std::accumulate(temps.begin(), temps.end(), 0ll) / temps.size());
}