#include <cstring>
#include <iostream>
#include <format>
#include <vector>

#define WIN32_LEAN_AND_MEAN
#include <Windows.h>

// Read length bytes of memory from location
std::vector<char> readMemory(LPVOID location, SIZE_T length) {
    std::vector<char> buffer(length);

    // Before reading the memory, we must enable reads.
    DWORD oldProtection;
    VirtualProtect(location, length, PAGE_EXECUTE_READWRITE, &oldProtection);
    memcpy(buffer.data(), location, length);

    // Restore old memory protection.
    VirtualProtect(location, length, oldProtection, &oldProtection);

    return buffer;
}

int main() {
    // Find address of kernel32
    HMODULE kernel32 = GetModuleHandleA("KERNEL32.DLL");

    if (kernel32 == NULL) {
        std::cout << "Failed to locate kernel32.dll\n";
        return 1;
    }

    // Get function pointer to QueryPerformanceCounter
    LPVOID codeLocation = GetProcAddress(kernel32, "QueryPerformanceCounter");

    if (codeLocation == NULL) {
        std::cout << "Failed to locate QueryPerformanceCounter()\n";
        return 1;
    }

    // Start out by reading 16 bytes from QueryPerformanceCounter, and then loop for more memory probes if necessary
    SIZE_T length = 16;

    std::cout << "QueryPerformanceCounter() ";

    do {
        // Print address
        std::cout << "@ " << std::format("{:016x}", reinterpret_cast<uintptr_t>(codeLocation)) << ":\n";

        // Read the memory
        std::vector<char> instructionBytes = readMemory(codeLocation, length);

        // Print bytes read from memory
        for (auto ch : instructionBytes)
            std::cout << std::format("{:02x}", static_cast<unsigned>(static_cast<unsigned char>(ch))) << ' ';

        std::cout << '\n';

        // Ask the user if more memory should be read
        std::cout << "Next read (0 to quit): ";

        // Get memory address of next read
        uintptr_t nextPtr;
        std::cin >> std::hex >> nextPtr;
        codeLocation = reinterpret_cast<LPVOID>(nextPtr);

        if (codeLocation != 0) {
            // Get size of next read
            std::cout << "Next length: ";
            std::cin >> std::hex >> length;
        }
    } while (codeLocation);

    return 0;
}