#include "prx/libc/include/Api.hpp"
#include <algorithm>
#include <array>
#include <cstddef>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <string>
#include <vector>

static void Require(bool condition) {
    if (!condition) {
        std::fputs("GuestWcscmpBoundary check failed\n", stderr);
        std::abort();
    }
}

#ifdef _WIN32
#include <windows.h>
#else
#include <sys/mman.h>
#include <unistd.h>
#endif

class Buffer {
    unsigned char* allocation;
    std::size_t page;
public:
    Buffer() {
#ifdef _WIN32
        SYSTEM_INFO info{};
        GetSystemInfo(&info);
        page = info.dwPageSize;
        allocation = static_cast<unsigned char*>(VirtualAlloc(nullptr, page * 3, MEM_RESERVE | MEM_COMMIT, PAGE_NOACCESS));
        Require(allocation != nullptr);
        DWORD previous;
        Require(VirtualProtect(allocation + page, page, PAGE_READWRITE, &previous) != 0);
#else
        const long size = sysconf(_SC_PAGESIZE);
        Require(size > 0);
        page = static_cast<std::size_t>(size);
        allocation = static_cast<unsigned char*>(mmap(nullptr, page * 3, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0));
        Require(allocation != MAP_FAILED);
        Require(mprotect(allocation + page, page, PROT_READ | PROT_WRITE) == 0);
#endif
        std::memset(allocation + page, 0xa5, page);
    }
    ~Buffer() {
#ifdef _WIN32
        Require(VirtualFree(allocation, 0, MEM_RELEASE) != 0);
#else
        Require(munmap(allocation, page * 3) == 0);
#endif
    }
    Buffer(const Buffer&) = delete;
    Buffer& operator=(const Buffer&) = delete;
    template<class T = unsigned char>
    T* At(std::size_t count) {
        Require(count <= (page - 32) / sizeof(T));
        return reinterpret_cast<T*>(allocation + page * 2 - (std::max)(count, std::size_t{1}) * sizeof(T));
    }
};

static int Sign(int value) {
    return (value > 0) - (value < 0);
}

int main() {
    Buffer first, second;
    for (std::size_t length = 0; length <= 128; ++length) {
        auto* left = first.At<char16_t>(length + 1);
        auto* right = second.At<char16_t>(length + 1);
        for (std::size_t i = 0; i < length; ++i) left[i] = static_cast<char16_t>(0x100 + i * 257);
        left[length] = 0;
        const std::u16string saved(left, length + 1);
        for (std::size_t position = 0; position <= length; ++position) {
            for (char16_t value : {0, 1, 0xff, 0x100, 0x8000, 0xd800, 0xffff}) {
                if (position == length && value != 0) continue;
                std::copy(saved.begin(), saved.end(), right);
                right[position] = value;
                int expected = 0;
                for (std::size_t i = 0; i <= length; ++i) {
                    if (left[i] != right[i]) { expected = left[i] > right[i] ? 1 : -1; break; }
                    if (left[i] == 0) break;
                }
                const std::u16string other(right, length + 1);
                Require(Sign(wcscmp_nid_postfix(left, right)) == expected);
                Require(Sign(wcscmp_nid_postfix(right, left)) == -expected);
                Require(std::equal(saved.begin(), saved.end(), left) && std::equal(other.begin(), other.end(), right));
            }
        }
    }
}