#include "doctest/parts/private/prelude.h"
#include "doctest/parts/private/signals.h"
#include "doctest/parts/private/context_state.h"

DOCTEST_SUPPRESS_PRIVATE_WARNINGS_PUSH

#ifndef DOCTEST_CONFIG_DISABLE

namespace doctest {
namespace detail {

#if !defined(DOCTEST_CONFIG_POSIX_SIGNALS) && !defined(DOCTEST_CONFIG_WINDOWS_SEH)
void FatalConditionHandler::reset() {}
void FatalConditionHandler::allocateAltStackMem() {}
void FatalConditionHandler::freeAltStackMem() {}
#else // DOCTEST_CONFIG_POSIX_SIGNALS || DOCTEST_CONFIG_WINDOWS_SEH

#ifdef DOCTEST_PLATFORM_WINDOWS

// There is no 1-1 mapping between signals and windows exceptions.
// Windows can easily distinguish between SO and SigSegV,
// but SigInt, SigTerm, etc are handled differently.
SignalDefs signalDefs[] = {
    {static_cast<DWORD>(EXCEPTION_ILLEGAL_INSTRUCTION), "SIGILL - Illegal instruction signal"},
    {static_cast<DWORD>(EXCEPTION_STACK_OVERFLOW), "SIGSEGV - Stack overflow"},
    {static_cast<DWORD>(EXCEPTION_ACCESS_VIOLATION), "SIGSEGV - Segmentation violation signal"},
    {static_cast<DWORD>(EXCEPTION_INT_DIVIDE_BY_ZERO), "Divide by zero error"},
};

LONG CALLBACK FatalConditionHandler::handleException(PEXCEPTION_POINTERS ExceptionInfo) {
    // Multiple threads may enter this filter/handler at once. We want the error message to be
    // printed on the console just once no matter how many threads have crashed.
    DOCTEST_DECLARE_STATIC_MUTEX(mutex)
    static bool execute = true;
    {
        DOCTEST_LOCK_MUTEX(mutex)
        if (execute) {
            bool reported = false;
            for (size_t i = 0; i < DOCTEST_COUNTOF(signalDefs); ++i) {
                if (ExceptionInfo->ExceptionRecord->ExceptionCode == signalDefs[i].id) {
                    reportFatal(signalDefs[i].name);
                    reported = true;
                    break;
                }
            }
            if (reported == false)
                reportFatal("Unhandled SEH exception caught");
            if (isDebuggerActive() && !g_cs->no_breaks)
                DOCTEST_BREAK_INTO_DEBUGGER();
        }
        execute = false;
    }
    std::exit(EXIT_FAILURE);
}

void FatalConditionHandler::allocateAltStackMem() {}
void FatalConditionHandler::freeAltStackMem() {}

FatalConditionHandler::FatalConditionHandler() {
    isSet = true;
    // 32k seems enough for doctest to handle stack overflow,
    // but the value was found experimentally, so there is no strong guarantee
    guaranteeSize = 32 * 1024;
    // Register an unhandled exception filter
    previousTop = SetUnhandledExceptionFilter(handleException);
    // Pass in guarantee size to be filled
    SetThreadStackGuarantee(&guaranteeSize);

    // On Windows uncaught exceptions from another thread, exceptions from
    // destructors, or calls to std::terminate are not a SEH exception

    // The terminal handler gets called when:
    // - std::terminate is called FROM THE TEST RUNNER THREAD
    // - an exception is thrown from a destructor FROM THE TEST RUNNER THREAD
    original_terminate_handler = std::get_terminate();
    std::set_terminate([]() DOCTEST_NOEXCEPT {
        reportFatal("Terminate handler called");
        if (isDebuggerActive() && !g_cs->no_breaks)
            DOCTEST_BREAK_INTO_DEBUGGER();
        std::exit(EXIT_FAILURE); // explicitly exit - otherwise the SIGABRT handler may be called as well
    });

    // SIGABRT is raised when:
    // - std::terminate is called FROM A DIFFERENT THREAD
    // - an exception is thrown from a destructor FROM A DIFFERENT THREAD
    // - an uncaught exception is thrown FROM A DIFFERENT THREAD
    prev_sigabrt_handler = std::signal(SIGABRT, [](int signal) DOCTEST_NOEXCEPT {
        if (signal == SIGABRT) {
            reportFatal("SIGABRT - Abort (abnormal termination) signal");
            if (isDebuggerActive() && !g_cs->no_breaks)
                DOCTEST_BREAK_INTO_DEBUGGER();
            std::exit(EXIT_FAILURE);
        }
    });

    // The following settings are taken from google test, and more
    // specifically from UnitTest::Run() inside of gtest.cc

    // the user does not want to see pop-up dialogs about crashes
    prev_error_mode_1 = SetErrorMode(
        SEM_FAILCRITICALERRORS | SEM_NOALIGNMENTFAULTEXCEPT | SEM_NOGPFAULTERRORBOX | SEM_NOOPENFILEERRORBOX
    );
    // This forces the abort message to go to stderr in all circumstances.
    prev_error_mode_2 = _set_error_mode(_OUT_TO_STDERR);
    // In the debug version, Visual Studio pops up a separate dialog
    // offering a choice to debug the aborted program - we want to disable that.
    prev_abort_behavior = _set_abort_behavior(0x0, _WRITE_ABORT_MSG | _CALL_REPORTFAULT);
    // In debug mode, the Windows CRT can crash with an assertion over invalid
    // input (e.g. passing an invalid file descriptor). The default handling
    // for these assertions is to pop up a dialog and wait for user input.
    // Instead ask the CRT to dump such assertions to stderr non-interactively.
    prev_report_mode = _CrtSetReportMode(_CRT_ASSERT, _CRTDBG_MODE_FILE | _CRTDBG_MODE_DEBUG);
    prev_report_file = _CrtSetReportFile(_CRT_ASSERT, _CRTDBG_FILE_STDERR);
}

void FatalConditionHandler::reset() {
    if (isSet) {
        // Unregister handler and restore the old guarantee
        SetUnhandledExceptionFilter(previousTop);
        SetThreadStackGuarantee(&guaranteeSize);
        std::set_terminate(original_terminate_handler);
        std::signal(SIGABRT, prev_sigabrt_handler);
        SetErrorMode(prev_error_mode_1);
        _set_error_mode(prev_error_mode_2);
        _set_abort_behavior(prev_abort_behavior, _WRITE_ABORT_MSG | _CALL_REPORTFAULT);
        static_cast<void>(_CrtSetReportMode(_CRT_ASSERT, prev_report_mode));
        static_cast<void>(_CrtSetReportFile(_CRT_ASSERT, prev_report_file));
        isSet = false;
    }
}

FatalConditionHandler::~FatalConditionHandler() {
    reset();
}

UINT FatalConditionHandler::prev_error_mode_1;
int FatalConditionHandler::prev_error_mode_2;
unsigned int FatalConditionHandler::prev_abort_behavior;
int FatalConditionHandler::prev_report_mode;
_HFILE FatalConditionHandler::prev_report_file;
void(DOCTEST_CDECL *FatalConditionHandler::prev_sigabrt_handler)(int);
std::terminate_handler FatalConditionHandler::original_terminate_handler;
bool FatalConditionHandler::isSet = false;
ULONG FatalConditionHandler::guaranteeSize = 0;
LPTOP_LEVEL_EXCEPTION_FILTER FatalConditionHandler::previousTop = nullptr;

#else // DOCTEST_PLATFORM_WINDOWS

SignalDefs signalDefs[] = {
    {SIGINT, "SIGINT - Terminal interrupt signal"},
    {SIGILL, "SIGILL - Illegal instruction signal"},
    {SIGFPE, "SIGFPE - Floating point error signal"},
    {SIGSEGV, "SIGSEGV - Segmentation violation signal"},
    {SIGTERM, "SIGTERM - Termination request signal"},
    {SIGABRT, "SIGABRT - Abort (abnormal termination) signal"}
};
static_assert(
    DOCTEST_COUNTOF(signalDefs) == DOCTEST_COUNTOF(FatalConditionHandler::oldSigActions), "arrays should match in size"
);

void FatalConditionHandler::handleSignal(int sig) {
    const char *name = "<unknown signal>";
    for (std::size_t i = 0; i < DOCTEST_COUNTOF(signalDefs); ++i) {
        const SignalDefs &def = signalDefs[i];
        if (sig == def.id) {
            name = def.name;
            break;
        }
    }
    reset();
    reportFatal(name);
    static_cast<void>(raise(sig));
}

void FatalConditionHandler::allocateAltStackMem() {
    altStackMem = new char[altStackSize];
}

void FatalConditionHandler::freeAltStackMem() {
    delete[] altStackMem;
}

FatalConditionHandler::FatalConditionHandler() {
    isSet = true;
    stack_t sigStack;
    sigStack.ss_sp = altStackMem;
    sigStack.ss_size = altStackSize;
    sigStack.ss_flags = 0;
    sigaltstack(&sigStack, &oldSigStack);
    struct sigaction sa = {};
    sa.sa_handler = handleSignal;
    sa.sa_flags = SA_ONSTACK;
    for (std::size_t i = 0; i < DOCTEST_COUNTOF(signalDefs); ++i) {
        sigaction(signalDefs[i].id, &sa, &oldSigActions[i]);
    }
}

FatalConditionHandler::~FatalConditionHandler() {
    reset();
}

void FatalConditionHandler::reset() {
    if (isSet) {
        // Set signals back to previous values -- hopefully nobody overwrote them in the meantime
        for (std::size_t i = 0; i < DOCTEST_COUNTOF(signalDefs); ++i) {
            sigaction(signalDefs[i].id, &oldSigActions[i], nullptr);
        }
        // Return the old stack
        sigaltstack(&oldSigStack, nullptr);
        isSet = false;
    }
}

bool FatalConditionHandler::isSet = false;
struct sigaction FatalConditionHandler::oldSigActions[DOCTEST_COUNTOF(signalDefs)] = {};
stack_t FatalConditionHandler::oldSigStack = {};
size_t FatalConditionHandler::altStackSize = 4 * SIGSTKSZ;
char *FatalConditionHandler::altStackMem = nullptr;

#endif // DOCTEST_PLATFORM_WINDOWS
#endif // DOCTEST_CONFIG_POSIX_SIGNALS || DOCTEST_CONFIG_WINDOWS_SEH

} // namespace detail
} // namespace doctest

#endif // DOCTEST_CONFIG_DISABLE

DOCTEST_SUPPRESS_PRIVATE_WARNINGS_POP
