#include "Diagnostics.h"

// If we're on Win32, we'll include our minidump writer
#ifdef _WIN32

#include <Windows.h>
#include <Dbghelp.h>

#include "Game.h"
#include "dLogger.h"

void make_minidump(EXCEPTION_POINTERS* e) {
    auto hDbgHelp = LoadLibraryA("dbghelp");
    if (hDbgHelp == nullptr)
        return;
    auto pMiniDumpWriteDump = (decltype(&MiniDumpWriteDump))GetProcAddress(hDbgHelp, "MiniDumpWriteDump");
    if (pMiniDumpWriteDump == nullptr)
        return;

    char name[MAX_PATH];
    {
        auto nameEnd = name + GetModuleFileNameA(GetModuleHandleA(0), name, MAX_PATH);
        SYSTEMTIME t;
        GetSystemTime(&t);
        wsprintfA(nameEnd - strlen(".exe"),
                  "_%4d%02d%02d_%02d%02d%02d.dmp",
                  t.wYear, t.wMonth, t.wDay, t.wHour, t.wMinute, t.wSecond);
    }

    auto hFile = CreateFileA(name, GENERIC_WRITE, FILE_SHARE_READ, 0, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, 0);
    if (hFile == INVALID_HANDLE_VALUE)
        return;

    MINIDUMP_EXCEPTION_INFORMATION exceptionInfo;
    exceptionInfo.ThreadId = GetCurrentThreadId();
    exceptionInfo.ExceptionPointers = e;
    exceptionInfo.ClientPointers = FALSE;

    auto dumped = pMiniDumpWriteDump(
        GetCurrentProcess(),
        GetCurrentProcessId(),
        hFile,
        MINIDUMP_TYPE(MiniDumpWithIndirectlyReferencedMemory | MiniDumpScanMemory),
        e ? &exceptionInfo : nullptr,
        nullptr,
        nullptr);

    CloseHandle(hFile);

    return;
}

LONG CALLBACK unhandled_handler(EXCEPTION_POINTERS* e) {
    make_minidump(e);
    if (Game::logger)
        Game::logger->Flush(); // Flush our log if we have one, before exiting.
    return EXCEPTION_CONTINUE_SEARCH;
}
#endif

#if defined(__linux__) //&& !defined(__clang__) // backtrace is a gcc exclusive system library
#include <execinfo.h>
#include <ucontext.h>
#include <unistd.h>

#include <csignal>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <exception>

#if defined(__include_backtrace__)
#include <backtrace.h>

#include <backtrace-supported.h>

struct bt_ctx {
    struct backtrace_state* state;
    int error;
};

static inline void Bt(struct backtrace_state* state) {
    std::string fileName = Diagnostics::GetOutDirectory() + "crash_" + Diagnostics::GetProcessName() + "_" + std::to_string(getpid()) + ".log";
    FILE* file = fopen(fileName.c_str(), "w+");
    if (file != nullptr) {
        backtrace_print(state, 2, file);
        fclose(file);
    }

    backtrace_print(state, 2, stdout);
}

static void ErrorCallback(void* data, const char* msg, int errnum) {
    auto* ctx = (struct bt_ctx*)data;
    fprintf(stderr, "ERROR: %s (%d)", msg, errnum);
    ctx->error = 1;

    std::string fileName = Diagnostics::GetOutDirectory() + "crash_" + Diagnostics::GetProcessName() + "_" + std::to_string(getpid()) + ".log";
    FILE* file = fopen(fileName.c_str(), "w+");
    if (file != nullptr) {
        fprintf(file, "ERROR: %s (%d)", msg, errnum);
        fclose(file);
    }
}
#endif

#include "Type.h"

void GenerateDump() {
    std::string cmd = "sudo gcore " + std::to_string(getpid());
    system(cmd.c_str());
}

void CatchUnhandled(int sig) {
#ifndef __include_backtrace__

    if (Diagnostics::GetProduceMemoryDump()) {
        GenerateDump();
    }

    void* array[10];
    size_t size;

    // get void*'s for all entries on the stack
    size = backtrace(array, 10);

    printf("Fatal error %i\nStacktrace:\n", sig);
#if defined(__GNUG__) and defined(__dynamic)

    // Loop through the returned addresses, and get the symbols to be demangled
    char** strings = backtrace_symbols(array, size);

    // Print the stack trace
    for (size_t i = 0; i < size; i++) {
        // Take a string like './WorldServer(_ZN19SlashCommandHandler17HandleChatCommandERKSbIDsSt11char_traitsIDsESaIDsEEP6EntityRK13SystemAddress+0x6187) [0x55869c44ecf7]' and extract the function name
        std::string functionName = strings[i];
        std::string::size_type start = functionName.find('(');
        std::string::size_type end = functionName.find('+');
        if (start != std::string::npos && end != std::string::npos) {
            std::string demangled = functionName.substr(start + 1, end - start - 1);

            demangled = demangle(functionName.c_str());

            if (demangled.empty()) {
                printf("[%02d] %s\n", i, demangled.c_str());
            } else {
                printf("[%02d] %s\n", i, functionName.c_str());
            }
        } else {
            printf("[%02d] %s\n", i, functionName.c_str());
        }
    }
#else
    backtrace_symbols_fd(array, size, STDOUT_FILENO);
#endif

    std::string fileName = Diagnostics::GetOutDirectory() + "crash_" + Diagnostics::GetProcessName() + "_" + std::to_string(getpid()) + ".log";
    FILE* file = fopen(fileName.c_str(), "w+");
    if (file != NULL) {
        // print out all the frames to stderr
        fprintf(file, "Error: signal %d:\n", sig);
        backtrace_symbols_fd(array, size, fileno(file));
        fclose(file);
    }

#else

    struct backtrace_state* state = backtrace_create_state(
        Diagnostics::GetProcessFileName().c_str(),
        BACKTRACE_SUPPORTS_THREADS,
        ErrorCallback,
        nullptr);

    // Print error code
    printf("Error code: %d\n", sig);

    struct bt_ctx ctx = {state, 0};
    Bt(state);

#endif

    exit(EXIT_FAILURE);
}

void CritErrHdlr(int sig_num, siginfo_t* info, void* ucontext) {
    CatchUnhandled(sig_num);
}

void OnTerminate() {
    CatchUnhandled(-1);
}

void MakeBacktrace() {
    struct sigaction sigact;

    sigact.sa_sigaction = CritErrHdlr;
    sigact.sa_flags = SA_RESTART | SA_SIGINFO;

    if (sigaction(SIGSEGV, &sigact, (struct sigaction*)nullptr) != 0 ||
        sigaction(SIGFPE, &sigact, (struct sigaction*)nullptr) != 0 ||
        sigaction(SIGABRT, &sigact, (struct sigaction*)nullptr) != 0 ||
        sigaction(SIGILL, &sigact, (struct sigaction*)nullptr) != 0) {
        fprintf(stderr, "error setting signal handler for %d (%s)\n",
                SIGSEGV,
                strsignal(SIGSEGV));

        exit(EXIT_FAILURE);
    }

    std::set_terminate(OnTerminate);
}
#endif

void Diagnostics::Initialize() {
#ifdef _WIN32
    SetUnhandledExceptionFilter(unhandled_handler);
#elif defined(__linux__) //&& !defined(__clang__)
    MakeBacktrace();
#else
    fprintf(stderr, "Diagnostics not supported on this platform.\n");
#endif
}

std::string Diagnostics::m_ProcessName{};
std::string Diagnostics::m_ProcessFileName{};
std::string Diagnostics::m_OutDirectory{};
bool Diagnostics::m_ProduceMemoryDump{};

void Diagnostics::SetProcessName(const std::string& name) {
    m_ProcessName = name;
}

void Diagnostics::SetProcessFileName(const std::string& name) {
    m_ProcessFileName = name;
}

void Diagnostics::SetOutDirectory(const std::string& path) {
    m_OutDirectory = path;
}

void Diagnostics::SetProduceMemoryDump(bool value) {
    m_ProduceMemoryDump = value;
}

const std::string& Diagnostics::GetProcessName() {
    return m_ProcessName;
}

const std::string& Diagnostics::GetProcessFileName() {
    return m_ProcessFileName;
}

const std::string& Diagnostics::GetOutDirectory() {
    return m_OutDirectory;
}

bool Diagnostics::GetProduceMemoryDump() {
    return m_ProduceMemoryDump;
}