#include "Client/UnhandledExceptionHandler.h"

#include <windows.h>
#include <dbghelp.h>
#include <psapi.h>
#include <ctime>
#include <cstdio>
#include <cstring>
#include <string>

// STATIC: 0x01389c78
// GLOBAL: gl_24469
CUnhandledExceptionHandler* g_unhandledExceptionHandler = nullptr;

// STATIC: 0x01389c7c
// GLOBAL: gl_24470
int (*g_unhandledExceptionCallback)() = nullptr;

// STATIC: 0x01389c80
// GLOBAL: gl_24359
char g_filename[264] = {};

// STATIC: 0x01389d88
// GLOBAL: gl_24471
char g_moduleBaseName[260] = {};

// STATIC: 0x01389e90
// GLOBAL: gl_24360
char g_crashString[8096] = {};

// STATIC: 0x0173ad64
// GLOBAL: gl_24472
extern uint32_t g_clientVersion;

// STATIC: 0x0171dd30
// GLOBAL: gl_24473
extern uint32_t g_launchInfo[32];

// STATIC: 0x01733550
// GLOBAL: gl_24476
extern int g_playerX;

// STATIC: 0x01733554
// GLOBAL: gl_24477
extern int g_playerY;

// STATIC: 0x0173a770
// GLOBAL: gl_24478
extern int64_t g_startTimeTicks;

// STATIC: 0x0173a778
// GLOBAL: gl_24479
extern int64_t g_loginTimeTicks;

// STATIC: 0x01732638
// GLOBAL: gl_24474
extern const uint8_t g_session[];

// STATIC: 0x013495b8
// GLOBAL: gl_24475
extern const uint8_t g_world[];

namespace {
  int ReadPlayerJob() {
    return *reinterpret_cast<const int*>(reinterpret_cast<uintptr_t>(g_session) + 0x1628);
  }

  const char* ReadPlayerJobName(int jobId) {
    const auto* const* namesBegin = *reinterpret_cast<const char* const* const*>(reinterpret_cast<uintptr_t>(g_session) + 0xFA8);
    const auto* const* namesEnd = *reinterpret_cast<const char* const* const*>(reinterpret_cast<uintptr_t>(g_session) + 0xFAC);
    if (!namesBegin || !namesEnd || namesBegin >= namesEnd) {
      return "";
    }
    size_t count = namesEnd - namesBegin;
    if (static_cast<size_t>(jobId) >= count || !namesBegin[jobId]) {
      return "";
    }
    return namesBegin[jobId];
  }

  const char* ReadCurrentMapName() {
    if (*reinterpret_cast<const int*>(reinterpret_cast<uintptr_t>(g_world) + 0x58) == 1) {
      void* zone = *reinterpret_cast<void* const*>(reinterpret_cast<uintptr_t>(g_world) + 0x04);
      if (zone != nullptr) {
        return reinterpret_cast<const char*>(reinterpret_cast<uintptr_t>(zone) + 0x68);
      }
    }
    return nullptr;
  }
}
extern "C" long long __cdecl _Xtime_get_ticks();

// OFFSET: 0x00635A70
// FUNCTION: fn_04701
CUnhandledExceptionHandler::CUnhandledExceptionHandler() {
}

// OFFSET: 0x00635A80
// FUNCTION: fn_04702
CUnhandledExceptionHandler::~CUnhandledExceptionHandler() = default;

// OFFSET: 0x00635AB0
// FUNCTION: fn_04703
bool InitUnhandledExceptionHandler(int (*callback)()) {
  if (g_unhandledExceptionHandler != nullptr) {
    return false;
  }

  auto* handler = new CUnhandledExceptionHandler();
  if (!handler) {
    g_unhandledExceptionHandler = nullptr;
    return false;
  }

  g_unhandledExceptionCallback = callback;
  GetModuleFileNameA(nullptr, g_filename, sizeof(g_filename));

  const char* baseName = strrchr(g_filename, '\\');
  if (baseName) {
    baseName++;
  } else {
    baseName = g_filename;
  }

  _snprintf_s(g_moduleBaseName, sizeof(g_moduleBaseName), static_cast<size_t>(-1), "%s", baseName);

  char* sep = strrchr(g_filename, '\\');
  if (sep) {
    *sep = '\0';
  }

  char* dot = strrchr(g_moduleBaseName, '.');
  if (dot) {
    *dot = '\0';
  }

  SetUnhandledExceptionFilter(TopLevelExceptionFilter);
  _set_invalid_parameter_handler(InvalidParameterHandler);
  _set_purecall_handler(PurecallHandler);

  g_unhandledExceptionHandler = handler;
  return true;
}

// OFFSET: 0x00635C10
// FUNCTION: fn_04704
int CleanupUnhandledExceptionHandler() {
  if (g_unhandledExceptionHandler != nullptr) {
    delete g_unhandledExceptionHandler;
    g_unhandledExceptionHandler = nullptr;
  }
  return 0;
}

// OFFSET: 0x00635C30
// FUNCTION: fn_04705
INT_PTR CALLBACK DialogFunc(HWND hDlg, UINT uMsg, WPARAM wParam, LPARAM lParam) {
  if (uMsg == WM_INITDIALOG) {
    HWND item = GetDlgItem(hDlg, 1006);
    RECT rect = {};
    SetWindowTextA(item, g_crashString);
    GetWindowRect(hDlg, &rect);

    int screenHeight = GetSystemMetrics(SM_CYSCREEN);
    int dlgHeight = rect.bottom - rect.top;
    int y = (screenHeight / 2) - (dlgHeight / 2);

    int screenWidth = GetSystemMetrics(SM_CXSCREEN);
    int dlgWidth = rect.right - rect.left;
    int x = (screenWidth / 2) - (dlgWidth / 2);

    MoveWindow(hDlg, x, y, dlgWidth, dlgHeight, TRUE);
  } else if (uMsg == WM_COMMAND) {
    if (LOWORD(wParam) == 2) {
      size_t len = strlen(g_crashString);
      HGLOBAL memory = GlobalAlloc(GMEM_MOVEABLE, len + 1);
      if (memory != nullptr) {
        char* locked = static_cast<char*>(GlobalLock(memory));
        if (locked != nullptr) {
          memcpy(locked, g_crashString, len + 1);
          GlobalUnWire(memory);

          if (OpenClipboard(hDlg)) {
            EmptyClipboard();
            SetClipboardData(CF_TEXT, memory);
            CloseClipboard();
          }

          HWND button = GetDlgItem(hDlg, 7);
          SetFocus(button);
        } else {
          GlobalFree(memory);
        }
      }
    } else if (LOWORD(wParam) == 7) {
      EndDialog(hDlg, 7);
    }
  } else {
    return FALSE;
  }

  return TRUE;
}

// OFFSET: 0x00635DB0
// FUNCTION: fn_04706
BOOL CALLBACK EnumerateLoadedModulesCallback(PCSTR moduleName, ULONG moduleBase, ULONG moduleSize, PVOID userContext) {
  auto* address = static_cast<const DWORD*>(userContext);
  if (*address < moduleBase || *address > moduleBase + moduleSize) {
    return TRUE;
  }

  sprintf(&g_crashString[strlen(g_crashString)], "%s", moduleName);
  return FALSE;
}

// OFFSET: 0x00635E00
// FUNCTION: fn_04707
void __cdecl InvalidParameterHandler(
  const wchar_t* expression,
  const wchar_t* function,
  const wchar_t* file,
  unsigned int line,
  uintptr_t pReserved
) {
  EXCEPTION_RECORD record = {};
  CONTEXT context = {};
  EXCEPTION_POINTERS exceptionInfo = {&record, &context};

  RtlCaptureContext(&context);

  record.ExceptionCode = 0xC000000D;
  record.NumberParameters = 3;
  record.ExceptionInformation[0] = reinterpret_cast<ULONG_PTR>(expression);
  record.ExceptionInformation[1] = reinterpret_cast<ULONG_PTR>(file);
  record.ExceptionInformation[2] = static_cast<ULONG_PTR>(line);

  TopLevelExceptionFilter(&exceptionInfo);
  abort();
}

// OFFSET: 0x00635E90
// FUNCTION: fn_04708
void __cdecl PurecallHandler() {
  EXCEPTION_RECORD record = {};
  CONTEXT context = {};
  EXCEPTION_POINTERS exceptionInfo = {&record, &context};

  RtlCaptureContext(&context);

  record.ExceptionCode = 0xC0000025;

  TopLevelExceptionFilter(&exceptionInfo);
  abort();
}

// OFFSET: 0x00635F00
// FUNCTION: fn_04709
LONG WINAPI TopLevelExceptionFilter(EXCEPTION_POINTERS* exceptionInfo) {
  PCONTEXT context = exceptionInfo->ContextRecord;
  HMODULE dbgHelp = LoadLibraryA("dbghelp.dll");

  if (dbgHelp != nullptr) {
    auto pStackWalk = reinterpret_cast<BOOL(WINAPI*)(
      DWORD, HANDLE, HANDLE, LPSTACKFRAME, PVOID, PREAD_PROCESS_MEMORY_ROUTINE,
      PFUNCTION_TABLE_ACCESS_ROUTINE, PGET_MODULE_BASE_ROUTINE, PTRANSLATE_ADDRESS_ROUTINE
    )>(GetProcAddress(dbgHelp, "StackWalk"));

    auto pGetTimestamp = reinterpret_cast<DWORD(WINAPI*)(HMODULE)>(
      GetProcAddress(dbgHelp, "GetTimestampForLoadedLibrary")
    );

    auto pEnumerateLoadedModules = reinterpret_cast<BOOL(WINAPI*)(
      HANDLE, PENUMLOADED_MODULES_CALLBACK, PVOID
    )>(GetProcAddress(dbgHelp, "EnumerateLoadedModules"));

    HMODULE module = GetModuleHandleA(nullptr);
    CHAR filename[256] = {};
    GetModuleFileNameA(module, filename, sizeof(filename));

    DWORD timestamp = pGetTimestamp ? pGetTimestamp(module) : 0;
    sprintf(&g_crashString[strlen(g_crashString)], "Module Name: %s\r\n", filename);

    const char* timeString = _ctime32(reinterpret_cast<const __time32_t*>(&timestamp));
    sprintf(&g_crashString[strlen(g_crashString)], "Time Stamp: 0x%08x - %s\r\n", timestamp, timeString);
    sprintf(&g_crashString[strlen(g_crashString)], "Version: 0x%08x\r\n", g_clientVersion);
    sprintf(&g_crashString[strlen(g_crashString)], "\r\n");
    sprintf(&g_crashString[strlen(g_crashString)], "Exception Type: 0x%08x\r\n", exceptionInfo->ExceptionRecord->ExceptionCode);
    sprintf(&g_crashString[strlen(g_crashString)], "\r\n");

    HANDLE process = GetCurrentProcess();
    HANDLE thread = GetCurrentThread();

    STACKFRAME frame = {};
    frame.AddrPC.Offset = context->Eip;
    frame.AddrPC.Mode = AddrModeFlat;
    frame.AddrStack.Offset = context->Esp;
    frame.AddrStack.Mode = AddrModeFlat;
    frame.AddrFrame.Offset = context->Ebp;
    frame.AddrFrame.Mode = AddrModeFlat;

    sprintf(&g_crashString[strlen(g_crashString)], "\r\n");
    sprintf(&g_crashString[strlen(g_crashString)], "eax: 0x%08x\tebx: 0x%08x\r\n", context->Eax, context->Ebx);
    sprintf(&g_crashString[strlen(g_crashString)], "ecx: 0x%08x\tedx: 0x%08x\r\n", context->Ecx, context->Edx);
    sprintf(&g_crashString[strlen(g_crashString)], "esi: 0x%08x\tedi: 0x%08x\r\n", context->Esi, context->Edi);
    sprintf(&g_crashString[strlen(g_crashString)], "ebp: 0x%08x\tesp: 0x%08x\r\n", context->Ebp, context->Esp);
    sprintf(&g_crashString[strlen(g_crashString)], "\r\n");

    for (int i = 0; i < 512; ++i) {
      if (frame.AddrPC.Offset == 0) {
        break;
      }
      if (!pStackWalk(IMAGE_FILE_MACHINE_I386, process, thread, &frame, context, nullptr, nullptr, nullptr, nullptr)) {
        break;
      }

      sprintf(&g_crashString[strlen(g_crashString)], "0x%08x\t", frame.AddrPC.Offset);
      pEnumerateLoadedModules(process, EnumerateLoadedModulesCallback, &frame.AddrPC.Offset);
      sprintf(&g_crashString[strlen(g_crashString)], "\r\n");
    }

    const auto* stack = reinterpret_cast<const unsigned char*>(context->Esp);
    sprintf(&g_crashString[strlen(g_crashString)], "\r\n");
    sprintf(
      &g_crashString[strlen(g_crashString)],
      "stack %08x - %08x\r\n",
      static_cast<unsigned int>(reinterpret_cast<uintptr_t>(stack)),
      static_cast<unsigned int>(reinterpret_cast<uintptr_t>(stack + 1024))
    );

    for (int i = 0; i < 16; ++i) {
      sprintf(&g_crashString[strlen(g_crashString)], "%08X : ", static_cast<unsigned int>(reinterpret_cast<uintptr_t>(stack)));
      for (int j = 0; j < 16; ++j) {
        sprintf(&g_crashString[strlen(g_crashString)], "%02X ", *stack++);
      }
      sprintf(&g_crashString[strlen(g_crashString)], "\r\n");
    }

    sprintf(&g_crashString[strlen(g_crashString)], "\r\nLaunch Info \r\n");
    int launchIndex = 0;
    for (int k = 0; k < 4; ++k) {
      for (int m = 0; m < 8; ++m) {
        sprintf(&g_crashString[strlen(g_crashString)], "%04X ", g_launchInfo[launchIndex++]);
      }
      sprintf(&g_crashString[strlen(g_crashString)], "\r\n");
    }

    int jobId = ReadPlayerJob();
    const char* jobName = ReadPlayerJobName(jobId);
    sprintf(&g_crashString[strlen(g_crashString)], "\r\nJob : %s\r\n", jobName);

    const char* mapName = ReadCurrentMapName();
    if (mapName != nullptr) {
      sprintf(&g_crashString[strlen(g_crashString)], "%s %d %d\r\n", mapName, g_playerX, g_playerY);
    }

    sprintf(
      &g_crashString[strlen(g_crashString)],
      "\r\n%I64d - %I64d",
      g_startTimeTicks / 10000000LL,
      g_loginTimeTicks / 10000000LL
    );

    int64_t reportTime = _Xtime_get_ticks() / 10000000LL;
    PROCESS_MEMORY_COUNTERS memCounters = {};
    double workingSet = 0.0;
    double pagefile = 0.0;

    if (K32GetProcessMemoryInfo(process, &memCounters, sizeof(memCounters))) {
      workingSet = static_cast<double>(static_cast<uint32_t>(memCounters.WorkingSetSize >> 10));
      pagefile = static_cast<double>(static_cast<uint32_t>(memCounters.PagefileUsage >> 10));
    }

    sprintf(&g_crashString[strlen(g_crashString)], "\r\nReport Time: %I64d(%.0lf/%.0lf)\r\n", reportTime, workingSet, pagefile);
    FreeLibrary(dbgHelp);
  } else {
    sprintf(&g_crashString[strlen(g_crashString)], "Can't find DbgHelp.DLL !!!");
  }

  DialogBoxParamA(GetModuleHandleA(nullptr), MAKEINTRESOURCEA(117), nullptr, DialogFunc, 0);

  if (g_unhandledExceptionCallback != nullptr) {
    g_unhandledExceptionCallback();
  }

  return EXCEPTION_EXECUTE_HANDLER;
}