/*
Looking Glass - KVM FrameRelay (KVMFR) Client
Copyright (C) 2017-2019 Geoffrey McRae <geoff@hostfission.com>
https://looking-glass.hostfission.com

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later
version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place, Suite 330, Boston, MA 02111-1307 USA
*/

#include <windows.h>
#include <setupapi.h>

#include "app.h"
#include "debug.h"
#include "windebug.h"
#include "ivshmem/Public.h"

static HANDLE       shmemHandle = INVALID_HANDLE_VALUE;
static bool         shmemOwned  = false;
static IVSHMEM_MMAP shmemMap    = {0};
static HWND         messageWnd;

struct osThreadHandle
{
  const char       * name;
  osThreadFunction   function;
  void             * opaque;
  HANDLE             handle;
  DWORD              threadID;
  int                resultCode;
};

LRESULT CALLBACK DummyWndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
  switch(msg)
  {
    case WM_CLOSE:
      DestroyWindow(hwnd);
      break;

    case WM_DESTROY:
      PostQuitMessage(0);
      break;

    default:
      return DefWindowProc(hwnd, msg, wParam, lParam);
  }
  return 0;
}

static int appThread(void * opaque)
{
  int result = app_main();
  SendMessage(messageWnd, WM_CLOSE, 0, 0);
  return result;
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
  int                              result = 0;
  HDEVINFO                         deviceInfoSet;
  PSP_DEVICE_INTERFACE_DETAIL_DATA infData = NULL;
  SP_DEVICE_INTERFACE_DATA         deviceInterfaceData;

#if 0
  // redirect stderr to a file
  {
    char tempPath[MAX_PATH+1];
    GetTempPathA(sizeof(tempPath), tempPath);
    int len = snprintf(NULL, 0, "%slooking-glass-host.txt", tempPath);
    char * path = malloc(len + 1);
    sprintf(path, "%slooking-glass-host.txt", tempPath);
    freopen(path, "a", stderr);
    free(path);
  }
#endif

  // always flush stderr
  setbuf(stderr, NULL);

  deviceInfoSet = SetupDiGetClassDevs(NULL, NULL, NULL, DIGCF_PRESENT | DIGCF_ALLCLASSES | DIGCF_DEVICEINTERFACE);
  memset(&deviceInterfaceData, 0, sizeof(SP_DEVICE_INTERFACE_DATA));
  deviceInterfaceData.cbSize = sizeof(SP_DEVICE_INTERFACE_DATA);

  if (SetupDiEnumDeviceInterfaces(deviceInfoSet, NULL, &GUID_DEVINTERFACE_IVSHMEM, 0, &deviceInterfaceData) == FALSE)
  {
    DWORD error = GetLastError();
    if (error == ERROR_NO_MORE_ITEMS)
    {
      DEBUG_WINERROR("Unable to enumerate the device, is it attached?", error);
      result = -1;
      goto finish;
    }

    DEBUG_WINERROR("SetupDiEnumDeviceInterfaces failed", error);
    result  = -1;
    goto finish;
  }

  DWORD reqSize = 0;
  SetupDiGetDeviceInterfaceDetail(deviceInfoSet, &deviceInterfaceData, NULL, 0, &reqSize, NULL);
  if (!reqSize)
  {
    DEBUG_WINERROR("SetupDiGetDeviceInterfaceDetail", GetLastError());
    result = -1;
    goto finish;
  }

  infData         = (PSP_DEVICE_INTERFACE_DETAIL_DATA)calloc(reqSize, 1);
  infData->cbSize = sizeof(SP_DEVICE_INTERFACE_DETAIL_DATA);
  if (!SetupDiGetDeviceInterfaceDetail(deviceInfoSet, &deviceInterfaceData, infData, reqSize, NULL, NULL))
  {
    free(infData);
    DEBUG_WINERROR("SetupDiGetDeviceInterfaceDetail", GetLastError());
    result = -1;
    goto finish;
  }

  shmemHandle = CreateFile(infData->DevicePath, 0, 0, NULL, OPEN_EXISTING, 0, 0);
  if (shmemHandle == INVALID_HANDLE_VALUE)
  {
    SetupDiDestroyDeviceInfoList(deviceInfoSet);
    free(infData);
    DEBUG_WINERROR("CreateFile returned INVALID_HANDLE_VALUE", GetLastError());
    result = -1;
    goto finish;
  }

  free(infData);
  SetupDiDestroyDeviceInfoList(deviceInfoSet);

  // create a message window so that our message pump works
  WNDCLASSEX wx    = {};
  wx.cbSize        = sizeof(WNDCLASSEX);
  wx.lpfnWndProc   = DummyWndProc;
  wx.hInstance     = hInstance;
  wx.lpszClassName = "DUMMY_CLASS";
  if (!RegisterClassEx(&wx))
  {
    DEBUG_ERROR("Failed to register message window class");
    result = -1;
    goto finish_shmem;
  }
  messageWnd = CreateWindowEx(0, "DUMMY_CLASS", "DUMMY_NAME", 0, 0, 0, 0, 0, HWND_MESSAGE, NULL, NULL, NULL);

  osThreadHandle * thread;
  if (!os_createThread("appThread", appThread, NULL, &thread))
  {
    DEBUG_ERROR("Failed to create the main application thread");
    result = -1;
    goto finish_shmem;
  }

  while(true)
  {
    MSG  msg;
    BOOL bRet = GetMessage(&msg, NULL, 0, 0);
    if (bRet > 0)
    {
      TranslateMessage(&msg);
      DispatchMessage(&msg);
    }
    else if (bRet < 0)
    {
      DEBUG_ERROR("Unknown error from GetMessage");
      result = -1;
      goto shutdown;
    }

    DEBUG_INFO("Platform shutdown");
    break;
  }

shutdown:
  app_quit();
  if (!os_joinThread(thread, &result))
  {
    DEBUG_ERROR("Failed to join the main application thread");
    result = -1;
  }
finish_shmem:
  os_shmemUnmap();
  CloseHandle(shmemHandle);
finish:
  return result;
}

unsigned int os_shmemSize()
{
  IVSHMEM_SIZE size;
  if (!DeviceIoControl(shmemHandle, IOCTL_IVSHMEM_REQUEST_SIZE, NULL, 0, &size, sizeof(IVSHMEM_SIZE), NULL, NULL))
  {
    DEBUG_WINERROR("DeviceIoControl Failed", GetLastError());
    return 0;
  }

  return (unsigned int)size;
}

bool os_shmemMmap(void **ptr)
{
  if (shmemOwned)
  {
    *ptr = shmemMap.ptr;
    return true;
  }

  memset(&shmemMap, 0, sizeof(IVSHMEM_MMAP));
  if (!DeviceIoControl(
    shmemHandle,
    IOCTL_IVSHMEM_REQUEST_MMAP,
    NULL, 0,
    &shmemMap, sizeof(IVSHMEM_MMAP),
    NULL, NULL))
  {
    DEBUG_WINERROR("DeviceIoControl Failed", GetLastError());
    return false;
  }

  *ptr = shmemMap.ptr;
  shmemOwned = true;
  return true;
}

void os_shmemUnmap()
{
  if (!shmemOwned)
    return;

  if (!DeviceIoControl(shmemHandle, IOCTL_IVSHMEM_RELEASE_MMAP, NULL, 0, NULL, 0, NULL, NULL))
    DEBUG_WINERROR("DeviceIoControl failed", GetLastError());
  else
    shmemOwned = false;
}

static DWORD WINAPI threadWrapper(LPVOID lpParameter)
{
  osThreadHandle * handle = (osThreadHandle *)lpParameter;
  handle->resultCode = handle->function(handle->opaque);
  return 0;
}

bool os_createThread(const char * name, osThreadFunction function, void * opaque, osThreadHandle ** handle)
{
  *handle             = (osThreadHandle *)malloc(sizeof(osThreadHandle));
  (*handle)->name     = name;
  (*handle)->function = function;
  (*handle)->opaque   = opaque;
  (*handle)->handle   = CreateThread(NULL, 0, threadWrapper, *handle, 0, &(*handle)->threadID);

  if (!(*handle)->handle)
  {
    free(*handle);
    *handle = NULL;
    DEBUG_WINERROR("CreateThread failed", GetLastError());
    return false;
  }

  return true;
}

bool os_joinThread(osThreadHandle * handle, int * resultCode)
{
  while(true)
  {
    switch(WaitForSingleObject(handle->handle, INFINITE))
    {
      case WAIT_OBJECT_0:
        if (resultCode)
          *resultCode = handle->resultCode;
        CloseHandle(handle->handle);
        free(handle);
        return true;

      case WAIT_ABANDONED:
      case WAIT_TIMEOUT:
        continue;

      case WAIT_FAILED:
        DEBUG_WINERROR("Wait for thread failed", GetLastError());
        CloseHandle(handle->handle);
        free(handle);
        return false;
    }

    break;
  }

  DEBUG_WINERROR("Unknown failure waiting for thread", GetLastError());
  return false;
}

osEventHandle * os_createEvent()
{
  HANDLE event = CreateEvent(NULL, FALSE, FALSE, NULL);
  return (osEventHandle*)event;
}

void os_freeEvent(osEventHandle * handle)
{
  CloseHandle((HANDLE)handle);
}

bool os_waitEvent(osEventHandle * handle)
{
  while(true)
  {
    switch(WaitForSingleObject((HANDLE)handle, INFINITE))
    {
      case WAIT_OBJECT_0:
        return true;

      case WAIT_ABANDONED:
      case WAIT_TIMEOUT:
        continue;

      case WAIT_FAILED:
        DEBUG_WINERROR("Wait for event failed", GetLastError());
        return false;
    }

    DEBUG_ERROR("Unknown wait event return code");
    return false;
  }
}

bool os_signalEvent(osEventHandle * handle)
{
  return SetEvent((HANDLE)handle);
}