#pragma region Includes
#include "ESignService.h"
#include "ThreadPool.h"

#include "PathName.h"

#include <cassert>
#include <zmq.h>

#include <Wtsapi32.h>
#pragma comment(lib, "Wtsapi32.lib")

#pragma endregion

///////////////////////////////////////////////////////////
// Utility
///////////////////////////////////////////////////////////

static errno_t GetIniString(const char* key, gt_string val)
{
  ::GetPrivateProfileStringA("Default", key, "", val, sizeof(gt_string), "./esigner.ini");
  return *val ? 0 : EINVAL;
}

static int GetIniInteger(const char* key)
{
  gt_string val = { 0 };
  GetIniString(key, val);
  return atoi(val);
}

///////////////////////////////////////////////////////////
// CESignService
///////////////////////////////////////////////////////////

CESignService::CESignService(LPCTSTR pszServiceName, BOOL fCanStop, BOOL fCanShutdown, BOOL fCanPauseContinue)
: CServiceBase(pszServiceName, fCanStop, fCanShutdown, fCanPauseContinue)
{
    m_fStopping = FALSE;

    // Create a manual-reset event that is not signaled at first to indicate 
    // the stopped signal of the service.
    m_hStoppedEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
    if (m_hStoppedEvent == NULL)
        throw GetLastError();
}


CESignService::~CESignService(void)
{
    if (m_hStoppedEvent)
    {
        CloseHandle(m_hStoppedEvent);
        m_hStoppedEvent = NULL;
    }
}


//
//   FUNCTION: CESignService::OnStart(DWORD, LPWSTR *)
//
//   PURPOSE: The function is executed when a Start command is sent to the 
//   service by the SCM or when the operating system starts (for a service 
//   that starts automatically). It specifies actions to take when the 
//   service starts. In this code sample, OnStart logs a service-start 
//   message to the Application log, and queues the main service function for 
//   execution in a thread pool worker thread.
//
//   PARAMETERS:
//   * dwArgc   - number of command line arguments
//   * lpszArgv - array of command line arguments
//
//   NOTE: A service application is designed to be long running. Therefore, 
//   it usually polls or monitors something in the system. The monitoring is 
//   set up in the OnStart method. However, OnStart does not actually do the 
//   monitoring. The OnStart method must return to the operating system after 
//   the service's operation has begun. It must not loop forever or block. To 
//   set up a simple monitoring mechanism, one general solution is to create 
//   a timer in OnStart. The timer would then raise events in your code 
//   periodically, at which time your service could do its monitoring. The 
//   other solution is to spawn a new thread to perform the main service 
//   functions, which is demonstrated in this code sample.
//
void CESignService::OnStart(DWORD dwArgc, LPWSTR *lpszArgv)
{
    // Log a service start message to the Application log.
    WriteEventLogEntry(TEXT("ESignService Starting"));

    // Queue the main service function for execution in a worker thread.
    CThreadPool::QueueUserWorkItem(&CESignService::ServiceLoop, this);
}

char CESignService::ParseHex(const char* hex) const
{
  int n = 0;
  sscanf_s(hex, "%2X", &n);
  return char(n);
}

const char* CESignService::ParseString(const char* equal, gt_string str) const
{
  gt_strcpy(str, "");
  const char* s = equal;
  int i = 0;
  for (; *s != '&' && *s > ' '; s++)
  {
    if (*s == '%')
    {
      const char h = ParseHex(s+1);
      gt_chrcat(str, h);
      s += 2;
    }
    else
      gt_chrcat(str, *s);
  }
  return s;
}

const char* CESignService::ParseString(const char* equal, CPathName& path) const
{
  gt_string str = { 0 };
  const char* s = ParseString(equal, str);
  path.Set(str);
  return s;
}


bool CESignService::ParseGET(const char* get, CPathName& src, CPathName& dst, CPathName& bck, 
                             gt_string pin, gt_string ext) const
{
  src = dst = bck = "";
  gt_strcpy(pin, "");
  gt_strcpy(ext, "");
  while (get != NULL)
  {
    const char* equal = strchr(get, '=');
    if (equal != NULL)
    {
      if (*(equal-1) > 'Z')
        break;

      switch (*(equal-3))
      {
      case 'B': get = ParseString(equal+1, bck); break; // BCK
      case 'D': get = ParseString(equal+1, dst); break; // DST
      case 'E': get = ParseString(equal+1, ext); break; // EXT
      case 'P': get = ParseString(equal+1, pin); break; // PIN
      case 'S': get = ParseString(equal+1, src); break; // SRC
      default : get = equal+1; break;
      }
    }
    else
      get = equal;
  }
  return !src.empty();
}

/*
DWORD CESignService::RunAsync(const char* strCmdLine) const
{
  DWORD ret = ::WinExec(strCmdLine, SW_SHOWDEFAULT);
 
  if (ret >= 32)
  {
    ret = 0;
  }
  else
  {
    LPWSTR messageBuffer = NULL;
    ret = ::GetLastError();
    size_t size = FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
                                 NULL, ret, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPWSTR)&messageBuffer, 0, NULL);

    WriteEventLogEntry(messageBuffer, EVENTLOG_ERROR_TYPE, ret);
    LocalFree(messageBuffer);
  }

  return ret;
}
*/

DWORD CESignService::RunSync(const char* strCmdLine) const
{
  STARTUPINFOA si = { 0 };
  PROCESS_INFORMATION pi = { 0 };
  si.cb = sizeof(si); 
  si.lpDesktop = "winsta0\\default";
  si.wShowWindow = SW_SHOW;
  
  DWORD activeSessionId = ::WTSGetActiveConsoleSessionId();
  HANDLE currentToken = NULL; ::WTSQueryUserToken(activeSessionId, &currentToken);

  DWORD err = 0;

  if (currentToken)
  {
    ::CreateProcessAsUserA(currentToken, NULL, 
                     (LPSTR)strCmdLine,  // lpCommandLine
                     NULL,  // lpProcessAttributes
                     NULL,  // lpThreadAttributes
                     FALSE, // no Handle inheritance
                     NORMAL_PRIORITY_CLASS, // creation flags
                     NULL,  // Use parent's environment block
                     NULL,  // Use parent's starting directory 
                     &si, 
                     &pi);
  }
  else
  {
    ::CreateProcessA(NULL, 
                     (LPSTR)strCmdLine,  // lpCommandLine
                     NULL,  // lpProcessAttributes
                     NULL,  // lpThreadAttributes
                     FALSE, // no Handle inheritance
                     NORMAL_PRIORITY_CLASS, // creation flags
                     NULL,  // Use parent's environment block
                     NULL,  // Use parent's starting directory 
                     &si, 
                     &pi);
  }

  if (pi.hProcess)
  {
    ::WaitForSingleObject(pi.hProcess, INFINITE);
    ::CloseHandle(pi.hProcess);
    ::CloseHandle(pi.hThread);
  }
  else
    err = ::GetLastError();

  if (currentToken)
  {
    ::CloseHandle(currentToken);
    currentToken = NULL;
  }

  return err;
}


void AppendVar(gt_string cmd, const char* var, const char* val)
{
  if (val && *val)
  {
    gt_chrcat(cmd, ' ');
    gt_strcat(cmd, var);
    gt_chrcat(cmd, '=');
    if (*val != '"' && strchr(val, ' '))
    {
      gt_chrcat(cmd, '"');
      gt_strcat(cmd, val);
      gt_chrcat(cmd, '"');
    }
    else
      gt_strcat(cmd, val);
  }
}

//
//   FUNCTION: CESignService::ServiceLoop(void)
//
//   PURPOSE: The method performs the main function of the service. It runs 
//   on a thread pool worker thread.
//
void CESignService::ServiceLoop(void)
{
  void *ctx = zmq_ctx_new ();
  assert (ctx);
  /* Create ZMQ_STREAM socket */
  void *socket = zmq_socket (ctx, ZMQ_STREAM);
  assert (socket);

  int nPort = GetIniInteger("PORT");
  if (nPort < 1000)
    nPort = 8083;
  char port[32]; sprintf_s(port, sizeof(port), "tcp://*:%d", nPort);
  int rc = zmq_bind (socket, port);
  assert (rc == 0);
  const int timeout = 5000; // 5 secondi di timeout per verificare anche m_fStopping
  zmq_setsockopt (socket, ZMQ_RCVTIMEO, &timeout, sizeof(timeout));

  /* Data structure to hold the ZMQ_STREAM ID */
  uint8_t id [256];
  /* Data structure to hold the ZMQ_STREAM received data */
  const size_t raw_max = 1024;
  char* raw = new char[raw_max];

  while (!m_fStopping) 
  {
    /* Get HTTP request; ID frame and then request */
    memset(id, 0, sizeof(id));
    const int id_size = zmq_recv (socket, id, sizeof(id), 0);
    if (id_size <= 0)
      continue;

    memset(raw, 0, raw_max);
    const size_t raw_size = zmq_recv (socket, raw, raw_max, 0);

    CPathName src, dst, bck;
    gt_string pin = { 0 }, ext = { 0 };
    ParseGET(raw, src, dst, bck, pin, ext);

    /* Sends the ID frame followed by the response */
    zmq_send (socket, id, id_size, ZMQ_SNDMORE);
    
    gt_string log = {0};
    gt_strcpy(log, "HTTP/1.0 200 OK\r\nContent-Type: text/plain\r\n\r\n");

    CPathName pdf; pdf.Set(src, "*", "pdf");
    const int nTotal = pdf.Count();

    if (nTotal > 0)
    { 
      const char* const cmdfile = "ESignCmd.exe";
      const char* const logfile = "ESignCmd.log";
      gt_string cmd = { 0 };
      gt_strcpy(cmd, cmdfile);
      AppendVar(cmd, "SRC", src);
      AppendVar(cmd, "DST", dst);
      AppendVar(cmd, "BCK", bck);
      AppendVar(cmd, "LOG", logfile);
      AppendVar(cmd, "PIN", pin);
      AppendVar(cmd, "EXT", ext);
      
      const DWORD err = RunSync(cmd);
      memset(raw, 0, raw_max);
      if (err == 0)
      {
        FILE* log = NULL;
        if (fopen_s(&log, logfile, "r") == 0) 
        {
          fread(raw, raw_max-1, 1, log);
          fclose(log); log = NULL;
        }
        else
          sprintf_s(raw, raw_max, 
                    "%s: bloccato nella firma di %d documenti.", 
                    cmdfile, nTotal);
      }
      else
        sprintf_s(raw, raw_max, 
                  "%s: errore 0x%X nella firma di %d documenti.", 
                  cmdfile, err, nTotal);
      
      gt_strcat(log, raw);
    }
    else
    {
      gt_strcat(log, "Non ci sono documenti da firmare!\r\n");
    }

    zmq_send (socket, log, strlen(log), ZMQ_SNDMORE);

    /* Closes the connection by sending the ID frame followed by a zero response */
    zmq_send (socket, id, id_size, ZMQ_SNDMORE);
    zmq_send (socket, 0, 0, ZMQ_SNDMORE);
    /* NOTE: If we don't use ZMQ_SNDMORE, then we won't be able to send more */
    /* message to any client */
  }
  delete [] raw;
  zmq_close (socket); 
  zmq_ctx_destroy (ctx);

  // Signal the stopped event.
  SetEvent(m_hStoppedEvent);
}


//
//   FUNCTION: CESignService::OnStop(void)
//
//   PURPOSE: The function is executed when a Stop command is sent to the 
//   service by SCM. It specifies actions to take when a service stops 
//   running. In this code sample, OnStop logs a service-stop message to the 
//   Application log, and waits for the finish of the main service function.
//
//   COMMENTS:
//   Be sure to periodically call ReportServiceStatus() with 
//   SERVICE_STOP_PENDING if the procedure is going to take long time. 
//
void CESignService::OnStop()
{
    // Log a service stop message to the Application log.
    WriteEventLogEntry(L"ESignService Stopping");

    // Indicate that the service is stopping and wait for the finish of the 
    // main service function (ServiceWorkerThread).
    m_fStopping = TRUE;
    if (::WaitForSingleObject(m_hStoppedEvent, INFINITE) != WAIT_OBJECT_0)
        throw ::GetLastError();
}