/*=========================================================================

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile$
  Language:  C++
  Date:      $Date$
  Version:   $Revision$

  Copyright (c) 2002 Insight Consortium. All rights reserved.
  See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even 
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 
     PURPOSE.  See the above copyright notices for more information.

=========================================================================*/
#include "cmWin32ProcessExecution.h"

#include "cmSystemTools.h"   

#include <malloc.h>
#include <io.h>
#include <fcntl.h>
#include <stdio.h>
#include <sys/stat.h>
#include <windows.h>

#define POPEN_1 1
#define POPEN_2 2
#define POPEN_3 3
#define POPEN_4 4

#define cmMAX(x,y) (((x)<(y))?(y):(x))

#define win32_error(x,y) std::cout << "Win32_Error(" << x << ", " << y << ")" << std::endl, false

bool cmWin32ProcessExecution::StartProcess(
  const char* cmd, const char* path, bool verbose)
{
  this->Initialize();
  this->m_Verbose = verbose;
  return this->PrivateOpen(cmd, path, _O_RDONLY | _O_TEXT, POPEN_3);
}

bool cmWin32ProcessExecution::Wait(int timeout)
{
  return this->PrivateClose(timeout);
}

/*
 * Internal dictionary mapping popen* file pointers to process handles,
 * for use when retrieving the process exit code.  See _PyPclose() below
 * for more information on this dictionary's use.
 */
static void *_PyPopenProcs = NULL;

static BOOL RealPopenCreateProcess(const char *cmdstring,
				   const char *path, 
				   const char *szConsoleSpawn,
				   HANDLE hStdin,
				   HANDLE hStdout,
				   HANDLE hStderr,
				   HANDLE *hProcess)
{
  PROCESS_INFORMATION piProcInfo;
  STARTUPINFO siStartInfo;
  char *s1,*s2, *s3 = " /c ";
  int i;
  int x;

  if (i = GetEnvironmentVariable("COMSPEC",NULL,0)) 
    {
    char *comshell;

    s1 = (char *)_alloca(i);
    if (!(x = GetEnvironmentVariable("COMSPEC", s1, i)))
      return x;

    /* Explicitly check if we are using COMMAND.COM.  If we are
     * then use the w9xpopen hack.
     */
    comshell = s1 + x;
    while (comshell >= s1 && *comshell != '\\')
      --comshell;
    ++comshell;

    if (GetVersion() < 0x80000000 &&
	_stricmp(comshell, "command.com") != 0) 
      {
      /* NT/2000 and not using command.com. */
      x = i + (int)strlen(s3) + (int)strlen(cmdstring) + 1;
      s2 = (char *)_alloca(x);
      ZeroMemory(s2, x);
      sprintf(s2, "%s%s%s", s1, s3, cmdstring);
      //std::cout << "s1: " << s1 << " s2: " << s2 << " s3: " << s3 
      //		<< std::endl;
      }
    else 
      {
      /*
       * Oh gag, we're on Win9x or using COMMAND.COM. Use
       * the workaround listed in KB: Q150956
       */
      char modulepath[_MAX_PATH];
      struct stat statinfo;
      GetModuleFileName(NULL, modulepath, sizeof(modulepath));
      for (i = x = 0; modulepath[i]; i++)
	if (modulepath[i] == '\\')
	  x = i+1;
      modulepath[x] = '\0';
      /* Create the full-name to w9xpopen, so we can test it exists */
      strncat(modulepath, 
	      szConsoleSpawn, 
	      (sizeof(modulepath)/sizeof(modulepath[0]))
	      -strlen(modulepath));
      if (stat(modulepath, &statinfo) != 0) 
	{
				/* Eeek - file-not-found - possibly an embedding 
				   situation - see if we can locate it in sys.prefix 
				*/
	strncpy(modulepath, 
		".", 
		sizeof(modulepath)/sizeof(modulepath[0]));
	if (modulepath[strlen(modulepath)-1] != '\\')
	  strcat(modulepath, "\\");
	strncat(modulepath, 
		szConsoleSpawn, 
		(sizeof(modulepath)/sizeof(modulepath[0]))
		-strlen(modulepath));
	/* No where else to look - raise an easily identifiable
	   error, rather than leaving Windows to report
	   "file not found" - as the user is probably blissfully
	   unaware this shim EXE is used, and it will confuse them.
	   (well, it confused me for a while ;-)
	*/
	if (stat(modulepath, &statinfo) != 0) 
	  {
	  std::cout 
	    << "Can not locate '" << szConsoleSpawn 
	    << "' which is needed "
	    "for popen to work with your shell "
	    "or platform." << std::endl;
	  return FALSE;
	  }
	}
      x = i + (int)strlen(s3) + (int)strlen(cmdstring) + 1 +
	(int)strlen(modulepath) + 
	(int)strlen(szConsoleSpawn) + 1;

      s2 = (char *)_alloca(x);
      ZeroMemory(s2, x);
      sprintf(
	s2,
	"%s \"%s%s%s\"",
	modulepath,
	s1,
	s3,
	cmdstring);
      }
    }

  /* Could be an else here to try cmd.exe / command.com in the path
     Now we'll just error out.. */
  else 
    {
    std::cout << "Cannot locate a COMSPEC environment variable to "
	      << "use as the shell" << std::endl;
    return FALSE;
    }
  
  ZeroMemory(&siStartInfo, sizeof(STARTUPINFO));
  siStartInfo.cb = sizeof(STARTUPINFO);
  siStartInfo.dwFlags = STARTF_USESTDHANDLES | STARTF_USESHOWWINDOW;
  siStartInfo.hStdInput = hStdin;
  siStartInfo.hStdOutput = hStdout;
  siStartInfo.hStdError = hStderr;
  siStartInfo.wShowWindow = SW_HIDE;

  if (CreateProcess(NULL,
		    s2,
		    NULL,
		    NULL,
		    TRUE,
		    CREATE_NEW_CONSOLE,
		    NULL,
		    path,
		    &siStartInfo,
		    &piProcInfo) ) 
    {
    /* Close the handles now so anyone waiting is woken. */
    CloseHandle(piProcInfo.hThread);

    /* Return process handle */
    *hProcess = piProcInfo.hProcess;
    return TRUE;
    }
  win32_error("CreateProcess", s2);
  return FALSE;
}

/* The following code is based off of KB: Q190351 */

bool cmWin32ProcessExecution::PrivateOpen(const char *cmdstring, 
					  const char* path,
					  int mode, 
					  int n)
{
  HANDLE hChildStdinRd, hChildStdinWr, hChildStdoutRd, hChildStdoutWr,
    hChildStderrRd, hChildStderrWr, hChildStdinWrDup, hChildStdoutRdDup,
    hChildStderrRdDup, hProcess; /* hChildStdoutWrDup; */

  SECURITY_ATTRIBUTES saAttr;
  BOOL fSuccess;
  int fd1, fd2, fd3;
  FILE *f1, *f2, *f3;
  long file_count;

  saAttr.nLength = sizeof(SECURITY_ATTRIBUTES);
  saAttr.bInheritHandle = TRUE;
  saAttr.lpSecurityDescriptor = NULL;

  if (!CreatePipe(&hChildStdinRd, &hChildStdinWr, &saAttr, 0))
    return win32_error("CreatePipe", NULL);

  /* Create new output read handle and the input write handle. Set
   * the inheritance properties to FALSE. Otherwise, the child inherits
   * the these handles; resulting in non-closeable handles to the pipes
   * being created. */
  fSuccess = DuplicateHandle(GetCurrentProcess(), hChildStdinWr,
			     GetCurrentProcess(), &hChildStdinWrDup, 0,
			     FALSE,
			     DUPLICATE_SAME_ACCESS);
  if (!fSuccess)
    return win32_error("DuplicateHandle", NULL);

  /* Close the inheritable version of ChildStdin
     that we're using. */
  CloseHandle(hChildStdinWr);

  if (!CreatePipe(&hChildStdoutRd, &hChildStdoutWr, &saAttr, 0))
    return win32_error("CreatePipe", NULL);

  fSuccess = DuplicateHandle(GetCurrentProcess(), hChildStdoutRd,
			     GetCurrentProcess(), &hChildStdoutRdDup, 0,
			     FALSE, DUPLICATE_SAME_ACCESS);
  if (!fSuccess)
    return win32_error("DuplicateHandle", NULL);

  /* Close the inheritable version of ChildStdout
     that we're using. */
  CloseHandle(hChildStdoutRd);

  if (n != POPEN_4) 
    {
    if (!CreatePipe(&hChildStderrRd, &hChildStderrWr, &saAttr, 0))
      return win32_error("CreatePipe", NULL);
    fSuccess = DuplicateHandle(GetCurrentProcess(),
			       hChildStderrRd,
			       GetCurrentProcess(),
			       &hChildStderrRdDup, 0,
			       FALSE, DUPLICATE_SAME_ACCESS);
    if (!fSuccess)
      return win32_error("DuplicateHandle", NULL);
    /* Close the inheritable version of ChildStdErr that we're using. */
    CloseHandle(hChildStderrRd);
    }
	  
  switch (n) 
    {
    case POPEN_1:
      switch (mode & (_O_RDONLY | _O_TEXT | _O_BINARY | _O_WRONLY)) 
	{
	case _O_WRONLY | _O_TEXT:
	  /* Case for writing to child Stdin in text mode. */
	  fd1 = _open_osfhandle((intptr_t)hChildStdinWrDup, mode);
	  f1 = _fdopen(fd1, "w");
	  /* We don't care about these pipes anymore,
	     so close them. */
	  CloseHandle(hChildStdoutRdDup);
	  CloseHandle(hChildStderrRdDup);
	  break;

	case _O_RDONLY | _O_TEXT:
	  /* Case for reading from child Stdout in text mode. */
	  fd1 = _open_osfhandle((intptr_t)hChildStdoutRdDup, mode);
	  f1 = _fdopen(fd1, "r");
	  /* We don't care about these pipes anymore,
	     so close them. */
	  CloseHandle(hChildStdinWrDup);
	  CloseHandle(hChildStderrRdDup);
	  break;

	case _O_RDONLY | _O_BINARY:
	  /* Case for readinig from child Stdout in
	     binary mode. */
	  fd1 = _open_osfhandle((intptr_t)hChildStdoutRdDup, mode);
	  f1 = _fdopen(fd1, "rb");
	  /* We don't care about these pipes anymore,
	     so close them. */
	  CloseHandle(hChildStdinWrDup);
	  CloseHandle(hChildStderrRdDup);
	  break;

	case _O_WRONLY | _O_BINARY:
	  /* Case for writing to child Stdin in binary mode. */
	  fd1 = _open_osfhandle((intptr_t)hChildStdinWrDup, mode);
	  f1 = _fdopen(fd1, "wb");
	  /* We don't care about these pipes anymore,
	     so close them. */
	  CloseHandle(hChildStdoutRdDup);
	  CloseHandle(hChildStderrRdDup);
	  break;
	}
      file_count = 1;
      break;
	
    case POPEN_2:
    case POPEN_4: 
      if ( 1 ) 
	{
	char *m1,  *m2;
	
	if (mode && _O_TEXT) 
	  {
	  m1 = "r";
	  m2 = "w";
	  } 
	else 
	  {
	  m1 = "rb";
	  m2 = "wb";
	  }

	fd1 = _open_osfhandle((intptr_t)hChildStdinWrDup, mode);
	f1 = _fdopen(fd1, m2);
	fd2 = _open_osfhandle((intptr_t)hChildStdoutRdDup, mode);
	f2 = _fdopen(fd2, m1);

	if (n != 4)
	  CloseHandle(hChildStderrRdDup);

	file_count = 2;
	break;
	}
	
    case POPEN_3:
      if ( 1) 
	{
	char *m1, *m2;
      
	if (mode && _O_TEXT) 
	  {
	  m1 = "r";
	  m2 = "w";
	  } 
	else 
	  {
	  m1 = "rb";
	  m2 = "wb";
	  }

	fd1 = _open_osfhandle((intptr_t)hChildStdinWrDup, mode);
	f1 = _fdopen(fd1, m2);
	fd2 = _open_osfhandle((intptr_t)hChildStdoutRdDup, mode);
	f2 = _fdopen(fd2, m1);
	fd3 = _open_osfhandle((intptr_t)hChildStderrRdDup, mode);
	f3 = _fdopen(fd3, m1);	

	file_count = 3;
	break;
	}
    }

  if (n == POPEN_4) 
    {
    if (!RealPopenCreateProcess(cmdstring,
				path,
				this->m_ConsoleSpawn.c_str(),
				hChildStdinRd,
				hChildStdoutWr,
				hChildStdoutWr,
				&hProcess))
      return NULL;
    }
  else 
    {
    if (!RealPopenCreateProcess(cmdstring,
				path,
				this->m_ConsoleSpawn.c_str(),
				hChildStdinRd,
				hChildStdoutWr,
				hChildStderrWr,
				&hProcess))
      return NULL;
    }

  /*
   * Insert the files we've created into the process dictionary
   * all referencing the list with the process handle and the
   * initial number of files (see description below in _PyPclose).
   * Since if _PyPclose later tried to wait on a process when all
   * handles weren't closed, it could create a deadlock with the
   * child, we spend some energy here to try to ensure that we
   * either insert all file handles into the dictionary or none
   * at all.  It's a little clumsy with the various popen modes
   * and variable number of files involved.
   */

  /* Child is launched. Close the parents copy of those pipe
   * handles that only the child should have open.  You need to
   * make sure that no handles to the write end of the output pipe
   * are maintained in this process or else the pipe will not close
   * when the child process exits and the ReadFile will hang. */

  if (!CloseHandle(hChildStdinRd))
    return win32_error("CloseHandle", NULL);
	  
  if (!CloseHandle(hChildStdoutWr))
    return win32_error("CloseHandle", NULL);
	  
  if ((n != 4) && (!CloseHandle(hChildStderrWr)))
    return win32_error("CloseHandle", NULL);
  
  this->m_ProcessHandle = hProcess;
  if ( f1 )
    {
    this->m_StdIn = f1;
    this->m_pStdIn = fd1;
    }
  if ( f2 )
    {
    this->m_StdOut = f2;
    this->m_pStdOut = fd2;
    }
  if ( f3 )
    {
    this->m_StdErr = f3;
    this->m_pStdErr = fd3;
    }

  return true;
}

/*
 * Wrapper for fclose() to use for popen* files, so we can retrieve the
 * exit code for the child process and return as a result of the close.
 *
 * This function uses the _PyPopenProcs dictionary in order to map the
 * input file pointer to information about the process that was
 * originally created by the popen* call that created the file pointer.
 * The dictionary uses the file pointer as a key (with one entry
 * inserted for each file returned by the original popen* call) and a
 * single list object as the value for all files from a single call.
 * The list object contains the Win32 process handle at [0], and a file
 * count at [1], which is initialized to the total number of file
 * handles using that list.
 *
 * This function closes whichever handle it is passed, and decrements
 * the file count in the dictionary for the process handle pointed to
 * by this file.  On the last close (when the file count reaches zero),
 * this function will wait for the child process and then return its
 * exit code as the result of the close() operation.  This permits the
 * files to be closed in any order - it is always the close() of the
 * final handle that will return the exit code.
 */

 /* RED_FLAG 31-Aug-2000 Tim
  * This is always called (today!) between a pair of
  * Py_BEGIN_ALLOW_THREADS/ Py_END_ALLOW_THREADS
  * macros.  So the thread running this has no valid thread state, as
  * far as Python is concerned.  However, this calls some Python API
  * functions that cannot be called safely without a valid thread
  * state, in particular PyDict_GetItem.
  * As a temporary hack (although it may last for years ...), we
  * *rely* on not having a valid thread state in this function, in
  * order to create our own "from scratch".
  * This will deadlock if _PyPclose is ever called by a thread
  * holding the global lock.
  */

bool cmWin32ProcessExecution::PrivateClose(int timeout)
{
  HANDLE hProcess = this->m_ProcessHandle;

  int result = -1;
  DWORD exit_code;

  std::string output = "";
  bool done = false;
  int stdoutloc = 0;
  int stderrloc = 0;
  while(!done)
    {
    Sleep(10);
    struct _stat fsout;
    struct _stat fserr;
    int rout = _fstat(this->m_pStdOut, &fsout);
    int rerr = _fstat(this->m_pStdErr, &fserr);
    if ( rout && rerr )
      {
      break;
      }
    if (fserr.st_size > 0)
      {
      int dist = fserr.st_size;
      char buffer[1023];
      int len = read(this->m_pStdErr, buffer, 1023);
      buffer[len] = 0;
      if ( this->m_Verbose )
	{
	std::cout << buffer << std::flush;
	}
      output += buffer;
      }
    if (fsout.st_size > 0)
      {
      int dist = fsout.st_size;
      char buffer[1023];
      int len = read(this->m_pStdOut, buffer, 1023);
      buffer[len] = 0;
      if ( this->m_Verbose )
	{
	std::cout << buffer << std::flush;
	}
      output += buffer;
      }
    unsigned long exitCode;
    GetExitCodeProcess(hProcess,&exitCode);
    if (exitCode != STILL_ACTIVE)
      {
      break;
      }
    }  
  
  if (WaitForSingleObject(hProcess, INFINITE) != WAIT_FAILED &&
      GetExitCodeProcess(hProcess, &exit_code)) 
    {
    result = exit_code;
    } 
  else 
    {
    /* Indicate failure - this will cause the file object
     * to raise an I/O error and translate the last Win32
     * error code from errno.  We do have a problem with
     * last errors that overlap the normal errno table,
     * but that's a consistent problem with the file object.
     */
    if (result != EOF) 
      {
      /* If the error wasn't from the fclose(), then
       * set errno for the file object error handling.
       */
      errno = GetLastError();
      }
    result = -1;
    }
	
  /* Free up the native handle at this point */
  CloseHandle(hProcess);
  this->m_ExitValue = result;
  this->m_Output = output;
  if ( result < 0 )
    {
    return false;
    }
  return true;
}

int cmWin32ProcessExecution::Windows9xHack(const char* command)
{
  BOOL bRet;
  STARTUPINFO si;
  PROCESS_INFORMATION pi;
  DWORD exit_code=0;

  if (!command) 
    {
    cmSystemTools::Error("Windows9xHack: Command not specified");
    return 1;
  }

  /* Make child process use this app's standard files. */
  ZeroMemory(&si, sizeof si);
  si.cb = sizeof si;
  si.dwFlags = STARTF_USESTDHANDLES;
  si.hStdInput = GetStdHandle(STD_INPUT_HANDLE);
  si.hStdOutput = GetStdHandle(STD_OUTPUT_HANDLE);
  si.hStdError = GetStdHandle(STD_ERROR_HANDLE);

  char* cmd = new char[ strlen(command) + 1 ];
  strcpy(cmd, command);

  bRet = CreateProcess(
    NULL, cmd,
    NULL, NULL,
    TRUE, 0,
    NULL, NULL,
    &si, &pi
    );
  delete [] cmd;

  if (bRet) 
    {
    if (WaitForSingleObject(pi.hProcess, INFINITE) != WAIT_FAILED) 
      {
      GetExitCodeProcess(pi.hProcess, &exit_code);
      }
    CloseHandle(pi.hProcess);
    CloseHandle(pi.hThread);
    return exit_code;
    }

  return 1;
}