/*
 *  Copyright (c) 1993, Intergraph Corporation
 *
 *  You may distribute under the terms of either the GNU General Public
 *  License or the Artistic License, as specified in the perl README file.
 *
 *  Various Unix compatibility functions and NT specific functions.
 *
 *  Some of this code was derived from the MSDOS port(s) and the OS/2 port.
 *
 */

#include "ruby.h"
#include "rubysig.h"
#include <fcntl.h>
#include <process.h>
#include <sys/stat.h>
/* #include <sys/wait.h> */
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <assert.h>

#include <windows.h>
#include <winbase.h>
#include <wincon.h>
#ifdef __MINGW32__
#include <mswsock.h>
#endif
#include "win32.h"
#include "dir.h"
#ifndef index
#define index(x, y) strchr((x), (y))
#endif
#define isdirsep(x) ((x) == '/' || (x) == '\\')

#undef fclose
#undef close
#undef setsockopt

#ifndef bool
#define bool int
#endif

#if USE_INTERRUPT_WINSOCK

# if defined(_MSC_VER) && _MSC_VER <= 1000
/* VC++4.0 doesn't have this. */
extern DWORD WSAWaitForMultipleEvents(DWORD nevent, const HANDLE *events,
				      BOOL waitall, DWORD timeout,
				      BOOL alertable);
# endif

# define WaitForMultipleEvents WSAWaitForMultipleEvents
# define CreateSignal() (HANDLE)WSACreateEvent()
# define SetSignal(ev) WSASetEvent(ev)
# define ResetSignal(ev) WSAResetEvent(ev)
#else  /* USE_INTERRUPT_WINSOCK */
# define WaitForMultipleEvents WaitForMultipleObjectsEx
# define CreateSignal() CreateEvent(NULL, FALSE, FALSE, NULL);
# define SetSignal(ev) SetEvent(ev)
# define ResetSignal(ev) (void)0
#endif /* USE_INTERRUPT_WINSOCK */

#ifdef WIN32_DEBUG
#define Debug(something) something
#else
#define Debug(something) /* nothing */
#endif

#define TO_SOCKET(x)	_get_osfhandle(x)

bool NtSyncProcess = TRUE;
#if 0  // declared in header file
extern char **environ;
#define environ _environ
#endif

static bool NtHasRedirection (char *);
static int valid_filename(char *s);
static void StartSockets ();
static char *str_grow(struct RString *str, size_t new_size);
static DWORD wait_events(HANDLE event, DWORD timeout);

char *NTLoginName;

DWORD Win32System = (DWORD)-1;

static DWORD
IdOS(void)
{
    static OSVERSIONINFO osver;

    if (osver.dwPlatformId != Win32System) {
	memset(&osver, 0, sizeof(OSVERSIONINFO));
	osver.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
	GetVersionEx(&osver);
	Win32System = osver.dwPlatformId;
    }
    return (Win32System);
}

static int 
IsWin95(void) {
    return (IdOS() == VER_PLATFORM_WIN32_WINDOWS);
}

static int
IsWinNT(void) {
    return (IdOS() == VER_PLATFORM_WIN32_NT);
}

/* main thread constants */
static struct {
    HANDLE handle;
    DWORD id;
} main_thread;

/* interrupt stuff */
static HANDLE interrupted_event;

HANDLE GetCurrentThreadHandle(void)
{
    static HANDLE current_process_handle = NULL;
    HANDLE h;

    if (!current_process_handle)
	current_process_handle = GetCurrentProcess();
    if (!DuplicateHandle(current_process_handle, GetCurrentThread(),
			 current_process_handle, &h,
			 0, FALSE, DUPLICATE_SAME_ACCESS))
	return NULL;
    return h;
}

/* simulate flock by locking a range on the file */


#define LK_ERR(f,i) ((f) ? (i = 0) : (errno = GetLastError() == ERROR_LOCK_VIOLATION ? EWOULDBLOCK : EACCES))
#define LK_LEN      ULONG_MAX

static VALUE
flock_winnt(VALUE self, int argc, VALUE* argv)
{
    OVERLAPPED o;
    int i = -1;
    const HANDLE fh = (HANDLE)self;
    const int oper = argc;

    memset(&o, 0, sizeof(o));

    switch(oper) {
      case LOCK_SH:		/* shared lock */
	LK_ERR(LockFileEx(fh, 0, 0, LK_LEN, 0, &o), i);
	break;
      case LOCK_EX:		/* exclusive lock */
	LK_ERR(LockFileEx(fh, LOCKFILE_EXCLUSIVE_LOCK, 0, LK_LEN, 0, &o), i);
	break;
      case LOCK_SH|LOCK_NB:	/* non-blocking shared lock */
	LK_ERR(LockFileEx(fh, LOCKFILE_FAIL_IMMEDIATELY, 0, LK_LEN, 0, &o), i);
	break;
      case LOCK_EX|LOCK_NB:	/* non-blocking exclusive lock */
	LK_ERR(LockFileEx(fh,
			  LOCKFILE_EXCLUSIVE_LOCK|LOCKFILE_FAIL_IMMEDIATELY,
			  0, LK_LEN, 0, &o), i);
	break;
      case LOCK_UN:		/* unlock lock */
	LK_ERR(UnlockFileEx(fh, 0, LK_LEN, 0, &o), i);
	break;
      default:            /* unknown */
	errno = EINVAL;
	break;
    }
    return i;
}

static VALUE
flock_win95(VALUE self, int argc, VALUE* argv)
{
    int i = -1;
    const HANDLE fh = (HANDLE)self;
    const int oper = argc;

    switch(oper) {
      case LOCK_EX:
	do {
	    LK_ERR(LockFile(fh, 0, 0, LK_LEN, 0), i);
	} while (i && errno == EWOULDBLOCK);
	break;
      case LOCK_EX|LOCK_NB:
	LK_ERR(LockFile(fh, 0, 0, LK_LEN, 0), i);
	break;
      case LOCK_UN:
	LK_ERR(UnlockFile(fh, 0, 0, LK_LEN, 0), i);
	break;
      default:
	errno = EINVAL;
	break;
    }
    return i;
}

#undef LK_ERR

int
flock(int fd, int oper)
{
    static asynchronous_func_t locker = NULL;

    if (!locker) {
	if (IsWinNT())
	    locker = flock_winnt;
	else
	    locker = flock_win95;
    }

    return win32_asynchronize(locker,
			      (VALUE)_get_osfhandle(fd), oper, NULL,
			      (DWORD)-1);
}

//#undef const
//FILE *fdopen(int, const char *);