/*
Copyright (C) 1996-1997 Id Software, Inc.

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.

*/
// sys_win.c -- Win32 system interface code

#include "quakedef.h"
#include "winquake.h"
#include "errno.h"
#include "resource.h"
#include "conproc.h"

#define MINIMUM_WIN_MEMORY    0x0880000
#define MAXIMUM_WIN_MEMORY    0x1000000

#define CONSOLE_ERROR_TIMEOUT 60.0  // # of seconds to wait on Sys_Error running
                    //  dedicated before exiting
#define PAUSE_SLEEP   50        // sleep time on pause or minimization
#define NOT_FOCUS_SLEEP 20        // sleep time when not focus

int     starttime;
qboolean  ActiveApp, Minimized;
qboolean  WinNT;

static double   pfreq;
static double   curtime = 0.0;
static double   lastcurtime = 0.0;
static int      lowshift;
qboolean      isDedicated;
static qboolean   sc_return_on_enter = false;
HANDLE        hinput, houtput;

static char     *tracking_tag = "Clams & Mooses";

static HANDLE tevent;
static HANDLE hFile;
static HANDLE heventParent;
static HANDLE heventChild;

void MaskExceptions (void);
void Sys_InitFloatTime (void);
void Sys_PushFPCW_SetHigh (void);
void Sys_PopFPCW (void);

volatile int          sys_checksum;


/*
================
Sys_PageIn
================
*/
void Sys_PageIn (void *ptr, int size)
{
  byte  *x;
  int   j, m, n;

// touch all the memory to make sure it's there. The 16-page skip is to
// keep Win 95 from thinking we're trying to page ourselves in (we are
// doing that, of course, but there's no reason we shouldn't)
  x = (byte *)ptr;

  for (n=0 ; n<4 ; n++)
  {
    for (m=0 ; m<(size - 16 * 0x1000) ; m += 4)
    {
      sys_checksum += *(int *)&x[m];
      sys_checksum += *(int *)&x[m + 16 * 0x1000];
    }
  }
}


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

FILE IO

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

#define MAX_HANDLES   10
FILE  *sys_handles[MAX_HANDLES];

int   findhandle (void)
{
  int   i;
  
  for (i=1 ; i<MAX_HANDLES ; i++)
    if (!sys_handles[i])
      return i;
  Sys_Error ("out of handles");
  return -1;
}

/*
================
filelength
================
*/
int filelength (FILE *f)
{
  int   pos;
  int   end;
  int   t;

  t = VID_ForceUnlockedAndReturnState ();

  pos = ftell (f);
  fseek (f, 0, SEEK_END);
  end = ftell (f);
  fseek (f, pos, SEEK_SET);

  VID_ForceLockState (t);

  return end;
}

int Sys_FileOpenRead (char *path, int *hndl)
{
  FILE  *f;
  int   i, retval;
  int   t;

  t = VID_ForceUnlockedAndReturnState ();

  i = findhandle ();

  f = fopen(path, "rb");

  if (!f)
  {
    *hndl = -1;
    retval = -1;
  }
  else
  {
    sys_handles[i] = f;
    *hndl = i;
    retval = filelength(f);
  }

  VID_ForceLockState (t);

  return retval;
}

int Sys_FileOpenWrite (char *path)
{
  FILE  *f;
  int   i;
  int   t;

  t = VID_ForceUnlockedAndReturnState ();
  
  i = findhandle ();

  f = fopen(path, "wb");
  if (!f)
    Sys_Error ("Error opening %s: %s", path,strerror(errno));
  sys_handles[i] = f;
  
  VID_ForceLockState (t);

  return i;
}

void Sys_FileClose (int handle)
{
  int   t;

  t = VID_ForceUnlockedAndReturnState ();
  fclose (sys_handles[handle]);
  sys_handles[handle] = NULL;
  VID_ForceLockState (t);
}

void Sys_FileSeek (int handle, int position)
{
  int   t;

  t = VID_ForceUnlockedAndReturnState ();
  fseek (sys_handles[handle], position, SEEK_SET);
  VID_ForceLockState (t);
}

int Sys_FileRead (int handle, void *dest, int count)
{
  int   t, x;

  t = VID_ForceUnlockedAndReturnState ();
  x = fread (dest, 1, count, sys_handles[handle]);
  VID_ForceLockState (t);
  return x;
}

int Sys_FileWrite (int handle, void *data, int count)
{
  int   t, x;

  t = VID_ForceUnlockedAndReturnState ();
  x = fwrite (data, 1, count, sys_handles[handle]);
  VID_ForceLockState (t);
  return x;
}

int Sys_FileTime (char *path)
{
  FILE  *f;
  int   t, retval;

  t = VID_ForceUnlockedAndReturnState ();
  
  f = fopen(path, "rb");

  if (f)
  {
    fclose(f);
    retval = 1;
  }
  else
  {
    retval = -1;
  }
  
  VID_ForceLockState (t);
  return retval;
}

void Sys_mkdir (char *path)
{
  _mkdir (path);
}


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

SYSTEM IO

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

/*
================
Sys_MakeCodeWriteable
================
*/
void Sys_MakeCodeWriteable (unsigned long startaddr, unsigned long length)
{
  DWORD  flOldProtect;

  if (!VirtualProtect((LPVOID)startaddr, length, PAGE_READWRITE, &flOldProtect))
      Sys_Error("Protection change failed\n");
}


#ifndef _M_IX86

void Sys_SetFPCW (void)
{
}

void Sys_PushFPCW_SetHigh (void)
{
}

void Sys_PopFPCW (void)
{
}

void MaskExceptions (void)
{
}

#endif

/*
================
Sys_Init
================
*/
void Sys_Init (void)
{
  LARGE_INTEGER PerformanceFreq;
  unsigned int  lowpart, highpart;
  OSVERSIONINFO vinfo;

  MaskExceptions ();
  Sys_SetFPCW ();

  if (!QueryPerformanceFrequency (&PerformanceFreq))
    Sys_Error ("No hardware timer available");

// get 32 out of the 64 time bits such that we have around
// 1 microsecond resolution
  lowpart = (unsigned int)PerformanceFreq.LowPart;
  highpart = (unsigned int)PerformanceFreq.HighPart;
  lowshift = 0;

  while (highpart || (lowpart > 2000000.0))
  {
    lowshift++;
    lowpart >>= 1;
    lowpart |= (highpart & 1) << 31;
    highpart >>= 1;
  }

  pfreq = 1.0 / (double)lowpart;

  Sys_InitFloatTime ();

  vinfo.dwOSVersionInfoSize = sizeof(vinfo);

  if (!GetVersionEx (&vinfo))
    Sys_Error ("Couldn't get OS info");

  if ((vinfo.dwMajorVersion < 4) ||
    (vinfo.dwPlatformId == VER_PLATFORM_WIN32s))
  {
    Sys_Error ("WinQuake requires at least Win95 or NT 4.0");
  }

  if (vinfo.dwPlatformId == VER_PLATFORM_WIN32_NT)
    WinNT = true;
  else
    WinNT = false;
}


void Sys_Error (char *error, ...)
{
  va_list   argptr;
  char    text[1024], text2[1024];
  char    *text3 = "Press Enter to exit\n";
  char    *text4 = "***********************************\n";
  char    *text5 = "\n";
  DWORD   dummy;
  double    starttime;
  static int  in_sys_error0 = 0;
  static int  in_sys_error1 = 0;
  static int  in_sys_error2 = 0;
  static int  in_sys_error3 = 0;

  if (!in_sys_error3)
  {
    in_sys_error3 = 1;
    VID_ForceUnlockedAndReturnState ();
  }

  va_start (argptr, error);
  vsprintf (text, error, argptr);
  va_end (argptr);

  if (isDedicated)
  {
    va_start (argptr, error);
    vsprintf (text, error, argptr);
    va_end (argptr);

    sprintf (text2, "ERROR: %s\n", text);
    WriteFile (houtput, text5, strlen (text5), &dummy, NULL);
    WriteFile (houtput, text4, strlen (text4), &dummy, NULL);
    WriteFile (houtput, text2, strlen (text2), &dummy, NULL);
    WriteFile (houtput, text3, strlen (text3), &dummy, NULL);
    WriteFile (houtput, text4, strlen (text4), &dummy, NULL);


    starttime = Sys_FloatTime ();
    sc_return_on_enter = true;  // so Enter will get us out of here

    while (!Sys_ConsoleInput () &&
        ((Sys_FloatTime () - starttime) < CONSOLE_ERROR_TIMEOUT))
    {
    }
  }
  else
  {
  // switch to windowed so the message box is visible, unless we already
  // tried that and failed
    if (!in_sys_error0)
    {
      in_sys_error0 = 1;
      VID_SetDefaultMode ();
      MessageBox(NULL, text, "Quake Error",
             MB_OK | MB_SETFOREGROUND | MB_ICONSTOP);
    }
    else
    {
      MessageBox(NULL, text, "Double Quake Error",
             MB_OK | MB_SETFOREGROUND | MB_ICONSTOP);
    }
  }

  if (!in_sys_error1)
  {
    in_sys_error1 = 1;
    Host_Shutdown ();
  }

// shut down QHOST hooks if necessary
  if (!in_sys_error2)
  {
    in_sys_error2 = 1;
    DeinitConProc ();
  }

  exit (1);
}

void Sys_Printf (char *fmt, ...)
{
  va_list   argptr;
  char    text[1024];
  DWORD   dummy;
  
  if (isDedicated)
  {
    va_start (argptr,fmt);
    vsprintf (text, fmt, argptr);
    va_end (argptr);

    WriteFile(houtput, text, strlen (text), &dummy, NULL);  
  }
}

void Sys_Quit (void)
{

  VID_ForceUnlockedAndReturnState ();

  Host_Shutdown();

  if (tevent)
    CloseHandle (tevent);

  if (isDedicated)
    FreeConsole ();

// shut down QHOST hooks if necessary
  DeinitConProc ();

  exit (0);
}


/*
================
Sys_FloatTime
================
*/
double Sys_FloatTime (void)
{
  static int      sametimecount;
  static unsigned int oldtime;
  static int      first = 1;
  LARGE_INTEGER   PerformanceCount;
  unsigned int    temp, t2;
  double        time;

  Sys_PushFPCW_SetHigh ();

  QueryPerformanceCounter (&PerformanceCount);

  temp = ((unsigned int)PerformanceCount.LowPart >> lowshift) |
       ((unsigned int)PerformanceCount.HighPart << (32 - lowshift));

  if (first)
  {
    oldtime = temp;
    first = 0;
  }
  else
  {
  // check for turnover or backward time
    if ((temp <= oldtime) && ((oldtime - temp) < 0x10000000))
    {
      oldtime = temp; // so we can't get stuck
    }
    else
    {
      t2 = temp - oldtime;

      time = (double)t2 * pfreq;
      oldtime = temp;

      curtime += time;

      if (curtime == lastcurtime)
      {
        sametimecount++;

        if (sametimecount > 100000)
        {
          curtime += 1.0;
          sametimecount = 0;
        }
      }
      else
      {
        sametimecount = 0;
      }

      lastcurtime = curtime;
    }
  }

  Sys_PopFPCW ();

    return curtime;
}


/*
================
Sys_InitFloatTime
================
*/
void Sys_InitFloatTime (void)
{
  int   j;

  Sys_FloatTime ();

  j = COM_CheckParm("-starttime");

  if (j)
  {
    curtime = (double) (Q_atof(com_argv[j+1]));
  }
  else
  {
    curtime = 0.0;
  }

  lastcurtime = curtime;
}


char *Sys_ConsoleInput (void)
{
  static char text[256];
  static int    len;
  INPUT_RECORD  recs[1024];
  int   count;
  int   i, dummy;
  int   ch, numread, numevents;

  if (!isDedicated)
    return NULL;


  for ( ;; )
  {
    if (!GetNumberOfConsoleInputEvents (hinput, &numevents))
      Sys_Error ("Error getting # of console events");

    if (numevents <= 0)
      break;

    if (!ReadConsoleInput(hinput, recs, 1, &numread))
      Sys_Error ("Error reading console input");

    if (numread != 1)
      Sys_Error ("Couldn't read console input");

    if (recs[0].EventType == KEY_EVENT)
    {
      if (!recs[0].Event.KeyEvent.bKeyDown)
      {
        ch = recs[0].Event.KeyEvent.uChar.AsciiChar;

        switch (ch)
        {
          case '\r':
            WriteFile(houtput, "\r\n", 2, &dummy, NULL);  

            if (len)
            {
              text[len] = 0;
              len = 0;
              return text;
            }
            else if (sc_return_on_enter)
            {
            // special case to allow exiting from the error handler on Enter
              text[0] = '\r';
              len = 0;
              return text;
            }

            break;

          case '\b':
            WriteFile(houtput, "\b \b", 3, &dummy, NULL); 
            if (len)
            {
              len--;
            }
            break;

          default:
            if (ch >= ' ')
            {
              WriteFile(houtput, &ch, 1, &dummy, NULL); 
              text[len] = ch;
              len = (len + 1) & 0xff;
            }

            break;

        }
      }
    }
  }

  return NULL;
}

void Sys_Sleep (void)
{
  Sleep (1);
}


void Sys_SendKeyEvents (void)
{
    MSG        msg;

  while (PeekMessage (&msg, NULL, 0, 0, PM_NOREMOVE))
  {
  // we always update if there are any event, even if we're paused
    scr_skipupdate = 0;

    if (!GetMessage (&msg, NULL, 0, 0))
      Sys_Quit ();

        TranslateMessage (&msg);
        DispatchMessage (&msg);
  }
}


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

 WINDOWS CRAP

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


/*
==================
WinMain
==================
*/
void SleepUntilInput (int time)
{

  MsgWaitForMultipleObjects(1, &tevent, FALSE, time, QS_ALLINPUT);
}


/*
==================
WinMain
==================
*/
HINSTANCE global_hInstance;
int     global_nCmdShow;
char    *argv[MAX_NUM_ARGVS];
static char *empty_string = "";
HWND    hwnd_dialog;


int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
    MSG       msg;
  quakeparms_t  parms;
  double      time, oldtime, newtime;
  MEMORYSTATUS  lpBuffer;
  static  char  cwd[1024];
  int       t;
  RECT      rect;

    /* previous instances do not exist in Win32 */
    if (hPrevInstance)
        return 0;

  global_hInstance = hInstance;
  global_nCmdShow = nCmdShow;

  lpBuffer.dwLength = sizeof(MEMORYSTATUS);
  GlobalMemoryStatus (&lpBuffer);

  if (!GetCurrentDirectory (sizeof(cwd), cwd))
    Sys_Error ("Couldn't determine current directory");

  if (cwd[Q_strlen(cwd)-1] == '/')
    cwd[Q_strlen(cwd)-1] = 0;

  parms.basedir = cwd;
  parms.cachedir = NULL;

  parms.argc = 1;
  argv[0] = empty_string;

  while (*lpCmdLine && (parms.argc < MAX_NUM_ARGVS))
  {
    while (*lpCmdLine && ((*lpCmdLine <= 32) || (*lpCmdLine > 126)))
      lpCmdLine++;

    if (*lpCmdLine)
    {
      argv[parms.argc] = lpCmdLine;
      parms.argc++;

      while (*lpCmdLine && ((*lpCmdLine > 32) && (*lpCmdLine <= 126)))
        lpCmdLine++;

      if (*lpCmdLine)
      {
        *lpCmdLine = 0;
        lpCmdLine++;
      }
      
    }
  }

  parms.argv = argv;

  COM_InitArgv (parms.argc, parms.argv);

  parms.argc = com_argc;
  parms.argv = com_argv;

  isDedicated = (COM_CheckParm ("-dedicated") != 0);

  if (!isDedicated)
  {
    hwnd_dialog = CreateDialog(hInstance, MAKEINTRESOURCE(IDD_DIALOG1), NULL, NULL);

    if (hwnd_dialog)
    {
      if (GetWindowRect (hwnd_dialog, &rect))
      {
        if (rect.left > (rect.top * 2))
        {
          SetWindowPos (hwnd_dialog, 0,
            (rect.left / 2) - ((rect.right - rect.left) / 2),
            rect.top, 0, 0,
            SWP_NOZORDER | SWP_NOSIZE);
        }
      }

      ShowWindow (hwnd_dialog, SW_SHOWDEFAULT);
      UpdateWindow (hwnd_dialog);
      SetForegroundWindow (hwnd_dialog);
    }
  }

// take the greater of all the available memory or half the total memory,
// but at least 8 Mb and no more than 16 Mb, unless they explicitly
// request otherwise
  parms.memsize = lpBuffer.dwAvailPhys;

  if (parms.memsize < MINIMUM_WIN_MEMORY)
    parms.memsize = MINIMUM_WIN_MEMORY;

  if (parms.memsize < (lpBuffer.dwTotalPhys >> 1))
    parms.memsize = lpBuffer.dwTotalPhys >> 1;

  if (parms.memsize > MAXIMUM_WIN_MEMORY)
    parms.memsize = MAXIMUM_WIN_MEMORY;

  if (COM_CheckParm ("-heapsize"))
  {
    t = COM_CheckParm("-heapsize") + 1;

    if (t < com_argc)
      parms.memsize = Q_atoi (com_argv[t]) * 1024;
  }

  parms.membase = malloc (parms.memsize);

  if (!parms.membase)
    Sys_Error ("Not enough memory free; check disk space\n");

  Sys_PageIn (parms.membase, parms.memsize);

  tevent = CreateEvent(NULL, FALSE, FALSE, NULL);

  if (!tevent)
    Sys_Error ("Couldn't create event");

  if (isDedicated)
  {
    if (!AllocConsole ())
    {
      Sys_Error ("Couldn't create dedicated server console");
    }

    hinput = GetStdHandle (STD_INPUT_HANDLE);
    houtput = GetStdHandle (STD_OUTPUT_HANDLE);

  // give QHOST a chance to hook into the console
    if ((t = COM_CheckParm ("-HFILE")) > 0)
    {
      if (t < com_argc)
        hFile = (HANDLE)Q_atoi (com_argv[t+1]);
    }
      
    if ((t = COM_CheckParm ("-HPARENT")) > 0)
    {
      if (t < com_argc)
        heventParent = (HANDLE)Q_atoi (com_argv[t+1]);
    }
      
    if ((t = COM_CheckParm ("-HCHILD")) > 0)
    {
      if (t < com_argc)
        heventChild = (HANDLE)Q_atoi (com_argv[t+1]);
    }

    InitConProc (hFile, heventParent, heventChild);
  }

  Sys_Init ();

// because sound is off until we become active
  S_BlockSound ();

  Sys_Printf ("Host_Init\n");
  Host_Init (&parms);

  oldtime = Sys_FloatTime ();

    /* main window message loop */
  while (1)
  {
    if (isDedicated)
    {
      newtime = Sys_FloatTime ();
      time = newtime - oldtime;

      while (time < sys_ticrate.value )
      {
        Sys_Sleep();
        newtime = Sys_FloatTime ();
        time = newtime - oldtime;
      }
    }
    else
    {
    // yield the CPU for a little while when paused, minimized, or not the focus
      if ((cl.paused && (!ActiveApp && !DDActive)) || Minimized || block_drawing)
      {
        SleepUntilInput (PAUSE_SLEEP);
        scr_skipupdate = 1;   // no point in bothering to draw
      }
      else if (!ActiveApp && !DDActive)
      {
        SleepUntilInput (NOT_FOCUS_SLEEP);
      }

      newtime = Sys_FloatTime ();
      time = newtime - oldtime;
    }

    Host_Frame (time);
    oldtime = newtime;
  }

    /* return success of application */
    return TRUE;
}