// -*- mode: C++; indent-tabs-mode: nil; -*-

#ifdef    HAVE_CONFIG_H
#  include "../config.h"
#endif // HAVE_CONFIG_H

extern "C" {
#include <X11/Xlib.h>
#include <X11/Xatom.h>
#include <X11/Xutil.h>
#include <X11/keysym.h>

#ifdef    SHAPE
#  include <X11/extensions/shape.h>
#endif // SHAPE

#ifdef    XINERAMA
#  include <X11/extensions/Xinerama.h>
#endif // XINERAMA

#ifdef    HAVE_FCNTL_H
#  include <fcntl.h>
#endif // HAVE_FCNTL_H

#ifdef    HAVE_STDIO_H
#  include <stdio.h>
#endif // HAVE_STDIO_H

#ifdef HAVE_STDLIB_H
#  include <stdlib.h>
#endif // HAVE_STDLIB_H

#ifdef HAVE_STRING_H
#  include <string.h>
#endif // HAVE_STRING_H

#ifdef    HAVE_UNISTD_H
#  include <sys/types.h>
#  include <unistd.h>
#endif // HAVE_UNISTD_H

#ifdef    HAVE_SYS_SELECT_H
#  include <sys/select.h>
#endif // HAVE_SYS_SELECT_H

#ifdef    HAVE_SIGNAL_H
#  include <signal.h>
#endif // HAVE_SIGNAL_H

#ifdef    HAVE_SYS_WAIT_H
#  include <sys/types.h>
#  include <sys/wait.h>
#endif // HAVE_SYS_WAIT_H
}

#include <string>
using std::string;

#include "basedisplay.hh"
#include "gccache.hh"
#include "timer.hh"
#include "util.hh"


// X error handler to handle any and all X errors while the application is
// running
static bool internal_error = False;

BaseDisplay *base_display;

static int handleXErrors(Display *d, XErrorEvent *e) {
#ifdef    DEBUG
  char errtxt[128];

  XGetErrorText(d, e->error_code, errtxt, 128); // XXX: use this!!
  fprintf(stderr, "%s:  X error: %s(%d) opcodes %d/%d\n  resource 0x%lx\n",
          base_display->getApplicationName(), errtxt, e->error_code,
          e->request_code, e->minor_code, e->resourceid);
#else
  // shutup gcc
  (void) d;
  (void) e;
#endif // DEBUG

  if (internal_error) abort();

  return(False);
}


// signal handler to allow for proper and gentle shutdown

static void signalhandler(int sig) {

  static int re_enter = 0;

  switch (sig) {
  case SIGCHLD:
    int status;
    waitpid(-1, &status, WNOHANG | WUNTRACED);
    break;

  default:
    if (base_display->handleSignal(sig))
      return;

    fprintf(stderr, "%s:  signal %d caught\n",
            base_display->getApplicationName(), sig);

    if (! base_display->isStartup() && ! re_enter) {
      internal_error = True;

      re_enter = 1;
      fprintf(stderr, "shutting down\n");
      base_display->shutdown();
    }

    if (sig != SIGTERM && sig != SIGINT) {
      fprintf(stderr, "aborting... dumping core\n");
      abort();
    }

    exit(0);

    break;
  }
}


BaseDisplay::BaseDisplay(const char *app_name, const char *dpy_name) {
  application_name = app_name;

  run_state = STARTUP;

  ::base_display = this;

  struct sigaction action;

  action.sa_handler = signalhandler;
  action.sa_mask = sigset_t();
  action.sa_flags = SA_NOCLDSTOP | SA_NODEFER;

  sigaction(SIGPIPE, &action, NULL);
  sigaction(SIGSEGV, &action, NULL);
  sigaction(SIGFPE, &action, NULL);
  sigaction(SIGTERM, &action, NULL);
  sigaction(SIGINT, &action, NULL);
  sigaction(SIGCHLD, &action, NULL);
  sigaction(SIGHUP, &action, NULL);
  sigaction(SIGUSR1, &action, NULL);
  sigaction(SIGUSR2, &action, NULL);

  if (! (display = XOpenDisplay(dpy_name))) {
    fprintf(stderr,
            "BaseDisplay::BaseDisplay: connection to X server failed.\n");
    ::exit(2);
  } else if (fcntl(ConnectionNumber(display), F_SETFD, 1) == -1) {
    fprintf(stderr,
            "BaseDisplay::BaseDisplay: couldn't mark display connection "
            "as close-on-exec\n");
    ::exit(2);
  }

  display_name = XDisplayName(dpy_name);

#ifdef    SHAPE
  shape.extensions = XShapeQueryExtension(display, &shape.event_basep,
                                          &shape.error_basep);
#else // !SHAPE
  shape.extensions = False;
#endif // SHAPE

#ifdef    XINERAMA
  if (XineramaQueryExtension(display, &xinerama.event_basep,
                             &xinerama.error_basep) &&
      XineramaQueryVersion(display, &xinerama.major, &xinerama.minor)) {
#ifdef    DEBUG
    fprintf(stderr,
            "BaseDisplay::BaseDisplay: Found Xinerama version %d.%d\n",
            xinerama.major, xinerama.minor);
#endif // DEBUG
    xinerama.extensions = True;
  } else {
    xinerama.extensions = False;
  }
#endif // XINERAMA

  XSetErrorHandler((XErrorHandler) handleXErrors);

  screenInfoList.reserve(ScreenCount(display));
  for (int i = 0; i < ScreenCount(display); ++i)
    screenInfoList.push_back(ScreenInfo(this, i));

  NumLockMask = ScrollLockMask = 0;

  const XModifierKeymap* const modmap = XGetModifierMapping(display);
  if (modmap && modmap->max_keypermod > 0) {
    const int mask_table[] = {
      ShiftMask, LockMask, ControlMask, Mod1Mask,
      Mod2Mask, Mod3Mask, Mod4Mask, Mod5Mask
    };
    const size_t size = (sizeof(mask_table) / sizeof(mask_table[0])) *
      modmap->max_keypermod;
    // get the values of the keyboard lock modifiers
    // Note: Caps lock is not retrieved the same way as Scroll and Num lock
    // since it doesn't need to be.
    const KeyCode num_lock = XKeysymToKeycode(display, XK_Num_Lock);
    const KeyCode scroll_lock = XKeysymToKeycode(display, XK_Scroll_Lock);

    for (size_t cnt = 0; cnt < size; ++cnt) {
      if (! modmap->modifiermap[cnt]) continue;

      if (num_lock == modmap->modifiermap[cnt])
        NumLockMask = mask_table[cnt / modmap->max_keypermod];
      if (scroll_lock == modmap->modifiermap[cnt])
        ScrollLockMask = mask_table[cnt / modmap->max_keypermod];
    }
  }

  MaskList[0] = 0;
  MaskList[1] = LockMask;
  MaskList[2] = NumLockMask;
  MaskList[3] = LockMask | NumLockMask;
  MaskList[4] = ScrollLockMask;
  MaskList[5] = ScrollLockMask | LockMask;
  MaskList[6] = ScrollLockMask | NumLockMask;
  MaskList[7] = ScrollLockMask | LockMask | NumLockMask;
  MaskListLength = sizeof(MaskList) / sizeof(MaskList[0]);

  if (modmap) XFreeModifiermap(const_cast<XModifierKeymap*>(modmap));

  gccache = (BGCCache *) 0;
}


BaseDisplay::~BaseDisplay(void) {
  delete gccache;

  XCloseDisplay(display);
}


void BaseDisplay::eventLoop(void) {
  run();

  const int xfd = ConnectionNumber(display);

  while (run_state == RUNNING && ! internal_error) {
    if (XPending(display)) {
      XEvent e;
      XNextEvent(display, &e);
      process_event(&e);
    } else {
      fd_set rfds;
      timeval now, tm, *timeout = (timeval *) 0;

      FD_ZERO(&rfds);
      FD_SET(xfd, &rfds);

      if (! timerList.empty()) {
        const BTimer* const timer = timerList.top();

        gettimeofday(&now, 0);
        tm = timer->timeRemaining(now);

        timeout = &tm;
      }

      select(xfd + 1, &rfds, 0, 0, timeout);

      // check for timer timeout
      gettimeofday(&now, 0);

      // there is a small chance for deadlock here:
      // *IF* the timer list keeps getting refreshed *AND* the time between
      // timer->start() and timer->shouldFire() is within the timer's period
      // then the timer will keep firing.  This should be VERY near impossible.
      while (! timerList.empty()) {
        BTimer *timer = timerList.top();
        if (! timer->shouldFire(now))
          break;

        timerList.pop();

        timer->fireTimeout();
        timer->halt();
        if (timer->isRecurring())
          timer->start();
      }
    }
  }
}


void BaseDisplay::addTimer(BTimer *timer) {
  if (! timer) return;

  timerList.push(timer);
}


void BaseDisplay::removeTimer(BTimer *timer) {
  timerList.release(timer);
}


/*
 * Grabs a button, but also grabs the button in every possible combination
 * with the keyboard lock keys, so that they do not cancel out the event.

 * if allow_scroll_lock is true then only the top half of the lock mask
 * table is used and scroll lock is ignored.  This value defaults to false.
 */
void BaseDisplay::grabButton(unsigned int button, unsigned int modifiers,
                             Window grab_window, bool owner_events,
                             unsigned int event_mask, int pointer_mode,
                             int keyboard_mode, Window confine_to,
                             Cursor cursor, bool allow_scroll_lock) const {
  unsigned int length = (allow_scroll_lock) ? MaskListLength / 2:
                                              MaskListLength;
  for (size_t cnt = 0; cnt < length; ++cnt)
    XGrabButton(display, button, modifiers | MaskList[cnt], grab_window,
                owner_events, event_mask, pointer_mode, keyboard_mode,
                confine_to, cursor);
}


/*
 * Releases the grab on a button, and ungrabs all possible combinations of the
 * keyboard lock keys.
 */
void BaseDisplay::ungrabButton(unsigned int button, unsigned int modifiers,
                               Window grab_window) const {
  for (size_t cnt = 0; cnt < MaskListLength; ++cnt)
    XUngrabButton(display, button, modifiers | MaskList[cnt], grab_window);
}


const ScreenInfo* BaseDisplay::getScreenInfo(unsigned int s) const {
  if (s < screenInfoList.size())
    return &screenInfoList[s];
  return (const ScreenInfo*) 0;
}


BGCCache* BaseDisplay::gcCache(void) const {
  if (! gccache)
    gccache = new BGCCache(this, screenInfoList.size());
  
  return gccache;
}