/* Copyright (C) 2000, 2001, 2002, 2003, 2004 Shawn Betts <sabetts@vcn.bc.ca>
 * Copyright (C) 2016 Mathieu OTHACEHE <m.othacehe@gmail.com>
 *
 * This file is part of ratpoison.
 *
 * ratpoison 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, or (at your option)
 * any later version.
 *
 * ratpoison 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 software; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307 USA
 */

#include "ratpoison.h"
#include <string.h>
#include <X11/cursorfont.h>

static void init_screen (rp_screen *s);

int
screen_width (rp_screen *s)
{
  return s->width - defaults.padding_right - defaults.padding_left;
}

int
screen_height (rp_screen *s)
{
  return s->height - defaults.padding_bottom - defaults.padding_top;
}

int
screen_left (rp_screen *s)
{
  return s->left + defaults.padding_left;
}

int
screen_right (rp_screen *s)
{
  return screen_left (s) + screen_width (s);
}

int
screen_top (rp_screen *s)
{
  return s->top + defaults.padding_top;
}

int
screen_bottom (rp_screen *s)
{
  return screen_top (s) + screen_height (s);
}

/* Returns a pointer to a list of frames. */
struct list_head *
screen_copy_frameset (rp_screen *s)
{
  struct list_head *head;
  rp_frame *cur;

  /* Init our new list. */
  head = xmalloc (sizeof (struct list_head));
  INIT_LIST_HEAD (head);

  /* Copy each frame to our new list. */
  list_for_each_entry (cur, &s->frames, node)
    {
      list_add_tail (&(frame_copy (cur))->node, head);
    }

  return head;
}

/* Set head as the frameset, deleting the existing one. */
void
screen_restore_frameset (rp_screen *s, struct list_head *head)
{
  frameset_free (&s->frames);
  INIT_LIST_HEAD (&s->frames);

  /* Hook in our new frameset. */
  list_splice (head, &s->frames);
}


/* Given a screen, free the frames' numbers from the numset. */
void
screen_free_nums (rp_screen *s)
{
  rp_frame *cur;

  list_for_each_entry (cur, &s->frames, node)
    {
      numset_release (s->frames_numset, cur->number);
    }
}

/* Given a list of frames, free them, but don't remove their numbers
   from the numset. */
void
frameset_free (struct list_head *head)
{
  rp_frame *frame;
  struct list_head *iter, *tmp;

  list_for_each_safe_entry (frame, iter, tmp, head, node)
    {
      /* FIXME: what if frames has memory inside its struct
         that needs to be freed? */
      free (frame);
    }
}

rp_frame *
screen_get_frame (rp_screen *s, int frame_num)
{
  rp_frame *cur;

  list_for_each_entry (cur, &s->frames, node)
    {
      if (cur->number == frame_num)
        return cur;
    }

  return NULL;
}

rp_frame *
screen_find_frame_by_frame (rp_screen *s, rp_frame *f)
{
  rp_frame *cur;

  list_for_each_entry (cur, &s->frames, node)
    {
      PRINT_DEBUG (("cur=%p f=%p\n", cur, f));
      if (cur == f)
        return cur;
    }

  return NULL;
}

/* Given a root window, return the rp_screen struct */
rp_screen *
find_screen (Window w)
{
  rp_screen *cur;

  list_for_each_entry (cur, &rp_screens, node)
    {
      if (cur->root == w)
        return cur;
    }

  return NULL;
}

/* Given a window attr, return the rp_screen struct */
rp_screen *
find_screen_by_attr (XWindowAttributes attr)
{
  rp_screen *cur;

  list_for_each_entry (cur, &rp_screens, node)
    {
      if (attr.x >= cur->left &&
          attr.x <= cur->left + cur->width &&
          attr.y >= cur->top &&
          attr.y <= cur->top + cur->height)
        return cur;
    }

  return NULL;
}

/* Return 1 if w is a root window of any of the screens. */
int
is_a_root_window (unsigned int w)
{
  rp_screen *cur;

  list_for_each_entry (cur, &rp_screens, node)
    {
      if (cur->root == w)
        return 1;
    }

  return 0;
}

rp_screen *
screen_number (int number)
{
  rp_screen *cur;

  list_for_each_entry (cur, &rp_screens, node)
    {
      if (cur->number == number)
        return cur;
    }

  return NULL;
}

static int
screen_cmp (void *priv UNUSED, struct list_head *a, struct list_head *b)
{
  rp_screen *sc_a = container_of (a, typeof(*sc_a), node);
  rp_screen *sc_b = container_of (b, typeof(*sc_b), node);

  if (sc_a->left < sc_b->left)
    return -1;
  if (sc_a->left > sc_b->left)
    return 1;

  if (sc_a->top > sc_b->top)
    return -1;
  if (sc_a->top < sc_b->top)
    return 1;

  return 0;
}

void
screen_sort (void)
{
  return list_sort (NULL, &rp_screens, screen_cmp);
}

static void
screen_set_numbers (void)
{
  rp_screen *cur;

  list_for_each_entry (cur, &rp_screens, node)
    {
      cur->number = numset_request (rp_glob_screen.numset);
    }
}

static void
screen_select_primary (void)
{
  rp_screen *cur;

  /* By default, take the first screen as current screen */
  list_first(cur, &rp_screens, node);
  if (!rp_current_screen)
    rp_current_screen = cur;

#ifdef HAVE_XRANDR
  if (!rp_have_xrandr)
    return;

  list_for_each_entry (cur, &rp_screens, node)
    {
      if (xrandr_is_primary(cur)) {
        rp_current_screen = cur;
        PRINT_DEBUG(("Xrandr primary screen %d detected\n",
                     rp_current_screen->number));
        break;
      }
    }
#endif
}

static void
init_global_screen (rp_global_screen *s)
{
  int screen_num;

  screen_num = DefaultScreen (dpy);
  s->root = RootWindow (dpy, screen_num);

  s->numset = numset_new ();
  s->fg_color = BlackPixel (dpy, screen_num);
  s->bg_color = WhitePixel (dpy, screen_num);
  s->fw_color = BlackPixel (dpy, screen_num);
  s->bw_color = BlackPixel (dpy, screen_num);
}

void
init_screens (void)
{
  int i;
  int screen_count = 0;
  int *rr_outputs = NULL;
  rp_screen *screen;

  /* Get the number of screens */
  if (rp_have_xrandr) {
#ifdef HAVE_XRANDR
    rr_outputs = xrandr_query_screen (&screen_count);
#endif
  } else {
    screen_count = ScreenCount (dpy);
  }

  /* Create our global frame numset */
  rp_frame_numset = numset_new();

  init_global_screen (&rp_glob_screen);

  for (i = 0; i < screen_count; i++)
    {
      screen = xmalloc (sizeof(*screen));
      list_add (&screen->node, &rp_screens);

#ifdef HAVE_XRANDR
      if (rp_have_xrandr)
        xrandr_fill_screen (rr_outputs[i], screen);
#endif
      init_screen (screen);
    }

  screen_sort ();
  screen_set_numbers ();
  screen_select_primary ();

  free (rr_outputs);
}

static void
init_rat_cursor (rp_screen *s)
{
  s->rat = XCreateFontCursor (dpy, XC_icon);
}

static void
init_screen (rp_screen *s)
{
  XGCValues gcv;
  struct sbuf *buf;
  char *colon;
  int screen_num;

  screen_num = DefaultScreen (dpy);

  if (!rp_have_xrandr)
    {
      s->left = 0;
      s->top = 0;
      s->width = DisplayWidth (dpy, screen_num);
      s->height = DisplayHeight (dpy, screen_num);
    }

  /* Select on some events on the root window, if this fails, then
     there is already a WM running and the X Error handler will catch
     it, terminating ratpoison. */
  XSelectInput (dpy, RootWindow (dpy, screen_num),
                PropertyChangeMask | ColormapChangeMask
                | SubstructureRedirectMask | SubstructureNotifyMask
                | StructureNotifyMask);
  XSync (dpy, False);

  /* Set the numset for the frames to our global numset. */
  s->frames_numset = rp_frame_numset;

  s->scratch_buffer = NULL;

  /* Build the display string for each screen */
  buf = sbuf_new (0);
  sbuf_printf (buf, "DISPLAY=%s", DisplayString (dpy));
  colon = strrchr (sbuf_get (buf), ':');
  if (colon)
    {
      char *dot;

      dot = strrchr (sbuf_get (buf), '.');
      if (!dot || dot < colon)
        {
          /* no dot was found or it belongs to fqdn - append screen_num
             to the end */
          sbuf_printf_concat (buf, ".%d", screen_num);
        }
    }
  s->display_string = sbuf_free_struct (buf);

  PRINT_DEBUG (("display string: %s\n", s->display_string));

  s->root = RootWindow (dpy, screen_num);
  s->screen_num = screen_num;
  s->def_cmap = DefaultColormap (dpy, screen_num);

  init_rat_cursor (s);

  /* Setup the GC for drawing the font. */
  gcv.foreground = rp_glob_screen.fg_color;
  gcv.background = rp_glob_screen.bg_color;
  gcv.function = GXcopy;
  gcv.line_width = 1;
  gcv.subwindow_mode = IncludeInferiors;
  s->normal_gc = XCreateGC(dpy, s->root,
                           GCForeground | GCBackground | GCFunction
                           | GCLineWidth | GCSubwindowMode,
                           &gcv);
  gcv.foreground = rp_glob_screen.bg_color;
  gcv.background = rp_glob_screen.fg_color;
  s->inverse_gc = XCreateGC(dpy, s->root,
                            GCForeground | GCBackground | GCFunction
                            | GCLineWidth | GCSubwindowMode,
                            &gcv);

  /* Create the program bar window. */
  s->bar_is_raised = 0;
  s->bar_window = XCreateSimpleWindow (dpy, s->root, 0, 0, 1, 1,
                                       defaults.bar_border_width,
                                       rp_glob_screen.fg_color, rp_glob_screen.bg_color);

  /* Setup the window that will receive all keystrokes once the prefix
     key has been pressed. */
  s->key_window = XCreateSimpleWindow (dpy, s->root, 0, 0, 1, 1, 0,
                                       WhitePixel (dpy, screen_num),
                                       BlackPixel (dpy, screen_num));
  XSelectInput (dpy, s->key_window, KeyPressMask | KeyReleaseMask);

  /* Create the input window. */
  s->input_window = XCreateSimpleWindow (dpy, s->root, 0, 0, 1, 1,
                                         defaults.bar_border_width,
                                         rp_glob_screen.fg_color, rp_glob_screen.bg_color);
  XSelectInput (dpy, s->input_window, KeyPressMask | KeyReleaseMask);

  /* Create the frame indicator window */
  s->frame_window = XCreateSimpleWindow (dpy, s->root, 1, 1, 1, 1, defaults.bar_border_width,
                                         rp_glob_screen.fg_color, rp_glob_screen.bg_color);

  /* Create the help window */
  s->help_window = XCreateSimpleWindow (dpy, s->root, s->left, s->top, s->width,
                                        s->height, 0, rp_glob_screen.fg_color, rp_glob_screen.bg_color);
  XSelectInput (dpy, s->help_window, KeyPressMask);

  activate_screen(s);

  XSync (dpy, 0);

#ifdef USE_XFT_FONT
  {
    s->xft_font = XftFontOpenName (dpy, screen_num, DEFAULT_XFT_FONT);
    if (!s->xft_font)
      {
        PRINT_ERROR(("Failed to open font\n"));
      }
    else
      {
        if (!XftColorAllocName (dpy, DefaultVisual (dpy, screen_num),
                                DefaultColormap (dpy, screen_num),
                                defaults.fgcolor_string, &s->xft_fg_color))
          {
            PRINT_ERROR(("Failed to allocate font fg color\n"));
            XftFontClose (dpy, s->xft_font);
            s->xft_font = NULL;
          }
        if (!XftColorAllocName (dpy, DefaultVisual (dpy, screen_num),
                                DefaultColormap (dpy, screen_num),
                                defaults.bgcolor_string, &s->xft_bg_color))
          {
            PRINT_ERROR(("Failed to allocate font fg color\n"));
            XftFontClose (dpy, s->xft_font);
            s->xft_font = NULL;
          }
      }
  }
#endif
}

void
activate_screen (rp_screen *s)
{
  /* Add netwm support. FIXME: I think this is busted. */
  XChangeProperty (dpy, RootWindow (dpy, s->screen_num),
                   _net_supported, XA_ATOM, 32, PropModeReplace,
                   (unsigned char*)&_net_wm_pid, 1);

  /* set window manager name */
  XChangeProperty (dpy, RootWindow (dpy, s->screen_num),
                   _net_wm_name, xa_utf8_string, 8, PropModeReplace,
                   (unsigned char*)"ratpoison", 9);
  XMapWindow (dpy, s->key_window);
}

void
deactivate_screen (rp_screen *s)
{
  /* Unmap its key window */
  XUnmapWindow (dpy, s->key_window);

  /* delete everything so noone sees them while we are not there */
  XDeleteProperty (dpy, RootWindow (dpy, s->screen_num),
                   _net_supported);
  XDeleteProperty (dpy, RootWindow (dpy, s->screen_num),
                   _net_wm_name);
}

static int
is_rp_window_for_given_screen (Window w, rp_screen *s)
{
  if (w != s->key_window &&
      w != s->bar_window &&
      w != s->input_window &&
      w != s->frame_window &&
      w != s->help_window)
    return 0;
  return 1;
}

int
is_rp_window (Window w)
{
  rp_screen *cur;

  list_for_each_entry (cur, &rp_screens, node)
    {
      if (is_rp_window_for_given_screen (w, cur))
        return 1;
    }

  return 0;
}

char *
screen_dump (rp_screen *screen)
{
  char *tmp;
  struct sbuf *s;

  s = sbuf_new (0);
  if (rp_have_xrandr)
    sbuf_printf(s, "%s ", sbuf_get (screen->xrandr.name));

  sbuf_printf_concat (s, "%d %d %d %d %d %d",
                      screen->number,
                      screen->left,
                      screen->top,
                      screen->width,
                      screen->height,
                      (rp_current_screen == screen)?1:0 /* is current? */
                      );

  /* Extract the string and return it, and don't forget to free s. */
  tmp = sbuf_get (s);
  free (s);
  return tmp;
}

int
screen_count (void)
{
  return list_size (&rp_screens);
}

rp_screen *
screen_next (void)
{
  return list_next_entry (rp_current_screen, &rp_screens, node);
}

rp_screen *
screen_prev (void)
{
  return list_prev_entry (rp_current_screen, &rp_screens, node);
}

static void
screen_remove_current (void)
{
  rp_screen *new_screen;
  rp_frame *new_frame;
  rp_window *cur_win;
  int cur_frame;

  cur_win = current_window ();
  new_screen = screen_next ();

  cur_frame = new_screen->current_frame;
  new_frame = screen_get_frame (new_screen, cur_frame);

  set_active_frame (new_frame, 1);

  hide_window (cur_win);
}

void
screen_update (rp_screen *s, int left, int top, int width, int height)
{
  rp_frame *f;
  int oldwidth, oldheight;

  PRINT_DEBUG (("screen_update (left=%d, top=%d, width=%d, height=%d)\n",
                left, top, width, height));

  if (s->width  == width  &&
      s->height == height &&
      s->left   == left   &&
      s->top    == top)
    /* nothing to do */
    return;

  oldwidth = s->width;
  oldheight = s->height;

  s->left = left;
  s->top = top;
  s->width = width;
  s->height = height;

  XMoveResizeWindow (dpy, s->help_window, s->left, s->top, s->width, s->height);

  list_for_each_entry (f, &s->frames, node)
    {
      f->x = (f->x*width)/oldwidth;
      f->width = (f->width*width)/oldwidth;
      f->y = (f->y*height)/oldheight;
      f->height = (f->height*height)/oldheight;
      maximize_all_windows_in_frame (f);
    }
}

rp_screen *
screen_add (int rr_output)
{
  rp_screen *screen;

  screen = xmalloc (sizeof(*screen));
  list_add (&screen->node, &rp_screens);

  screen->number = numset_request (rp_glob_screen.numset);

#ifdef HAVE_XRANDR
  if (rp_have_xrandr)
    xrandr_fill_screen (rr_output, screen);
#endif
  init_screen (screen);
  init_frame_list (screen);

  if (screen_count () == 1)
    {
      rp_current_screen = screen;
      change_windows_screen (NULL, rp_current_screen);
      set_window_focus (rp_current_screen->key_window);
    }

  return screen;
}

void
screen_del (rp_screen *s)
{
  if (s == rp_current_screen)
    {
      if (screen_count () == 1)
        {
          hide_screen_windows (s);
          rp_current_screen = NULL;
        }
      else
        {
          /*
           * The deleted screen cannot be the current screen anymore,
           * focus the next one.
           */
          screen_remove_current ();
        }
    }
  else
    {
      hide_screen_windows (s);
    }

  /* Affect window's screen backpointer to the new current screen */
  change_windows_screen (s, rp_current_screen);

  numset_release (rp_glob_screen.numset, s->number);

  screen_free (s);

  list_del (&s->node);
  free (s);
}

void
screen_free (rp_screen *s)
{
  rp_frame *frame;
  struct list_head *iter, *tmp;

  list_for_each_safe_entry (frame, iter, tmp, &s->frames, node)
    {
      frame_free (s, frame);
    }

  deactivate_screen(s);

  XDestroyWindow (dpy, s->bar_window);
  XDestroyWindow (dpy, s->key_window);
  XDestroyWindow (dpy, s->input_window);
  XDestroyWindow (dpy, s->frame_window);
  XDestroyWindow (dpy, s->help_window);

#ifdef USE_XFT_FONT
  if (s->xft_font)
    {
      XftColorFree (dpy, DefaultVisual (dpy, s->screen_num),
                    DefaultColormap (dpy, s->screen_num), &s->xft_fg_color);
      XftColorFree (dpy, DefaultVisual (dpy, s->screen_num),
                    DefaultColormap (dpy, s->screen_num), &s->xft_bg_color);
      XftFontClose (dpy, s->xft_font);
    }
#endif

  XFreeCursor (dpy, s->rat);
  XFreeColormap (dpy, s->def_cmap);
  XFreeGC (dpy, s->normal_gc);
  XFreeGC (dpy, s->inverse_gc);

  free (s->display_string);

  if (rp_have_xrandr)
    free (s->xrandr.name);
}

void
screen_free_final (void)
{
  /* Relinquish our hold on the root window. */
  XSelectInput(dpy, RootWindow (dpy, DefaultScreen (dpy)), 0);

  numset_free (rp_glob_screen.numset);
}