/*
  Copyright 2011-2020 David Robillard <http://drobilla.net>

  Permission to use, copy, modify, and/or distribute this software for any
  purpose with or without fee is hereby granted, provided that the above
  copyright notice and this permission notice appear in all copies.

  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

 SPDX-License-Identifier: ISC
*/

#include "zrythm-config.h"

#ifndef HAVE_SUIL

#  ifdef HAVE_X11

#    include <stdbool.h>
#    include <stdio.h>
#    include <stdlib.h>
#    include <string.h>

#    include <gtk/gtk.h>
#    include <gtk/gtkx.h>

#    include "lv2/options/options.h"
#    include "lv2/urid/urid.h"
#    include "suil/suil.h"
#    include <X11/Xatom.h>
#    include <gdk/gdkx.h>

#    define SUIL_X11_WRAPPER_TYPE (suil_x11_wrapper_get_type ())
#    define Z_SUIL_X11_WRAPPER(obj) \
      (G_TYPE_CHECK_INSTANCE_CAST ( \
        (obj), SUIL_X11_WRAPPER_TYPE, SuilX11Wrapper))

typedef struct
{
  bool is_set;
  int  width;
  int  height;
} SuilX11SizeHints;

typedef struct
{
  GtkSocket                    socket;
  GtkPlug *                    plug;
  SuilWrapper *                wrapper;
  SuilInstance *               instance;
  const LV2UI_Idle_Interface * idle_iface;
  guint                        idle_id;
  guint                        idle_ms;
  guint                        idle_size_request_id;
  SuilX11SizeHints             max_size;
  SuilX11SizeHints             custom_size;
  SuilX11SizeHints             base_size;
  SuilX11SizeHints             min_size;
  bool                         query_wm;
} SuilX11Wrapper;

typedef struct
{
  GtkSocketClass parent_class;
} SuilX11WrapperClass;

GType
suil_x11_wrapper_get_type (void); // Accessor for SUIL_TYPE_X11_WRAPPER

#    define SUIL_TYPE_X11_WRAPPER (suil_x11_wrapper_get_type ())
#    define SUIL_X11_WRAPPER(obj) \
      (G_TYPE_CHECK_INSTANCE_CAST ( \
        (obj), SUIL_TYPE_X11_WRAPPER, SuilX11Wrapper))

G_DEFINE_TYPE (SuilX11Wrapper, suil_x11_wrapper, GTK_TYPE_SOCKET)

/**
   Check if 'swallowed' subwindow is known to the X server.

   Gdk/GTK can mark the window as realized, mapped and visible even though
   there is no window-ID on the X server for it yet.  Then,
   suil_x11_on_size_allocate() will cause a "BadWinow" X error.
*/
static bool
x_window_is_valid (SuilX11Wrapper * socket)
{
  GdkWindow * window = gtk_widget_get_window (GTK_WIDGET (socket->plug));
  Window      root = 0;
  Window      parent = 0;
  Window *    children = NULL;
  unsigned    childcount = 0;

  XQueryTree (
    GDK_WINDOW_XDISPLAY (window), GDK_WINDOW_XID (window), &root, &parent,
    &children, &childcount);
  for (unsigned i = 0; i < childcount; ++i)
    {
      if (children[i] == (Window) socket->instance->ui_widget)
        {
          XFree (children);
          return true;
        }
    }

  XFree (children);
  return false;
}

static Window
get_parent_window (Display * display, Window child)
{
  Window   root = 0;
  Window   parent = 0;
  Window * children = NULL;
  unsigned count = 0;

  if (child)
    {
      if (XQueryTree (display, child, &root, &parent, &children, &count))
        {
          if (children)
            {
              XFree (children);
            }
        }
    }

  return (parent == root) ? 0 : parent;
}

static gboolean
on_plug_removed (GtkSocket * sock, gpointer data)
{
  (void) data;

  SuilX11Wrapper * const self = SUIL_X11_WRAPPER (sock);

  if (self->idle_id)
    {
      g_source_remove (self->idle_id);
      self->idle_id = 0;
    }

  if (self->idle_size_request_id)
    {
      g_source_remove (self->idle_size_request_id);
      self->idle_size_request_id = 0;
    }

  if (self->instance->handle)
    {
      self->instance->descriptor->cleanup (self->instance->handle);
      self->instance->handle = NULL;
    }

  self->plug = NULL;
  return TRUE;
}

static void
suil_x11_wrapper_finalize (GObject * gobject)
{
  SuilX11Wrapper * const self = SUIL_X11_WRAPPER (gobject);

  self->wrapper->impl = NULL;

  G_OBJECT_CLASS (suil_x11_wrapper_parent_class)->finalize (gobject);
}

static void
suil_x11_wrapper_realize (GtkWidget * w)
{
  SuilX11Wrapper * const wrap = SUIL_X11_WRAPPER (w);
  GtkSocket * const      socket = GTK_SOCKET (w);

  if (GTK_WIDGET_CLASS (suil_x11_wrapper_parent_class)->realize)
    {
      GTK_WIDGET_CLASS (suil_x11_wrapper_parent_class)->realize (w);
    }

  gtk_socket_add_id (socket, gtk_plug_get_id (wrap->plug));

  gtk_widget_realize (GTK_WIDGET (wrap->plug));

  gtk_widget_set_sensitive (GTK_WIDGET (wrap->plug), TRUE);
  gtk_widget_set_can_focus (GTK_WIDGET (wrap->plug), TRUE);
  gtk_widget_grab_focus (GTK_WIDGET (wrap->plug));

  // Setup drag/drop proxy from parent/grandparent window
  GdkWindow * gwindow = gtk_widget_get_window (GTK_WIDGET (wrap->plug));
  Window      xwindow = GDK_WINDOW_XID (gwindow);
  Atom        xdnd_proxy_atom = gdk_x11_get_xatom_by_name ("XdndProxy");
  Window      plugin = (Window) wrap->instance->ui_widget;

  while (xwindow)
    {
      XChangeProperty (
        GDK_WINDOW_XDISPLAY (gwindow), xwindow, xdnd_proxy_atom, XA_WINDOW, 32,
        PropModeReplace, (unsigned char *) &plugin, 1);

      xwindow = get_parent_window (GDK_WINDOW_XDISPLAY (gwindow), xwindow);
    }
}

static void
suil_x11_wrapper_show (GtkWidget * w)
{
  SuilX11Wrapper * const wrap = SUIL_X11_WRAPPER (w);

  if (GTK_WIDGET_CLASS (suil_x11_wrapper_parent_class)->show)
    {
      GTK_WIDGET_CLASS (suil_x11_wrapper_parent_class)->show (w);
    }

  gtk_widget_show (GTK_WIDGET (wrap->plug));
}

static gboolean
forward_key_event (SuilX11Wrapper * socket, GdkEvent * gdk_event)
{
  GdkWindow * window = gtk_widget_get_window (GTK_WIDGET (socket->plug));
  GdkScreen * screen = gdk_visual_get_screen (gdk_window_get_visual (window));

  Window target_window = 0;
  if (gdk_event->any.window == window)
    {
      // Event sent up to the plug window, forward it up to the parent
      GtkWidget * widget = GTK_WIDGET (socket->instance->host_widget);
      GdkWindow * parent = gtk_widget_get_parent_window (widget);
      if (parent)
        {
          target_window = GDK_WINDOW_XID (parent);
        }
      else
        {
          return FALSE; // Wrapper is a top-level window, do nothing
        }
    }
  else
    {
      // Event sent anywhere else, send to the plugin
      target_window = (Window) socket->instance->ui_widget;
    }

  XKeyEvent xev;
  memset (&xev, 0, sizeof (xev));
  xev.type = (gdk_event->type == GDK_KEY_PRESS) ? KeyPress : KeyRelease;
  xev.root = GDK_WINDOW_XID (gdk_screen_get_root_window (screen));
  xev.window = target_window;
  xev.subwindow = None;
  xev.time = gdk_event->key.time;
  xev.state = gdk_event->key.state;
  xev.keycode = gdk_event->key.hardware_keycode;

  XSendEvent (
    GDK_WINDOW_XDISPLAY (window), target_window, False, NoEventMask,
    (XEvent *) &xev);

  return (gdk_event->any.window != window);
}

static gboolean
idle_size_request (gpointer user_data)
{
  SuilX11Wrapper * socket = (SuilX11Wrapper *) user_data;
  GtkWidget *      w = GTK_WIDGET (socket->plug);
  gtk_widget_queue_resize (w);
  socket->idle_size_request_id = 0;
  return FALSE;
}

/// Read XSizeHints and store the values for later use
static void
query_wm_hints (SuilX11Wrapper * wrap)
{
  GdkWindow * window = gtk_widget_get_window (GTK_WIDGET (wrap->plug));
  XSizeHints  hints = { 0 };
  long        supplied = 0;

  XGetWMNormalHints (
    GDK_WINDOW_XDISPLAY (window), (Window) wrap->instance->ui_widget, &hints,
    &supplied);

  if (hints.flags & PMaxSize)
    {
      wrap->max_size.width = hints.max_width;
      wrap->max_size.height = hints.max_height;
      wrap->max_size.is_set = true;
    }

  if (hints.flags & PBaseSize)
    {
      wrap->base_size.width = hints.base_width;
      wrap->base_size.height = hints.base_height;
      wrap->base_size.is_set = true;
    }

  if (hints.flags & PMinSize)
    {
      wrap->min_size.width = hints.min_width;
      wrap->min_size.height = hints.min_height;
      wrap->min_size.is_set = true;
    }

  wrap->query_wm = false;
}

static void
forward_size_request (SuilX11Wrapper * socket, GtkAllocation * allocation)
{
  GdkWindow * window = gtk_widget_get_window (GTK_WIDGET (socket->plug));
  if (x_window_is_valid (socket))
    {
      // Calculate allocation size constrained to X11 limits for widget
      int        width = allocation->width;
      int        height = allocation->height;
      XSizeHints hints;
      memset (&hints, 0, sizeof (hints));
      XGetNormalHints (
        GDK_WINDOW_XDISPLAY (window), (Window) socket->instance->ui_widget,
        &hints);
      if (hints.flags & PMaxSize)
        {
          width = MIN (width, hints.max_width);
          height = MIN (height, hints.max_height);
        }
      if (hints.flags & PMinSize)
        {
          width = MAX (width, hints.min_width);
          height = MAX (height, hints.min_height);
        }

      // Resize widget window
      XResizeWindow (
        GDK_WINDOW_XDISPLAY (window), (Window) socket->instance->ui_widget,
        (unsigned) width, (unsigned) height);

      // Get actual widget geometry
      Window       root = 0;
      int          wx = 0;
      int          wy = 0;
      unsigned int ww = 0;
      unsigned int wh = 0;
      unsigned int ignored = 0;
      XGetGeometry (
        GDK_WINDOW_XDISPLAY (window), (Window) socket->instance->ui_widget,
        &root, &wx, &wy, &ww, &wh, &ignored, &ignored);

      // Center widget in allocation
      wx = (allocation->width - (int) ww) / 2;
      wy = (allocation->height - (int) wh) / 2;
      XMoveWindow (
        GDK_WINDOW_XDISPLAY (window), (Window) socket->instance->ui_widget, wx,
        wy);
    }
  else
    {
      /* Child has not been realized, so unable to resize now.
       Queue an idle resize. */
      socket->idle_size_request_id = g_idle_add (idle_size_request, socket);
    }
}

static gboolean
suil_x11_wrapper_key_event (GtkWidget * widget, GdkEventKey * event)
{
  SuilX11Wrapper * const self = SUIL_X11_WRAPPER (widget);

  if (self->plug)
    {
      return forward_key_event (self, (GdkEvent *) event);
    }

  return FALSE;
}

static void
suil_x11_wrapper_get_preferred_width (
  GtkWidget * widget,
  gint *      minimum_width,
  gint *      natural_width)
{
  SuilX11Wrapper * const self = SUIL_X11_WRAPPER (widget);
  if (x_window_is_valid (self))
    {
      query_wm_hints (self);

      if (self->custom_size.is_set)
        *natural_width = self->custom_size.width;
      else if (self->base_size.is_set)
        *natural_width = self->base_size.width;
      else if (self->min_size.is_set)
        *natural_width = self->min_size.width;
      else
        g_return_if_reached ();

      if (self->min_size.is_set)
        *minimum_width = self->min_size.width;
      else if (self->custom_size.is_set)
        *natural_width = self->base_size.width;
      else if (self->base_size.is_set)
        *natural_width = self->base_size.width;
      else
        g_return_if_reached ();
    }
}

static void
suil_x11_wrapper_get_preferred_height (
  GtkWidget * widget,
  gint *      minimum_height,
  gint *      natural_height)
{
  SuilX11Wrapper * const self = SUIL_X11_WRAPPER (widget);
  if (x_window_is_valid (self))
    {
      query_wm_hints (self);

      if (self->custom_size.is_set)
        *natural_height = self->custom_size.height;
      else if (self->base_size.is_set)
        *natural_height = self->base_size.height;
      else if (self->min_size.is_set)
        *natural_height = self->min_size.height;
      else
        g_return_if_reached ();

      if (self->min_size.is_set)
        *minimum_height = self->min_size.height;
      else if (self->custom_size.is_set)
        *natural_height = self->base_size.height;
      else if (self->base_size.is_set)
        *natural_height = self->base_size.height;
      else
        g_return_if_reached ();
    }
}

static void
suil_x11_on_size_allocate (GtkWidget * widget, GtkAllocation * a)
{
  SuilX11Wrapper * const self = SUIL_X11_WRAPPER (widget);

  if (
    self->plug && gtk_widget_get_realized (widget)
    && gtk_widget_get_mapped (widget) && gtk_widget_get_visible (widget))
    {
      forward_size_request (self, a);
    }
}

static void
suil_x11_wrapper_class_init (SuilX11WrapperClass * klass)
{
  GObjectClass * const   gobject_class = G_OBJECT_CLASS (klass);
  GtkWidgetClass * const widget_class = GTK_WIDGET_CLASS (klass);

  gobject_class->finalize = suil_x11_wrapper_finalize;
  widget_class->realize = suil_x11_wrapper_realize;
  widget_class->show = suil_x11_wrapper_show;
  widget_class->key_press_event = suil_x11_wrapper_key_event;
  widget_class->key_release_event = suil_x11_wrapper_key_event;
  widget_class->get_preferred_width = suil_x11_wrapper_get_preferred_width;
  widget_class->get_preferred_height = suil_x11_wrapper_get_preferred_height;
}

static void
suil_x11_wrapper_init (SuilX11Wrapper * self)
{
  self->plug = GTK_PLUG (gtk_plug_new (0));
  self->wrapper = NULL;
  self->instance = NULL;
  self->idle_iface = NULL;
  self->idle_ms = 1000 / 30; // 30 Hz default
  self->max_size = (SuilX11SizeHints){ false, 0, 0 };
  self->custom_size = (SuilX11SizeHints){ false, 0, 0 };
  self->base_size = (SuilX11SizeHints){ false, 0, 0 };
  self->min_size = (SuilX11SizeHints){ false, 0, 0 };
  self->query_wm = true;
}

static int
wrapper_resize (LV2UI_Feature_Handle handle, int width, int height)
{
  SuilX11Wrapper * const wrap = SUIL_X11_WRAPPER (handle);

  wrap->custom_size.width = width;
  wrap->custom_size.height = height;
  wrap->custom_size.is_set = width > 0 && height > 0;

  // Assume the plugin has also updated min/max size constraints
  wrap->query_wm = true;

  gtk_widget_queue_resize (GTK_WIDGET (handle));
  return 0;
}

static gboolean
suil_x11_wrapper_idle (void * data)
{
  SuilX11Wrapper * const wrap = SUIL_X11_WRAPPER (data);

  wrap->idle_iface->idle (wrap->instance->handle);

  return TRUE; // Continue calling
}

static int
wrapper_wrap (SuilWrapper * wrapper, SuilInstance * instance)
{
  SuilX11Wrapper * const wrap = SUIL_X11_WRAPPER (wrapper->impl);

  instance->host_widget = GTK_WIDGET (wrap);
  wrap->wrapper = wrapper;
  wrap->instance = instance;

  GdkWindow *  window = gtk_widget_get_window (GTK_WIDGET (wrap->plug));
  GdkDisplay * display = gdk_window_get_display (window);
  Display *    xdisplay = GDK_WINDOW_XDISPLAY (window);
  Window       xwindow = (Window) instance->ui_widget;

  gdk_display_sync (display);
  if (x_window_is_valid (wrap))
    {
      XWindowAttributes attrs;
      XGetWindowAttributes (xdisplay, xwindow, &attrs);

      query_wm_hints (wrap);

      if (!wrap->base_size.is_set)
        {
          // Fall back to using initial size as base size
          wrap->base_size.is_set = true;
          wrap->base_size.width = attrs.width;
          wrap->base_size.height = attrs.height;
        }
    }

  const LV2UI_Idle_Interface * idle_iface = NULL;
  if (instance->descriptor->extension_data)
    {
      idle_iface =
        (const LV2UI_Idle_Interface *) instance->descriptor->extension_data (
          LV2_UI__idleInterface);
    }

  if (idle_iface)
    {
      wrap->idle_iface = idle_iface;
      wrap->idle_id = g_timeout_add (wrap->idle_ms, suil_x11_wrapper_idle, wrap);
    }

  g_signal_connect (
    G_OBJECT (wrap), "plug-removed", G_CALLBACK (on_plug_removed), NULL);

  g_signal_connect (
    G_OBJECT (wrap), "size-allocate", G_CALLBACK (suil_x11_on_size_allocate),
    NULL);

  return 0;
}

static void
wrapper_free (SuilWrapper * wrapper)
{
  if (wrapper->impl)
    {
      SuilX11Wrapper * const wrap = SUIL_X11_WRAPPER (wrapper->impl);
      gtk_widget_destroy (GTK_WIDGET (wrap));
    }
}

SuilWrapper *
suil_wrapper_new_x11 (
  SuilHost *      host,
  const char *    host_type_uri,
  const char *    ui_type_uri,
  LV2_Feature *** features,
  unsigned        n_features)
{
  (void) host;
  (void) host_type_uri;
  (void) ui_type_uri;

  SuilWrapper * wrapper = (SuilWrapper *) calloc (1, sizeof (SuilWrapper));
  wrapper->wrap = wrapper_wrap;
  wrapper->free = wrapper_free;

  SuilX11Wrapper * const wrap =
    SUIL_X11_WRAPPER (g_object_new (SUIL_TYPE_X11_WRAPPER, NULL));

  wrapper->impl = wrap;
  wrapper->resize.handle = wrap;
  wrapper->resize.ui_resize = wrapper_resize;

  gtk_widget_set_sensitive (GTK_WIDGET (wrap), TRUE);
  gtk_widget_set_can_focus (GTK_WIDGET (wrap), TRUE);

  const intptr_t parent_id = (intptr_t) gtk_plug_get_id (wrap->plug);
  suil_add_feature (features, &n_features, LV2_UI__parent, (void *) parent_id);
  suil_add_feature (features, &n_features, LV2_UI__resize, &wrapper->resize);
  suil_add_feature (features, &n_features, LV2_UI__idleInterface, NULL);

  // Scan for URID map and options
  LV2_URID_Map *       map = NULL;
  LV2_Options_Option * options = NULL;
  for (LV2_Feature ** f = *features; *f && (!map || !options); ++f)
    {
      if (!strcmp ((*f)->URI, LV2_OPTIONS__options))
        {
          options = (LV2_Options_Option *) (*f)->data;
        }
      else if (!strcmp ((*f)->URI, LV2_URID__map))
        {
          map = (LV2_URID_Map *) (*f)->data;
        }
    }

  if (map && options)
    {
      // Set UI update rate if given
      LV2_URID ui_updateRate = map->map (map->handle, LV2_UI__updateRate);
      for (LV2_Options_Option * o = options; o->key; ++o)
        {
          if (o->key == ui_updateRate)
            {
              wrap->idle_ms = (guint) (1000.0f / *(const float *) o->value);
              break;
            }
        }
    }

  return wrapper;
}

#  endif /* ifdef HAVE X11 */

#endif /* ifndef HAVE_SUIL */
