#include "config.h"

#ifdef HAVE_LINUX_MEMFD_H
#include <linux/memfd.h>
#endif

#ifdef HAVE_SYS_MMAN_H
#include <sys/mman.h>
#endif
#include <sys/stat.h>
#include <fcntl.h>

#include "gdkbroadway-server.h"

#include "gdkprivate-broadway.h"
#include <gdk/gdktextureprivate.h>

#include <glib.h>
#include <glib/gprintf.h>
#include <gio/gunixsocketaddress.h>
#include <gio/gunixfdmessage.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#elif defined (G_OS_WIN32)
#include <io.h>
#define ftruncate _chsize_s
#endif
#include <sys/types.h>
#ifdef G_OS_WIN32
#include <windows.h>
#endif
#include "gdkintl.h"

typedef struct BroadwayInput BroadwayInput;

struct _GdkBroadwayServer {
  GObject parent_instance;
  GdkDisplay *display;

  guint32 next_serial;
  guint32 next_texture_id;
  GSocketConnection *connection;

  guint32 recv_buffer_size;
  guint8 recv_buffer[1024];

  guint process_input_idle;
  GList *incoming;
};

struct _GdkBroadwayServerClass
{
  GObjectClass parent_class;
};

static gboolean input_available_cb (gpointer stream, gpointer user_data);

static GType gdk_broadway_server_get_type (void);

G_DEFINE_TYPE (GdkBroadwayServer, gdk_broadway_server, G_TYPE_OBJECT)

static void
gdk_broadway_server_init (GdkBroadwayServer *server)
{
  server->next_serial = 1;
  server->next_texture_id = 1;
}

static void
gdk_broadway_server_finalize (GObject *object)
{
  G_OBJECT_CLASS (gdk_broadway_server_parent_class)->finalize (object);
}

static void
gdk_broadway_server_class_init (GdkBroadwayServerClass * class)
{
  GObjectClass *object_class = G_OBJECT_CLASS (class);

  object_class->finalize = gdk_broadway_server_finalize;
}

gboolean
_gdk_broadway_server_lookahead_event (GdkBroadwayServer  *server,
                                      const char         *types)
{
  return FALSE;
}

gulong
_gdk_broadway_server_get_next_serial (GdkBroadwayServer *server)
{
  return (gulong)server->next_serial;
}

GdkBroadwayServer *
_gdk_broadway_server_new (GdkDisplay *display,
                          const char *display_name,
                          GError **error)
{
  GdkBroadwayServer *server;
  GSocketClient *client;
  GSocketConnection *connection;
  GSocketAddress *address;
  GPollableInputStream *pollable;
  GInputStream *in;
  GSource *source;
  char *local_socket_type = NULL;
  int port;

  if (display_name == NULL)
    display_name = ":0";

  if (display_name[0] == ':' && g_ascii_isdigit(display_name[1]))
    {
      char *path, *basename;

      port = strtol (display_name + strlen (":"), NULL, 10);
      basename = g_strdup_printf ("broadway%d.socket", port + 1);
      path = g_build_filename (g_get_user_runtime_dir (), basename, NULL);
      g_free (basename);

      address = g_unix_socket_address_new_with_type (path, -1,
                                                     G_UNIX_SOCKET_ADDRESS_PATH);
      g_free (path);
    }
  else
    {
      g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
                   _("Broadway display type not supported: %s"), display_name);
      return NULL;
    }

  g_free (local_socket_type);

  client = g_socket_client_new ();

  connection = g_socket_client_connect (client, G_SOCKET_CONNECTABLE (address), NULL, error);

  g_object_unref (address);
  g_object_unref (client);

  if (connection == NULL)
    return NULL;

  server = g_object_new (GDK_TYPE_BROADWAY_SERVER, NULL);
  server->connection = connection;
  server->display = display;

  in = g_io_stream_get_input_stream (G_IO_STREAM (server->connection));
  pollable = G_POLLABLE_INPUT_STREAM (in);

  source = g_pollable_input_stream_create_source (pollable, NULL);
  g_source_attach (source, NULL);
  g_source_set_callback (source, (GSourceFunc)input_available_cb, server, NULL);

  return server;
}

static guint32
gdk_broadway_server_send_message_with_size (GdkBroadwayServer *server, BroadwayRequestBase *base,
                                            gsize size, guint32 type, int fd)
{
  GOutputStream *out;
  gsize written;
  guchar *buf;

  base->size = size;
  base->type = type;
  base->serial = server->next_serial++;

  buf = (guchar *)base;

  if (fd != -1)
    {
      GUnixFDList *fd_list = g_unix_fd_list_new_from_array (&fd, 1);
      GSocketControlMessage *control_message = g_unix_fd_message_new_with_fd_list (fd_list);
      GSocket *socket = g_socket_connection_get_socket (server->connection);
      GOutputVector vector;
      gssize bytes_written;

      vector.buffer = buf;
      vector.size = size;

      bytes_written = g_socket_send_message (socket,
                                             NULL, /* address */
                                             &vector,
                                             1,
                                             &control_message, 1,
                                             G_SOCKET_MSG_NONE,
                                             NULL,
                                             NULL);

      if (bytes_written <= 0)
        {
          g_printerr ("Unable to write to server\n");
          exit (1);
        }

      buf += bytes_written;
      size -= bytes_written;

      g_object_unref (control_message);
      g_object_unref (fd_list);
    }

  if (size > 0)
    {
      out = g_io_stream_get_output_stream (G_IO_STREAM (server->connection));
      if (!g_output_stream_write_all (out, buf, size, &written, NULL, NULL))
        {
          g_printerr ("Unable to write to server\n");
          exit (1);
        }

      g_assert (written == size);
    }


  return base->serial;
}

#define gdk_broadway_server_send_message(_server, _msg, _type) \
  gdk_broadway_server_send_message_with_size(_server, (BroadwayRequestBase *)&_msg, sizeof (_msg), _type, -1)

#define gdk_broadway_server_send_fd_message(_server, _msg, _type, _fd)      \
  gdk_broadway_server_send_message_with_size(_server, (BroadwayRequestBase *)&_msg, sizeof (_msg), _type, _fd)

static void
parse_all_input (GdkBroadwayServer *server)
{
  guint8 *p, *end;
  guint32 size;
  BroadwayReply *reply;

  p = server->recv_buffer;
  end = p + server->recv_buffer_size;

  while (p + sizeof (guint32) <= end)
    {
      memcpy (&size, p, sizeof (guint32));
      if (p + size > end)
        break;

      reply = g_memdup (p, size);
      p += size;

      server->incoming = g_list_append (server->incoming, reply);
    }

  if (p < end)
    memmove (server->recv_buffer, p, end - p);
  server->recv_buffer_size = end - p;
}

static void
read_some_input_blocking (GdkBroadwayServer *server)
{
  GInputStream *in;
  gssize res;

  in = g_io_stream_get_input_stream (G_IO_STREAM (server->connection));

  g_assert (server->recv_buffer_size < sizeof (server->recv_buffer));
  res = g_input_stream_read (in, &server->recv_buffer[server->recv_buffer_size],
                             sizeof (server->recv_buffer) - server->recv_buffer_size,
                             NULL, NULL);

  if (res <= 0)
    {
      g_printerr ("Unable to read from broadway server\n");
      exit (1);
    }

  server->recv_buffer_size += res;
}

static void
read_some_input_nonblocking (GdkBroadwayServer *server)
{
  GInputStream *in;
  GPollableInputStream *pollable;
  gssize res;
  GError *error;

  in = g_io_stream_get_input_stream (G_IO_STREAM (server->connection));
  pollable = G_POLLABLE_INPUT_STREAM (in);

  g_assert (server->recv_buffer_size < sizeof (server->recv_buffer));
  error = NULL;
  res = g_pollable_input_stream_read_nonblocking (pollable, &server->recv_buffer[server->recv_buffer_size],
                                                  sizeof (server->recv_buffer) - server->recv_buffer_size,
                                                  NULL, &error);

  if (res < 0 && g_error_matches (error, G_IO_ERROR, G_IO_ERROR_WOULD_BLOCK))
    {
      g_error_free (error);
      res = 0;
    }
  else if (res <= 0)
    {
      g_printerr ("Unable to read from broadway server: %s\n", error ? error->message : "eof");
      exit (1);
    }

  server->recv_buffer_size += res;
}

static BroadwayReply *
find_response_by_serial (GdkBroadwayServer *server, guint32 serial)
{
  GList *l;

  for (l = server->incoming; l != NULL; l = l->next)
    {
      BroadwayReply *reply = l->data;

      if (reply->base.in_reply_to == serial)
        return reply;
    }

  return NULL;
}

static void
process_input_messages (GdkBroadwayServer *server)
{
  BroadwayReply *reply;

  if (server->process_input_idle != 0)
    {
      g_source_remove (server->process_input_idle);
      server->process_input_idle = 0;
    }

  while (server->incoming)
    {
      reply = server->incoming->data;
      server->incoming =
        g_list_delete_link (server->incoming,
                            server->incoming);

      if (reply->base.type == BROADWAY_REPLY_EVENT)
        _gdk_broadway_events_got_input (server->display, &reply->event.msg);
      else
        g_warning ("Unhandled reply type %d", reply->base.type);
      g_free (reply);
    }
}

static gboolean
process_input_idle_cb (GdkBroadwayServer *server)
{
  server->process_input_idle = 0;
  process_input_messages (server);
  return G_SOURCE_REMOVE;
}

static void
queue_process_input_at_idle (GdkBroadwayServer *server)
{
  if (server->process_input_idle == 0)
    server->process_input_idle =
      g_idle_add_full (G_PRIORITY_DEFAULT, (GSourceFunc)process_input_idle_cb, server, NULL);
}

static gboolean
input_available_cb (gpointer stream, gpointer user_data)
{
  GdkBroadwayServer *server = user_data;

  read_some_input_nonblocking (server);
  parse_all_input (server);

  process_input_messages (server);

  return G_SOURCE_CONTINUE;
}

static BroadwayReply *
gdk_broadway_server_wait_for_reply (GdkBroadwayServer *server,
                                    guint32 serial)
{
  BroadwayReply *reply;

  while (TRUE)
    {
      reply = find_response_by_serial (server, serial);
      if (reply)
        {
          server->incoming = g_list_remove (server->incoming, reply);
          break;
        }

      read_some_input_blocking (server);
      parse_all_input (server);
    }

  queue_process_input_at_idle (server);
  return reply;
}

void
_gdk_broadway_server_flush (GdkBroadwayServer *server)
{
  BroadwayRequestFlush msg;

  gdk_broadway_server_send_message (server, msg, BROADWAY_REQUEST_FLUSH);
}

void
_gdk_broadway_server_sync (GdkBroadwayServer *server)
{
  BroadwayRequestSync msg;
  guint32 serial;
  BroadwayReply *reply;

  serial = gdk_broadway_server_send_message (server, msg,
                                             BROADWAY_REQUEST_SYNC);
  reply = gdk_broadway_server_wait_for_reply (server, serial);

  g_assert (reply->base.type == BROADWAY_REPLY_SYNC);

  g_free (reply);

  return;
}

void
_gdk_broadway_server_roundtrip (GdkBroadwayServer *server,
                                gint32            id,
                                guint32           tag)
{
  BroadwayRequestRoundtrip msg;

  msg.id = id;
  msg.tag = tag;
  gdk_broadway_server_send_message (server, msg,
                                    BROADWAY_REQUEST_ROUNDTRIP);
}

void
_gdk_broadway_server_query_mouse (GdkBroadwayServer *server,
                                  guint32            *surface,
                                  gint32             *root_x,
                                  gint32             *root_y,
                                  guint32            *mask)
{
  BroadwayRequestQueryMouse msg;
  guint32 serial;
  BroadwayReply *reply;

  serial = gdk_broadway_server_send_message (server, msg,
                                             BROADWAY_REQUEST_QUERY_MOUSE);
  reply = gdk_broadway_server_wait_for_reply (server, serial);

  g_assert (reply->base.type == BROADWAY_REPLY_QUERY_MOUSE);

  if (surface)
    *surface = reply->query_mouse.surface;
  if (root_x)
    *root_x = reply->query_mouse.root_x;
  if (root_y)
    *root_y = reply->query_mouse.root_y;
  if (mask)
    *mask = reply->query_mouse.mask;

  g_free (reply);
}

guint32
_gdk_broadway_server_new_surface (GdkBroadwayServer *server,
                                 int x,
                                 int y,
                                 int width,
                                 int height)
{
  BroadwayRequestNewSurface msg;
  guint32 serial, id;
  BroadwayReply *reply;

  msg.x = x;
  msg.y = y;
  msg.width = width;
  msg.height = height;
  serial = gdk_broadway_server_send_message (server, msg,
                                             BROADWAY_REQUEST_NEW_SURFACE);
  reply = gdk_broadway_server_wait_for_reply (server, serial);

  g_assert (reply->base.type == BROADWAY_REPLY_NEW_SURFACE);

  id = reply->new_surface.id;

  g_free (reply);

  return id;
}

void
_gdk_broadway_server_destroy_surface (GdkBroadwayServer *server,
                                     int id)
{
  BroadwayRequestDestroySurface msg;

  msg.id = id;
  gdk_broadway_server_send_message (server, msg,
                                    BROADWAY_REQUEST_DESTROY_SURFACE);
}

gboolean
_gdk_broadway_server_surface_show (GdkBroadwayServer *server,
                                  int id)
{
  BroadwayRequestShowSurface msg;

  msg.id = id;
  gdk_broadway_server_send_message (server, msg,
                                    BROADWAY_REQUEST_SHOW_SURFACE);

  return TRUE;
}

gboolean
_gdk_broadway_server_surface_hide (GdkBroadwayServer *server,
                                  int id)
{
  BroadwayRequestHideSurface msg;

  msg.id = id;
  gdk_broadway_server_send_message (server, msg,
                                    BROADWAY_REQUEST_HIDE_SURFACE);

  return TRUE;
}

void
_gdk_broadway_server_surface_focus (GdkBroadwayServer *server,
                                   int id)
{
  BroadwayRequestFocusSurface msg;

  msg.id = id;
  gdk_broadway_server_send_message (server, msg,
                                    BROADWAY_REQUEST_FOCUS_SURFACE);
}

void
_gdk_broadway_server_surface_set_transient_for (GdkBroadwayServer *server,
                                               int id, int parent)
{
  BroadwayRequestSetTransientFor msg;

  msg.id = id;
  msg.parent = parent;
  gdk_broadway_server_send_message (server, msg,
                                    BROADWAY_REQUEST_SET_TRANSIENT_FOR);
}

static int
open_shared_memory (void)
{
  static gboolean force_shm_open = FALSE;
  int ret = -1;

#if !defined (__NR_memfd_create)
  force_shm_open = TRUE;
#endif

  do
    {
#if defined (__NR_memfd_create)
      if (!force_shm_open)
        {
          ret = syscall (__NR_memfd_create, "gdk-broadway", MFD_CLOEXEC);

          /* fall back to shm_open until debian stops shipping 3.16 kernel
           * See bug 766341
           */
          if (ret < 0 && errno == ENOSYS)
            force_shm_open = TRUE;
        }
#endif

      if (force_shm_open)
        {
          char name[NAME_MAX - 1] = "";

          sprintf (name, "/gdk-broadway-%x", g_random_int ());

          ret = shm_open (name, O_CREAT | O_EXCL | O_RDWR | O_CLOEXEC, 0600);

          if (ret >= 0)
            shm_unlink (name);
          else if (errno == EEXIST)
            continue;
        }
    }
  while (ret < 0 && errno == EINTR);

  if (ret < 0)
    g_critical (G_STRLOC ": creating shared memory file (using %s) failed: %m",
                force_shm_open? "shm_open" : "memfd_create");

  return ret;
}

typedef struct {
  int fd;
  gsize size;
} PngData;

static cairo_status_t
write_png_cb (void         *closure,
              const guchar *data,
              unsigned int  length)
{
  PngData *png_data = closure;
  int fd = png_data->fd;

  while (length)
    {
      gssize ret = write (fd, data, length);

      if (ret <= 0)
        return CAIRO_STATUS_WRITE_ERROR;

      png_data->size += ret;
      length -= ret;
      data += ret;
    }

  return CAIRO_STATUS_SUCCESS;
}

guint32
gdk_broadway_server_upload_texture (GdkBroadwayServer *server,
                                    GdkTexture        *texture)
{
  guint32 id;
  cairo_surface_t *surface = gdk_texture_download_surface (texture);
  BroadwayRequestUploadTexture msg;
  PngData data;

  id = server->next_texture_id++;

  data.fd = open_shared_memory ();
  data.size = 0;
  cairo_surface_write_to_png_stream (surface, write_png_cb, &data);

  msg.id = id;
  msg.offset = 0;
  msg.size = data.size;

  /* This passes ownership of fd */
  gdk_broadway_server_send_fd_message (server, msg,
                                       BROADWAY_REQUEST_UPLOAD_TEXTURE, data.fd);

  return id;
}


void
gdk_broadway_server_release_texture (GdkBroadwayServer *server,
                                     guint32            id)
{
  BroadwayRequestReleaseTexture msg;

  msg.id = id;

  gdk_broadway_server_send_message (server, msg,
                                    BROADWAY_REQUEST_RELEASE_TEXTURE);
}

void
gdk_broadway_server_surface_set_nodes (GdkBroadwayServer *server,
                                      guint32 id,
                                      GArray *nodes)
{
  gsize size = sizeof(BroadwayRequestSetNodes) + sizeof(guint32) * (nodes->len - 1);
  BroadwayRequestSetNodes *msg = g_alloca (size);
  int i;

  for (i = 0; i < nodes->len; i++)
    msg->data[i] = g_array_index (nodes, guint32, i);

  msg->id = id;
  gdk_broadway_server_send_message_with_size (server, (BroadwayRequestBase *) msg, size, BROADWAY_REQUEST_SET_NODES, -1);
}

gboolean
_gdk_broadway_server_surface_move_resize (GdkBroadwayServer *server,
                                         int id,
                                         gboolean with_move,
                                         int x,
                                         int y,
                                         int width,
                                         int height)
{
  BroadwayRequestMoveResize msg;

  msg.id = id;
  msg.with_move = with_move;
  msg.x = x;
  msg.y = y;
  msg.width = width;
  msg.height = height;

  gdk_broadway_server_send_message (server, msg,
                                    BROADWAY_REQUEST_MOVE_RESIZE);

  return TRUE;
}

GdkGrabStatus
_gdk_broadway_server_grab_pointer (GdkBroadwayServer *server,
                                   int id,
                                   gboolean owner_events,
                                   guint32 event_mask,
                                   guint32 time_)
{
  BroadwayRequestGrabPointer msg;
  guint32 serial, status;
  BroadwayReply *reply;

  msg.id = id;
  msg.owner_events = owner_events;
  msg.event_mask = event_mask;
  msg.time_ = time_;

  serial = gdk_broadway_server_send_message (server, msg,
                                             BROADWAY_REQUEST_GRAB_POINTER);
  reply = gdk_broadway_server_wait_for_reply (server, serial);

  g_assert (reply->base.type == BROADWAY_REPLY_GRAB_POINTER);

  status = reply->grab_pointer.status;

  g_free (reply);

  return status;
}

guint32
_gdk_broadway_server_ungrab_pointer (GdkBroadwayServer *server,
                                     guint32    time_)
{
  BroadwayRequestUngrabPointer msg;
  guint32 serial, status;
  BroadwayReply *reply;

  msg.time_ = time_;

  serial = gdk_broadway_server_send_message (server, msg,
                                             BROADWAY_REQUEST_UNGRAB_POINTER);
  reply = gdk_broadway_server_wait_for_reply (server, serial);

  g_assert (reply->base.type == BROADWAY_REPLY_UNGRAB_POINTER);

  status = reply->ungrab_pointer.status;

  g_free (reply);

  return status;
}

void
_gdk_broadway_server_set_show_keyboard (GdkBroadwayServer *server,
                                        gboolean show)
{
  BroadwayRequestSetShowKeyboard msg;

  msg.show_keyboard = show;
  gdk_broadway_server_send_message (server, msg,
                                    BROADWAY_REQUEST_SET_SHOW_KEYBOARD);
}