/*
 * Copyright (C) 2021 Purism SPC
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 * Author: Guido Günther <agx@sigxcpu.org>
 */

#define G_LOG_DOMAIN "CallsDBusMmanager"

#include "config.h"
#include "calls-call.h"
#include "calls-call-dbus.h"
#include "calls-dbus-manager.h"
#include "calls-manager.h"

/**
 * SECTION:calls-dbus-manager
 * @short_description: Manages the Call DBus interface
 * @Title: CallsCallDBusManager
 *
 * The #CallsCallManager is responsible for exposing the
 * call objects on the session bus using #GDBusObjectManager.
 *
 * Call objects are exported like /org/gnome/Calls/ as
 * /org/gnome/Calls/Call/1, /org/gnome/Calls/Call/2, … using
 * org.freedesktop.DBus.ObjectManager.
 */

typedef struct _CallsDBusManager {
  GObject                   parent;

  GDBusObjectManagerServer *object_manager;

  guint                     iface_num;
  GListStore               *objs;
  char                     *object_path;
} CallsDBusManager;


G_DEFINE_TYPE (CallsDBusManager, calls_dbus_manager, G_TYPE_OBJECT);

static char *
get_obj_path (CallsDBusManager *self, guint num)
{
  return g_strdup_printf ("%s/Call/%u", self->object_path, num);
}


static CallsDBusObjectSkeleton *
find_call (CallsDBusManager *self, CallsCall *call, int *pos)
{
  CallsDBusObjectSkeleton *found = NULL;

  g_return_val_if_fail (CALLS_IS_CALL (call), NULL);

  for (int i = 0; i >= 0; i++) {
    g_autoptr (CallsDBusObjectSkeleton) item = g_list_model_get_item (G_LIST_MODEL (self->objs), i);

    if (!item)
      break;

    if (call == g_object_get_data (G_OBJECT (item), "call")) {
      *pos = i;
      found = item;
      break;
    }
  }

  return found;
}


static gboolean
on_handle_call_accept (CallsDBusCallsCall    *skeleton,
                       GDBusMethodInvocation *invocation,
                       CallsCall             *call)
{
  g_return_val_if_fail (CALLS_DBUS_IS_CALLS_CALL (skeleton), FALSE);
  g_return_val_if_fail (CALLS_IS_CALL (call), FALSE);

  calls_call_answer (call);

  calls_dbus_calls_call_complete_accept (skeleton, invocation);
  return TRUE;
}


static gboolean
on_handle_call_hangup (CallsDBusCallsCall    *skeleton,
                       GDBusMethodInvocation *invocation,
                       CallsCall             *call)
{
  g_return_val_if_fail (CALLS_DBUS_IS_CALLS_CALL (skeleton), FALSE);
  g_return_val_if_fail (CALLS_IS_CALL (call), FALSE);

  calls_call_hang_up (call);

  calls_dbus_calls_call_complete_hangup (skeleton, invocation);
  return TRUE;
}


static void
call_added_cb (CallsDBusManager *self, CallsCall *call)
{
  g_autofree char *path = NULL;
  g_autoptr (GError) error = NULL;
  g_autoptr (CallsDBusObjectSkeleton) object = NULL;
  g_autoptr (CallsDBusCallsCall) iface = NULL;

  path = get_obj_path (self, self->iface_num++);
  object = calls_dbus_object_skeleton_new (path);
  iface = calls_dbus_calls_call_skeleton_new ();
  g_dbus_object_skeleton_add_interface (G_DBUS_OBJECT_SKELETON (object),
                                        G_DBUS_INTERFACE_SKELETON (iface));
  g_object_set_data_full (G_OBJECT (object), "call", g_object_ref (call), g_object_unref);

  g_object_connect (iface,
                    "object_signal::handle-accept", G_CALLBACK (on_handle_call_accept), call,
                    "object_signal::handle-hangup", G_CALLBACK (on_handle_call_hangup), call,
                    NULL);

  g_object_bind_property (call, "state", iface, "state", G_BINDING_SYNC_CREATE);
  g_object_bind_property (call, "inbound", iface, "inbound", G_BINDING_SYNC_CREATE);
  g_object_bind_property (call, "number", iface, "id", G_BINDING_SYNC_CREATE);

  /* Export with properties bound to reduce DBus traffic: */
  g_debug ("Exporting %p at %s", call, path);
  g_dbus_object_manager_server_export (self->object_manager, G_DBUS_OBJECT_SKELETON (object));

  g_list_store_append (self->objs, g_steal_pointer (&object));
}


static void
call_removed_cb (CallsDBusManager *self, CallsCall *call)
{
  const char *path = NULL;
  CallsDBusObjectSkeleton *obj = NULL;
  gint pos = -1;

  g_debug ("Call %p removed", call);

  obj = find_call (self, call, &pos);
  g_return_if_fail (CALLS_DBUS_IS_OBJECT (obj));

  path = g_dbus_object_get_object_path (G_DBUS_OBJECT (obj));
  g_dbus_object_manager_server_unexport (self->object_manager, path);

  g_list_store_remove (self->objs, pos);
}


static void
calls_dbus_manager_constructed (GObject *object)
{
  g_autoptr (GList) calls = NULL;
  GList *c;
  CallsDBusManager *self = CALLS_DBUS_MANAGER (object);

  G_OBJECT_CLASS (calls_dbus_manager_parent_class)->constructed (object);

  self->objs = g_list_store_new (CALLS_DBUS_TYPE_OBJECT_SKELETON);

  g_signal_connect_swapped (calls_manager_get_default (),
                            "call-add",
                            G_CALLBACK (call_added_cb),
                            self);

  g_signal_connect_swapped (calls_manager_get_default (),
                            "call-remove",
                            G_CALLBACK (call_removed_cb),
                            self);
  calls = calls_manager_get_calls (calls_manager_get_default ());
  for (c = calls; c != NULL; c = c->next) {
    call_added_cb (self, c->data);
  }
}


static void
calls_dbus_manager_dispose (GObject *object)
{
  CallsDBusManager *self = CALLS_DBUS_MANAGER (object);

  if (self->objs) {
    for (int i = 0; i >= 0; i++) {
      const char *path;
      g_autoptr (CallsDBusObjectSkeleton) obj = g_list_model_get_item (G_LIST_MODEL (self->objs), i);

      if (!obj)
        break;

      path = g_dbus_object_get_object_path (G_DBUS_OBJECT (obj));
      g_dbus_object_manager_server_unexport (self->object_manager, path);
    }
  }
  g_clear_object (&self->objs);
  g_clear_object (&self->object_manager);
  g_clear_pointer (&self->object_path, g_free);

  G_OBJECT_CLASS (calls_dbus_manager_parent_class)->dispose (object);
}


static void
calls_dbus_manager_class_init (CallsDBusManagerClass *klass)
{
  GObjectClass *object_class = G_OBJECT_CLASS (klass);

  object_class->constructed = calls_dbus_manager_constructed;
  object_class->dispose = calls_dbus_manager_dispose;
}


static void
calls_dbus_manager_init (CallsDBusManager *self)
{
  self->iface_num = 1;
}


CallsDBusManager *
calls_dbus_manager_new (void)
{
  return g_object_new (CALLS_TYPE_DBUS_MANAGER, NULL);
}


gboolean
calls_dbus_manager_register (CallsDBusManager *self,
                             GDBusConnection  *connection,
                             const char       *object_path,
                             GError          **error)
{
  g_return_val_if_fail (CALLS_IS_DBUS_MANAGER (self), FALSE);

  self->object_path = g_strdup (object_path);
  g_debug ("Registering at %s", self->object_path);
  self->object_manager = g_dbus_object_manager_server_new (object_path);
  g_dbus_object_manager_server_set_connection (self->object_manager, connection);

  return TRUE;
}