/* Pinos
 * Copyright (C) 2015 Wim Taymans <wim.taymans@gmail.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#include "client/pinos.h"

#include "client/context.h"
#include "client/enumtypes.h"
#include "client/subscribe.h"

#include "client/private.h"

#define PINOS_CONTEXT_GET_PRIVATE(obj)  \
   (G_TYPE_INSTANCE_GET_PRIVATE ((obj), PINOS_TYPE_CONTEXT, PinosContextPrivate))

G_DEFINE_TYPE (PinosContext, pinos_context, G_TYPE_OBJECT);

static void subscription_state (GObject *object, GParamSpec *pspec, gpointer user_data);
static void subscription_cb (PinosSubscribe         *subscribe,
                             PinosSubscriptionEvent  event,
                             PinosSubscriptionFlags  flags,
                             GDBusProxy             *object,
                             gpointer                user_data);

enum
{
  PROP_0,
  PROP_MAIN_CONTEXT,
  PROP_NAME,
  PROP_PROPERTIES,
  PROP_STATE,
  PROP_CONNECTION,
  PROP_SUBSCRIPTION_MASK,
};

enum
{
  SIGNAL_SUBSCRIPTION_EVENT,
  LAST_SIGNAL
};

static guint signals[LAST_SIGNAL] = { 0 };

static void
pinos_context_get_property (GObject    *_object,
                            guint       prop_id,
                            GValue     *value,
                            GParamSpec *pspec)
{
  PinosContext *context = PINOS_CONTEXT (_object);
  PinosContextPrivate *priv = context->priv;

  switch (prop_id) {
    case PROP_MAIN_CONTEXT:
      g_value_set_boxed (value, priv->context);
      break;

    case PROP_NAME:
      g_value_set_string (value, priv->name);
      break;

    case PROP_PROPERTIES:
      g_value_set_variant (value, priv->properties);
      break;

    case PROP_STATE:
      g_value_set_enum (value, priv->state);
      break;

    case PROP_CONNECTION:
      g_value_set_object (value, priv->connection);
      break;

    case PROP_SUBSCRIPTION_MASK:
      g_value_set_flags (value, priv->subscription_mask);
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (context, prop_id, pspec);
      break;
  }
}

static void
pinos_context_set_property (GObject      *_object,
                            guint         prop_id,
                            const GValue *value,
                            GParamSpec   *pspec)
{
  PinosContext *context = PINOS_CONTEXT (_object);
  PinosContextPrivate *priv = context->priv;

  switch (prop_id) {
    case PROP_MAIN_CONTEXT:
      priv->context = g_value_dup_boxed (value);
      break;

    case PROP_NAME:
      g_free (priv->name);
      priv->name = g_value_dup_string (value);
      break;

    case PROP_PROPERTIES:
      if (priv->properties)
        g_variant_unref (priv->properties);
      priv->properties = g_value_dup_variant (value);
      break;

    case PROP_SUBSCRIPTION_MASK:
      priv->subscription_mask = g_value_get_flags (value);
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (context, prop_id, pspec);
      break;
  }
}

static void
pinos_context_finalize (GObject * object)
{
  PinosContext *context = PINOS_CONTEXT (object);
  PinosContextPrivate *priv = context->priv;

  g_clear_pointer (&priv->context, g_main_context_unref);
  g_free (priv->name);
  if (priv->properties)
    g_variant_unref (priv->properties);

  g_clear_object (&priv->subscribe);
  g_clear_error (&priv->error);

  G_OBJECT_CLASS (pinos_context_parent_class)->finalize (object);
}

static void
pinos_context_class_init (PinosContextClass * klass)
{
  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);

  g_type_class_add_private (klass, sizeof (PinosContextPrivate));

  gobject_class->finalize = pinos_context_finalize;
  gobject_class->set_property = pinos_context_set_property;
  gobject_class->get_property = pinos_context_get_property;

  /**
   * PinosContext:main-context
   *
   * The main context to use
   */
  g_object_class_install_property (gobject_class,
                                   PROP_MAIN_CONTEXT,
                                   g_param_spec_boxed ("main-context",
                                                       "Main Context",
                                                       "The main context to use",
                                                       G_TYPE_MAIN_CONTEXT,
                                                       G_PARAM_READWRITE |
                                                       G_PARAM_CONSTRUCT_ONLY |
                                                       G_PARAM_STATIC_STRINGS));
  /**
   * PinosContext:name
   *
   * The application name of the context.
   */
  g_object_class_install_property (gobject_class,
                                   PROP_NAME,
                                   g_param_spec_string ("name",
                                                        "Name",
                                                        "The application name",
                                                        NULL,
                                                        G_PARAM_READWRITE |
                                                        G_PARAM_STATIC_STRINGS));
  /**
   * PinosContext:properties
   *
   * Properties of the context.
   */
  g_object_class_install_property (gobject_class,
                                   PROP_PROPERTIES,
                                   g_param_spec_variant ("properties",
                                                         "Properties",
                                                         "Extra properties",
                                                          G_VARIANT_TYPE_DICTIONARY,
                                                          NULL,
                                                          G_PARAM_READWRITE |
                                                          G_PARAM_STATIC_STRINGS));
  /**
   * PinosContext:state
   *
   * The state of the context.
   */
  g_object_class_install_property (gobject_class,
                                   PROP_STATE,
                                   g_param_spec_enum ("state",
                                                      "State",
                                                      "The context state",
                                                      PINOS_TYPE_CONTEXT_STATE,
                                                      PINOS_CONTEXT_STATE_UNCONNECTED,
                                                      G_PARAM_READABLE |
                                                      G_PARAM_STATIC_STRINGS));
  /**
   * PinosContext:connection
   *
   * The connection of the context.
   */
  g_object_class_install_property (gobject_class,
                                   PROP_CONNECTION,
                                   g_param_spec_object ("connection",
                                                        "Connection",
                                                        "The DBus connection",
                                                        G_TYPE_DBUS_CONNECTION,
                                                        G_PARAM_READABLE |
                                                        G_PARAM_STATIC_STRINGS));
  /**
   * PinosContext:subscription-mask
   *
   * The subscription mask
   */
  g_object_class_install_property (gobject_class,
                                   PROP_SUBSCRIPTION_MASK,
                                   g_param_spec_flags ("subscription-mask",
                                                       "Subscription Mask",
                                                       "The object to receive subscription events of",
                                                       PINOS_TYPE_SUBSCRIPTION_FLAGS,
                                                       0,
                                                       G_PARAM_READWRITE |
                                                       G_PARAM_STATIC_STRINGS));
  /**
   * PinosContext:subscription-event
   * @subscribe: The #PinosContext emitting the signal.
   * @event: A #PinosSubscriptionEvent
   * @flags: #PinosSubscriptionFlags indicating the object
   * @object: the GDBusProxy object
   *
   * Notify about a new object that was added/removed/modified.
   */
  signals[SIGNAL_SUBSCRIPTION_EVENT] = g_signal_new ("subscription-event",
                                                     G_TYPE_FROM_CLASS (klass),
                                                     G_SIGNAL_RUN_LAST,
                                                     0,
                                                     NULL,
                                                     NULL,
                                                     g_cclosure_marshal_generic,
                                                     G_TYPE_NONE,
                                                     3,
                                                     PINOS_TYPE_SUBSCRIPTION_EVENT,
                                                     PINOS_TYPE_SUBSCRIPTION_FLAGS,
                                                     G_TYPE_DBUS_PROXY);

}

static void
pinos_context_init (PinosContext * context)
{
  PinosContextPrivate *priv = context->priv = PINOS_CONTEXT_GET_PRIVATE (context);

  priv->state = PINOS_CONTEXT_STATE_UNCONNECTED;
  priv->subscribe = pinos_subscribe_new ();
  g_object_set (priv->subscribe, "subscription-mask", PINOS_SUBSCRIPTION_FLAGS_ALL, NULL);
  g_signal_connect (priv->subscribe, "subscription-event", (GCallback) subscription_cb, context);
  g_signal_connect (priv->subscribe, "notify::state", (GCallback) subscription_state, context);
}

/**
 * pinos_context_new:
 * @name: an application name
 * @properties: optional properties
 *
 * Make a new unconnected #PinosContext
 *
 * Returns: a new unconnected #PinosContext
 */
PinosContext *
pinos_context_new (GMainContext *context,
                   const gchar  *name,
                   GVariant     *properties)
{
  g_return_val_if_fail (name != NULL, NULL);

  if (properties == NULL) {
    GVariantBuilder builder;

    g_variant_builder_init (&builder, G_VARIANT_TYPE ("a{sv}"));
    g_variant_builder_add (&builder, "{sv}", "name", g_variant_new_string (name));
    properties = g_variant_builder_end (&builder);
  }
  return g_object_new (PINOS_TYPE_CONTEXT, "main-context", context, "name", name, "properties", properties, NULL);
}

static gboolean
do_notify_state (PinosContext *context)
{
  g_object_notify (G_OBJECT (context), "state");
  g_object_unref (context);
  return FALSE;
}

static void
context_set_state (PinosContext      *context,
                   PinosContextState  state)
{
  if (context->priv->state != state) {
    context->priv->state = state;
    g_main_context_invoke (context->priv->context,
                           (GSourceFunc) do_notify_state,
                           g_object_ref (context));
  }
}
static void
on_client_proxy (GObject      *source_object,
                 GAsyncResult *res,
                 gpointer      user_data)
{
  PinosContext *context = user_data;
  PinosContextPrivate *priv = context->priv;
  GError *error = NULL;

  priv->client = pinos_subscribe_get_proxy_finish (priv->subscribe,
                                                res,
                                                &error);
  if (priv->client == NULL)
    goto client_failed;

  context_set_state (context, PINOS_CONTEXT_STATE_READY);

  return;

client_failed:
  {
    priv->error = error;
    context_set_state (context, PINOS_STREAM_STATE_ERROR);
    g_warning ("failed to get client proxy: %s", error->message);
    return;
  }
}

static void
on_client_connected (GObject      *source_object,
                     GAsyncResult *res,
                     gpointer      user_data)
{
  PinosContext *context = user_data;
  PinosContextPrivate *priv = context->priv;
  GVariant *ret;
  GError *error = NULL;
  const gchar *client_path;

  ret = g_dbus_proxy_call_finish (priv->daemon, res, &error);
  if (ret == NULL) {
    g_warning ("failed to connect client: %s", error->message);
    priv->error = error;
    context_set_state (context, PINOS_CONTEXT_STATE_ERROR);
    return;
  }

  g_variant_get (ret, "(&o)", &client_path);

  pinos_subscribe_get_proxy (priv->subscribe,
                          PINOS_DBUS_SERVICE,
                          client_path,
                          "org.pinos.Client1",
                          NULL,
                          on_client_proxy,
                          context);
  g_variant_unref (ret);
}

static void
on_daemon_connected (GObject      *source_object,
                     GAsyncResult *res,
                     gpointer      user_data)
{
  PinosContext *context = user_data;
  PinosContextPrivate *priv = context->priv;

  context_set_state (context, PINOS_CONTEXT_STATE_REGISTERING);

  g_dbus_proxy_call (priv->daemon,
                     "ConnectClient",
                     g_variant_new ("(@a{sv})", priv->properties),
                     G_DBUS_CALL_FLAGS_NONE,
                     -1,
                     NULL,
                     on_client_connected,
                     context);
}

static void
subscription_cb (PinosSubscribe         *subscribe,
                 PinosSubscriptionEvent  event,
                 PinosSubscriptionFlags  flags,
                 GDBusProxy             *object,
                 gpointer                user_data)
{
  PinosContext *context = user_data;
  PinosContextPrivate *priv = context->priv;

  switch (flags) {
    case PINOS_SUBSCRIPTION_FLAGS_DAEMON:
      priv->daemon = g_object_ref (object);
      break;

    case PINOS_SUBSCRIPTION_FLAGS_CLIENT:
      if (event == PINOS_SUBSCRIPTION_EVENT_REMOVE) {
        if (object == priv->client) {
          priv->error = g_error_new_literal (G_IO_ERROR, G_IO_ERROR_CLOSED, "Client disappeared");
          context_set_state (context, PINOS_CONTEXT_STATE_ERROR);
        }
      }
      break;

    case PINOS_SUBSCRIPTION_FLAGS_SOURCE:
      if (event == PINOS_SUBSCRIPTION_EVENT_NEW)
        priv->sources = g_list_prepend (priv->sources, object);
      else if (event == PINOS_SUBSCRIPTION_EVENT_REMOVE)
        priv->sources = g_list_remove (priv->sources, object);
      break;

    case PINOS_SUBSCRIPTION_FLAGS_SOURCE_OUTPUT:
      break;
  }

  if (flags & priv->subscription_mask)
    g_signal_emit (context,
                   signals[SIGNAL_SUBSCRIPTION_EVENT],
                   0,
                   event,
                   flags,
                   object);

}

static void
subscription_state (GObject    *object,
                    GParamSpec *pspec,
                    gpointer    user_data)
{
  PinosContext *context = user_data;
  PinosContextPrivate *priv = context->priv;
  PinosSubscriptionState state;

  g_assert (object == G_OBJECT (priv->subscribe));

  state = pinos_subscribe_get_state (priv->subscribe);

  switch (state) {
    case PINOS_SUBSCRIPTION_STATE_READY:
      on_daemon_connected (NULL, NULL, context);
      break;

    default:
      break;
  }

}

static void
on_name_appeared (GDBusConnection *connection,
                  const gchar     *name,
                  const gchar     *name_owner,
                  gpointer         user_data)
{
  PinosContext *context = user_data;
  PinosContextPrivate *priv = context->priv;

  priv->connection = connection;

  g_object_set (priv->subscribe, "connection", priv->connection,
                                 "service", name, NULL);
}

static void
on_name_vanished (GDBusConnection *connection,
                  const gchar     *name,
                  gpointer         user_data)
{
  PinosContext *context = user_data;
  PinosContextPrivate *priv = context->priv;

  priv->connection = connection;

  g_object_set (priv->subscribe, "connection", connection, NULL);

  if (priv->flags & PINOS_CONTEXT_FLAGS_NOFAIL) {
    context_set_state (context, PINOS_CONTEXT_STATE_CONNECTING);
  } else {
    priv->error = g_error_new_literal (G_IO_ERROR, G_IO_ERROR_CLOSED, "Connection closed");
    context_set_state (context, PINOS_CONTEXT_STATE_ERROR);
  }
}

static gboolean
do_connect (PinosContext *context)
{
  PinosContextPrivate *priv = context->priv;
  GBusNameWatcherFlags nw_flags;

  nw_flags = G_BUS_NAME_WATCHER_FLAGS_NONE;
  if (!(priv->flags & PINOS_CONTEXT_FLAGS_NOAUTOSPAWN))
    nw_flags = G_BUS_NAME_WATCHER_FLAGS_AUTO_START;

  priv->id = g_bus_watch_name (G_BUS_TYPE_SESSION,
                               PINOS_DBUS_SERVICE,
                               nw_flags,
                               on_name_appeared,
                               on_name_vanished,
                               context,
                               g_object_unref);
  return FALSE;
}

/**
 * pinos_context_connect:
 * @context: a #PinosContext
 * @flags: #PinosContextFlags
 *
 * Connect to the daemon with @flags
 *
 * Returns: %TRUE on success.
 */
gboolean
pinos_context_connect (PinosContext      *context,
                       PinosContextFlags  flags)
{
  PinosContextPrivate *priv;

  g_return_val_if_fail (PINOS_IS_CONTEXT (context), FALSE);

  priv = context->priv;
  g_return_val_if_fail (priv->connection == NULL, FALSE);

  priv->flags = flags;

  context_set_state (context, PINOS_CONTEXT_STATE_CONNECTING);
  g_main_context_invoke (priv->context,
                         (GSourceFunc) do_connect,
                         g_object_ref (context));

  return TRUE;
}

static void
finish_client_disconnect (PinosContext *context)
{
  PinosContextPrivate *priv = context->priv;

  g_clear_object (&priv->client);
  g_clear_object (&priv->daemon);
  g_bus_unwatch_name(priv->id);
  priv->id = 0;

  context_set_state (context, PINOS_CONTEXT_STATE_UNCONNECTED);
}

static void
on_client_disconnected (GObject      *source_object,
                        GAsyncResult *res,
                        gpointer      user_data)
{
  PinosContext *context = user_data;
  PinosContextPrivate *priv = context->priv;
  GError *error = NULL;
  GVariant *ret;

  ret = g_dbus_proxy_call_finish (priv->client, res, &error);
  if (ret == NULL) {
    g_warning ("failed to disconnect client: %s", error->message);
    priv->error = error;
    context_set_state (context, PINOS_CONTEXT_STATE_ERROR);
    g_object_unref (context);
    return;
  }
  g_variant_unref (ret);

  finish_client_disconnect (context);
  g_object_unref (context);
}

static gboolean
do_disconnect (PinosContext *context)
{
  PinosContextPrivate *priv = context->priv;

  g_dbus_proxy_call (priv->client,
                     "Disconnect",
                     g_variant_new ("()"),
                     G_DBUS_CALL_FLAGS_NONE,
                     -1,
                     NULL,
                     on_client_disconnected,
                     context);

  return FALSE;
}

/**
 * pinos_context_disconnect:
 * @context: a #PinosContext
 *
 * Disonnect from the daemon.
 *
 * Returns: %TRUE on success.
 */
gboolean
pinos_context_disconnect (PinosContext *context)
{
  PinosContextPrivate *priv;

  g_return_val_if_fail (PINOS_IS_CONTEXT (context), FALSE);

  priv = context->priv;

  if (priv->client == NULL) {
    finish_client_disconnect (context);
    return TRUE;
  }

  g_main_context_invoke (priv->context,
                         (GSourceFunc) do_disconnect,
                         g_object_ref (context));

  return TRUE;
}

/**
 * pinos_context_get_state:
 * @context: a #PinosContext
 *
 * Get the state of @context.
 *
 * Returns: the state of @context
 */
PinosContextState
pinos_context_get_state (PinosContext *context)
{
  PinosContextPrivate *priv;

  g_return_val_if_fail (PINOS_IS_CONTEXT (context), PINOS_CONTEXT_STATE_ERROR);
  priv = context->priv;

  return priv->state;
}

/**
 * pinos_context_get_error:
 * @context: a #PinosContext
 *
 * Get the current error of @context or %NULL when the context state
 * is not #PINOS_CONTEXT_STATE_ERROR
 *
 * Returns: the last error or %NULL
 */
const GError *
pinos_context_get_error (PinosContext *context)
{
  PinosContextPrivate *priv;

  g_return_val_if_fail (PINOS_IS_CONTEXT (context), NULL);
  priv = context->priv;

  return priv->error;
}