/* 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.
 */

#define _GNU_SOURCE

#include <string.h>
#include <sys/socket.h>
#include <errno.h>
#include <sys/mman.h>
#include <unistd.h>
#include <fcntl.h>
#include <dlfcn.h>
#include <poll.h>


#include <gio/gunixfdlist.h>

#include "pinos/client/pinos.h"
#include "pinos/client/enumtypes.h"
#include "pinos/client/private.h"

#include "pinos/server/daemon.h"
#include "pinos/server/client-node.h"
#include "pinos/server/utils.h"
#include "pinos/server/link.h"

#include "pinos/dbus/org-pinos.h"

#include "spa/include/spa/control.h"


struct _PinosClientNodePrivate
{
  int fd;
  GSocket *sockets[2];

  SpaPollFd fds[16];
  unsigned int n_fds;
  SpaPollItem poll;

  gboolean running;
  pthread_t thread;
};

#define PINOS_CLIENT_NODE_GET_PRIVATE(obj)  \
   (G_TYPE_INSTANCE_GET_PRIVATE ((obj), PINOS_TYPE_CLIENT_NODE, PinosClientNodePrivate))

G_DEFINE_TYPE (PinosClientNode, pinos_client_node, PINOS_TYPE_NODE);

enum
{
  PROP_0,
};

enum
{
  SIGNAL_NONE,
  LAST_SIGNAL
};

//static guint signals[LAST_SIGNAL] = { 0 };

static void
pinos_client_node_get_property (GObject    *_object,
                                  guint       prop_id,
                                  GValue     *value,
                                  GParamSpec *pspec)
{
  PinosClientNode *node = PINOS_CLIENT_NODE (_object);

  switch (prop_id) {
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (node, prop_id, pspec);
      break;
  }
}

static void
pinos_client_node_set_property (GObject      *_object,
                            guint         prop_id,
                            const GValue *value,
                            GParamSpec   *pspec)
{
  PinosClientNode *node = PINOS_CLIENT_NODE (_object);

  switch (prop_id) {
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (node, prop_id, pspec);
      break;
  }
}

/**
 * pinos_client_node_get_socket_pair:
 * @node: a #PinosClientNode
 * @error: a #GError
 *
 * Create or return a previously create socket pair for @node. The
 * Socket for the other end is returned.
 *
 * Returns: a #GSocket that can be used to send/receive buffers to node.
 */
GSocket *
pinos_client_node_get_socket_pair (PinosClientNode  *this,
                                   GError          **error)
{
  PinosNode *node;
  PinosClientNodePrivate *priv;

  g_return_val_if_fail (PINOS_IS_CLIENT_NODE (this), FALSE);
  node = PINOS_NODE (this);
  priv = this->priv;

  if (priv->sockets[1] == NULL) {
    SpaProps *props;
    SpaPropValue value;
    int fd[2];

    if (socketpair (AF_UNIX, SOCK_STREAM, 0, fd) != 0)
      goto no_sockets;

    priv->sockets[0] = g_socket_new_from_fd (fd[0], error);
    if (priv->sockets[0] == NULL)
      goto create_failed;

    priv->sockets[1] = g_socket_new_from_fd (fd[1], error);
    if (priv->sockets[1] == NULL)
      goto create_failed;

    priv->fd = g_socket_get_fd (priv->sockets[0]);

    spa_node_get_props (node->node, &props);
    value.type = SPA_PROP_TYPE_INT;
    value.value = &priv->fd;
    value.size = sizeof (int);
    spa_props_set_prop (props, spa_props_index_for_name (props, "socket"), &value);
    spa_node_set_props (node->node, props);
  }
  return g_object_ref (priv->sockets[1]);

  /* ERRORS */
no_sockets:
  {
    g_set_error (error,
                 G_IO_ERROR,
                 g_io_error_from_errno (errno),
                 "could not create socketpair: %s", strerror (errno));
    return NULL;
  }
create_failed:
  {
    g_clear_object (&priv->sockets[0]);
    g_clear_object (&priv->sockets[1]);
    return NULL;
  }
}

static gboolean
on_received_buffer (PinosPort *port, uint32_t buffer_id, GError **error, gpointer user_data)
{
  PinosNode *node = user_data;
  SpaResult res;
  SpaInputInfo info[1];

  info[0].port_id =  port->id;
  info[0].buffer_id = buffer_id;
  info[0].flags = SPA_INPUT_FLAG_NONE;
  info[0].offset = 0;
  info[0].size = -1;

  if ((res = spa_node_port_push_input (node->node, 1, info)) < 0)
    g_warning ("client-node %p: error pushing buffer: %d, %d", node, res, info[0].status);

  return TRUE;
}

static gboolean
on_received_event (PinosPort *port, SpaEvent *event, GError **error, gpointer user_data)
{
  PinosNode *node = user_data;
  SpaResult res;

  if ((res = spa_node_port_push_event (node->node, port->id, event)) < 0)
    g_warning ("client-node %p: error pushing event: %d", node, res);

  return TRUE;
}

static void *
loop (void *user_data)
{
  PinosClientNode *this = user_data;
  PinosClientNodePrivate *priv = this->priv;
  int r;

  g_debug ("client-node %p: enter thread", this);
  while (priv->running) {
    SpaPollNotifyData ndata;

    r = poll ((struct pollfd *) priv->fds, priv->n_fds, -1);
    if (r < 0) {
      if (errno == EINTR)
        continue;
      break;
    }
    if (r == 0) {
      g_debug ("client-node %p: select timeout", this);
      break;
    }
    if (priv->poll.after_cb) {
      ndata.fds = priv->poll.fds;
      ndata.n_fds = priv->poll.n_fds;
      ndata.user_data = priv->poll.user_data;
      priv->poll.after_cb (&ndata);
    }
  }
  g_debug ("client-node %p: leave thread", this);

  return NULL;
}

static void
start_thread (PinosClientNode *this)
{
  PinosClientNodePrivate *priv = this->priv;
  int err;

  if (!priv->running) {
    priv->running = true;
    if ((err = pthread_create (&priv->thread, NULL, loop, this)) != 0) {
      g_debug ("client-node %p: can't create thread", strerror (err));
      priv->running = false;
    }
  }
}

static void
stop_thread (PinosClientNode *this)
{
  PinosClientNodePrivate *priv = this->priv;

  if (priv->running) {
    priv->running = false;
    pthread_join (priv->thread, NULL);
  }
}

static void
on_node_event (SpaNode *node, SpaEvent *event, void *user_data)
{
  PinosClientNode *this = user_data;
  PinosClientNodePrivate *priv = this->priv;

  switch (event->type) {
    case SPA_EVENT_TYPE_PORT_ADDED:
    {
      SpaEventPortAdded *pa = event->data;
      PinosPort *port, *target;
      PinosLink *link;
      PinosNode *pnode = PINOS_NODE (this);
      GError *error = NULL;

      port = PINOS_NODE_CLASS (pinos_client_node_parent_class)->add_port (pnode,
                                                                          pa->direction,
                                                                          event->port_id,
                                                                          &error);

      if (port == NULL) {
        g_warning ("proxy %p: can't create port: %s", this, error->message);
        g_clear_error (&error);
        break;
      }
      pinos_port_set_received_cb (port, on_received_buffer, on_received_event, this, NULL);

      target = pinos_daemon_find_port (pinos_node_get_daemon (pnode),
                                       pinos_direction_reverse (pa->direction),
                                       "/org/pinos/node_1",
                                       NULL,
                                       NULL,
                                       &error);
      if (target == NULL) {
        g_warning ("proxy %p: can't find port target: %s", this, error->message);
        g_clear_error (&error);
        break;
      }
      link = pinos_link_new (pinos_node_get_daemon (pnode), port, target, NULL);

      break;
    }
    case SPA_EVENT_TYPE_PORT_REMOVED:
    {
      break;
    }
    case SPA_EVENT_TYPE_STATE_CHANGE:
    {
      SpaEventStateChange *sc = event->data;

      switch (sc->state) {
        case SPA_NODE_STATE_CONFIGURE:
        {
          GList *ports, *walk;

          ports = pinos_node_get_ports (PINOS_NODE (this));
          for (walk = ports; walk; walk = g_list_next (walk)) {
            PinosPort *port = walk->data;
            pinos_port_activate (port);
          }
        }
        default:
          break;
      }
      break;
    }
    case SPA_EVENT_TYPE_ADD_POLL:
    {
      SpaPollItem *poll = event->data;

      priv->poll = *poll;
      priv->fds[0] = poll->fds[0];
      priv->n_fds = 1;
      priv->poll.fds = priv->fds;

      start_thread (this);
      break;
    }
    case SPA_EVENT_TYPE_REMOVE_POLL:
    {
      stop_thread (this);
      break;
    }
    case SPA_EVENT_TYPE_REUSE_BUFFER:
    {
      PinosPort *port;
      GError *error = NULL;

      port = pinos_node_find_port (PINOS_NODE (this), event->port_id);
      pinos_port_send_event (port, event, &error);
      break;
    }
    default:
      g_debug ("client-node %p: got event %d", this, event->type);
      break;
  }
}

static void
setup_node (PinosClientNode *this)
{
  PinosNode *node = PINOS_NODE (this);
  SpaResult res;

  if ((res = spa_node_set_event_callback (node->node, on_node_event, this)) < 0)
    g_warning ("client-node %p: error setting callback", this);
}

static PinosPort *
add_port (PinosNode       *node,
          PinosDirection   direction,
          guint            id,
          GError         **error)
{
  PinosPort *port;

  if (spa_node_add_port (node->node, direction, id) < 0)
    g_warning ("client-node %p: error adding port", node);

  port = PINOS_NODE_CLASS (pinos_client_node_parent_class)->add_port (node, direction, id, error);

  if (port) {
    pinos_port_set_received_cb (port, on_received_buffer, on_received_event, node, NULL);
  }
  return port;
}

static gboolean
remove_port (PinosNode       *node,
             guint            id)
{
  if (spa_node_remove_port (node->node, id) < 0)
    g_warning ("client-node %p: error removing port", node);

  return PINOS_NODE_CLASS (pinos_client_node_parent_class)->remove_port (node, id);
}

static void
pinos_client_node_dispose (GObject * object)
{
  PinosClientNode *this = PINOS_CLIENT_NODE (object);

  g_debug ("client-node %p: dispose", this);

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

static void
pinos_client_node_finalize (GObject * object)
{
  PinosClientNode *this = PINOS_CLIENT_NODE (object);

  g_debug ("client-node %p: finalize", this);

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

static void
pinos_client_node_constructed (GObject * object)
{
  PinosClientNode *this = PINOS_CLIENT_NODE (object);

  g_debug ("client-node %p: constructed", this);

  G_OBJECT_CLASS (pinos_client_node_parent_class)->constructed (object);

  setup_node (this);
}

static void
pinos_client_node_class_init (PinosClientNodeClass * klass)
{
  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
  PinosNodeClass *node_class = PINOS_NODE_CLASS (klass);

  g_type_class_add_private (klass, sizeof (PinosClientNodePrivate));

  gobject_class->constructed = pinos_client_node_constructed;
  gobject_class->dispose = pinos_client_node_dispose;
  gobject_class->finalize = pinos_client_node_finalize;
  gobject_class->set_property = pinos_client_node_set_property;
  gobject_class->get_property = pinos_client_node_get_property;

  node_class->add_port = add_port;
  node_class->remove_port = remove_port;
}

static void
pinos_client_node_init (PinosClientNode * node)
{
  node->priv = PINOS_CLIENT_NODE_GET_PRIVATE (node);

  g_debug ("client-node %p: new", node);
}

static SpaResult
make_node (SpaNode **node, const char *lib, const char *name)
{
  SpaHandle *handle;
  SpaResult res;
  void *hnd, *state = NULL;
  SpaEnumHandleFactoryFunc enum_func;

  if ((hnd = dlopen (lib, RTLD_NOW)) == NULL) {
    g_error ("can't load %s: %s", lib, dlerror());
    return SPA_RESULT_ERROR;
  }
  if ((enum_func = dlsym (hnd, "spa_enum_handle_factory")) == NULL) {
    g_error ("can't find enum function");
    return SPA_RESULT_ERROR;
  }

  while (true) {
    const SpaHandleFactory *factory;
    void *iface;

    if ((res = enum_func (&factory, &state)) < 0) {
      if (res != SPA_RESULT_ENUM_END)
        g_error ("can't enumerate factories: %d", res);
      break;
    }
    if (strcmp (factory->name, name))
      continue;

    handle = calloc (1, factory->size);
    if ((res = factory->init (factory, handle)) < 0) {
      g_error ("can't make factory instance: %d", res);
      return res;
    }
    if ((res = handle->get_interface (handle, SPA_INTERFACE_ID_NODE, &iface)) < 0) {
      g_error ("can't get interface %d", res);
      return res;
    }
    *node = iface;
    return SPA_RESULT_OK;
  }
  return SPA_RESULT_ERROR;
}

/**
 * pinos_client_node_new:
 * @daemon: a #PinosDaemon
 * @sender: the path of the owner
 * @name: a name
 * @properties: extra properties
 *
 * Create a new #PinosNode.
 *
 * Returns: a new #PinosNode
 */
PinosNode *
pinos_client_node_new (PinosDaemon     *daemon,
                       const gchar     *sender,
                       const gchar     *name,
                       PinosProperties *properties)
{
  SpaNode *n;
  SpaResult res;

  g_return_val_if_fail (PINOS_IS_DAEMON (daemon), NULL);

  if ((res = make_node (&n,
                        "spa/build/plugins/remote/libspa-remote.so",
                        "proxy")) < 0) {
    g_error ("can't create proxy: %d", res);
    return NULL;
  }

  return g_object_new (PINOS_TYPE_CLIENT_NODE,
                       "daemon", daemon,
                       "sender", sender,
                       "name", name,
                       "properties", properties,
                       "node", n,
                       NULL);
}