/* GStreamer
 * Copyright (C) 2008 Nokia Corporation. (contact <stefan.kost@nokia.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., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/**
 * SECTION:element-output-selector
 * @short_description: 1-to-N stream selectoring
 * @see_also: #GstTee, #GstInputSelector
 *
 * Direct input stream to one out of N output pads.
 */

/* FIXME: By default basesinks require some prerolled data before changing
   to playing state. Also pipeline with output-selector connected to multiple 
   sink elements won't change to playing until all sink elements have received
   the preroll data. Currently this can be worked around using live source element
   and and exporting GST_COMPAT="no-live-preroll".
*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <string.h>

#include "gstoutputselector.h"

GST_DEBUG_CATEGORY_STATIC (output_selector_debug);
#define GST_CAT_DEFAULT output_selector_debug

static const GstElementDetails gst_output_selector_details =
GST_ELEMENT_DETAILS ("Output selector",
    "Generic",
    "1-to-N output stream selectoring",
    "Stefan Kost <stefan.kost@nokia.com>");

static GstStaticPadTemplate gst_output_selector_sink_factory =
GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS_ANY);

static GstStaticPadTemplate gst_output_selector_src_factory =
GST_STATIC_PAD_TEMPLATE ("src%d",
    GST_PAD_SRC,
    GST_PAD_REQUEST,
    GST_STATIC_CAPS_ANY);

enum
{
  PROP_ACTIVE_PAD = 1,
  PROP_RESEND_LATEST
};

static void gst_output_selector_dispose (GObject * object);
static void gst_output_selector_init (GstOutputSelector * sel);
static void gst_output_selector_base_init (GstOutputSelectorClass * klass);
static void gst_output_selector_class_init (GstOutputSelectorClass * klass);
static void gst_output_selector_set_property (GObject * object,
    guint prop_id, const GValue * value, GParamSpec * pspec);
static void gst_output_selector_get_property (GObject * object,
    guint prop_id, GValue * value, GParamSpec * pspec);
static GstPad *gst_output_selector_request_new_pad (GstElement * element,
    GstPadTemplate * templ, const gchar * unused);
static void gst_output_selector_release_pad (GstElement * element,
    GstPad * pad);
static GstFlowReturn gst_output_selector_chain (GstPad * pad, GstBuffer * buf);
static GstStateChangeReturn gst_output_selector_change_state (GstElement *
    element, GstStateChange transition);
static gboolean gst_output_selector_handle_sink_event (GstPad * pad,
    GstEvent * event);

static GstElementClass *parent_class = NULL;

GType
gst_output_selector_get_type (void)
{
  static GType output_selector_type = 0;

  if (!output_selector_type) {
    static const GTypeInfo output_selector_info = {
      sizeof (GstOutputSelectorClass),
      (GBaseInitFunc) gst_output_selector_base_init,
      NULL,
      (GClassInitFunc) gst_output_selector_class_init,
      NULL,
      NULL,
      sizeof (GstOutputSelector),
      0,
      (GInstanceInitFunc) gst_output_selector_init,
    };
    output_selector_type =
        g_type_register_static (GST_TYPE_ELEMENT,
        "GstOutputSelector", &output_selector_info, 0);
    GST_DEBUG_CATEGORY_INIT (output_selector_debug,
        "output-selector", 0, "An output stream selector element");
  }

  return output_selector_type;
}

static void
gst_output_selector_base_init (GstOutputSelectorClass * klass)
{
  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);

  gst_element_class_set_details (element_class, &gst_output_selector_details);
  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&gst_output_selector_sink_factory));
  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&gst_output_selector_src_factory));
}

static void
gst_output_selector_class_init (GstOutputSelectorClass * klass)
{
  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
  GstElementClass *gstelement_class = GST_ELEMENT_CLASS (klass);

  parent_class = g_type_class_peek_parent (klass);
  gobject_class->set_property =
      GST_DEBUG_FUNCPTR (gst_output_selector_set_property);
  gobject_class->get_property =
      GST_DEBUG_FUNCPTR (gst_output_selector_get_property);
  g_object_class_install_property (gobject_class, PROP_ACTIVE_PAD,
      g_param_spec_string ("active-pad", "Active pad",
          "Name of the currently active src pad", NULL, G_PARAM_READWRITE));
  g_object_class_install_property (gobject_class, PROP_RESEND_LATEST,
      g_param_spec_boolean ("resend-latest", "Resend latest buffer",
          "Resend latest buffer after a switch to a new pad", FALSE,
          G_PARAM_READWRITE));
  gobject_class->dispose = gst_output_selector_dispose;
  gstelement_class->request_new_pad =
      GST_DEBUG_FUNCPTR (gst_output_selector_request_new_pad);
  gstelement_class->release_pad =
      GST_DEBUG_FUNCPTR (gst_output_selector_release_pad);
  gstelement_class->change_state = gst_output_selector_change_state;

}

static void
gst_output_selector_init (GstOutputSelector * sel)
{
  sel->sinkpad =
      gst_pad_new_from_static_template (&gst_output_selector_sink_factory,
      "sink");
  gst_pad_set_chain_function (sel->sinkpad,
      GST_DEBUG_FUNCPTR (gst_output_selector_chain));
  gst_pad_set_event_function (sel->sinkpad,
      GST_DEBUG_FUNCPTR (gst_output_selector_handle_sink_event));

  gst_element_add_pad (GST_ELEMENT (sel), sel->sinkpad);

  /*
     gst_pad_set_bufferalloc_function (sel->sinkpad,
     GST_DEBUG_FUNCPTR (gst_output_selector_bufferalloc));
     gst_pad_set_setcaps_function (sel->sinkpad,
     GST_DEBUG_FUNCPTR (gst_pad_proxy_setcaps));
     gst_pad_set_getcaps_function (sel->sinkpad,
     GST_DEBUG_FUNCPTR (gst_pad_proxy_getcaps));
   */
  /* srcpad management */
  sel->active_srcpad = NULL;
  sel->nb_srcpads = 0;
  gst_segment_init (&sel->segment, GST_FORMAT_UNDEFINED);
  sel->pending_srcpad = NULL;

  sel->resend_latest = FALSE;
  sel->latest_buffer = NULL;
}

static void
gst_output_selector_dispose (GObject * object)
{
  GstOutputSelector *osel = GST_OUTPUT_SELECTOR (object);

  if (osel->pending_srcpad != NULL) {
    gst_object_unref (osel->pending_srcpad);
    osel->pending_srcpad = NULL;
  }
  if (osel->latest_buffer != NULL) {
    gst_buffer_unref (osel->latest_buffer);
    osel->latest_buffer = NULL;
  }

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

static void
gst_output_selector_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  GstOutputSelector *sel = GST_OUTPUT_SELECTOR (object);

  switch (prop_id) {
    case PROP_ACTIVE_PAD:{
      GstPad *next_pad =
          gst_element_get_static_pad (GST_ELEMENT (sel),
          g_value_get_string (value));
      if (next_pad && (next_pad != sel->active_srcpad)) {
        /* switch to new srcpad in next chain run */
        if (sel->pending_srcpad != NULL) {
          GST_INFO ("replacing pending switch");
          gst_object_unref (sel->pending_srcpad);
        }
        sel->pending_srcpad = next_pad;
      } else {
        GST_WARNING ("setting active pad failed");
      }
      break;
    }
    case PROP_RESEND_LATEST:{
      sel->resend_latest = g_value_get_boolean (value);
      break;
    }
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_output_selector_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec)
{
  GstOutputSelector *sel = GST_OUTPUT_SELECTOR (object);

  switch (prop_id) {
    case PROP_ACTIVE_PAD:{
      GST_OBJECT_LOCK (object);
      if (sel->active_srcpad != NULL) {
        g_value_take_string (value, gst_pad_get_name (sel->active_srcpad));
      } else {
        g_value_set_string (value, "");
      }
      GST_OBJECT_UNLOCK (object);
      break;
    }
    case PROP_RESEND_LATEST:{
      GST_OBJECT_LOCK (object);
      g_value_set_boolean (value, sel->resend_latest);
      GST_OBJECT_UNLOCK (object);
      break;
    }
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static GstPad *
gst_output_selector_request_new_pad (GstElement * element,
    GstPadTemplate * templ, const gchar * name)
{
  gchar *padname;
  GstPad *srcpad;
  GstOutputSelector *osel;

  osel = GST_OUTPUT_SELECTOR (element);

  GST_DEBUG_OBJECT (osel, "requesting pad");

  GST_OBJECT_LOCK (osel);
  padname = g_strdup_printf ("src%d", osel->nb_srcpads++);
  srcpad = gst_pad_new_from_template (templ, padname);
  GST_OBJECT_UNLOCK (osel);

  gst_pad_set_active (srcpad, TRUE);
  gst_element_add_pad (GST_ELEMENT (osel), srcpad);

  /* Set the first requested src pad as active by default */
  if (osel->active_srcpad == NULL) {
    osel->active_srcpad = srcpad;
  }
  g_free (padname);

  return srcpad;
}

static void
gst_output_selector_release_pad (GstElement * element, GstPad * pad)
{
  GstOutputSelector *osel;

  osel = GST_OUTPUT_SELECTOR (element);

  GST_DEBUG_OBJECT (osel, "releasing pad");

  gst_pad_set_active (pad, FALSE);

  gst_element_remove_pad (GST_ELEMENT_CAST (osel), pad);
}

static gboolean
gst_output_selector_switch (GstOutputSelector * osel)
{
  gboolean res = TRUE;
  GstEvent *ev = NULL;
  GstSegment *seg = NULL;
  gint64 start = 0, position = 0;

  GST_INFO ("switching to pad %" GST_PTR_FORMAT, osel->pending_srcpad);

  if (gst_pad_is_linked (osel->pending_srcpad)) {
    /* Send NEWSEGMENT to the pad we are going to switch to */
    seg = &osel->segment;
    /* If resending then mark newsegment start and position accordingly */
    if (osel->resend_latest && osel->latest_buffer &&
        GST_BUFFER_TIMESTAMP_IS_VALID (osel->latest_buffer)) {
      start = position = GST_BUFFER_TIMESTAMP (osel->latest_buffer);
    } else {
      start = position = seg->last_stop;
    }
    ev = gst_event_new_new_segment (TRUE, seg->rate,
        seg->format, start, seg->stop, position);
    if (!gst_pad_push_event (osel->pending_srcpad, ev)) {
      GST_WARNING ("newsegment handling failed in %" GST_PTR_FORMAT,
          osel->pending_srcpad);
    }

    /* Resend latest buffer to newly switched pad */
    if (osel->resend_latest && osel->latest_buffer) {
      GST_INFO ("resending latest buffer");
      gst_pad_push (osel->pending_srcpad, osel->latest_buffer);
      osel->latest_buffer = NULL;
    }

    /* Switch */
    osel->active_srcpad = osel->pending_srcpad;
  } else {
    GST_WARNING ("switch failed, pad not linked");
    res = FALSE;
  }

  gst_object_unref (osel->pending_srcpad);
  osel->pending_srcpad = NULL;

  return res;
}

static GstFlowReturn
gst_output_selector_chain (GstPad * pad, GstBuffer * buf)
{
  GstFlowReturn res;
  GstOutputSelector *osel;
  GstClockTime last_stop, duration;

  osel = GST_OUTPUT_SELECTOR (gst_pad_get_parent (pad));

  if (osel->pending_srcpad) {
    /* Do the switch */
    gst_output_selector_switch (osel);
  }

  /* Keep reference to latest buffer to resend it after switch */
  if (osel->resend_latest) {
    if (osel->latest_buffer)
      gst_buffer_unref (osel->latest_buffer);
    osel->latest_buffer = gst_buffer_ref (buf);
  }

  /* Keep track of last stop and use it in NEWSEGMENT start after 
     switching to a new src pad */
  last_stop = GST_BUFFER_TIMESTAMP (buf);
  if (GST_CLOCK_TIME_IS_VALID (last_stop)) {
    duration = GST_BUFFER_DURATION (buf);
    if (GST_CLOCK_TIME_IS_VALID (duration)) {
      last_stop += duration;
    }
    GST_LOG ("setting last stop %" GST_TIME_FORMAT, GST_TIME_ARGS (last_stop));
    gst_segment_set_last_stop (&osel->segment, osel->segment.format, last_stop);
  }

  GST_LOG ("pushing buffer to %" GST_PTR_FORMAT, osel->active_srcpad);
  res = gst_pad_push (osel->active_srcpad, buf);
  gst_object_unref (osel);

  return res;
}

static GstStateChangeReturn
gst_output_selector_change_state (GstElement * element,
    GstStateChange transition)
{
  return GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
}

static gboolean
gst_output_selector_handle_sink_event (GstPad * pad, GstEvent * event)
{
  gboolean res = TRUE;
  GstOutputSelector *sel;

  sel = GST_OUTPUT_SELECTOR (gst_pad_get_parent (pad));

  switch (GST_EVENT_TYPE (event)) {
    case GST_EVENT_NEWSEGMENT:
    {
      gboolean update;
      GstFormat format;
      gdouble rate, arate;
      gint64 start, stop, time;

      gst_event_parse_new_segment_full (event, &update, &rate, &arate, &format,
          &start, &stop, &time);

      GST_DEBUG ("configured NEWSEGMENT update %d, rate %lf, applied rate %lf, "
          "format %d, "
          "%" G_GINT64_FORMAT " -- %" G_GINT64_FORMAT ", time %"
          G_GINT64_FORMAT, update, rate, arate, format, start, stop, time);

      gst_segment_set_newsegment_full (&sel->segment, update,
          rate, arate, format, start, stop, time);

      /* Send newsegment to all src pads */
      gst_pad_event_default (pad, event);

      break;
    }
    case GST_EVENT_EOS:
      /* Send eos to all src pads */
      gst_pad_event_default (pad, event);
      break;
    default:
      /* Send other events to active src pad */
      res = gst_pad_push_event (sel->active_srcpad, event);
      break;
  }

  gst_object_unref (sel);

  return res;
}