/* GStreamer
 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
 *                    2000 Wim Taymans <wim.taymans@chello.be>
 *                    2001 Thomas <thomas@apestaart.org>
 *
 * adder.c: Adder element, N in, one out, samples are added
 *
 * 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.
 */
/* Element-Checklist-Version: 5 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gstadder.h"
#include <gst/audio/audio.h>
#include <string.h>             /* strcmp */

/* highest positive/lowest negative x-bit value we can use for clamping */
//#define MAX_INT_x ((guint) 1 << (x - 1))
#define MAX_INT_32 2147483647L
#define MAX_INT_16 32767
#define MAX_INT_8 127

//#define MIN_INT_x (-((guint) 1 << (x - 1)))
/* to make non-C90 happy we need to specify the constant differently */
#define MIN_INT_32 (-2147483647L -1L)
#define MIN_INT_16 -32768
#define MIN_INT_8 -128

#define GST_ADDER_BUFFER_SIZE 4096
#define GST_ADDER_NUM_BUFFERS 8

GST_DEBUG_CATEGORY_STATIC (gst_adder_debug);
#define GST_CAT_DEFAULT gst_adder_debug

/* elementfactory information */
static GstElementDetails adder_details = GST_ELEMENT_DETAILS ("Adder",
    "Generic/Audio",
    "Add N audio channels together",
    "Thomas <thomas@apestaart.org>");

/* Adder signals and args */
enum
{
  /* FILL ME */
  LAST_SIGNAL
};

enum
{
  ARG_0,
  ARG_NUM_PADS
      /* FILL ME */
};

static GstStaticPadTemplate gst_adder_src_template =
    GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (GST_AUDIO_INT_PAD_TEMPLATE_CAPS "; "
        GST_AUDIO_FLOAT_PAD_TEMPLATE_CAPS)
    );

static GstStaticPadTemplate gst_adder_sink_template =
    GST_STATIC_PAD_TEMPLATE ("sink%d",
    GST_PAD_SINK,
    GST_PAD_REQUEST,
    GST_STATIC_CAPS (GST_AUDIO_INT_PAD_TEMPLATE_CAPS "; "
        GST_AUDIO_FLOAT_PAD_TEMPLATE_CAPS)
    );

static void gst_adder_class_init (GstAdderClass * klass);
static void gst_adder_init (GstAdder * adder);

static void gst_adder_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec);

static GstPad *gst_adder_request_new_pad (GstElement * element,
    GstPadTemplate * temp, const gchar * unused);
static GstElementStateReturn gst_adder_change_state (GstElement * element);

/* we do need a loop function */
static void gst_adder_loop (GstElement * element);

static GstElementClass *parent_class = NULL;

/* static guint gst_adder_signals[LAST_SIGNAL] = { 0 }; */

GType
gst_adder_get_type (void)
{
  static GType adder_type = 0;

  if (!adder_type) {
    static const GTypeInfo adder_info = {
      sizeof (GstAdderClass), NULL, NULL,
      (GClassInitFunc) gst_adder_class_init, NULL, NULL,
      sizeof (GstAdder), 0,
      (GInstanceInitFunc) gst_adder_init,
    };

    adder_type = g_type_register_static (GST_TYPE_ELEMENT, "GstAdder",
        &adder_info, 0);
    GST_DEBUG_CATEGORY_INIT (gst_adder_debug, "adder", 0,
        "audio channel mixing element");
  }
  return adder_type;
}

static GstPadLinkReturn
gst_adder_link (GstPad * pad, const GstCaps * caps)
{
  GstAdder *adder;
  const char *media_type;
  const GList *pads;
  GstStructure *structure;
  GstPadLinkReturn ret;
  GstElement *element;

  g_return_val_if_fail (caps != NULL, GST_PAD_LINK_REFUSED);
  g_return_val_if_fail (pad != NULL, GST_PAD_LINK_REFUSED);

  element = GST_PAD_PARENT (pad);
  adder = GST_ADDER (element);

  pads = gst_element_get_pad_list (element);
  while (pads) {
    GstPad *otherpad = GST_PAD (pads->data);

    if (otherpad != pad) {
      ret = gst_pad_try_set_caps (otherpad, caps);
      if (GST_PAD_LINK_FAILED (ret)) {
        return ret;
      }
    }
    pads = g_list_next (pads);
  }


  pads = gst_element_get_pad_list (GST_ELEMENT (adder));
  while (pads) {
    GstPad *otherpad = GST_PAD (pads->data);

    if (otherpad != pad) {
      ret = gst_pad_try_set_caps (otherpad, caps);
      if (GST_PAD_LINK_FAILED (ret)) {
        return ret;
      }
    }
    pads = g_list_next (pads);
  }

  structure = gst_caps_get_structure (caps, 0);
  media_type = gst_structure_get_name (structure);
  if (strcmp (media_type, "audio/x-raw-int") == 0) {
    GST_DEBUG ("parse_caps sets adder to format int");
    adder->format = GST_ADDER_FORMAT_INT;
    gst_structure_get_int (structure, "width", &adder->width);
    gst_structure_get_int (structure, "depth", &adder->depth);
    gst_structure_get_int (structure, "endianness", &adder->endianness);
    gst_structure_get_boolean (structure, "signed", &adder->is_signed);
    gst_structure_get_int (structure, "channels", &adder->channels);
    gst_structure_get_int (structure, "rate", &adder->rate);
  } else if (strcmp (media_type, "audio/x-raw-float") == 0) {
    GST_DEBUG ("parse_caps sets adder to format float");
    adder->format = GST_ADDER_FORMAT_FLOAT;
    gst_structure_get_int (structure, "width", &adder->width);
    gst_structure_get_int (structure, "channels", &adder->channels);
    gst_structure_get_int (structure, "rate", &adder->rate);
  }

  return GST_PAD_LINK_OK;
}

static void
gst_adder_class_init (GstAdderClass * klass)
{
  GObjectClass *gobject_class;
  GstElementClass *gstelement_class;

  gobject_class = (GObjectClass *) klass;
  gstelement_class = (GstElementClass *) klass;

  gst_element_class_add_pad_template (gstelement_class,
      gst_static_pad_template_get (&gst_adder_src_template));
  gst_element_class_add_pad_template (gstelement_class,
      gst_static_pad_template_get (&gst_adder_sink_template));
  gst_element_class_set_details (gstelement_class, &adder_details);

  parent_class = g_type_class_ref (GST_TYPE_ELEMENT);

  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_NUM_PADS,
      g_param_spec_int ("num_pads", "number of pads", "Number Of Pads",
          0, G_MAXINT, 0, G_PARAM_READABLE));

  gobject_class->get_property = gst_adder_get_property;

  gstelement_class->request_new_pad = gst_adder_request_new_pad;
  gstelement_class->change_state = gst_adder_change_state;
}

static void
gst_adder_init (GstAdder * adder)
{
  adder->srcpad =
      gst_pad_new_from_template (gst_static_pad_template_get
      (&gst_adder_src_template), "src");
  gst_element_add_pad (GST_ELEMENT (adder), adder->srcpad);
  gst_element_set_loop_function (GST_ELEMENT (adder), gst_adder_loop);
  gst_pad_set_getcaps_function (adder->srcpad, gst_pad_proxy_getcaps);
  gst_pad_set_link_function (adder->srcpad, gst_adder_link);

  adder->format = GST_ADDER_FORMAT_UNSET;

  /* keep track of the sinkpads requested */

  adder->numsinkpads = 0;
  adder->input_channels = NULL;
}

static GstPad *
gst_adder_request_new_pad (GstElement * element, GstPadTemplate * templ,
    const gchar * unused)
{
  gchar *name;
  GstAdder *adder;
  GstAdderInputChannel *input;

  g_return_val_if_fail (GST_IS_ADDER (element), NULL);

  if (templ->direction != GST_PAD_SINK) {
    g_warning ("gstadder: request new pad that is not a SINK pad\n");
    return NULL;
  }

  /* allocate space for the input_channel */

  input = (GstAdderInputChannel *) g_malloc (sizeof (GstAdderInputChannel));
  if (input == NULL) {
    g_warning ("gstadder: could not allocate adder input channel !\n");
    return NULL;
  }

  adder = GST_ADDER (element);

  /* fill in input_channel structure */

  name = g_strdup_printf ("sink%d", adder->numsinkpads);
  input->sinkpad = gst_pad_new_from_template (templ, name);
  input->bytestream = gst_bytestream_new (input->sinkpad);

  gst_element_add_pad (GST_ELEMENT (adder), input->sinkpad);
  gst_pad_set_getcaps_function (input->sinkpad, gst_pad_proxy_getcaps);
  gst_pad_set_link_function (input->sinkpad, gst_adder_link);

  /* add the input_channel to the list of input channels */

  adder->input_channels = g_slist_append (adder->input_channels, input);
  adder->numsinkpads++;

  return input->sinkpad;
}

static void
gst_adder_get_property (GObject * object, guint prop_id, GValue * value,
    GParamSpec * pspec)
{
  GstAdder *adder;

  /* it's not null if we got it, but it might not be ours */
  g_return_if_fail (GST_IS_ADDER (object));

  adder = GST_ADDER (object);

  switch (prop_id) {
    case ARG_NUM_PADS:
      g_value_set_int (value, adder->numsinkpads);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

/* use this loop */
static void
gst_adder_loop (GstElement * element)
{
  /*
   * combine channels by adding sample values
   * basic algorithm :
   * - request an output buffer from the pool
   * - repeat for each input pipe :
   *   - get number of bytes from the channel's bytestream to fill output buffer
   *   - if there's an EOS event, remove the input channel
   *   - otherwise add the gotten bytes to the output buffer
   * - push out the output buffer
   */
  GstAdder *adder;
  GstBuffer *buf_out;

  GSList *inputs;

  register guint i;

  g_return_if_fail (element != NULL);
  g_return_if_fail (GST_IS_ADDER (element));

  adder = GST_ADDER (element);

  /* get new output buffer */
  /* FIXME the 1024 is arbitrary */
  buf_out = gst_buffer_new_and_alloc (1024);

  if (buf_out == NULL) {
    GST_ELEMENT_ERROR (adder, CORE, TOO_LAZY, (NULL),
        ("could not get new output buffer"));
    return;
  }

  /* initialize the output data to 0 */
  memset (GST_BUFFER_DATA (buf_out), 0, GST_BUFFER_SIZE (buf_out));

  /* get data from all of the sinks */
  inputs = adder->input_channels;

  GST_LOG ("starting to cycle through channels");

  while (inputs) {
    guint32 got_bytes;
    guint8 *raw_in;
    GstAdderInputChannel *input;

    input = (GstAdderInputChannel *) inputs->data;

    inputs = inputs->next;

    GST_LOG_OBJECT (adder, "  looking into channel %p", input);

    if (!GST_PAD_IS_USABLE (input->sinkpad)) {
      GST_LOG_OBJECT (adder, "    adder ignoring pad %s:%s",
          GST_DEBUG_PAD_NAME (input->sinkpad));
      continue;
    }

    /* Get data from the bytestream of each input channel. We need to check for
       events before passing on the data to the output buffer. */
  repeat:
    got_bytes = gst_bytestream_peek_bytes (input->bytestream, &raw_in,
        GST_BUFFER_SIZE (buf_out));

    /* FIXME we should do something with the data if got_bytes > 0 */
    if (got_bytes < GST_BUFFER_SIZE (buf_out)) {
      GstEvent *event = NULL;
      guint32 waiting;

      /* we need to check for an event. */
      gst_bytestream_get_status (input->bytestream, &waiting, &event);

      if (event) {
        switch (GST_EVENT_TYPE (event)) {
          case GST_EVENT_EOS:
            /* if we get an EOS event from one of our sink pads, we assume that
               pad's finished handling data. just skip this pad. */
            GST_DEBUG ("    got an EOS event");
            gst_event_unref (event);
            continue;
          case GST_EVENT_INTERRUPT:
            gst_event_unref (event);
            GST_DEBUG ("    got an interrupt event");
            /* we have to call interrupt here, the scheduler will switch out
               this element ASAP or returns TRUE if we need to exit the loop */
            if (gst_element_interrupt (GST_ELEMENT (adder))) {
              gst_buffer_unref (buf_out);
              return;
            }
          default:
            GST_LOG_OBJECT (adder, "pulling again after event");
            goto repeat;
        }
      }
    } else {
      /* here's where the data gets copied. */

      GST_LOG ("    copying %d bytes (format %d,%d)",
          GST_BUFFER_SIZE (buf_out), adder->format, adder->width);
      GST_LOG ("      from channel %p from input data %p", input, raw_in);
      GST_LOG ("      to output data %p in buffer %p",
          GST_BUFFER_DATA (buf_out), buf_out);

      if (adder->format == GST_ADDER_FORMAT_INT) {
        if (adder->width == 32) {
          gint32 *in = (gint32 *) raw_in;
          gint32 *out = (gint32 *) GST_BUFFER_DATA (buf_out);

          for (i = 0; i < GST_BUFFER_SIZE (buf_out) / 4; i++)
            out[i] = CLAMP (((gint64) out[i]) + ((gint64) in[i]),
                MIN_INT_32, MAX_INT_32);
        } else if (adder->width == 16) {
          gint16 *in = (gint16 *) raw_in;
          gint16 *out = (gint16 *) GST_BUFFER_DATA (buf_out);

          for (i = 0; i < GST_BUFFER_SIZE (buf_out) / 2; i++)
            out[i] = CLAMP (out[i] + in[i], MIN_INT_16, MAX_INT_16);
        } else if (adder->width == 8) {
          gint8 *in = (gint8 *) raw_in;
          gint8 *out = (gint8 *) GST_BUFFER_DATA (buf_out);

          for (i = 0; i < GST_BUFFER_SIZE (buf_out); i++)
            out[i] = CLAMP (out[i] + in[i], MIN_INT_8, MAX_INT_8);
        } else {
          GST_ELEMENT_ERROR (adder, STREAM, FORMAT, (NULL),
              ("invalid width (%u) for integer audio in gstadder",
                  adder->width));
          return;
        }
      } else if (adder->format == GST_ADDER_FORMAT_FLOAT) {
        if (adder->width == 64) {
          gdouble *in = (gdouble *) raw_in;
          gdouble *out = (gdouble *) GST_BUFFER_DATA (buf_out);

          for (i = 0; i < GST_BUFFER_SIZE (buf_out) / sizeof (gdouble); i++)
            out[i] = CLAMP (out[i] + in[i], -1.0, 1.0);
        } else if (adder->width == 32) {
          gfloat *in = (gfloat *) raw_in;
          gfloat *out = (gfloat *) GST_BUFFER_DATA (buf_out);

          for (i = 0; i < GST_BUFFER_SIZE (buf_out) / sizeof (gfloat); i++)
            out[i] = CLAMP (out[i] + in[i], -1.0, 1.0);
        } else {
          GST_ELEMENT_ERROR (adder, STREAM, FORMAT, (NULL),
              ("invalid width (%u) for float audio in gstadder", adder->width));
          return;
        }
      } else {
        GST_ELEMENT_ERROR (adder, STREAM, FORMAT, (NULL),
            ("invalid audio format (%d) in gstadder", adder->format));
        return;
      }

      gst_bytestream_flush (input->bytestream, GST_BUFFER_SIZE (buf_out));

      GST_LOG ("done copying data");
    }
  }
  if (adder->width == 0) {
    GST_ELEMENT_ERROR (adder, CORE, NEGOTIATION, (NULL), ("width is 0"));
    return;
  }
  if (adder->channels == 0) {
    GST_ELEMENT_ERROR (adder, CORE, NEGOTIATION, (NULL), ("channels is 0"));
    return;
  }
  if (adder->rate == 0) {
    GST_ELEMENT_ERROR (adder, CORE, NEGOTIATION, (NULL), ("rate is 0"));
    return;
  }

  GST_BUFFER_TIMESTAMP (buf_out) = adder->timestamp;
  if (adder->format == GST_ADDER_FORMAT_FLOAT)
    adder->offset += GST_BUFFER_SIZE (buf_out) / adder->width / adder->channels;
  else
    adder->offset +=
        GST_BUFFER_SIZE (buf_out) * 8 / adder->width / adder->channels;
  adder->timestamp = adder->offset * GST_SECOND / adder->rate;

  /* send it out */

  GST_LOG ("pushing buf_out");
  gst_pad_push (adder->srcpad, GST_DATA (buf_out));
}


static GstElementStateReturn
gst_adder_change_state (GstElement * element)
{
  GstAdder *adder;

  adder = GST_ADDER (element);

  switch (GST_STATE_TRANSITION (element)) {
    case GST_STATE_NULL_TO_READY:
      break;
    case GST_STATE_READY_TO_PAUSED:
      adder->timestamp = 0;
      adder->offset = 0;
      break;
    case GST_STATE_PAUSED_TO_PLAYING:
    case GST_STATE_PLAYING_TO_PAUSED:
    case GST_STATE_PAUSED_TO_READY:
    case GST_STATE_READY_TO_NULL:
    default:
      break;
  }

  if (GST_ELEMENT_CLASS (parent_class)->change_state)
    return GST_ELEMENT_CLASS (parent_class)->change_state (element);

  return GST_STATE_SUCCESS;
}


static gboolean
plugin_init (GstPlugin * plugin)
{
  if (!gst_library_load ("gstbytestream"))
    return FALSE;

  if (!gst_element_register (plugin, "adder", GST_RANK_NONE, GST_TYPE_ADDER)) {
    return FALSE;
  }

  return TRUE;
}

GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
    GST_VERSION_MINOR,
    "adder",
    "Adds multiple streams",
    plugin_init, VERSION, "LGPL", GST_PACKAGE, GST_ORIGIN)