#include "util.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <glib.h>

#include <gst/base/gstbytewriter.h>

gpointer
cmumble_find_by_id(GList *list, gsize member_offset, guint id)
{
	gpointer el = NULL;
	GList *l;

	for (l = list; l; l = l->next) {
		if (G_STRUCT_MEMBER(uint32_t, l->data, member_offset) == id) {
			el = l->data;
			break;
		}
	}

	return el;
}

gchar *
cmumble_get_os_name(void)
{
	FILE *f;
	char *line = NULL;
	char *os = NULL, *value, *end;
	size_t key_len = strlen("PRETTY_NAME=");
	size_t n;

	f = fopen("/etc/os-release", "r");
	if (f == NULL)
		return NULL;

	while (getline(&line, &n, f) != -1) {
		if (strncmp("PRETTY_NAME=", line, key_len) == 0 && (n - key_len) > 1) {
			value = &line[key_len];
			if (strlen(value) == 0)
				continue;

			end = &value[strlen(value) - 1];
			if (*end == '\n')
				*end-- = '\0';

			if (strlen(value) < 2)
				continue;

			if (value[0] == '"')
				value++;

			if (*end == '"')
				*end = '\0';

			os = strdup(value);
			goto out;
		}
	}

out:
	free(line);
	fclose(f);
	return os;
}

/* This code is taken from gst-plugins-bad/ext/opus/gstopusheader.c */
GstBuffer *
_gst_opus_enc_create_id_buffer(gint nchannels, gint n_stereo_streams,
			       gint sample_rate, guint8 channel_mapping_family,
			       const guint8 *channel_mapping)
{
  GstBuffer *buffer;
  GstByteWriter bw;
  gboolean hdl = TRUE;

  g_return_val_if_fail (nchannels > 0 && nchannels < 256, NULL);
  g_return_val_if_fail (n_stereo_streams >= 0, NULL);
  g_return_val_if_fail (n_stereo_streams <= nchannels - n_stereo_streams, NULL);

  gst_byte_writer_init (&bw);

  /* See http://wiki.xiph.org/OggOpus */
  hdl &= gst_byte_writer_put_data (&bw, (const guint8 *) "OpusHead", 8);
  hdl &= gst_byte_writer_put_uint8 (&bw, 0x01); /* version number */
  hdl &= gst_byte_writer_put_uint8 (&bw, nchannels);
  hdl &= gst_byte_writer_put_uint16_le (&bw, 0);        /* pre-skip */
  hdl &= gst_byte_writer_put_uint32_le (&bw, sample_rate);
  hdl &= gst_byte_writer_put_uint16_le (&bw, 0);        /* output gain */
  hdl &= gst_byte_writer_put_uint8 (&bw, channel_mapping_family);
  if (channel_mapping_family > 0) {
    hdl &= gst_byte_writer_put_uint8 (&bw, nchannels - n_stereo_streams);
    hdl &= gst_byte_writer_put_uint8 (&bw, n_stereo_streams);
    hdl &= gst_byte_writer_put_data (&bw, channel_mapping, nchannels);
  }

  if (!hdl)
    GST_WARNING ("Error creating header");

  buffer = gst_byte_writer_reset_and_get_buffer (&bw);

  GST_BUFFER_OFFSET (buffer) = 0;
  GST_BUFFER_OFFSET_END (buffer) = 0;

  return buffer;
}

static int
create_gst_buffer_array (GValue *array, GstBuffer * buf, ...)
{
  va_list va;
  GValue value = { 0 };

  g_value_init (array, GST_TYPE_ARRAY);

  va_start (va, buf);
  /* put buffers in a fixed list */
  while (buf) {
    g_assert (gst_buffer_is_writable (buf));

    /* mark buffer */
    GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_HEADER);

    g_value_init (&value, GST_TYPE_BUFFER);
    buf = gst_buffer_copy (buf);
    GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_HEADER);
    gst_value_set_buffer (&value, buf);
    gst_buffer_unref (buf);
    gst_value_array_append_value (&array, &value);
    g_value_unset (&value);

    buf = va_arg (va, GstBuffer *);
  }

  return 0;