/* GIO - GLib Input, Output and Streaming Library
 *
 * SPDX-FileCopyrightText: 2009 Red Hat, Inc.
 * SPDX-FileCopyrightText: 2010 Christian Persch
 * SPDX-License-Identifier: LGPL-2.1-or-later
 */

#include "config.h"

#include "gbase64decoder.h"

#include <string.h>

#include <glib.h>

#include "gioenums.h"
#include "gioenumtypes.h"
#include "gioerror.h"
#include "glibintl.h"

/**
 * GBase64Decoder:
 *
 * `GBase64Decoder` is an implementation of [iface@Gio.Converter]
 * that converts data from base64 encoding.
 *
 * Since: 2.82
 */

struct _GBase64Decoder
{
  GObject parent_instance;

  int state;
  guint save;
};

static void
g_base64_decoder_reset (GConverter *converter)
{
  GBase64Decoder *decoder = G_BASE64_DECODER (converter);

  decoder->state = 0;
  decoder->save = 0;
}

static GConverterResult
g_base64_decoder_convert (GConverter       *converter,
                          const void       *inbuf,
                          gsize             inbuf_size,
                          void             *outbuf,
                          gsize             outbuf_size,
                          GConverterFlags   flags,
                          gsize            *bytes_read,
                          gsize            *bytes_written,
                          GError          **error)
{
  GBase64Decoder *decoder = G_BASE64_DECODER (converter);

  if (outbuf_size < ((inbuf_size / 4) * 3 + 3))
    {
      g_set_error (error,
                   G_IO_ERROR, G_IO_ERROR_NO_SPACE,
                  "Not enough space in dest");
      return G_CONVERTER_ERROR;
    }

  *bytes_read = inbuf_size;
  *bytes_written = g_base64_decode_step (inbuf, inbuf_size, outbuf,
                                         &decoder->state, &decoder->save);

  if (flags & G_CONVERTER_FLUSH)
    return G_CONVERTER_FLUSHED;
  if (*bytes_read == inbuf_size && (flags & G_CONVERTER_INPUT_AT_END))
    return G_CONVERTER_FINISHED;

  return G_CONVERTER_CONVERTED;
}

static void
g_base64_decoder_iface_init (GConverterIface *iface)
{
  iface->convert = g_base64_decoder_convert;
  iface->reset = g_base64_decoder_reset;
}

G_DEFINE_TYPE_WITH_CODE (GBase64Decoder, g_base64_decoder, G_TYPE_OBJECT,
                         G_IMPLEMENT_INTERFACE (G_TYPE_CONVERTER, g_base64_decoder_iface_init))

static void
g_base64_decoder_init (GBase64Decoder *decoder)
{
  decoder->state = 0;
  decoder->save = 0;
}

static void
g_base64_decoder_class_init (GBase64DecoderClass *klass)
{
}

/**
 * g_base64_decoder_new:
 *
 * Creates a new `GBase64Decoder`.
 *
 * Returns: (transfer full): a new `GBase64Decoder`
 *
 * Since: 2.82
 */
GConverter *
g_base64_decoder_new (void)
{
  return g_object_new (G_TYPE_BASE64_DECODER, NULL);
}