/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*-
 *
 * Copyright (C) 2015 Richard Hughes <richard@hughsie.com>
 *
 * Licensed under the GNU Lesser General Public License Version 2.1
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
 */

/**
 * SECTION:dfu-image
 * @short_description: Object representing a a firmware image
 *
 * A #DfuImage is typically made up of several #DfuElements, although
 * typically there will only be one.
 *
 * See also: #DfuElement
 */

#include "config.h"

#include <string.h>
#include <stdio.h>

#include "dfu-common.h"
#include "dfu-element-private.h"
#include "dfu-error.h"
#include "dfu-image-private.h"

static void dfu_image_finalize			 (GObject *object);

/**
 * DfuImagePrivate:
 *
 * Private #DfuImage data
 **/
typedef struct {
	GPtrArray		*elements;
	gchar			 name[255];
	guint8			 alt_setting;
} DfuImagePrivate;

G_DEFINE_TYPE_WITH_PRIVATE (DfuImage, dfu_image, G_TYPE_OBJECT)
#define GET_PRIVATE(o) (dfu_image_get_instance_private (o))

/**
 * dfu_image_class_init:
 **/
static void
dfu_image_class_init (DfuImageClass *klass)
{
	GObjectClass *object_class = G_OBJECT_CLASS (klass);
	object_class->finalize = dfu_image_finalize;
}

/**
 * dfu_image_init:
 **/
static void
dfu_image_init (DfuImage *image)
{
	DfuImagePrivate *priv = GET_PRIVATE (image);
	priv->elements = g_ptr_array_new_with_free_func ((GDestroyNotify) g_object_unref);
	memset (priv->name, 0x00, 255);
}

/**
 * dfu_image_finalize:
 **/
static void
dfu_image_finalize (GObject *object)
{
	DfuImage *image = DFU_IMAGE (object);
	DfuImagePrivate *priv = GET_PRIVATE (image);

	g_ptr_array_unref (priv->elements);

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

/**
 * dfu_image_new:
 *
 * Creates a new DFU image object.
 *
 * Return value: a new #DfuImage
 *
 * Since: 0.5.4
 **/
DfuImage *
dfu_image_new (void)
{
	DfuImage *image;
	image = g_object_new (DFU_TYPE_IMAGE, NULL);
	return image;
}

/**
 * dfu_image_get_elements:
 * @image: a #DfuImage
 *
 * Gets the element data.
 *
 * Return value: (transfer none) (element-type DfuElement): element data
 *
 * Since: 0.5.4
 **/
GPtrArray *
dfu_image_get_elements (DfuImage *image)
{
	DfuImagePrivate *priv = GET_PRIVATE (image);
	g_return_val_if_fail (DFU_IS_IMAGE (image), NULL);
	return priv->elements;
}

/**
 * dfu_image_get_element:
 * @image: a #DfuImage
 * @idx: an array index
 *
 * Gets the element.
 *
 * Return value: (transfer none): element data, or %NULL for invalid
 *
 * Since: 0.5.4
 **/
DfuElement *
dfu_image_get_element (DfuImage *image, guint8 idx)
{
	DfuImagePrivate *priv = GET_PRIVATE (image);
	g_return_val_if_fail (DFU_IS_IMAGE (image), NULL);
	if (idx >= priv->elements->len)
		return NULL;
	return g_ptr_array_index (priv->elements, idx);
}

/**
 * dfu_image_get_alt_setting:
 * @image: a #DfuImage
 *
 * Gets the alternate setting.
 *
 * Return value: integer, or 0x00 for unset
 *
 * Since: 0.5.4
 **/
guint8
dfu_image_get_alt_setting (DfuImage *image)
{
	DfuImagePrivate *priv = GET_PRIVATE (image);
	g_return_val_if_fail (DFU_IS_IMAGE (image), 0xff);
	return priv->alt_setting;
}

/**
 * dfu_image_get_name:
 * @image: a #DfuImage
 *
 * Gets the target name.
 *
 * Return value: a string, or %NULL for unset
 *
 * Since: 0.5.4
 **/
const gchar *
dfu_image_get_name (DfuImage *image)
{
	DfuImagePrivate *priv = GET_PRIVATE (image);
	g_return_val_if_fail (DFU_IS_IMAGE (image), NULL);
	return priv->name;
}

/**
 * dfu_image_get_size:
 * @image: a #DfuImage
 *
 * Gets the size of all the elements in the image.
 *
 * This only returns actual data that would be sent to the device and
 * does not include any padding.
 *
 * Return value: a integer value, or 0 if there are no elements.
 *
 * Since: 0.5.4
 **/
guint32
dfu_image_get_size (DfuImage *image)
{
	DfuImagePrivate *priv = GET_PRIVATE (image);
	guint32 length = 0;
	guint i;
	g_return_val_if_fail (DFU_IS_IMAGE (image), 0);
	for (i = 0; i < priv->elements->len; i++) {
		DfuElement *element = g_ptr_array_index (priv->elements, i);
		length += g_bytes_get_size (dfu_element_get_contents (element));
	}
	return length;
}

/**
 * dfu_image_add_element:
 * @image: a #DfuImage
 * @element: a #DfuElement
 *
 * Adds an element to the image.
 *
 * Since: 0.5.4
 **/
void
dfu_image_add_element (DfuImage *image, DfuElement *element)
{
	DfuImagePrivate *priv = GET_PRIVATE (image);
	g_return_if_fail (DFU_IS_IMAGE (image));
	g_return_if_fail (DFU_IS_ELEMENT (element));
	g_ptr_array_add (priv->elements, g_object_ref (element));
}

/**
 * dfu_image_set_alt_setting:
 * @image: a #DfuImage
 * @alt_setting: vendor ID, or 0xffff for unset
 *
 * Sets the vendor ID.
 *
 * Since: 0.5.4
 **/
void
dfu_image_set_alt_setting (DfuImage *image, guint8 alt_setting)
{
	DfuImagePrivate *priv = GET_PRIVATE (image);
	g_return_if_fail (DFU_IS_IMAGE (image));
	priv->alt_setting = alt_setting;
}

/**
 * dfu_image_set_name:
 * @image: a #DfuImage
 * @name: a target string, or %NULL
 *
 * Sets the target name.
 *
 * Since: 0.5.4
 **/
void
dfu_image_set_name (DfuImage *image, const gchar *name)
{
	guint16 sz;
	DfuImagePrivate *priv = GET_PRIVATE (image);
	g_return_if_fail (DFU_IS_IMAGE (image));

	/* this is a hard limit in DfuSe */
	memset (priv->name, 0x00, 0xff);
	if (name != NULL) {
		sz = MIN (strlen (name), 0xff - 1);
		memcpy (priv->name, name, sz);
	}
}

/**
 * dfu_image_to_string:
 * @image: a #DfuImage
 *
 * Returns a string representaiton of the object.
 *
 * Return value: NULL terminated string, or %NULL for invalid
 *
 * Since: 0.5.4
 **/
gchar *
dfu_image_to_string (DfuImage *image)
{
	DfuImagePrivate *priv = GET_PRIVATE (image);
	GString *str;
	guint i;

	g_return_val_if_fail (DFU_IS_IMAGE (image), NULL);

	str = g_string_new ("");
	g_string_append_printf (str, "alt_setting: 0x%02x\n", priv->alt_setting);
	if (priv->name[0] != '\0')
		g_string_append_printf (str, "name:        %s\n", priv->name);
	g_string_append_printf (str, "elements:    0x%02x\n",
				priv->elements->len);

	/* add elements */
	for (i = 0; i < priv->elements->len; i++) {
		DfuElement *element = g_ptr_array_index (priv->elements, i);
		g_autofree gchar *tmp = NULL;
		tmp = dfu_element_to_string (element);
		g_string_append_printf (str, "== ELEMENT %i ==\n", i);
		g_string_append_printf (str, "%s\n", tmp);
	}

	g_string_truncate (str, str->len - 1);
	return g_string_free (str, FALSE);
}

/* DfuSe image header */
typedef struct __attribute__((packed)) {
	guint8		 sig[6];
	guint8		 alt_setting;
	guint32		 target_named;
	gchar		 target_name[255];
	guint32		 target_size;
	guint32		 elements;
} DfuSeImagePrefix;

/**
 * dfu_image_from_dfuse: (skip)
 * @data: data buffer
 * @length: length of @data we can access
 * @consumed: (out): the number of bytes we consued
 * @error: a #GError, or %NULL
 *
 * Unpacks an image from DfuSe data.
 *
 * Returns: a #DfuImage, or %NULL for error
 **/
DfuImage *
dfu_image_from_dfuse (const guint8 *data,
		      guint32 length,
		      guint32 *consumed,
		      GError **error)
{
	DfuImagePrivate *priv;
	DfuSeImagePrefix *im;
	guint32 offset = sizeof(DfuSeImagePrefix);
	guint j;
	g_autoptr(DfuImage) image = NULL;

	g_assert_cmpint(sizeof(DfuSeImagePrefix), ==, 274);

	/* check input buffer size */
	if (length < sizeof(DfuSeImagePrefix)) {
		g_set_error (error,
			     DFU_ERROR,
			     DFU_ERROR_INTERNAL,
			     "invalid image data size %u",
			     (guint32) length);
		return NULL;
	}

	/* verify image signature */
	im = (DfuSeImagePrefix *) data;
	if (memcmp (im->sig, "Target", 6) != 0) {
		g_set_error_literal (error,
				     DFU_ERROR,
				     DFU_ERROR_INVALID_FILE,
				     "invalid DfuSe target signature");
		return NULL;
	}

	/* create new image */
	image = dfu_image_new ();
	priv = GET_PRIVATE (image);
	priv->alt_setting = im->alt_setting;
	if (im->target_named == 0x01)
		memcpy (priv->name, im->target_name, 255);

	/* parse elements */
	length -= offset;
	for (j = 0; j < im->elements; j++) {
		guint32 consumed_local;
		g_autoptr(DfuElement) element = NULL;
		element = dfu_element_from_dfuse (data + offset, length,
						  &consumed_local, error);
		if (element == NULL)
			return NULL;
		dfu_image_add_element (image, element);
		offset += consumed_local;
		length -= consumed_local;
	}

	/* return size */
	if (consumed != NULL)
		*consumed = offset;

	return g_object_ref (image);
}

/**
 * dfu_image_to_dfuse: (skip)
 * @image: a #DfuImage
 *
 * Packs a DfuSe image
 *
 * Returns: (transfer full): the packed data
 **/
GBytes *
dfu_image_to_dfuse (DfuImage *image)
{
	DfuImagePrivate *priv = GET_PRIVATE (image);
	DfuElement *element;
	DfuSeImagePrefix *im;
	GBytes *bytes;
	guint32 length_total = 0;
	guint32 offset = sizeof (DfuSeImagePrefix);
	guint8 *buf;
	guint i;
	g_autoptr(GPtrArray) element_array = NULL;

	/* get total size */
	element_array = g_ptr_array_new_with_free_func ((GDestroyNotify) g_bytes_unref);
	for (i = 0; i < priv->elements->len; i++) {
		element = g_ptr_array_index (priv->elements, i);
		bytes = dfu_element_to_dfuse (element);
		g_ptr_array_add (element_array, bytes);
		length_total += g_bytes_get_size (bytes);
	}

	/* add prefix */
	buf = g_malloc0 (length_total + sizeof (DfuSeImagePrefix));
	im = (DfuSeImagePrefix *) buf;
	memcpy (im->sig, "Target", 6);
	im->alt_setting = priv->alt_setting;
	if (priv->name != NULL) {
		im->target_named = 0x01;
		memcpy (im->target_name, priv->name, 255);
	}
	im->target_size = length_total;
	im->elements = priv->elements->len;

	/* copy data */
	for (i = 0; i < element_array->len; i++) {
		const guint8 *data;
		gsize length;
		bytes = g_ptr_array_index (element_array, i);
		data = g_bytes_get_data (bytes, &length);
		memcpy (buf + offset, data, length);
		offset += length;
	}
	return g_bytes_new_take (buf, length_total + sizeof (DfuSeImagePrefix));
}