/*
 * Copyright (C) 2006 John Ellis
 * Copyright (C) 2008 - 2016 The Geeqie Team
 *
 * Author: Lars Ellenberg
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "format-raw.h"

#include <sys/mman.h>
#include <sys/stat.h>
#include <unistd.h>

#include <cstdio>
#include <cstring>

#include <glib.h>

#include "exif.h"
#include "format-canon.h"
#include "format-fuji.h"
#include "format-nikon.h"
#include "format-olympus.h"


struct FormatRawEntry {
	const gchar *extension;
	FormatRawMatchType magic_type;
	guint magic_offset;
	gconstpointer magic_pattern;
	guint magic_length;
	FormatRawExifType exif_type;
	FormatRawExifParseFunc exif_func;
	const gchar *description;
	FormatRawParseFunc func_parse;
};

static FormatRawEntry format_raw_list[] = {
#if DEBUG_RAW_TIFF
	FORMAT_RAW_DEBUG_TIFF,
#endif
	FORMAT_RAW_CANON,
	FORMAT_RAW_FUJI,
	FORMAT_RAW_NIKON,
	FORMAT_RAW_OLYMPUS,
	FORMAT_RAW_PENTAX,
	FORMAT_RAW_SAMSUNG,
	{ nullptr, static_cast<FormatRawMatchType>(0), 0, nullptr, 0, static_cast<FormatRawExifType>(0), nullptr, nullptr, nullptr }
};


struct FormatExifEntry {
	FormatExifMatchType header_type;
	gconstpointer header_pattern;
	guint header_length;
	const gchar *description;
	FormatExifParseFunc func_parse;
};

static FormatExifEntry format_exif_list[] = {
	FORMAT_EXIF_CANON,
	FORMAT_EXIF_FUJI,
	FORMAT_EXIF_NIKON,
	FORMAT_EXIF_OLYMPUS,
	{ static_cast<FormatExifMatchType>(0), nullptr, 0, nullptr, nullptr }
};


static guint tiff_table(guchar *data, const guint len, guint offset, ExifByteOrder bo,
			guint tag, ExifFormatType type,
			guint *result_offset, guint *result_count)
{
	guint count;
	guint i;

	if (len < offset + 2) return 0;
	if (type > EXIF_FORMAT_COUNT) return 0;

	count = exif_byte_get_int16(data + offset, bo);
	offset += 2;
	if (len < offset + (count * 12) + 4) return 0;

	for (i = 0; i < count; i++)
		{
		guint segment;

		segment = offset + (i * 12);
		if (exif_byte_get_int16(data + segment, bo) == tag &&
		    exif_byte_get_int16(data + segment + 2, bo) == type)
			{
			guint chunk_count;
			guint chunk_offset;
			guint chunk_length;

			chunk_count = exif_byte_get_int32(data + segment + 4, bo);
			chunk_length = ExifFormatList[type].size * chunk_count;

			if (chunk_length > 4)
				{
				chunk_offset = exif_byte_get_int32(data + segment + 8, bo);
				}
			else
				{
				chunk_offset = segment + 8;
				}

			if (chunk_offset + chunk_length <= len)
				{
				*result_offset = chunk_offset;
				*result_count = chunk_count;
				}

			return 0;
			}
		}

	return exif_byte_get_int32(data + offset + (count * 12), bo);
}

static gboolean format_tiff_find_tag_data(guchar *data, const guint len,
				          guint tag, ExifFormatType type,
				          guint *result_offset, guint *result_count)
{
	ExifByteOrder bo;
	guint offset;

	if (len < 8) return FALSE;

	if (memcmp(data, "II", 2) == 0)
		{
		bo = EXIF_BYTE_ORDER_INTEL;
		}
	else if (memcmp(data, "MM", 2) == 0)
		{
		bo = EXIF_BYTE_ORDER_MOTOROLA;
		}
	else
		{
		return FALSE;
		}

	if (exif_byte_get_int16(data + 2, bo) != 0x002A)
		{
		return FALSE;
		}

	offset = exif_byte_get_int32(data + 4, bo);

	while (offset != 0)
		{
		guint ro = 0;
		guint rc = 0;

		offset = tiff_table(data, len, offset, bo, tag, type, &ro, &rc);
		if (ro != 0)
			{
			*result_offset = ro;
			*result_count = rc;
			return TRUE;
			}
		}

	return FALSE;
}

static FormatRawEntry *format_raw_find(guchar *data, const guint len)
{
	gint n;
	gboolean tiff;
	guint make_count = 0;
	guint make_offset = 0;

	tiff = (len > 8 &&
		(memcmp(data, "II\x2a\x00", 4) == 0 ||
		 memcmp(data, "MM\x00\x2a", 4) == 0));

	n = 0;
	while (format_raw_list[n].magic_pattern)
		{
		FormatRawEntry *entry = &format_raw_list[n];

		switch (entry->magic_type)
			{
			case FORMAT_RAW_MATCH_MAGIC:
				if (entry->magic_length + entry->magic_offset <= len &&
				    memcmp(data + entry->magic_offset,
					   entry->magic_pattern, entry->magic_length) == 0)
					{
					return entry;
					}
				break;
			case FORMAT_RAW_MATCH_TIFF_MAKE:
				if (tiff &&
				    make_offset == 0 &&
				    !format_tiff_find_tag_data(data, len, 0x10f, EXIF_FORMAT_STRING,
							       &make_offset, &make_count))
					{
					tiff = FALSE;
					}
				if (make_offset != 0 &&
				    make_count >= entry->magic_offset + entry->magic_length &&
				    memcmp(entry->magic_pattern,
					   data + make_offset + entry->magic_offset, entry->magic_length) == 0)
					{
					return entry;
					}
				break;
			default:
				break;
			}
		n++;
		}

	return nullptr;
}

static gboolean format_raw_parse(FormatRawEntry *entry,
			         guchar *data, const guint len,
			         guint *image_offset, guint *exif_offset)
{
	guint io = 0;
	guint eo = 0;
	gboolean found;

	if (!entry || !entry->func_parse) return FALSE;

	DEBUG_1("RAW using file parser for %s", entry->description);

	found = entry->func_parse(data, len, &io, &eo);

	if (!found ||
	    io >= len - 4 ||
	    eo >= len)
		{
		return FALSE;
		}

	if (image_offset) *image_offset = io;
	if (exif_offset) *exif_offset = eo;

	return TRUE;
}

gboolean format_raw_img_exif_offsets(guchar *data, const guint len,
				     guint *image_offset, guint *exif_offset)
{
	FormatRawEntry *entry;

	if (!data || len < 1) return FALSE;

	entry = format_raw_find(data, len);

	if (!entry || !entry->func_parse) return FALSE;

	return format_raw_parse(entry, data, len, image_offset, exif_offset);
}


FormatRawExifType format_raw_exif_offset(guchar *data, const guint len, guint *exif_offset,
					 FormatRawExifParseFunc *exif_parse_func)
{
	FormatRawEntry *entry;

	if (!data || len < 1) return static_cast<FormatRawExifType>FALSE;

	entry = format_raw_find(data, len);

	if (!entry || !entry->func_parse) return static_cast<FormatRawExifType>FALSE;

	if (!format_raw_parse(entry, data, len, nullptr, exif_offset)) return FORMAT_RAW_EXIF_NONE;

	if (entry->exif_type == FORMAT_RAW_EXIF_PROPRIETARY && exif_parse_func)
		{
		*exif_parse_func = entry->exif_func;
		}

	return entry->exif_type;
}


gboolean format_raw_img_exif_offsets_fd(gint fd, const gchar *path,
				        guchar *header_data, const guint header_len,
				        guint *image_offset, guint *exif_offset)
{
	FormatRawEntry *entry;
	gpointer map_data = nullptr;
	size_t map_len = 0;
	struct stat st;
	gboolean success;

	if (!header_data || fd < 0) return FALSE;

	/* given image pathname, first do simple (and fast) file extension test */
	if (path)
		{
		const gchar *ext;
		gboolean match = FALSE;
		gint i;

		ext = strrchr(path, '.');
		if (!ext) return FALSE;
		ext++;

		i = 0;
		while (!match && format_raw_list[i].magic_pattern)
			{
			if (format_raw_list[i].extension &&
			    g_ascii_strcasecmp(format_raw_list[i].extension, ext) == 0)
				{
				match = TRUE;
				}
			i++;
			}

		if (!match) return FALSE;

		DEBUG_1("RAW file parser extension match");
		}

	/**
	 * @FIXME when the target is a tiff file it should be mmaped prior to format_raw_find as
	 * the make field data may not always be within header_data + header_len
	 */
	entry = format_raw_find(header_data, header_len);

	if (!entry || !entry->func_parse) return FALSE;

	if (fstat(fd, &st) == -1)
		{
		log_printf("Failed to stat file %d\n", fd);
		return FALSE;
		}
	map_len = st.st_size;
	map_data = mmap(nullptr, map_len, PROT_READ, MAP_PRIVATE, fd, 0);
	if (map_data == MAP_FAILED)
		{
		log_printf("Failed to mmap file %d\n", fd);
		return FALSE;
		}

	success = format_raw_parse(entry, static_cast<guchar*>(map_data), map_len, image_offset, exif_offset);

	if (munmap(map_data, map_len) == -1)
		{
		log_printf("Failed to unmap file %d\n", fd);
		}

	if (success && image_offset)
		{
		if (lseek(fd, *image_offset, SEEK_SET) != static_cast<off_t>(*image_offset))
			{
			log_printf("Failed to seek to embedded image\n");

			*image_offset = 0;
			if (*exif_offset) *exif_offset = 0;
			success = FALSE;
			}
		}

	return success;
}


static FormatExifEntry *format_exif_makernote_find(ExifData *exif, guchar *tiff,
						   guint offset, guint size)
{
	ExifItem *make;
	gint n;

	make = exif_get_item(exif, "Exif.Image.Make");

	n = 0;
	while (format_exif_list[n].header_pattern)
		{
		switch (format_exif_list[n].header_type)
			{
			case FORMAT_EXIF_MATCH_MAKERNOTE:
				if (format_exif_list[n].header_length + offset < size &&
				    memcmp(tiff + offset, format_exif_list[n].header_pattern,
							  format_exif_list[n].header_length) == 0)
					{
					return &format_exif_list[n];
					}
				break;
			case FORMAT_EXIF_MATCH_MAKE:
				if (make &&
				    make->data_len >= format_exif_list[n].header_length &&
				    memcmp(make->data, format_exif_list[n].header_pattern,
						       format_exif_list[n].header_length) == 0)
					{
					return &format_exif_list[n];
					}
				break;
			}
		n++;
		}

	return FALSE;
}

gboolean format_exif_makernote_parse(ExifData *exif, guchar *tiff, guint offset,
				     guint size, ExifByteOrder bo)
{
	FormatExifEntry *entry;

	entry = format_exif_makernote_find(exif, tiff, offset, size);

	if (!entry || !entry->func_parse) return FALSE;

	DEBUG_1("EXIF using makernote parser for %s", entry->description);

	return entry->func_parse(exif, tiff, offset, size, bo);
}

/*
 *-----------------------------------------------------------------------------
 * Basic TIFF debugger, prints all IFD entries within tiff file
 *-----------------------------------------------------------------------------
 */
#if DEBUG_RAW_TIFF

static guint format_debug_tiff_table(guchar *data, const guint len, guint offset,
				     ExifByteOrder bo, gint level);

static void format_debug_tiff_entry(guchar *data, const guint len, guint offset,
				    ExifByteOrder bo, gint level)
{
	guint tag;
	guint type;
	guint count;
	guint segment;
	guint seg_len;

	tag = exif_byte_get_int16(data + offset + EXIF_TIFD_OFFSET_TAG, bo);
	type = exif_byte_get_int16(data + offset + EXIF_TIFD_OFFSET_FORMAT, bo);
	count = exif_byte_get_int32(data + offset + EXIF_TIFD_OFFSET_COUNT, bo);

	seg_len = ExifFormatList[type].size * count;
	if (seg_len > 4)
		{
		segment = exif_byte_get_int32(data + offset + EXIF_TIFD_OFFSET_DATA, bo);
		if (segment + seg_len > len) return;
		}
	else
		{
		segment = offset + EXIF_TIFD_OFFSET_DATA;
		}

	log_printf("%*stag:0x%04X (%05d), type:%2d %9s, len:%6d [%02X %02X %02X %02X] @ offset:%d\n",
		level, "", tag, tag, type,
		(type < EXIF_FORMAT_COUNT) ? ExifFormatList[type].short_name : "???", count,
		data[segment], data[segment + 1], data[segment + 2], data[segment + 3], segment);

	if (tag == 0x8769 || tag == 0x14a)
		{
		gint i;

		log_printf("%*s~~~ found %s table\n", level, "", (tag == 0x14a) ? "subIFD" : "EXIF" );

		for (i = 0; i < count; i++)
			{
			guint subset;

			subset = exif_byte_get_int32(data + segment + i * 4, bo);
			format_debug_tiff_table(data, len, subset, bo, level + 1);
			}
		}
	else if (tag == 0x8773 && type == EXIF_FORMAT_UNDEFINED)
		{
		log_printf("%*s~~~ found ICC color profile at offset %d, length %d\n", level, "", segment, seg_len);
		}
	else if (tag == 0x201 && (type == EXIF_FORMAT_LONG_UNSIGNED || type == EXIF_FORMAT_LONG))
		{
		guint subset = exif_byte_get_int32(data + segment, bo);
		log_printf("%*s~~~ found jpeg data at offset %d\n", level, "", subset);
		}
	else if (tag == 0x202 && (type == EXIF_FORMAT_LONG_UNSIGNED || type == EXIF_FORMAT_LONG))
		{
		guint subset = exif_byte_get_int32(data + segment, bo);
		log_printf("%*s~~~ found jpeg data length of %d\n", level, "", subset);
		}
}

static guint format_debug_tiff_table(guchar *data, const guint len, guint offset,
				     ExifByteOrder bo, gint level)
{
	guint count;
	guint i;

	if (level > EXIF_TIFF_MAX_LEVELS) return 0;

	if (len < offset + 2) return FALSE;

	count = exif_byte_get_int16(data + offset, bo);
	offset += 2;
	if (len < offset + count * EXIF_TIFD_SIZE + 4) return 0;

	log_printf("%*s== tiff table #%d has %d entries ==\n", level, "", level, count);

	for (i = 0; i < count; i++)
		{
		format_debug_tiff_entry(data, len, offset + i * EXIF_TIFD_SIZE, bo, level);
		}

	log_printf("%*s----------- end of #%d ------------\n", level, "", level);

	return exif_byte_get_int32(data + offset + count * EXIF_TIFD_SIZE, bo);
}

/**
 * @brief Used for debugging only
 */
gboolean format_debug_tiff_raw(guchar *data, const guint len,
			       guint *image_offset, guint *exif_offset)
{
	ExifByteOrder bo;
	gint level;
	guint offset;

	if (len < 8) return FALSE;

	/* for debugging, we are more relaxed as to magic header */
	if (memcmp(data, "II", 2) == 0)
		{
		bo = EXIF_BYTE_ORDER_INTEL;
		}
	else if (memcmp(data, "MM", 2) == 0)
		{
		bo = EXIF_BYTE_ORDER_MOTOROLA;
		}
	else
		{
		return FALSE;
		}

	log_printf("*** debug parsing tiff\n");

	offset = exif_byte_get_int32(data + 4, bo);
	level = 0;
	while (offset && level < EXIF_TIFF_MAX_LEVELS)
		{
		offset = format_debug_tiff_table(data, len, offset, bo, 0);
		level++;
		}

	log_printf("*** end\n");

	/* we are debugging, not trying to return any data */
	return FALSE;
}
#endif
/* vim: set shiftwidth=8 softtabstop=0 cindent cinoptions={1s: */
