/*
 * join.c
 *
 * Join split WIMs (sometimes named as .swm files) together into one WIM.
 */

/*
 * Copyright (C) 2012, 2013 Eric Biggers
 *
 * This file is part of wimlib, a library for working with WIM files.
 *
 * wimlib 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 3 of the License, or (at your option)
 * any later version.
 *
 * wimlib 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 wimlib; if not, see http://www.gnu.org/licenses/.
 */

#ifdef HAVE_CONFIG_H
#  include "config.h"
#endif

#include "wimlib.h"
#include "wimlib/lookup_table.h"
#include "wimlib/metadata.h"
#include "wimlib/resource.h"
#include "wimlib/swm.h"
#include "wimlib/wim.h"
#include "wimlib/write.h"
#include "wimlib/xml.h"

#include <stdlib.h> /* for qsort() */

static int
move_lte_to_table(struct wim_lookup_table_entry *lte, void *combined_table)
{
	hlist_del(&lte->hash_list);
	lookup_table_insert((struct wim_lookup_table*)combined_table, lte);
	return 0;
}

static void
lookup_table_join(struct wim_lookup_table *combined_table,
		  struct wim_lookup_table *part_table)
{
	for_lookup_table_entry(part_table, move_lte_to_table, combined_table);
	part_table->num_entries = 0;
}

/*
 * merge_lookup_tables() - Merge lookup tables from the parts of a split WIM.
 *
 * @w specifies the first part, while @additional_swms and @num_additional_swms
 * specify an array of pointers to the WIMStruct's for additional split WIM parts.
 *
 * The reason we join the lookup tables is so we only have to search one lookup
 * table to find the location of a resource in the entire WIM.
 */
void
merge_lookup_tables(WIMStruct *w,
		    WIMStruct **additional_swms,
		    unsigned num_additional_swms)
{
	for (unsigned i = 0; i < num_additional_swms; i++)
		lookup_table_join(w->lookup_table, additional_swms[i]->lookup_table);
}

static int
move_lte_to_orig_table(struct wim_lookup_table_entry *lte, void *_wim)
{
	WIMStruct *wim = _wim;
	if (lte->wim != wim) {
		move_lte_to_table(lte, lte->wim->lookup_table);
		wim->lookup_table->num_entries--;
	}
	return 0;
}

/* Undo merge_lookup_tables(), given the first WIM part that contains the merged
 * lookup table. */
void
unmerge_lookup_table(WIMStruct *wim)
{
	for_lookup_table_entry(wim->lookup_table, move_lte_to_orig_table, wim);
}


static int
join_wims(WIMStruct **swms, unsigned num_swms,
	  WIMStruct *joined_wim, int write_flags,
	  wimlib_progress_func_t progress_func)
{
	int ret;
	unsigned i;
	union wimlib_progress_info progress;
	u64 total_bytes = 0;
	u64 part_bytes;
	u64 swm_part_sizes[num_swms];

	/* Calculate total size of the streams in the split WIM parts. */
	for (i = 0; i < num_swms; i++) {
		part_bytes = lookup_table_total_stream_size(swms[i]->lookup_table);
		swm_part_sizes[i] = part_bytes;
		total_bytes += part_bytes;
	}

	if (progress_func) {
		progress.join.total_bytes     = total_bytes;
		progress.join.total_parts     = swms[0]->hdr.total_parts;
		progress.join.completed_bytes = 0;
		progress.join.completed_parts = 0;
		progress_func(WIMLIB_PROGRESS_MSG_JOIN_STREAMS, &progress);
	}

	/* Write the non-metadata resources from each SWM part */
	for (i = 0; i < num_swms; i++) {
		ret = reopen_wim(swms[i]);
		if (ret)
			return ret;
		swms[i]->out_fd = joined_wim->out_fd;
		swms[i]->hdr.part_number = 1;

		ret = for_lookup_table_entry_pos_sorted(swms[i]->lookup_table,
							copy_resource,
							swms[i]);
		swms[i]->out_fd = -1;
		if (i != 0)
			close_wim(swms[i]);

		if (ret)
			return ret;

		if (progress_func) {
			progress.join.completed_bytes += swm_part_sizes[i];
			progress.join.completed_parts++;
			progress_func(WIMLIB_PROGRESS_MSG_JOIN_STREAMS, &progress);
		}
	}

	/* Copy the metadata resources from the first SWM part */
	joined_wim->hdr.image_count = swms[0]->hdr.image_count;
	for (i = 0; i < joined_wim->hdr.image_count; i++) {
		ret = copy_resource(swms[0]->image_metadata[i]->metadata_lte,
				    joined_wim);
		if (ret)
			return ret;
	}

	/* Write lookup table, XML data, and optional integrity table */
	for (i = 0; i < num_swms; i++)
		lookup_table_join(joined_wim->lookup_table, swms[i]->lookup_table);

	free_wim_info(joined_wim->wim_info);
	joined_wim->wim_info = swms[0]->wim_info;
	joined_wim->image_metadata = swms[0]->image_metadata;
	ret = finish_write(joined_wim, WIMLIB_ALL_IMAGES, write_flags, progress_func);
	joined_wim->wim_info = NULL;
	joined_wim->image_metadata = NULL;
	return ret;
}

static int
cmp_swms_by_part_number(const void *swm1, const void *swm2)
{
	u16 partno_1 = (*(const WIMStruct**)swm1)->hdr.part_number;
	u16 partno_2 = (*(const WIMStruct**)swm2)->hdr.part_number;
	return (int)partno_1 - (int)partno_2;
}

/*
 * Join a set of split WIMs into a stand-alone WIM.
 */
WIMLIBAPI int
wimlib_join(const tchar * const *swm_names,
	    unsigned num_swms,
	    const tchar *output_path,
	    int swm_open_flags,
	    int wim_write_flags,
	    wimlib_progress_func_t progress_func)
{
	int ret;
	WIMStruct *joined_wim = NULL;
	unsigned i;

	swm_open_flags |= WIMLIB_OPEN_FLAG_SPLIT_OK;
	wim_write_flags &= WIMLIB_WRITE_MASK_PUBLIC;

	if (num_swms < 1 || num_swms > 0xffff)
		return WIMLIB_ERR_INVALID_PARAM;

	WIMStruct *swms[num_swms];
	ZERO_ARRAY(swms);

	for (i = 0; i < num_swms; i++) {
		ret = wimlib_open_wim(swm_names[i], swm_open_flags, &swms[i],
				      progress_func);
		if (ret)
			goto out_free_wims;

		/* Don't open all the parts at the same time, in case there are
		 * a lot of them */
		close_wim(swms[i]);
	}

	qsort(swms, num_swms, sizeof(swms[0]), cmp_swms_by_part_number);

	ret = verify_swm_set(swms[0], &swms[1], num_swms - 1);
	if (ret)
		goto out_free_wims;

	ret = wimlib_create_new_wim(wimlib_get_compression_type(swms[0]),
				    &joined_wim);
	if (ret)
		goto out_free_wims;

	ret = begin_write(joined_wim, output_path, wim_write_flags);
	if (ret)
		goto out_free_wims;
	ret = join_wims(swms, num_swms, joined_wim, wim_write_flags,
			progress_func);
out_free_wims:
	for (i = 0; i < num_swms; i++)
		wimlib_free(swms[i]);
	wimlib_free(joined_wim);
	return ret;
}