/*
 * Copyright 2014-2018, Intel Corporation
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *
 *     * Neither the name of the copyright holder nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * convert.c -- pmempool convert command source file
 */

#include <stdio.h>
#include <libgen.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <getopt.h>
#include <stdbool.h>
#include <sys/mman.h>
#include <endian.h>
#include "common.h"
#include "set.h"
#include "libpmem.h"
#include "convert.h"
#include "util_pmem.h"

static const char *help_str = "";

/*
 * print_usage -- print application usage short description
 */
static void
print_usage(char *appname)
{
	printf("Usage: %s convert <file>\n", appname);
}

/*
 * print_version -- print version string
 */
static void
print_version(char *appname)
{
	printf("%s %s\n", appname, SRCVERSION);
}

/*
 * pmempool_convert_help -- print help message for convert command
 */
void
pmempool_convert_help(char *appname)
{
	print_usage(appname);
	print_version(appname);
	printf(help_str, appname);
}

typedef int (*convert_func)(void *poolset, void *addr);

/*
 * convert_v2_v3 -- (internal) informs the user of the unfortunate fate of their
 *	pools.
 *
 * The change introduced in the third major layout version impacts the internal
 * alignment of user structures and as such, a generic conversion is not
 * possible.
 */
static int
convert_v2_v3(void *poolset, void *addr)
{
	printf("The conversion can only be made automatically if the\n"
		"PMEMmutex, PMEMrwlock and PMEMcond types are not used in the\n"
		"pool or all of the variables of those three types are aligned "
		"to 8 bytes.\nProceed only if you are sure that the above is "
		"true for this pool.\n");
	char ans = ask_Yn('?', "convert the pool ?");
	if (ans == INV_ANS)
		return -1;

	if (ans == 'y')
		return 0;

	return -1;
}

/*
 * Collection of pool converting functions. Each array index is used as a
 * source version.
 */
static convert_func version_convert[] = {
	NULL, /* from version 0 to version 1 - does not exist */
	convert_v1_v2, /* from v1 to v2 */
	convert_v2_v3, /* from v2 to v3 */
	convert_v3_v4, /* from v3 to v4 */
};

/*
 * pmempool_convert_persist -- calls the appropriate persist func for poolset
 */
void
pmempool_convert_persist(void *poolset, const void *addr, size_t len)
{
	pool_set_file_persist(poolset, addr, len);
}

/*
 * pmempool_convert_func -- main function for convert command
 */
int
pmempool_convert_func(char *appname, int argc, char *argv[])
{
	if (argc != 2) {
		print_usage(appname);

		return -1;
	}

	int ret = 0;
	const char *f = argv[1];

	struct pmem_pool_params params;
	if (pmem_pool_parse_params(f, &params, 1)) {
		fprintf(stderr, "Cannot determine type of pool.\n");
		return -1;
	}

	if (params.is_part) {
		fprintf(stderr, "Conversion cannot be performed on "
			"a poolset part.\n");
		return -1;
	}

	if (params.type != PMEM_POOL_TYPE_OBJ) {
		fprintf(stderr, "Conversion is currently supported only for "
				"pmemobj pools.\n");
		return -1;
	}

	struct pool_set_file *psf = pool_set_file_open(f, 0, 1);
	if (psf == NULL) {
		perror(f);
		return -1;
	}

	if (psf->poolset->remote) {
		fprintf(stderr, "Conversion of remotely replicated  pools is "
			"currently not supported. Remove the replica first\n");
		pool_set_file_close(psf);
		return -1;
	}

	void *addr = pool_set_file_map(psf, 0);
	if (addr == NULL) {
		perror(f);
		ret = -1;
		goto out;
	}

	struct pool_hdr *phdr = addr;
	uint32_t m = le32toh(phdr->major);
	if (m >= COUNT_OF(version_convert) || !version_convert[m]) {
		fprintf(stderr, "There's no conversion method for the pool.\n"
				"Please make sure the pmempool utility "
				"is up-to-date.\n");
		ret = -1;
		goto out;
	}

	printf("This tool will update the pool to the latest available "
		"layout version.\nThis process is NOT fail-safe.\n"
		"Proceed only if the pool has been backed up or\n"
		"the risks are fully understood and acceptable.\n");
	char ans = ask_Yn('?', "convert the pool '%s' ?", f);
	if (ans == INV_ANS) {
		fprintf(stderr, "invalid answer");
		ret = -1;
		goto out;
	}

	if (ans != 'y') {
		ret = 0;
		goto out;
	}

	PMEMobjpool *pop = addr;

	for (unsigned r = 0; r < psf->poolset->nreplicas; ++r) {
		struct pool_replica *rep = psf->poolset->replica[r];
		for (unsigned p = 0; p < rep->nparts; ++p) {
			struct pool_set_part *part = &rep->part[p];
			if (util_map_hdr(part, MAP_SHARED, 0) != 0) {
				fprintf(stderr, "Failed to map headers.\n"
						"Conversion did not start.\n");
				ret = -1;
				goto out;
			}
		}
	}

	uint32_t i;
	for (i = m; i < COUNT_OF(version_convert); ++i) {
		if (version_convert[i](psf, pop) != 0) {
			fprintf(stderr, "Failed to convert the pool\n");
			break;
		} else {
			/* need to update every header of every part */
			uint32_t target_m = i + 1;
			for (unsigned r = 0; r < psf->poolset->nreplicas; ++r) {
				struct pool_replica *rep =
					psf->poolset->replica[r];
				for (unsigned p = 0; p < rep->nparts; ++p) {
					struct pool_set_part *part =
						&rep->part[p];

					struct pool_hdr *hdr = part->hdr;
					hdr->major = htole32(target_m);
					util_checksum(hdr, sizeof(*hdr),
						&hdr->checksum, 1,
						POOL_HDR_CSUM_END_OFF);
					util_persist_auto(part->is_dev_dax, hdr,
						sizeof(struct pool_hdr));
				}
			}
		}
	}

	if (i != m) /* at least one step has been performed */
		printf("The pool has been converted to version %d\n", i);

	util_persist_auto(psf->poolset->replica[0]->part[0].is_dev_dax, pop,
			psf->size);

out:
	for (unsigned r = 0; r < psf->poolset->nreplicas; ++r) {
		struct pool_replica *rep = psf->poolset->replica[r];
		for (unsigned p = 0; p < rep->nparts; ++p) {
			struct pool_set_part *part = &rep->part[p];
			if (part->hdr != NULL)
				util_unmap_hdr(part);
		}
	}

	pool_set_file_close(psf);

	return ret;
}
