/*  Copyright (C) 2018 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>

    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 3 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, see <http://www.gnu.org/licenses/>.
*/

#include <stdlib.h>
#include <getopt.h>
#include <sys/stat.h>

#include "libknot/libknot.h"
#include "knot/journal/journal.h"
#include "knot/zone/zone-dump.h"
#include "utils/common/exec.h"
#include "contrib/dynarray.h"
#include "contrib/strtonum.h"
#include "contrib/string.h"

#define PROGRAM_NAME	"kjournalprint"

#define RED		"\x1B[31m"
#define GRN		"\x1B[32m"
#define YLW		"\x1B[93m"
#define RESET		"\x1B[0m"

static void print_help(void)
{
	printf("Usage: %s [parameter] <journal_db> <zone_name>\n"
	       "\n"
	       "Parameters:\n"
	       " -l, --limit <num>  Read only <num> newest changes.\n"
	       " -n, --no-color     Get output without terminal coloring.\n"
	       " -z, --zone-list    Instead of reading jurnal, display the list\n"
	       "                    of zones in the DB (<zone_name> not needed).\n"
	       " -d, --debug        Debug mode output.\n"
	       " -h, --help         Print the program help.\n"
	       " -V, --version      Print the program version.\n",
	       PROGRAM_NAME);
}

// workaround: LMDB fails to detect proper mapsize
static int reconfigure_mapsize(const char *journal_path, size_t *mapsize)
{
	char *data_mdb = sprintf_alloc("%s/data.mdb", journal_path);
	if (data_mdb == NULL) {
		return KNOT_ENOMEM;
	}

	struct stat st;
	if (stat(data_mdb, &st) != 0 || st.st_size == 0) {
		fprintf(stderr, "Journal does not exist: %s\n", journal_path);
		free(data_mdb);
		return KNOT_ENOENT;
	}

	*mapsize = st.st_size + st.st_size / 8; // 112.5% to allow opening when growing
	free(data_mdb);
	return KNOT_EOK;
}

static void print_changeset(const changeset_t *chs, bool color)
{
	printf(color ? YLW : "");
	if (chs->soa_from == NULL) {
		printf(";; Zone-in-journal, serial: %u\n",
		       knot_soa_serial(chs->soa_to->rrs.rdata));
	} else {
		printf(";; Changes between zone versions: %u -> %u\n",
		       knot_soa_serial(chs->soa_from->rrs.rdata),
		       knot_soa_serial(chs->soa_to->rrs.rdata));
	}
	changeset_print(chs, stdout, color);
}

dynarray_declare(rrtype, uint16_t, DYNARRAY_VISIBILITY_STATIC, 100)
dynarray_define(rrtype, uint16_t, DYNARRAY_VISIBILITY_STATIC)

typedef struct {
	rrtype_dynarray_t *arr;
	size_t *counter;
} rrtypelist_ctx_t;

static void rrtypelist_add(rrtype_dynarray_t *arr, uint16_t add_type)
{
	bool already_present = false;
	dynarray_foreach(rrtype, uint16_t, i, *arr) {
		if (*i == add_type) {
			already_present = true;
			break;
		}
	}
	if (!already_present) {
		rrtype_dynarray_add(arr, &add_type);
	}
}

static int rrtypelist_callback(zone_node_t *node, void *data)
{
	rrtypelist_ctx_t *ctx = data;
	for (int i = 0; i < node->rrset_count; i++) {
		knot_rrset_t rrset = node_rrset_at(node, i);
		rrtypelist_add(ctx->arr, rrset.type);
		*ctx->counter += rrset.rrs.count;
	}
	return KNOT_EOK;
}

static void print_changeset_debugmode(const changeset_t *chs)
{
	// detect all types
	rrtype_dynarray_t types = { 0 };
	size_t count_minus = 1, count_plus = 1; // 1 for SOA which is always present but not iterated
	rrtypelist_ctx_t ctx_minus = { &types, &count_minus }, ctx_plus = { &types, &count_plus };
	(void)zone_contents_apply(chs->remove, rrtypelist_callback, &ctx_minus);
	(void)zone_contents_nsec3_apply(chs->remove, rrtypelist_callback, &ctx_minus);
	(void)zone_contents_apply(chs->add, rrtypelist_callback, &ctx_plus);
	(void)zone_contents_nsec3_apply(chs->add, rrtypelist_callback, &ctx_plus);

	if (chs->soa_from == NULL) {
		printf("Zone-in-journal %u  +++: %zu\t size: %zu\t", knot_soa_serial(chs->soa_to->rrs.rdata),
		       count_plus, changeset_serialized_size(chs));
	} else {
		printf("%u -> %u  ---: %zu\t  +++: %zu\t size: %zu\t", knot_soa_serial(chs->soa_from->rrs.rdata),
		       knot_soa_serial(chs->soa_to->rrs.rdata), count_minus, count_plus, changeset_serialized_size(chs));
	}

	char temp[100];
	dynarray_foreach(rrtype, uint16_t, i, types) {
		(void)knot_rrtype_to_string(*i, temp, sizeof(temp));
		printf(" %s", temp);
	}
	printf("\n");
}

int print_journal(char *path, knot_dname_t *name, uint32_t limit, bool color, bool debugmode)
{
	list_t db;
	init_list(&db);
	int ret;
	journal_db_t *jdb = NULL;

	ret = journal_db_init(&jdb, path, 1, JOURNAL_MODE_ROBUST);
	if (ret != KNOT_EOK) {
		return ret;
	}

	ret = reconfigure_mapsize(jdb->path, &jdb->fslimit);
	if (ret != KNOT_EOK) {
		journal_db_close(&jdb);
		return ret;
	}

	ret = journal_open_db(&jdb);
	if (ret != KNOT_EOK) {
		journal_db_close(&jdb);
		return ret;
	}

	if (!journal_exists(&jdb, name)) {
		fprintf(stderr, "This zone does not exist in DB %s\n", path);
		ret = KNOT_ENOENT;
	}

	journal_t *j = journal_new();

	if (ret == KNOT_EOK) {
		ret = journal_open(j, &jdb, name);
	}
	if (ret != KNOT_EOK) {
		journal_free(&j);
		journal_db_close(&jdb);
		return ret;
	}

	bool has_bootstrap;
	kserial_t merged_serial, serial_from, last_flushed, serial_to;
	uint64_t occupied, occupied_all;
	journal_metadata_info(j, &has_bootstrap, &merged_serial, &serial_from,
			      &last_flushed, &serial_to, &occupied, &occupied_all);

	bool alternative_from = (has_bootstrap || merged_serial.valid);
	bool is_empty = (!alternative_from && !serial_from.valid);
	if (is_empty) {
		ret = KNOT_ENOENT;
		goto pj_finally;
	}

	if (has_bootstrap) {
		ret = journal_load_bootstrap(j, &db);
	} else if (merged_serial.valid) {
		ret = journal_load_changesets(j, &db, merged_serial.serial);
	} else {
		ret = journal_load_changesets(j, &db, serial_from.serial);
	}
	if (ret != KNOT_EOK) {
		goto pj_finally;
	}

	changeset_t *chs = NULL;

	size_t db_remains = list_size(&db);

	WALK_LIST(chs, db) {
		if (--db_remains >= limit && limit > 0) {
			continue;
		}
		if (debugmode) {
			print_changeset_debugmode(chs);
		} else {
			print_changeset(chs, color);
		}
	}

	changesets_free(&db);

	if (debugmode) {
		if ((alternative_from && serial_from.valid) ||
		    kserial_equal(serial_from, last_flushed)) {
			init_list(&db);

			ret = journal_load_changesets(j, &db, serial_from.serial);
			switch (ret) {
			case KNOT_EOK:
				printf("---- Additional history ----\n");
				break;
			case KNOT_ENOENT:
				printf("---- No additional history ----\n");
				ret = KNOT_EOK;
				break;
			default:
				goto pj_finally;
			}
			WALK_LIST(chs, db) {
				print_changeset_debugmode(chs);
				if (last_flushed.valid &&
				    serial_equal(knot_soa_serial(chs->soa_from->rrs.rdata), last_flushed.serial)) {
					break;
				}
			}
			changesets_free(&db);
		} else {
			printf("---- No additional history ----\n");
		}
	}

	if (debugmode) {
		printf("Occupied this zone (approx): %"PRIu64" KiB\n", occupied / 1024);
		printf("Occupied all zones together: %"PRIu64" KiB\n", occupied_all / 1024);
	}

pj_finally:
	journal_close(j);
	journal_free(&j);
	journal_db_close(&jdb);

	return ret;
}

int list_zones(char *path)
{
	journal_db_t *jdb = NULL;
	int ret = journal_db_init(&jdb, path, 1, JOURNAL_MODE_ROBUST);
	if (ret != KNOT_EOK) {
		return ret;
	}

	ret = reconfigure_mapsize(jdb->path, &jdb->fslimit);
	if (ret != KNOT_EOK) {
		journal_db_close(&jdb);
		return ret;
	}

	ret = journal_open_db(&jdb);
	if (ret != KNOT_EOK) {
		journal_db_close(&jdb);
		return ret;
	}

	list_t zones;
	init_list(&zones);
	ret = journal_db_list_zones(&jdb, &zones);
	if (ret == KNOT_EOK) {
		ptrnode_t *zn;
		char buff[KNOT_DNAME_TXT_MAXLEN + 1];
		WALK_LIST(zn, zones) {
			printf("%s\n", knot_dname_to_str(buff, (knot_dname_t *)zn->d, sizeof(buff)));
			free(zn->d);
		}
		ptrlist_free(&zones, NULL);
	}

	journal_db_close(&jdb);
	return ret;
}

int main(int argc, char *argv[])
{
	uint32_t limit = 0;
	bool color = true, justlist = false, debugmode = false;

	struct option opts[] = {
		{ "limit",     required_argument, NULL, 'l' },
		{ "no-color",  no_argument,       NULL, 'n' },
		{ "zone-list", no_argument,       NULL, 'z' },
		{ "debug",     no_argument,       NULL, 'd' },
		{ "help",      no_argument,       NULL, 'h' },
		{ "version",   no_argument,       NULL, 'V' },
		{ NULL }
	};

	int opt = 0;
	while ((opt = getopt_long(argc, argv, "l:nzdhV", opts, NULL)) != -1) {
		switch (opt) {
		case 'l':
			if (str_to_u32(optarg, &limit) != KNOT_EOK) {
				print_help();
				return EXIT_FAILURE;
			}
			break;
		case 'n':
			color = false;
			break;
		case 'z':
			justlist = true;
			break;
		case 'd':
			debugmode = true;
			break;
		case 'h':
			print_help();
			return EXIT_SUCCESS;
		case 'V':
			print_version(PROGRAM_NAME);
			return EXIT_SUCCESS;
		default:
			print_help();
			return EXIT_FAILURE;
		}
	}

	char *db = NULL;
	knot_dname_t *name = NULL;

	switch (argc - optind) {
	case 2:
		name = knot_dname_from_str_alloc(argv[optind + 1]);
		knot_dname_to_lower(name);
		// FALLTHROUGH
	case 1:
		db = argv[optind];
		break;
	default:
		print_help();
		return EXIT_FAILURE;
	}

	if (db == NULL) {
		fprintf(stderr, "Journal DB path not specified\n");
		return EXIT_FAILURE;
	}

	if (justlist) {
		int ret = list_zones(db);
		switch (ret) {
		case KNOT_ENOENT:
			printf("No zones in journal DB\n");
			// FALLTHROUGH
		case KNOT_EOK:
			return EXIT_SUCCESS;
		case KNOT_EMALF:
			fprintf(stderr, "The journal DB is broken\n");
			return EXIT_FAILURE;
		default:
			fprintf(stderr, "Failed to load zone list (%s)\n", knot_strerror(ret));
			return EXIT_FAILURE;
		}
	}

	if (name == NULL) {
		fprintf(stderr, "Zone not specified\n");
		return EXIT_FAILURE;
	}

	int ret = print_journal(db, name, limit, color, debugmode);
	free(name);

	switch (ret) {
	case KNOT_ENOENT:
		printf("The journal is empty\n");
		break;
	case KNOT_EOUTOFZONE:
		fprintf(stderr, "The specified journal DB does not contain the specified zone\n");
		return EXIT_FAILURE;
	case KNOT_EOK:
		break;
	default:
		fprintf(stderr, "Failed to load changesets (%s)\n", knot_strerror(ret));
		return EXIT_FAILURE;
	}

	return EXIT_SUCCESS;
}