/*
Copyright (c) 2010-2021 Roger Light <roger@atchoo.org>

All rights reserved. This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
and Eclipse Distribution License v1.0 which accompany this distribution.

The Eclipse Public License is available at
   https://www.eclipse.org/legal/epl-2.0/
and the Eclipse Distribution License is available at
  http://www.eclipse.org/org/documents/edl-v10.php.

SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause

Contributors:
   Roger Light - initial implementation and documentation.
*/

#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <time.h>

#include "db_dump.h"
#include <mosquitto_broker_internal.h>
#include <persist.h>

#define mosquitto_malloc(A) malloc((A))
#define mosquitto_free(A) free((A))
#define _mosquitto_malloc(A) malloc((A))
#define _mosquitto_free(A) free((A))
#include <uthash.h>

#include "db_dump.h"

struct client_data
{
	UT_hash_handle hh_id;
	char *id;
	uint32_t subscriptions;
	uint32_t subscription_size;
	int messages;
	long message_size;
};

struct base_msg_chunk
{
	UT_hash_handle hh;
	dbid_t store_id;
	uint32_t length;
};

struct mosquitto_db db;

extern uint32_t db_version;
static int stats = 0;
static int client_stats = 0;
static int do_print = 1;

/* Counts */
static long cfg_count = 0;
static long client_count = 0;
static long client_msg_count = 0;
static long base_msg_count = 0;
static long retain_count = 0;
static long sub_count = 0;
/* ====== */


struct client_data *clients_by_id = NULL;
struct base_msg_chunk *msgs_by_id = NULL;


static void free__sub(struct P_sub *chunk)
{
	free(chunk->clientid);
	free(chunk->topic);
}

static void free__client(struct P_client *chunk)
{
	free(chunk->username);
	free(chunk->clientid);
}


static void free__client_msg(struct P_client_msg *chunk)
{
	free(chunk->clientid);
}


static void free__base_msg(struct P_base_msg *chunk)
{
	free(chunk->topic);
	free(chunk->payload);
	mosquitto_property_free_all(&chunk->properties);
}


static int dump__cfg_chunk_process(FILE *db_fd, uint32_t length)
{
	struct PF_cfg chunk;
	int rc;

	cfg_count++;

	memset(&chunk, 0, sizeof(struct PF_cfg));

	if(db_version == 6 || db_version == 5){
		rc = persist__chunk_cfg_read_v56(db_fd, &chunk);
	}else{
		rc = persist__chunk_cfg_read_v234(db_fd, &chunk);
	}
	if(rc){
		fprintf(stderr, "Error: Corrupt persistent database.\n");
		return rc;
	}

	if(do_print) printf("DB_CHUNK_CFG:\n");
	if(do_print) printf("\tLength: %d\n", length);
	if(do_print) printf("\tShutdown: %d\n", chunk.shutdown);
	if(do_print) printf("\tDB ID size: %d\n", chunk.dbid_size);
	if(chunk.dbid_size != sizeof(dbid_t)){
		fprintf(stderr, "Error: Incompatible database configuration (dbid size is %d bytes, expected %zu)",
				chunk.dbid_size, sizeof(dbid_t));
		return MOSQ_ERR_INVAL;
	}
	if(do_print) printf("\tLast DB ID: %" PRIu64 "\n", chunk.last_db_id);

	return 0;
}


static int dump__client_chunk_process(FILE *db_fd, uint32_t length)
{
	struct P_client chunk;
	int rc = 0;
	struct client_data *cc = NULL;

	client_count++;

	memset(&chunk, 0, sizeof(struct P_client));

	if(db_version == 6 || db_version == 5){
		rc = persist__chunk_client_read_v56(db_fd, &chunk, db_version);
	}else{
		rc = persist__chunk_client_read_v234(db_fd, &chunk, db_version);
	}
	if(rc){
		fprintf(stderr, "Error: Corrupt persistent database.\n");
		return rc;
	}

	if(client_stats && chunk.clientid){
		cc = calloc(1, sizeof(struct client_data));
		if(!cc){
			fprintf(stderr, "Error: Out of memory.\n");
			free(chunk.clientid);
			return MOSQ_ERR_NOMEM;
		}
		cc->id = strdup(chunk.clientid);
		HASH_ADD_KEYPTR(hh_id, clients_by_id, cc->id, strlen(cc->id), cc);
	}

	if(do_print) {
		print__client(&chunk, length);
	}
	free__client(&chunk);

	return 0;
}


static int dump__client_msg_chunk_process(FILE *db_fd, uint32_t length)
{
	struct P_client_msg chunk;
	struct client_data *cc;
	struct base_msg_chunk *msc;
	int rc;

	client_msg_count++;

	memset(&chunk, 0, sizeof(struct P_client_msg));
	if(db_version == 6 || db_version == 5){
		rc = persist__chunk_client_msg_read_v56(db_fd, &chunk, length);
	}else{
		rc = persist__chunk_client_msg_read_v234(db_fd, &chunk);
	}
	if(rc){
		fprintf(stderr, "Error: Corrupt persistent database.\n");
		return rc;
	}

	if(client_stats && chunk.clientid){
		HASH_FIND(hh_id, clients_by_id, chunk.clientid, strlen(chunk.clientid), cc);
		if(cc){
			cc->messages++;
			cc->message_size += length;

			HASH_FIND(hh, msgs_by_id, &chunk.F.store_id, sizeof(dbid_t), msc);
			if(msc){
				cc->message_size += msc->length;
			}
		}
	}

	if(do_print) {
		print__client_msg(&chunk, length);
	}
	free__client_msg(&chunk);
	return 0;
}


static int dump__base_msg_chunk_process(FILE *db_fptr, uint32_t length)
{
	struct P_base_msg chunk;
	struct mosquitto__base_msg *stored = NULL;
	int64_t message_expiry_interval64;
	uint32_t message_expiry_interval;
	int rc = 0;
	struct base_msg_chunk *mcs;

	base_msg_count++;

	memset(&chunk, 0, sizeof(struct P_base_msg));
	if(db_version == 6 || db_version == 5){
		rc = persist__chunk_base_msg_read_v56(db_fptr, &chunk, length);
	}else{
		rc = persist__chunk_base_msg_read_v234(db_fptr, &chunk, db_version);
	}
	if(rc){
		fprintf(stderr, "Error: Corrupt persistent database.\n");
		return rc;
	}

	if(chunk.F.expiry_time > 0){
		message_expiry_interval64 = chunk.F.expiry_time - time(NULL);
		if(message_expiry_interval64 < 0 || message_expiry_interval64 > UINT32_MAX){
			message_expiry_interval = 0;
		}else{
			message_expiry_interval = (uint32_t)message_expiry_interval64;
		}
	}else{
		message_expiry_interval = 0;
	}

	stored = mosquitto_calloc(1, sizeof(struct mosquitto__base_msg));
	if(stored == NULL){
		fprintf(stderr, "Error: Out of memory.\n");
		mosquitto_free(chunk.source.id);
		mosquitto_free(chunk.source.username);
		mosquitto_free(chunk.topic);
		mosquitto_free(chunk.payload);
		return MOSQ_ERR_NOMEM;
	}
	stored->data.store_id = chunk.F.store_id;
	stored->data.source_mid = chunk.F.source_mid;
	stored->data.topic = chunk.topic;
	stored->data.qos = chunk.F.qos;
	stored->data.retain = chunk.F.retain;
	stored->data.payloadlen = chunk.F.payloadlen;
	stored->data.payload =  chunk.payload;
	stored->data.properties = chunk.properties;

	rc = db__message_store(&chunk.source, stored, &message_expiry_interval,
			mosq_mo_client);

	mosquitto_free(chunk.source.id);
	mosquitto_free(chunk.source.username);
	chunk.source.id = NULL;
	chunk.source.username = NULL;

	if(rc == MOSQ_ERR_SUCCESS){
		stored->source_listener = chunk.source.listener;
		stored->data.store_id = chunk.F.store_id;

		HASH_ADD(hh, db.msg_store, data.store_id, sizeof(dbid_t), stored);
	}else{
		fprintf(stderr, "Error: Out of memory.\n");
		return rc;
	}

	if(client_stats){
		mcs = calloc(1, sizeof(struct base_msg_chunk));
		if(!mcs){
			fprintf(stderr, "Error: Out of memory.\n");
			return MOSQ_ERR_NOMEM;
		}
		mcs->store_id = chunk.F.store_id;
		mcs->length = length;
		HASH_ADD(hh, msgs_by_id, store_id, sizeof(dbid_t), mcs);
	}

	if(do_print){
		print__base_msg(&chunk, length);
	}
	free__base_msg(&chunk);

	return 0;
}


static int dump__retain_chunk_process(FILE *db_fd, uint32_t length)
{
	struct P_retain chunk;
	int rc;

	retain_count++;
	if(do_print) printf("DB_CHUNK_RETAIN:\n");
	if(do_print) printf("\tLength: %d\n", length);

	if(db_version == 6 || db_version == 5){
		rc = persist__chunk_retain_read_v56(db_fd, &chunk);
	}else{
		rc = persist__chunk_retain_read_v234(db_fd, &chunk);
	}
	if(rc){
		fprintf(stderr, "Error: Corrupt persistent database.\n");
		return rc;
	}

	if(do_print) printf("\tStore ID: %" PRIu64 "\n", chunk.F.store_id);
	return 0;
}


static int dump__sub_chunk_process(FILE *db_fd, uint32_t length)
{
	int rc = 0;
	struct P_sub chunk;
	struct client_data *cc;

	sub_count++;

	memset(&chunk, 0, sizeof(struct P_sub));
	if(db_version == 6 || db_version == 5){
		rc = persist__chunk_sub_read_v56(db_fd, &chunk);
	}else{
		rc = persist__chunk_sub_read_v234(db_fd, &chunk);
	}
	if(rc){
		fprintf(stderr, "Error: Corrupt persistent database.\n");
		return rc;
	}

	if(client_stats && chunk.clientid){
		HASH_FIND(hh_id, clients_by_id, chunk.clientid, strlen(chunk.clientid), cc);
		if(cc){
			cc->subscriptions++;
			cc->subscription_size += length;
		}
	}

	if(do_print) {
		print__sub(&chunk, length);
	}
	free__sub(&chunk);

	return 0;
}


static void report_client_stats(void)
{
	if(client_stats){
		struct client_data *cc, *cc_tmp;

		HASH_ITER(hh_id, clients_by_id, cc, cc_tmp){
			printf("SC: %d SS: %d MC: %d MS: %ld   ", cc->subscriptions, cc->subscription_size, cc->messages, cc->message_size);
			printf("%s\n", cc->id);
		}
	}
}


static void cleanup_client_stats()
{
	struct base_msg_chunk *msg, *msg_tmp;
	struct client_data *cc, *cc_tmp;

	HASH_ITER(hh, msgs_by_id, msg, msg_tmp){
		HASH_DELETE(hh, msgs_by_id, msg);
		free(msg);
	}

	HASH_ITER(hh_id, clients_by_id, cc, cc_tmp){
		HASH_DELETE(hh_id, clients_by_id, cc);
		free(cc->id);
		free(cc);
	}
}


static void cleanup_msg_store()
{
	struct mosquitto__base_msg *msg, *msg_tmp;

	HASH_ITER(hh, db.msg_store, msg, msg_tmp){
		HASH_DELETE(hh, db.msg_store, msg);
		free(msg);
	}
}


#ifdef WITH_FUZZING
int db_dump_fuzz_main(int argc, char *argv[])
#else
int main(int argc, char *argv[])
#endif
{
	FILE *fd;
	char header[15];
	int rc = 0;
	uint32_t crc;
	uint32_t i32temp;
	uint32_t length;
	uint32_t chunk;
	char *filename;

	if(argc == 2){
		filename = argv[1];
	}else if(argc == 3 && !strcmp(argv[1], "--stats")){
		stats = 1;
		do_print = 0;
		filename = argv[2];
	}else if(argc == 3 && !strcmp(argv[1], "--client-stats")){
		client_stats = 1;
		do_print = 0;
		filename = argv[2];
	}else{
		fprintf(stderr, "Usage: db_dump [--stats | --client-stats] <mosquitto db filename>\n");
		return 1;
	}
	memset(&db, 0, sizeof(struct mosquitto_db));
	fd = fopen(filename, "rb");
	if(!fd){
		fprintf(stderr, "Error: Unable to open %s\n", filename);
		return 0;
	}
	read_e(fd, &header, 15);
	if(!memcmp(header, magic, 15)){
		if(do_print) printf("Mosquitto DB dump\n");
		/* Restore DB as normal */
		read_e(fd, &crc, sizeof(uint32_t));
		if(do_print) printf("CRC: %d\n", crc);
		read_e(fd, &i32temp, sizeof(uint32_t));
		db_version = ntohl(i32temp);
		if(do_print) printf("DB version: %d\n", db_version);

		if(db_version > MOSQ_DB_VERSION){
			if(do_print) printf("Warning: mosquitto_db_dump does not support this DB version, continuing but expecting errors.\n");
		}

		while(persist__chunk_header_read(fd, &chunk, &length) == MOSQ_ERR_SUCCESS){
			switch(chunk){
				case DB_CHUNK_CFG:
					if(dump__cfg_chunk_process(fd, length)) goto error;
					break;

				case DB_CHUNK_BASE_MSG:
					if(dump__base_msg_chunk_process(fd, length)) goto error;
					break;

				case DB_CHUNK_CLIENT_MSG:
					if(dump__client_msg_chunk_process(fd, length)) goto error;
					break;

				case DB_CHUNK_RETAIN:
					if(dump__retain_chunk_process(fd, length)) goto error;
					break;

				case DB_CHUNK_SUB:
					if(dump__sub_chunk_process(fd, length)) goto error;
					break;

				case DB_CHUNK_CLIENT:
					if(dump__client_chunk_process(fd, length)) goto error;
					break;

				default:
					fprintf(stderr, "Warning: Unsupported chunk \"%d\" of length %d in persistent database file at position %ld. Ignoring.\n", chunk, length, ftell(fd));
					if(fseek(fd, length, SEEK_CUR)){
						fprintf(stderr, "Error: %s\n", strerror(errno));
						goto error;
					}
					break;
			}
		}
	}else{
		fprintf(stderr, "Error: Unrecognised file format.\n");
		rc = 1;
	}

	fclose(fd);

	if(stats){
		printf("DB_CHUNK_CFG:        %ld\n", cfg_count);
		printf("DB_CHUNK_BASE_MSG:   %ld\n", base_msg_count);
		printf("DB_CHUNK_CLIENT_MSG: %ld\n", client_msg_count);
		printf("DB_CHUNK_RETAIN:     %ld\n", retain_count);
		printf("DB_CHUNK_SUB:        %ld\n", sub_count);
		printf("DB_CHUNK_CLIENT:     %ld\n", client_count);
	}

	report_client_stats();
	cleanup_client_stats();
	cleanup_msg_store();

	return rc;
error:
	cleanup_msg_store();
	if(fd) fclose(fd);
	return 1;
}
