/*
 * oid2name, a PostgreSQL app to map OIDs on the filesystem
 * to table and database names.
 *
 * Originally by
 * B. Palmer, bpalmer@crimelabs.net 1-17-2001
 *
 * $PostgreSQL: pgsql/contrib/oid2name/oid2name.c,v 1.35 2009/02/27 09:30:21 petere Exp $
 */
#include "postgres_fe.h"

#include <unistd.h>
#ifdef HAVE_GETOPT_H
#include <getopt.h>
#endif

extern char *optarg;

#include "libpq-fe.h"

/* an extensible array to keep track of elements to show */
typedef struct
{
	char	  **array;
	int			num;
	int			alloc;
}	eary;

/* these are the opts structures for command line params */
struct options
{
	eary	   *tables;
	eary	   *oids;
	eary	   *filenodes;

	bool		quiet;
	bool		systables;
	bool		indexes;
	bool		nodb;
	bool		extended;
	bool		tablespaces;

	char	   *dbname;
	char	   *hostname;
	char	   *port;
	char	   *username;
};

/* function prototypes */
static void help(const char *progname);
void		get_opts(int, char **, struct options *);
void	   *myalloc(size_t size);
char	   *mystrdup(const char *str);
void		add_one_elt(char *eltname, eary * eary);
char	   *get_comma_elts(eary * eary);
PGconn	   *sql_conn(struct options *);
int			sql_exec(PGconn *, const char *sql, bool quiet);
void		sql_exec_dumpalldbs(PGconn *, struct options *);
void		sql_exec_dumpalltables(PGconn *, struct options *);
void		sql_exec_searchtables(PGconn *, struct options *);
void		sql_exec_dumpalltbspc(PGconn *, struct options *);

/* function to parse command line options and check for some usage errors. */
void
get_opts(int argc, char **argv, struct options * my_opts)
{
	int			c;
	const char *progname;

	progname = get_progname(argv[0]);

	/* set the defaults */
	my_opts->quiet = false;
	my_opts->systables = false;
	my_opts->indexes = false;
	my_opts->nodb = false;
	my_opts->extended = false;
	my_opts->tablespaces = false;
	my_opts->dbname = NULL;
	my_opts->hostname = NULL;
	my_opts->port = NULL;
	my_opts->username = NULL;

	if (argc > 1)
	{
		if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
		{
			help(progname);
			exit(0);
		}
		if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
		{
			puts("oid2name (PostgreSQL) " PG_VERSION);
			exit(0);
		}
	}

	/* get opts */
	while ((c = getopt(argc, argv, "H:p:U:d:t:o:f:qSxish")) != -1)
	{
		switch (c)
		{
				/* specify the database */
			case 'd':
				my_opts->dbname = mystrdup(optarg);
				break;

				/* specify one tablename to show */
			case 't':
				add_one_elt(optarg, my_opts->tables);
				break;

				/* specify one Oid to show */
			case 'o':
				add_one_elt(optarg, my_opts->oids);
				break;

				/* specify one filenode to show */
			case 'f':
				add_one_elt(optarg, my_opts->filenodes);
				break;

				/* don't show headers */
			case 'q':
				my_opts->quiet = true;
				break;

				/* host to connect to */
			case 'H':
				my_opts->hostname = mystrdup(optarg);
				break;

				/* port to connect to on remote host */
			case 'p':
				my_opts->port = mystrdup(optarg);
				break;

				/* username */
			case 'U':
				my_opts->username = mystrdup(optarg);
				break;

				/* display system tables */
			case 'S':
				my_opts->systables = true;
				break;

				/* also display indexes */
			case 'i':
				my_opts->indexes = true;
				break;

				/* display extra columns */
			case 'x':
				my_opts->extended = true;
				break;

				/* dump tablespaces only */
			case 's':
				my_opts->tablespaces = true;
				break;

			case 'h':
				help(progname);
				exit(0);
				break;

			default:
				fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
				exit(1);
		}
	}
}

static void
help(const char *progname)
{
	printf("%s helps examining the file structure used by PostgreSQL.\n\n"
		   "Usage:\n"
		   "  %s [OPTIONS]...\n"
		   "\nOptions:\n"
		   "  -d DBNAME    database to connect to\n"
		   "  -f FILENODE  show info for table with given file node\n"
		   "  -H HOSTNAME  database server host or socket directory\n"
		   "  -i           show indexes and sequences too\n"
		   "  -o OID       show info for table with given OID\n"
		   "  -p PORT      database server port number\n"
		   "  -q           quiet (don't show headers)\n"
		   "  -s           show all tablespaces\n"
		   "  -S           show system objects too\n"
		   "  -t TABLE     show info for named table\n"
		   "  -U NAME      connect as specified database user\n"
		   "  -x           extended (show additional columns)\n"
		   "  --help       show this help, then exit\n"
		   "  --version    output version information, then exit\n"
		   "\nThe default action is to show all database OIDs.\n\n"
		   "Report bugs to <pgsql-bugs@postgresql.org>.\n",
		   progname, progname);
}

void *
myalloc(size_t size)
{
	void	   *ptr = malloc(size);

	if (!ptr)
	{
		fprintf(stderr, "out of memory");
		exit(1);
	}
	return ptr;
}

char *
mystrdup(const char *str)
{
	char	   *result = strdup(str);

	if (!result)
	{
		fprintf(stderr, "out of memory");
		exit(1);
	}
	return result;
}

/*
 * add_one_elt
 *
 * Add one element to a (possibly empty) eary struct.
 */
void
add_one_elt(char *eltname, eary * eary)
{
	if (eary->alloc == 0)
	{
		eary->alloc = 8;
		eary->array = (char **) myalloc(8 * sizeof(char *));
	}
	else if (eary->num >= eary->alloc)
	{
		eary->alloc *= 2;
		eary->array = (char **)
			realloc(eary->array, eary->alloc * sizeof(char *));
		if (!eary->array)
		{
			fprintf(stderr, "out of memory");
			exit(1);
		}
	}

	eary->array[eary->num] = mystrdup(eltname);
	eary->num++;
}

/*
 * get_comma_elts
 *
 * Return the elements of an eary as a (freshly allocated) single string, in
 * single quotes, separated by commas and properly escaped for insertion in an
 * SQL statement.
 */
char *
get_comma_elts(eary * eary)
{
	char	   *ret,
			   *ptr;
	int			i,
				length = 0;

	if (eary->num == 0)
		return mystrdup("");

	/*
	 * PQescapeString wants 2 * length + 1 bytes of breath space.  Add two
	 * chars per element for the single quotes and one for the comma.
	 */
	for (i = 0; i < eary->num; i++)
		length += strlen(eary->array[i]);

	ret = (char *) myalloc(length * 2 + 4 * eary->num);
	ptr = ret;

	for (i = 0; i < eary->num; i++)
	{
		if (i != 0)
			sprintf(ptr++, ",");
		sprintf(ptr++, "'");
		ptr += PQescapeString(ptr, eary->array[i], strlen(eary->array[i]));
		sprintf(ptr++, "'");
	}

	return ret;
}

/* establish connection with database. */
PGconn *
sql_conn(struct options * my_opts)
{
	PGconn	   *conn;
	char	   *password = NULL;
	bool		new_pass;

	/*
	 * Start the connection.  Loop until we have a password if requested by
	 * backend.
	 */
	do
	{
		new_pass = false;
		conn = PQsetdbLogin(my_opts->hostname,
							my_opts->port,
							NULL,	/* options */
							NULL,	/* tty */
							my_opts->dbname,
							my_opts->username,
							password);
		if (!conn)
		{
			fprintf(stderr, "%s: could not connect to database %s\n",
					"oid2name", my_opts->dbname);
			exit(1);
		}

		if (PQstatus(conn) == CONNECTION_BAD &&
			PQconnectionNeedsPassword(conn) &&
			password == NULL)
		{
			PQfinish(conn);
			password = simple_prompt("Password: ", 100, false);
			new_pass = true;
		}
	} while (new_pass);

	if (password)
		free(password);

	/* check to see that the backend connection was successfully made */
	if (PQstatus(conn) == CONNECTION_BAD)
	{
		fprintf(stderr, "%s: could not connect to database %s: %s",
				"oid2name", my_opts->dbname, PQerrorMessage(conn));
		PQfinish(conn);
		exit(1);
	}

	/* return the conn if good */
	return conn;
}

/*
 * Actual code to make call to the database and print the output data.
 */
int
sql_exec(PGconn *conn, const char *todo, bool quiet)
{
	PGresult   *res;

	int			nfields;
	int			nrows;
	int			i,
				j,
				l;
	int		   *length;
	char	   *pad;

	/* make the call */
	res = PQexec(conn, todo);

	/* check and deal with errors */
	if (!res || PQresultStatus(res) > 2)
	{
		fprintf(stderr, "oid2name: query failed: %s\n", PQerrorMessage(conn));
		fprintf(stderr, "oid2name: query was: %s\n", todo);

		PQclear(res);
		PQfinish(conn);
		exit(-1);
	}

	/* get the number of fields */
	nrows = PQntuples(res);
	nfields = PQnfields(res);

	/* for each field, get the needed width */
	length = (int *) myalloc(sizeof(int) * nfields);
	for (j = 0; j < nfields; j++)
		length[j] = strlen(PQfname(res, j));

	for (i = 0; i < nrows; i++)
	{
		for (j = 0; j < nfields; j++)
		{
			l = strlen(PQgetvalue(res, i, j));
			if (l > length[j])
				length[j] = strlen(PQgetvalue(res, i, j));
		}
	}

	/* print a header */
	if (!quiet)
	{
		for (j = 0, l = 0; j < nfields; j++)
		{
			fprintf(stdout, "%*s", length[j] + 2, PQfname(res, j));
			l += length[j] + 2;
		}
		fprintf(stdout, "\n");
		pad = (char *) myalloc(l + 1);
		MemSet(pad, '-', l);
		pad[l] = '\0';
		fprintf(stdout, "%s\n", pad);
		free(pad);
	}

	/* for each row, dump the information */
	for (i = 0; i < nrows; i++)
	{
		for (j = 0; j < nfields; j++)
			fprintf(stdout, "%*s", length[j] + 2, PQgetvalue(res, i, j));
		fprintf(stdout, "\n");
	}

	/* cleanup */
	PQclear(res);
	free(length);

	return 0;
}

/*
 * Dump all databases.	There are no system objects to worry about.
 */
void
sql_exec_dumpalldbs(PGconn *conn, struct options * opts)
{
	char		todo[1024];

	/* get the oid and database name from the system pg_database table */
	snprintf(todo, sizeof(todo),
			 "SELECT d.oid AS \"Oid\", datname AS \"Database Name\", "
	  "spcname AS \"Tablespace\" FROM pg_database d JOIN pg_tablespace t ON "
			 "(dattablespace = t.oid) ORDER BY 2");

	sql_exec(conn, todo, opts->quiet);
}

/*
 * Dump all tables, indexes and sequences in the current database.
 */
void
sql_exec_dumpalltables(PGconn *conn, struct options * opts)
{
	char		todo[1024];
	char	   *addfields = ",c.oid AS \"Oid\", nspname AS \"Schema\", spcname as \"Tablespace\" ";

	snprintf(todo, sizeof(todo),
		  "SELECT relfilenode as \"Filenode\", relname as \"Table Name\" %s "
			 "FROM pg_class c "
		   "	LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace "
	"	LEFT JOIN pg_catalog.pg_database d ON d.datname = current_database(),"
			 "	pg_catalog.pg_tablespace t "
			 "WHERE relkind IN ('r'%s%s) AND "
			 "	%s"
			 "		t.oid = CASE"
			 "			WHEN reltablespace <> 0 THEN reltablespace"
			 "			ELSE dattablespace"
			 "		END "
			 "ORDER BY relname",
			 opts->extended ? addfields : "",
			 opts->indexes ? ", 'i', 'S'" : "",
			 opts->systables ? ", 't'" : "",
			 opts->systables ? "" : "n.nspname NOT IN ('pg_catalog', 'information_schema') AND n.nspname !~ '^pg_toast' AND");

	sql_exec(conn, todo, opts->quiet);
}

/*
 * Show oid, relfilenode, name, schema and tablespace for each of the
 * given objects in the current database.
 */
void
sql_exec_searchtables(PGconn *conn, struct options * opts)
{
	char	   *todo;
	char	   *qualifiers,
			   *ptr;
	char	   *comma_oids,
			   *comma_filenodes,
			   *comma_tables;
	bool		written = false;
	char	   *addfields = ",c.oid AS \"Oid\", nspname AS \"Schema\", spcname as \"Tablespace\" ";

	/* get tables qualifiers, whether names, relfilenodes, or OIDs */
	comma_oids = get_comma_elts(opts->oids);
	comma_tables = get_comma_elts(opts->tables);
	comma_filenodes = get_comma_elts(opts->filenodes);

	/* 80 extra chars for SQL expression */
	qualifiers = (char *) myalloc(strlen(comma_oids) + strlen(comma_tables) +
								  strlen(comma_filenodes) + 80);
	ptr = qualifiers;

	if (opts->oids->num > 0)
	{
		ptr += sprintf(ptr, "c.oid IN (%s)", comma_oids);
		written = true;
	}
	if (opts->filenodes->num > 0)
	{
		if (written)
			ptr += sprintf(ptr, " OR ");
		ptr += sprintf(ptr, "c.relfilenode IN (%s)", comma_filenodes);
		written = true;
	}
	if (opts->tables->num > 0)
	{
		if (written)
			ptr += sprintf(ptr, " OR ");
		sprintf(ptr, "c.relname ~~ ANY (ARRAY[%s])", comma_tables);
	}
	free(comma_oids);
	free(comma_tables);
	free(comma_filenodes);

	/* now build the query */
	todo = (char *) myalloc(650 + strlen(qualifiers));
	snprintf(todo, 650 + strlen(qualifiers),
		 "SELECT relfilenode as \"Filenode\", relname as \"Table Name\" %s\n"
			 "FROM pg_class c \n"
		 "	LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace \n"
			 "	LEFT JOIN pg_catalog.pg_database d ON d.datname = current_database(),\n"
			 "	pg_catalog.pg_tablespace t \n"
			 "WHERE relkind IN ('r', 'i', 'S', 't') AND \n"
			 "		t.oid = CASE\n"
			 "			WHEN reltablespace <> 0 THEN reltablespace\n"
			 "			ELSE dattablespace\n"
			 "		END AND \n"
			 "  (%s) \n"
			 "ORDER BY relname\n",
			 opts->extended ? addfields : "",
			 qualifiers);

	free(qualifiers);

	sql_exec(conn, todo, opts->quiet);
}

void
sql_exec_dumpalltbspc(PGconn *conn, struct options * opts)
{
	char		todo[1024];

	snprintf(todo, sizeof(todo),
			 "SELECT oid AS \"Oid\", spcname as \"Tablespace Name\"\n"
			 "FROM pg_tablespace");

	sql_exec(conn, todo, opts->quiet);
}

int
main(int argc, char **argv)
{
	struct options *my_opts;
	PGconn	   *pgconn;

	my_opts = (struct options *) myalloc(sizeof(struct options));

	my_opts->oids = (eary *) myalloc(sizeof(eary));
	my_opts->tables = (eary *) myalloc(sizeof(eary));
	my_opts->filenodes = (eary *) myalloc(sizeof(eary));

	my_opts->oids->num = my_opts->oids->alloc = 0;
	my_opts->tables->num = my_opts->tables->alloc = 0;
	my_opts->filenodes->num = my_opts->filenodes->alloc = 0;

	/* parse the opts */
	get_opts(argc, argv, my_opts);

	if (my_opts->dbname == NULL)
	{
		my_opts->dbname = "postgres";
		my_opts->nodb = true;
	}
	pgconn = sql_conn(my_opts);

	/* display only tablespaces */
	if (my_opts->tablespaces)
	{
		if (!my_opts->quiet)
			printf("All tablespaces:\n");
		sql_exec_dumpalltbspc(pgconn, my_opts);

		PQfinish(pgconn);
		exit(0);
	}

	/* display the given elements in the database */
	if (my_opts->oids->num > 0 ||
		my_opts->tables->num > 0 ||
		my_opts->filenodes->num > 0)
	{
		if (!my_opts->quiet)
			printf("From database \"%s\":\n", my_opts->dbname);
		sql_exec_searchtables(pgconn, my_opts);

		PQfinish(pgconn);
		exit(0);
	}

	/* no elements given; dump the given database */
	if (my_opts->dbname && !my_opts->nodb)
	{
		if (!my_opts->quiet)
			printf("From database \"%s\":\n", my_opts->dbname);
		sql_exec_dumpalltables(pgconn, my_opts);

		PQfinish(pgconn);
		exit(0);
	}

	/* no database either; dump all databases */
	if (!my_opts->quiet)
		printf("All databases:\n");
	sql_exec_dumpalldbs(pgconn, my_opts);

	PQfinish(pgconn);
	return 0;
}
