/* -------------------------------------------------------------------------
 * pg_dumplo
 *
 *	Portions Copyright (c) 1999-2000, PostgreSQL, Inc
 *
 * $Header: /cvsroot/pgsql/contrib/pg_dumplo/Attic/lo_export.c,v 1.4 2000/11/22 00:00:55 tgl Exp $
 *
 *					Karel Zak 1999-2000
 * -------------------------------------------------------------------------
 */

#include <stdio.h>	
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <fcntl.h>
#include <errno.h>                            
#include <time.h>

#include <libpq-fe.h>
#include <libpq/libpq-fs.h>

#include "pg_dumplo.h"

extern int 	errno;        


void 
load_lolist( LODumpMaster *pgLO ) 
{
	LOlist		*ll;
	int		i;
	int		n;

 	/* ----------
	 * Now find any candidate tables who have columns of type oid.
	 *
	 * NOTE: System tables including pg_largeobject will be ignored.
	 * Otherwise we'd end up dumping all LOs, referenced or not.
	 *
	 * NOTE: the system oid column is ignored, as it has attnum < 1.
	 * This shouldn't matter for correctness, but it saves time.
 	 * ----------
 	 */	
	pgLO->res = PQexec(pgLO->conn,
					   "SELECT c.relname, a.attname "
					   "FROM pg_class c, pg_attribute a, pg_type t "
					   "WHERE a.attnum > 0 "
					   "    AND a.attrelid = c.oid "
					   "    AND a.atttypid = t.oid "
					   "    AND t.typname = 'oid' "
					   "    AND c.relkind = 'r' "
					   "    AND c.relname NOT LIKE 'pg_%'");

	if (PQresultStatus(pgLO->res) != PGRES_TUPLES_OK) {
		fprintf(stderr, "%s: Failed to get LO OIDs:\n%s", progname,
				PQerrorMessage(pgLO->conn));
		exit(RE_ERROR);
	}

	if ((n = PQntuples(pgLO->res)) == 0) {
		fprintf(stderr, "%s: No OID columns in the database.\n", progname);
		exit(RE_ERROR);
 	}
	
	pgLO->lolist = (LOlist *) malloc((n + 1) * sizeof(LOlist));
	
	if (!pgLO->lolist) {
		fprintf(stderr, "%s: can't allocate memory\n", progname);
		exit(RE_ERROR);
  	}
  	
	for (i = 0, ll = pgLO->lolist; i < n; i++, ll++) {
		ll->lo_table = strdup(PQgetvalue(pgLO->res, i, 0));
		ll->lo_attr  = strdup(PQgetvalue(pgLO->res, i, 1));
	}
 	ll->lo_table = ll->lo_attr = (char *) NULL;
	
	PQclear(pgLO->res);
}

void 
pglo_export(LODumpMaster *pgLO)
{
	LOlist		*ll;
	int		tuples;
	char		path[BUFSIZ],
			Qbuff[QUERY_BUFSIZ];
	
	if (pgLO->action != ACTION_SHOW) {
		time_t	t;
		time(&t);
		fprintf(pgLO->index, "#\n# This is the PostgreSQL large object dump index\n#\n");
		fprintf(pgLO->index, "#\tDate:     %s", ctime(&t));
		fprintf(pgLO->index, "#\tHost:     %s\n", pgLO->host);
		fprintf(pgLO->index, "#\tDatabase: %s\n", pgLO->db);
		fprintf(pgLO->index, "#\tUser:     %s\n", pgLO->user);
		fprintf(pgLO->index, "#\n# oid\ttable\tattribut\tinfile\n#\n");
	}
	
	pgLO->counter = 0;

	for(ll=pgLO->lolist; ll->lo_table != NULL; ll++) {
		
		/* ----------
		 * Query: find the LOs referenced by this column
		 * ----------
		 */
		sprintf(Qbuff, "SELECT DISTINCT l.loid FROM \"%s\" x, pg_largeobject l WHERE x.\"%s\" = l.loid",
				ll->lo_table, ll->lo_attr);
		
		/* puts(Qbuff); */
			
		pgLO->res = PQexec(pgLO->conn, Qbuff);

        if (PQresultStatus(pgLO->res) != PGRES_TUPLES_OK) {
			fprintf(stderr, "%s: Failed to get LO OIDs:\n%s", progname,
					PQerrorMessage(pgLO->conn));
        }
		else if ((tuples = PQntuples(pgLO->res)) == 0) {
			if (!pgLO->quiet && pgLO->action == ACTION_EXPORT_ATTR)
				printf("%s: no large objects in \"%s\".\"%s\"\n",
					   progname, ll->lo_table, ll->lo_attr);	
		} else {
		
			int	t;
			char	*val;
	
			/* ----------
			 * Create DIR/FILE
			 * ----------
			 */
			if (pgLO->action != ACTION_SHOW) {
			
				sprintf(path, "%s/%s/%s", pgLO->space, pgLO->db,
						ll->lo_table);

				if (mkdir(path, DIR_UMASK) == -1) {
					if (errno != EEXIST) {
						perror(path);
						exit(RE_ERROR);					
					}	
				}

				sprintf(path, "%s/%s/%s/%s", pgLO->space, pgLO->db,
						ll->lo_table, ll->lo_attr);          
				
				if (mkdir(path, DIR_UMASK) == -1) {
					if (errno != EEXIST) {
						perror(path);
						exit(RE_ERROR);					
					}	
				}
				
				if (!pgLO->quiet)
					printf("dump %s.%s (%d large obj)\n", 
						ll->lo_table, ll->lo_attr, tuples);
			}

			pgLO->counter += tuples;
			
			for(t=0; t<tuples; t++) {
				Oid lo;
				
				val = PQgetvalue(pgLO->res, t, 0);
				
				lo = atooid(val);
				
				if (pgLO->action == ACTION_SHOW) {
					printf("%s.%s: %u\n", ll->lo_table, ll->lo_attr, lo);
					continue;
				}
				
				sprintf(path, "%s/%s/%s/%s/%s", pgLO->space, 
					pgLO->db, ll->lo_table, ll->lo_attr, val);
				
				if (lo_export(pgLO->conn, lo, path) < 0) 
					fprintf(stderr, "%s: lo_export failed:\n%s", progname,
							PQerrorMessage(pgLO->conn));
					
				else 
					fprintf(pgLO->index, "%s\t%s\t%s\t%s/%s/%s/%s\n", val, 
						ll->lo_table, ll->lo_attr, pgLO->db, ll->lo_table, ll->lo_attr, val);
			}
		}

		PQclear(pgLO->res);
	}
}
