/* GNOME DB libary
 * Copyright (C) 1999 Rodrigo Moya
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the Free
 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include "gda-postgres.h"

static GdaServerRecordset *init_recset_fields (GdaServerRecordset * recset,
					       POSTGRES_Recordset * prc);

/*
 * Public functions
 */
gboolean
gda_postgres_command_new (GdaServerCommand * cmd)
{
	/* no structure POSTGRES_Command because everything inside this struct is held
	   in the GdaServerCommand object */
	return TRUE;
}

GdaServerRecordset *
gda_postgres_command_execute (GdaServerCommand * cmd,
			      GdaError * error,
			      const GDA_CmdParameterSeq * params,
			      gulong * affected, gulong options)
{
	GdaServerConnection *cnc;
	POSTGRES_Connection *pc;
	gchar *cmd_string;
	GdaServerRecordset *recset = NULL;

	cnc = gda_server_command_get_connection (cmd);
	if (cnc) {
		pc = (POSTGRES_Connection *)
			gda_server_connection_get_user_data (cnc);
		if (pc) {
			/* determine command string by command type */
			switch (gda_server_command_get_cmd_type (cmd)) {
			case GDA_COMMAND_TYPE_TEXT:
				cmd_string =
					g_strdup (gda_server_command_get_text
						  (cmd));
				break;
			case GDA_COMMAND_TYPE_TABLE:
				cmd_string =
					g_strdup_printf ("SELECT * FROM %s",
							 gda_server_command_get_text
							 (cmd));
				break;
			default:
				cmd_string = NULL;
			}

			if (cmd_string) {
				PGresult *res;
				POSTGRES_Recordset *prc;

				/* execute query */
				res = PQexec (pc->pq_conn, cmd_string);
				g_free ((gpointer) cmd_string);

				if (res) {
					switch (PQresultStatus (res)) {
					case PGRES_EMPTY_QUERY:
					case PGRES_TUPLES_OK:
						recset = gda_server_recordset_new (cnc);
						prc = (POSTGRES_Recordset *)
							gda_server_recordset_get_user_data
							(recset);
						prc->pq_data = res;
						gda_server_recordset_set_at_begin
							(recset, TRUE);
						gda_server_recordset_set_at_end
							(recset, FALSE);
						prc->pos = 0;
						*affected =
							PQntuples (prc->
								   pq_data);
						/*recset->affected = *affected */
						return (init_recset_fields
							(recset, prc));
					case PGRES_COMMAND_OK:
					case PGRES_COPY_OUT:
					case PGRES_COPY_IN:
						recset = gda_server_recordset_new (cnc);
						prc = (POSTGRES_Recordset *)
							gda_server_recordset_get_user_data
							(recset);
						prc->pq_data = res;
						gda_server_recordset_set_at_begin
							(recset, TRUE);
						gda_server_recordset_set_at_end
							(recset, TRUE);
						recset->fields = 0;
						prc->pos = 0;
						*affected = 0;
						return (recset);
					default:
						gda_postgres_error_make
							(error, NULL,
							 cmd->cnc, "PQexec");
						*affected = 0;
						return (0);
					}
				}
				else
					gda_postgres_error_make (error, NULL,
								 cmd->cnc,
								 "PQexec");
			}
		}
	}
	return (0);
}

GdaServerRecordset *
gda_postgres_command_build_recset_with_builtin (GdaServerConnection * cnc,
						GdaBuiltin_Result * res,
						gulong * affected)
{
	GdaServerRecordset *recset;
	POSTGRES_Recordset *prc;

	recset = gda_server_recordset_new (cnc);
	prc = (POSTGRES_Recordset *)
		gda_server_recordset_get_user_data (recset);
	prc->pq_data = NULL;
	prc->btin_res = res;
	gda_server_recordset_set_at_begin (recset, TRUE);
	gda_server_recordset_set_at_end (recset, FALSE);
	prc->pos = 0;
	*affected = GdaBuiltin_Result_get_nbtuples (res);
	return (init_recset_fields (recset, prc));
}

POSTGRES_Connection *
gda_postgres_cmd_set_connection (POSTGRES_Command * cmd,
				 POSTGRES_Connection * cnc)
{
	POSTGRES_Connection *rc = cmd->cnc;
	cmd->cnc = cnc;
	return (rc);
}

static GdaServerRecordset *
init_recset_fields (GdaServerRecordset * recset, POSTGRES_Recordset * prc)
{
	register gint cnt;
	guint ncols;

	if (prc->pq_data)
		ncols = PQnfields (prc->pq_data);
	else
		ncols = GdaBuiltin_Result_get_nbfields (prc->btin_res);

	/* check parameters */
	g_return_val_if_fail (recset != NULL, NULL);
	for (cnt = 0; cnt < ncols; cnt++) {
		GdaServerField *f = gda_server_field_new ();
		if (prc->pq_data) {
			gda_server_field_set_name (f,
						   PQfname (prc->pq_data,
							    cnt));
			gda_server_field_set_sql_type (f,
						       PQftype (prc->pq_data,
								cnt));
		}
		else {
			gda_server_field_set_name (f,
						   GdaBuiltin_Result_get_fname
						   (prc->btin_res, cnt));
			/* The Sql Type will be modified when there is 
			   a replacement function */
			gda_server_field_set_sql_type (f,
						       GdaBuiltin_Result_get_ftype
						       (prc->btin_res, cnt));
		}

		f->c_type =
			gda_postgres_connection_get_c_type_psql (prc->cnc,
								 f->sql_type);
		/* f->nullable can not be set because no way of getting it
		   from the beckend! */
		f->value = NULL;
		f->precision = 0;
		gda_server_field_set_scale (f, 0);	/* ???? */

		/* these things will be set when the field is filled */
		/*if (prc->pq_data)
		   f->defined_length = f->actual_length = PQfsize(prc->pq_data, cnt);
		   else
		   f->defined_length = f->actual_length = GdaBuiltin_Result_get_fsize
		   (prc->btin_res, cnt);; */
		/*f->malloced = 0; */

		/* add field definition to list */
		recset->fields = g_list_append (recset->fields, f);
	}
	return (recset);
}


void
gda_postgres_command_free (GdaServerCommand * cmd)
{
}