/* GNOME DB Interbase Provider
 * Copyright (C) 2000 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-interbase.h"

/*
 * Private functions
 */
static void
init_recordset_fields (GdaServerRecordset * recset,
		       INTERBASE_Recordset * ib_recset,
		       INTERBASE_Connection * ib_cnc,
		       GdaServerConnection * cnc)
{
	gint num_cols, i;

	g_return_if_fail (recset != NULL);
	g_return_if_fail (ib_recset != NULL);
	g_return_if_fail (ib_recset->sqlda != NULL);
	g_return_if_fail (ib_cnc != NULL);

	/* reallocate sqlda area with correct size if necessary */
	num_cols = ib_recset->sqlda->sqld;
	if (ib_recset->sqlda->sqln < ib_recset->sqlda->sqld) {
		ib_recset->sqlda =
			(XSQLDA *) g_malloc0 (XSQLDA_LENGTH (num_cols));
		ib_recset->sqlda->sqln = num_cols;
		ib_recset->sqlda->version = 1;

		/* re-describe statement */
		if (isc_dsql_describe
		    (ib_cnc->status, &ib_recset->ib_cmd, 1,
		     ib_recset->sqlda)) {
			gda_server_error_make (gda_error_new (), NULL, cnc,
					       __PRETTY_FUNCTION__);
			return;
		}
		num_cols = ib_recset->sqlda->sqld;
	}

	/* get fields description */
	for (i = 0; i < num_cols; i++) {
		GdaServerField *field = gda_server_field_new ();

		gda_server_field_set_name (field,
					   ib_recset->sqlda->sqlvar[i].
					   sqlname);
		gda_server_field_set_sql_type (field,
					       ib_recset->sqlda->sqlvar[i].
					       sqltype);
		gda_server_field_set_defined_length (field,
						     ib_recset->sqlda->
						     sqlvar[i].sqllen);
		gda_server_field_set_actual_length (field,
						    ib_recset->sqlda->
						    sqlvar[i].sqllen);
		gda_server_field_set_scale (field,
					    ib_recset->sqlda->sqlvar[i].
					    sqlscale);

		gda_server_recordset_add_field (recset, field);
		gda_log_message ("Sending description for field %s",
				 ib_recset->sqlda->sqlvar[i].sqlname);
	}
}

/*
 * Public functions
 */
gboolean
gda_interbase_command_new (GdaServerCommand * cmd)
{
	isc_stmt_handle stmt = NULL;
	INTERBASE_Connection *ib_cnc;

	g_return_val_if_fail (cmd != NULL, FALSE);
	g_return_val_if_fail (cmd->cnc != NULL, FALSE);

	ib_cnc = (INTERBASE_Connection *)
		gda_server_connection_get_user_data (cmd->cnc);
	if (ib_cnc) {
		if (isc_dsql_allocate_statement
		    (ib_cnc->status, &ib_cnc->db, &stmt) == 0) {
			gda_server_command_set_user_data (cmd,
							  (gpointer) stmt);
			return TRUE;
		}

		gda_server_error_make (gda_error_new (), 0, cmd->cnc,
				       __PRETTY_FUNCTION__);
	}
	return FALSE;
}

GdaServerRecordset *
gda_interbase_command_execute (GdaServerCommand * cmd,
			       GdaError * error,
			       const GDA_CmdParameterSeq * params,
			       gulong * affected, gulong options)
{
	GdaServerRecordset *recset;
	INTERBASE_Connection *ib_cnc;

	g_return_val_if_fail (cmd != NULL, NULL);
	g_return_val_if_fail (cmd->cnc != NULL, NULL);

	ib_cnc = (INTERBASE_Connection *)
		gda_server_connection_get_user_data (cmd->cnc);
	if (ib_cnc) {
		switch (gda_server_command_get_cmd_type (cmd)) {
		case GDA_COMMAND_TYPE_TABLE:{
				/* it's a TABLE command, command's text is the name of a table */
				gchar *tmp =
					g_strdup_printf ("SELECT * FROM %s",
							 gda_server_command_get_text
							 (cmd));
				gda_server_command_set_text (cmd, tmp);
				g_free ((gpointer) tmp);
			}
		case GDA_COMMAND_TYPE_TEXT:{
				isc_stmt_handle stmt =
					(isc_stmt_handle)
					gda_server_command_get_user_data
					(cmd);
				if (stmt) {
					INTERBASE_Recordset *ib_recset;

					/* initialize stuff */
					if (affected)
						*affected = 0;
					if (!error)
						error = gda_error_new ();
					recset = gda_server_recordset_new
						(cmd->cnc);
					ib_recset =
						(INTERBASE_Recordset *)
						gda_server_recordset_get_user_data
						(recset);
					if (ib_recset) {
						ib_recset->ib_cmd = stmt;

						/* prepare statement */
						if (isc_dsql_prepare
						    (ib_cnc->status,
						     &ib_cnc->trans, &stmt, 0,
						     gda_server_command_get_text
						     (cmd), 1,
						     ib_recset->sqlda) == 0) {
							if (ib_recset->sqlda->
							    sqld) {
								/* it's a SELECT statement, so prepare field buffers */
								init_recordset_fields
									(recset,
									 ib_recset,
									 ib_cnc,
									 cmd->
									 cnc);
							}

							/* execute command */
							if (isc_dsql_execute
							    (ib_cnc->status,
							     &ib_cnc->trans,
							     &stmt, 1,
							     NULL) == 0)
								return recset;
						}
						gda_server_error_make (error,
								       NULL,
								       cmd->
								       cnc,
								       __PRETTY_FUNCTION__);
					}

					/* free memory on error */
					gda_server_recordset_free (recset);
				}
				break;
			}
		}
	}
	return NULL;
}

void
gda_interbase_command_free (GdaServerCommand * cmd)
{
	INTERBASE_Connection *ib_cnc;

	g_return_if_fail (cmd != NULL);
	g_return_if_fail (cmd->cnc != NULL);

	ib_cnc = (INTERBASE_Connection *)
		gda_server_connection_get_user_data (cmd->cnc);
	if (ib_cnc) {
		isc_stmt_handle stmt =
			(isc_stmt_handle)
			gda_server_command_get_user_data (cmd);
		if (stmt) {
			if (isc_dsql_free_statement
			    (ib_cnc->status, &stmt, DSQL_close))
				gda_server_error_make (gda_error_new (), 0,
						       cmd->cnc,
						       __PRETTY_FUNCTION__);
		}
	}
}