/* 
   Unix SMB/CIFS mplementation.
   DSDB replication service outgoing Pull-Replication
   
   Copyright (C) Stefan Metzmacher 2007
    
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.
   
   This program 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 General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
   
*/

#include "includes.h"
#include "dsdb/samdb/samdb.h"
#include "auth/auth.h"
#include "smbd/service.h"
#include "lib/events/events.h"
#include "lib/messaging/irpc.h"
#include "dsdb/repl/drepl_service.h"
#include "lib/ldb/include/ldb_errors.h"
#include "lib/util/dlinklist.h"
#include "librpc/gen_ndr/ndr_misc.h"
#include "librpc/gen_ndr/ndr_drsuapi.h"
#include "librpc/gen_ndr/ndr_drsblobs.h"
#include "libcli/composite/composite.h"

static WERROR dreplsrv_schedule_partition_pull_source(struct dreplsrv_service *s,
						      struct dreplsrv_partition *p,
						      struct dreplsrv_partition_source_dsa *source,
						      TALLOC_CTX *mem_ctx)
{
	struct dreplsrv_out_operation *op;

	op = talloc_zero(mem_ctx, struct dreplsrv_out_operation);
	W_ERROR_HAVE_NO_MEMORY(op);

	op->service	= s;
	op->source_dsa	= source;

	DLIST_ADD_END(s->ops.pending, op, struct dreplsrv_out_operation *);
	talloc_steal(s, op);
	return WERR_OK;
}

static WERROR dreplsrv_schedule_partition_pull(struct dreplsrv_service *s,
					       struct dreplsrv_partition *p,
					       TALLOC_CTX *mem_ctx)
{
	WERROR status;
	struct dreplsrv_partition_source_dsa *cur;

	for (cur = p->sources; cur; cur = cur->next) {
		status = dreplsrv_schedule_partition_pull_source(s, p, cur, mem_ctx);
		W_ERROR_NOT_OK_RETURN(status);
	}

	return WERR_OK;
}

WERROR dreplsrv_schedule_pull_replication(struct dreplsrv_service *s, TALLOC_CTX *mem_ctx)
{
	WERROR status;
	struct dreplsrv_partition *p;

	for (p = s->partitions; p; p = p->next) {
		status = dreplsrv_schedule_partition_pull(s, p, mem_ctx);
		W_ERROR_NOT_OK_RETURN(status);
	}

	return WERR_OK;
}

static void dreplsrv_pending_op_callback(struct dreplsrv_out_operation *op)
{
	struct repsFromTo1 *rf = op->source_dsa->repsFrom1;
	struct dreplsrv_service *s = op->service;
	time_t t;
	NTTIME now;

	t = time(NULL);
	unix_to_nt_time(&now, t);

	rf->result_last_attempt = dreplsrv_op_pull_source_recv(op->creq);
	if (W_ERROR_IS_OK(rf->result_last_attempt)) {
		rf->consecutive_sync_failures	= 0;
		rf->last_success		= now;
		DEBUG(2,("dreplsrv_op_pull_source(%s)\n",
			win_errstr(rf->result_last_attempt)));
		goto done;
	}

	rf->consecutive_sync_failures++;

	DEBUG(1,("dreplsrv_op_pull_source(%s/%s) failures[%u]\n",
		win_errstr(rf->result_last_attempt),
		nt_errstr(werror_to_ntstatus(rf->result_last_attempt)),
		rf->consecutive_sync_failures));

done:
	talloc_free(op);
	s->ops.current = NULL;
	dreplsrv_run_pending_ops(s);
}

static void dreplsrv_pending_op_callback_creq(struct composite_context *creq)
{
	struct dreplsrv_out_operation *op = talloc_get_type(creq->async.private_data,
							   struct dreplsrv_out_operation);
	dreplsrv_pending_op_callback(op);
}

void dreplsrv_run_pending_ops(struct dreplsrv_service *s)
{
	struct dreplsrv_out_operation *op;
	time_t t;
	NTTIME now;

	if (s->ops.current) {
		/* if there's still one running, we're done */
		return;
	}

	if (!s->ops.pending) {
		/* if there're no pending operations, we're done */
		return;
	}

	t = time(NULL);
	unix_to_nt_time(&now, t);

	op = s->ops.pending;
	s->ops.current = op;
	DLIST_REMOVE(s->ops.pending, op);

	op->source_dsa->repsFrom1->last_attempt = now;

	op->creq = dreplsrv_op_pull_source_send(op);
	if (!op->creq) {
		dreplsrv_pending_op_callback(op);
		return;
	}

	op->creq->async.fn		= dreplsrv_pending_op_callback_creq;
	op->creq->async.private_data	= op;
}