/*
  Copyright (c) 2012, Matthias Schiffer <mschiffer@universe-factory.net>
  All rights reserved.

  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions are met:

    1. Redistributions of source code must retain the above copyright notice,
       this list of conditions and the following disclaimer.
    2. Redistributions in binary form must reproduce the above copyright notice,
       this list of conditions and the following disclaimer in the documentation
       and/or other materials provided with the distribution.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/


#include "ffd.h"
#include "neigh.h"
#include "queue.h"
#include "send.h"

#include <stdio.h>


static ffd_queue_t *pending_updates = NULL;


typedef struct _update_arg_t {
	ffd_node_id_t node;
	uint16_t type;
	uint16_t key;

	ffd_neigh_t *neigh;
	unsigned ref;
} update_arg_t;


static inline update_arg_t* update_new(const ffd_node_id_t *node, uint16_t type, uint16_t key, ffd_neigh_t *neigh) {
	update_arg_t *arg = malloc(sizeof(update_arg_t));

	arg->node = *node;
	arg->type = type;
	arg->key = key;

	if (neigh)
		ffd_neigh_ref(neigh);
	arg->neigh = neigh;

	arg->ref = 0;

	return arg;
}

static inline update_arg_t* update_ref(update_arg_t *arg) {
	arg->ref++;
	return arg;
}

static inline void update_unref(update_arg_t *arg) {
	if (!--arg->ref) {
		if (arg->neigh)
			ffd_neigh_unref(arg->neigh);

		free(arg);
	}
}

static void update_request_ack(uint16_t nonce, void *argp) {
	update_arg_t *arg = argp;

	fprintf(stderr, "debug: sending acked update with nonce %u.\n", nonce);

	ffd_update_t *update = ffd_send_update_new(NULL, arg->neigh, &nonce);

	ffd_announce_t *announce = ffd_announce_find(&arg->node, arg->type, arg->key);

	if (announce)
		ffd_send_update_add(update, announce);
	else
		ffd_send_update_retract(update, arg->node, arg->type, arg->key);

	ffd_send_update_finish(update);
}

static void update_request_ack_free(uint16_t nonce, void *arg) {
	update_unref(arg);
}

void ffd_update_enqueue(const ffd_node_id_t *node, uint16_t type, uint16_t key, ffd_neigh_t *neigh, bool urgent) {
	if (neigh)
		ffd_neigh_ref(neigh);

	update_arg_t *arg = update_new(node, type, key, neigh);

	if (urgent) {
		if (neigh) {
			ffd_ack_request(update_request_ack, update_request_ack_free, FFD_ACK_INTERVAL, 10, update_ref(arg));
		}
		else {
			int i;
			for (i = 1; i <= 5; i++)
				ffd_queue_put_delayed(&pending_updates, NULL, &now, i*FFD_URGENT_DELAY, update_ref(arg));
		}
	}
	else {
		ffd_queue_put_delayed(&pending_updates, NULL, &now, FFD_DELAY, update_ref(arg));
	}
}

int ffd_update_timeout(void) {
	return ffd_queue_timeout(&pending_updates);
}

void ffd_update_run(void) {
	while (!ffd_update_timeout()) {
		ffd_neigh_t *neigh = ((update_arg_t*)pending_updates->arg)->neigh;

		ffd_update_t *update = ffd_send_update_new(NULL, neigh, NULL);

		fprintf(stderr, "debug: sending scheduled updates.\n");

		ffd_queue_t **entry;
		for (entry = &pending_updates; *entry;) {
			update_arg_t *arg = (*entry)->arg;

			if (arg->neigh != neigh) {
				entry = &(*entry)->next;
				continue;
			}

			ffd_announce_t *announce = ffd_announce_find(&arg->node, arg->type, arg->key);
			bool ret;

			if (announce)
				ret = ffd_send_update_add(update, announce);
			else
				ret = ffd_send_update_retract(update, arg->node, arg->type, arg->key);

			if (!ret)
				break;

			update_unref(arg);
			ffd_queue_drop(entry);
		}

		ffd_send_update_finish(update);
	}
}