/*
 * Copyright (c) 2017-2021 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include <vnet/fib/fib_entry_track.h>

#include "face.h"
#include "../hicn.h"
#include "../params.h"
#include "../error.h"
#include "../mapme.h"
#include "../mapme_eventmgr.h"

dpo_id_t *face_dpo_vec;
hicn_face_vft_t *face_vft_vec;
char **face_type_names_vec;

hicn_face_t *hicn_dpoi_face_pool;

dpo_type_t first_type = DPO_FIRST;

vlib_combined_counter_main_t *counters;

dpo_type_t hicn_face_type;

fib_node_type_t hicn_face_fib_node_type;

const char *HICN_FACE_CTRX_STRING[] = {
#define _(a, b, c) c,
  foreach_hicn_face_counter
#undef _
};

u8 *
face_show (u8 *s, int face_id, u32 indent)
{
  s = format (s, "%U Faces:\n", format_white_space, indent);
  indent += 4;
  int i;
  vec_foreach_index (i, face_dpo_vec)
    {
      s = format (s, "%U", face_vft_vec[i].format_face,
		  face_dpo_vec[face_id].dpoi_index, indent);
    }

  return (s);
}

mhash_t hicn_face_vec_hashtb;
mhash_t hicn_face_hashtb;

hicn_face_vec_t *hicn_vec_pool;

const static char *const hicn_face6_nodes[] = {
  "hicn6-face-output",	// this is the name you give your node in
			// VLIB_REGISTER_NODE
  "hicn6-iface-output", // this is the name you give your node in
			// VLIB_REGISTER_NODE
  NULL,
};

const static char *const hicn_face4_nodes[] = {
  "hicn4-face-output",	// this is the name you give your node in
			// VLIB_REGISTER_NODE
  "hicn4-iface-output", // this is the name you give your node in
			// VLIB_REGISTER_NODE
  NULL,
};

const static char *const *const hicn_face_nodes[DPO_PROTO_NUM] = {
  [DPO_PROTO_IP4] = hicn_face4_nodes, [DPO_PROTO_IP6] = hicn_face6_nodes
};

const static dpo_vft_t hicn_face_dpo_vft = {
  .dv_lock = hicn_face_lock,
  .dv_unlock = hicn_face_unlock,
  .dv_format = format_hicn_face,
};

static fib_node_t *
hicn_face_node_get (fib_node_index_t index)
{
  hicn_face_t *face;

  face = hicn_dpoi_get_from_idx (index);

  return (&face->fib_node);
}

static void
hicn_face_last_lock_gone (fib_node_t *node)
{
}

static hicn_face_t *
hicn_face_from_fib_node (fib_node_t *node)
{
  return ((hicn_face_t *) (((char *) node) -
			   STRUCT_OFFSET_OF (hicn_face_t, fib_node)));
}

static fib_node_back_walk_rc_t
hicn_face_back_walk_notify (fib_node_t *node, fib_node_back_walk_ctx_t *ctx)
{

  hicn_face_t *face = hicn_face_from_fib_node (node);

  const dpo_id_t *dpo_loadbalance =
    fib_entry_contribute_ip_forwarding (face->fib_entry_index);
  const load_balance_t *lb0 = load_balance_get (dpo_loadbalance->dpoi_index);

  const dpo_id_t *dpo = load_balance_get_bucket_i (lb0, 0);

  dpo_stack (hicn_face_type, face->dpo.dpoi_proto, &face->dpo, dpo);
  /* if (dpo_is_adj(dpo)) */
  /*   { */
  /*     ip_adjacency_t * adj = adj_get (dpo->dpoi_index); */

  /*     if (dpo->dpoi_type == DPO_ADJACENCY_MIDCHAIN || */
  /*         dpo->dpoi_type == DPO_ADJACENCY_MCAST_MIDCHAIN) */
  /*       { */
  /*         adj_nbr_midchain_stack(dpo->dpoi_index, &face->dpo); */
  /*       } */
  /*     else */
  /*       { */
  /*         dpo_stack(hicn_face_type, face->dpo.dpoi_proto, &face->dpo, dpo);
   */
  /*       } */
  /*   } */

  return (FIB_NODE_BACK_WALK_CONTINUE);
}

static void
hicn_face_show_memory (void)
{
}

static const fib_node_vft_t hicn_face_fib_node_vft = {
  .fnv_get = hicn_face_node_get,
  .fnv_last_lock = hicn_face_last_lock_gone,
  .fnv_back_walk = hicn_face_back_walk_notify,
  .fnv_mem_show = hicn_face_show_memory,
};

// Make this more flexible for future types face
void
hicn_face_module_init (vlib_main_t *vm)
{
  pool_validate (hicn_dpoi_face_pool);
  pool_alloc (hicn_dpoi_face_pool, 1024);
  counters = vec_new (vlib_combined_counter_main_t,
		      HICN_PARAM_FACES_MAX * HICN_N_COUNTER);

  mhash_init (&hicn_face_vec_hashtb,
	      sizeof (hicn_face_input_faces_t) /* value */,
	      sizeof (hicn_face_key_t) /* key */);
  mhash_init (&hicn_face_hashtb, sizeof (hicn_face_id_t) /* value */,
	      sizeof (hicn_face_key_t) /* key */);

  pool_alloc (hicn_vec_pool, 100);

  /*
   * How much useful is the following registration?
   * So far it seems that we need it only for setting the dpo_type.
   */
  hicn_face_type = dpo_register_new_type (&hicn_face_dpo_vft, hicn_face_nodes);

  /*
   * We register a new node type to get informed when the adjacency
   * corresponding to a face is updated
   */
  hicn_face_fib_node_type =
    fib_node_register_new_type (&hicn_face_fib_node_vft);
}

u8 *
format_hicn_face (u8 *s, va_list *args)
{
  index_t index = va_arg (*args, index_t);
  u32 indent = va_arg (*args, u32);
  hicn_face_t *face;

  face = hicn_dpoi_get_from_idx (index);

  if (face->flags & HICN_FACE_FLAGS_FACE)
    {
      hicn_face_id_t face_id = hicn_dpoi_get_index (face);
      s = format (s, "%U Face %d: ", format_white_space, indent, face_id);
      s = format (s, "nat address %U locks %u, path_label %u",
		  format_ip46_address, &face->nat_addr, IP46_TYPE_ANY,
		  face->locks, face->pl_id);

      if ((face->flags & HICN_FACE_FLAGS_APPFACE_PROD))
	s = format (s, " (producer)");
      else if ((face->flags & HICN_FACE_FLAGS_APPFACE_CONS))
	s = format (s, " (consumer)");

      if ((face->flags & HICN_FACE_FLAGS_DELETED))
	s = format (s, " (deleted)");

      s = format (s, "\n%U%U", format_white_space, indent + 2, format_dpo_id,
		  &face->dpo, indent + 3);
    }
  else
    {
      hicn_face_id_t face_id = hicn_dpoi_get_index (face);
      s = format (s, "%U iFace %d: ", format_white_space, indent, face_id);
      s = format (s, "nat address %U locks %u, path_label %u",
		  format_ip46_address, &face->nat_addr, IP46_TYPE_ANY,
		  face->locks, face->pl_id);

      if ((face->flags & HICN_FACE_FLAGS_APPFACE_PROD))
	s = format (s, " (producer)");
      else if ((face->flags & HICN_FACE_FLAGS_APPFACE_CONS))
	s = format (s, " (consumer)");

      if ((face->flags & HICN_FACE_FLAGS_DELETED))
	s = format (s, " (deleted)");
    }

  return s;
}

u8 *
format_hicn_face_all (u8 *s, int n, ...)
{
  va_list ap;
  va_start (ap, n);
  u32 indent = va_arg (ap, u32);

  s = format (s, "%U Faces:\n", format_white_space, indent);

  hicn_face_t *face;

  pool_foreach (face, hicn_dpoi_face_pool)
    {
      s = format (s, "%U\n", format_hicn_face, hicn_dpoi_get_index (face),
		  indent);
    }

  return s;
}

int
hicn_face_del (hicn_face_id_t face_id)
{
  hicn_face_t *face = hicn_dpoi_get_from_idx (face_id);
  hicn_face_key_t key;
  hicn_face_key_t old_key;
  hicn_face_key_t old_key2;

  hicn_face_get_key (&(face->nat_addr), face->sw_if, &(face->dpo), &key);
  hicn_face_input_faces_t *in_faces_vec =
    hicn_face_get_vec (&(face->nat_addr), &hicn_face_vec_hashtb);
  if (in_faces_vec != NULL)
    {
      hicn_face_vec_t *vec =
	pool_elt_at_index (hicn_vec_pool, in_faces_vec->vec_id);
      u32 index_face = vec_search (*vec, face_id);
      vec_del1 (*vec, index_face);

      if (vec_len (*vec) == 0)
	{
	  pool_put_index (hicn_vec_pool, in_faces_vec->vec_id);
	  mhash_unset (&hicn_face_vec_hashtb, &key, (uword *) &old_key);
	  vec_free (*vec);
	}
      else
	{
	  /* Check if the face we are deleting is the preferred one. */
	  /* If so, repleace with another. */
	  if (in_faces_vec->face_id == face_id)
	    {
	      in_faces_vec->face_id = (*vec)[0];
	    }
	}

      mhash_unset (&hicn_face_hashtb, &key, (uword *) &old_key2);
    }

  int ret = HICN_ERROR_NONE;

  if (hicn_dpoi_idx_is_valid (face_id))
    {
      hicn_face_t *face = hicn_dpoi_get_from_idx (face_id);
      face->locks--;
      if (face->locks == 0)
	pool_put_index (hicn_dpoi_face_pool, face_id);
      else
	face->flags |= HICN_FACE_FLAGS_DELETED;
    }
  else
    ret = HICN_ERROR_FACE_NOT_FOUND;

  return ret;
}

static void
hicn_iface_to_face (hicn_face_t *face, const dpo_id_t *dpo)
{
  dpo_stack (hicn_face_type, dpo->dpoi_proto, &face->dpo, dpo);

  face->flags &= ~HICN_FACE_FLAGS_IFACE;
  face->flags |= HICN_FACE_FLAGS_FACE;

  if (dpo_is_adj (dpo))
    {
      fib_node_init (&face->fib_node, hicn_face_fib_node_type);
      fib_node_lock (&face->fib_node);

      if (dpo->dpoi_type != DPO_ADJACENCY_MIDCHAIN ||
	  dpo->dpoi_type != DPO_ADJACENCY_MCAST_MIDCHAIN)
	{
	  ip_adjacency_t *adj = adj_get (dpo->dpoi_index);
	  ip46_address_t *nh = &(adj->sub_type.nbr.next_hop);
	  fib_prefix_t prefix;

	  if (!ip46_address_is_zero (nh))
	    {
	      fib_prefix_from_ip46_addr (nh, &prefix);

	      u32 fib_index = fib_table_find (prefix.fp_proto, HICN_FIB_TABLE);

	      face->fib_entry_index = fib_entry_track (
		fib_index, &prefix, hicn_face_fib_node_type,
		hicn_dpoi_get_index (face), &face->fib_sibling);
	    }
	}
    }
}

/*
 * Utility that adds a new face cache entry. For the moment we assume that
 * the ip_adjacency has already been set up.
 */
int
hicn_face_add (const dpo_id_t *dpo_nh, ip46_address_t *nat_address, int sw_if,
	       hicn_face_id_t *pfaceid, u8 is_app_prod)
{

  hicn_face_flags_t flags = (hicn_face_flags_t) 0;
  flags |= HICN_FACE_FLAGS_FACE;

  hicn_face_t *face;

  face =
    hicn_face_get_with_dpo (nat_address, sw_if, dpo_nh, &hicn_face_hashtb);

  if (face != NULL)
    {
      *pfaceid = hicn_dpoi_get_index (face);
      return HICN_ERROR_FACE_ALREADY_CREATED;
    }

  face =
    hicn_face_get (nat_address, sw_if, &hicn_face_hashtb, dpo_nh->dpoi_index);

  dpo_id_t temp_dpo = DPO_INVALID;
  temp_dpo.dpoi_index = dpo_nh->dpoi_index;
  hicn_face_key_t key;
  hicn_face_get_key (nat_address, sw_if, dpo_nh, &key);

  if (face == NULL)
    {

      hicn_iface_add (nat_address, sw_if, pfaceid, dpo_nh->dpoi_proto,
		      dpo_nh->dpoi_index);
      face = hicn_dpoi_get_from_idx (*pfaceid);

      mhash_set_mem (&hicn_face_hashtb, &key, (uword *) pfaceid, 0);

      hicn_face_get_key (nat_address, sw_if, &temp_dpo, &key);
      mhash_set_mem (&hicn_face_hashtb, &key, (uword *) pfaceid, 0);
    }
  else
    {
      /* We found an iface and we convert it to a face */
      *pfaceid = hicn_dpoi_get_index (face);
      mhash_set_mem (&hicn_face_hashtb, &key, (uword *) pfaceid, 0);
    }

  hicn_iface_to_face (face, dpo_nh);

  temp_dpo.dpoi_index = ~0;

  hicn_face_input_faces_t *in_faces =
    hicn_face_get_vec (nat_address, &hicn_face_vec_hashtb);

  if (in_faces == NULL)
    {
      hicn_face_input_faces_t in_faces_temp;
      hicn_face_vec_t *vec;
      pool_get (hicn_vec_pool, vec);
      *vec = vec_new (hicn_face_id_t, 0);
      u32 index = vec - hicn_vec_pool;
      in_faces_temp.vec_id = index;
      vec_add1 (*vec, *pfaceid);

      in_faces_temp.face_id = *pfaceid;

      hicn_face_get_key (nat_address, 0, &temp_dpo, &key);

      mhash_set_mem (&hicn_face_vec_hashtb, &key, (uword *) &in_faces_temp, 0);
    }
  else
    {
      hicn_face_vec_t *vec =
	pool_elt_at_index (hicn_vec_pool, in_faces->vec_id);

      /* */
      if (vec_search (*vec, *pfaceid) != ~0)
	return HICN_ERROR_FACE_ALREADY_CREATED;

      vec_add1 (*vec, *pfaceid);

      hicn_iface_to_face (face, dpo_nh);

      hicn_face_get_key (nat_address, 0, &temp_dpo, &key);

      mhash_set_mem (&hicn_face_vec_hashtb, &key, (uword *) in_faces, 0);

      /* If the face is an application producer face, we set it as the
       * preferred incoming face. */
      /* This is required to handle the CS separation, and the push api in a
       * lightway */
      if (is_app_prod)
	{
	  in_faces->face_id = *pfaceid;
	}
    }

  retx_t *retx = vlib_process_signal_event_data (
    vlib_get_main (), hicn_mapme_eventmgr_process_node.index,
    HICN_MAPME_EVENT_FACE_ADD, 1, sizeof (retx_t));

  *retx = (retx_t){
    .face_id = *pfaceid,
  };

  return HICN_ERROR_NONE;
}

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */