/*
 * Copyright (c) 2017-2019 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.
 */

/**
 * \file facemgr.c
 * \brief Implementation of Face manager library interface
 */

#include <assert.h>
#include <stdio.h>
#include <string.h>

#include <hicn/facemgr/api.h>
#include <hicn/facemgr/cfg.h>
#include <hicn/util/log.h>

#ifdef __APPLE__
#include "interfaces/network_framework/network_framework.h"
#endif /* __APPLE__ */

#ifdef __linux__
#include "interfaces/bonjour/bonjour.h"
#endif /* __linux__ */

#ifdef __ANDROID__
#include <hicn/android_utility/android_utility.h>
#endif /* __ANDROID__ */

#include <hicn/ctrl/face.h>
#include "common.h"
#include "facelet.h"
#include "interface.h"
#include "util/map.h"
#include "util/set.h"

#define RAND_NAME_LEN 5

#define DEFAULT_PORT 9695

typedef struct {
    interface_t * interface;
    void * event;
} interface_map_data_t;

TYPEDEF_SET_H(facelet_cache, facelet_t *);
TYPEDEF_SET(facelet_cache, facelet_t *, facelet_cmp, facelet_snprintf);

TYPEDEF_MAP_H(interface_map, const char *, interface_map_data_t *);
TYPEDEF_MAP(interface_map, const char *, interface_map_data_t *, strcmp, string_snprintf, generic_snprintf);

int int_cmp(int x, int y) { return x - y; }

TYPEDEF_MAP_H(bonjour_map, netdevice_t *, interface_t *);
TYPEDEF_MAP(bonjour_map, netdevice_t *, interface_t *, netdevice_cmp, generic_snprintf, generic_snprintf);

/* TODO automatically register interfaces */

#ifdef __APPLE__
extern interface_ops_t network_framework_ops;
#endif
#ifdef __linux__
extern interface_ops_t netlink_ops;
extern interface_ops_t bonjour_ops;
#endif
#ifdef __ANDROID__
extern interface_ops_t android_utility_ops;
#endif /* __ANDROID__ */
#ifdef WITH_EXAMPLE_DUMMY
extern interface_ops_t dummy_ops;
#endif
#ifdef WITH_EXAMPLE_UPDOWN
extern interface_ops_t updown_ops;
#endif
extern interface_ops_t hicn_light_ops;


int
facemgr_overlay_snprintf(char * s, size_t size, const facemgr_overlay_t * overlay)
{
    return -1;
}

struct facemgr_s {
    /**************************************************/
    /* Configuration parameters (exposed through API) */

    facemgr_cfg_t * cfg;

#ifdef __ANDROID__
    /*
     * Those two pointers are needed to call java functions from the face
     * manager.
     */
    JavaVM *jvm;
#endif /* __ANDROID__ */

    /* Event loop support */
    void * loop;
    void * (*loop_register_fd)(void * loop, int fd, void * cb, void * cb_args);
    int (*loop_unregister_event)(void * loop, void * event);

    /****************************/
    /* Internal data structures */

    /* Map of interfaces index by name */
    interface_map_t interface_map;

    /* Faces under construction */
    facelet_cache_t facelet_cache;

    /********************************************************/
    /* Interfaces - Those should be fully replaced by a map */

    interface_t * hl;

#ifdef __ANDROID__
    interface_t * au; /* android_utility */
#endif /* __ANDROID__ */

#ifdef __APPLE__
    interface_t * nf; /* network_framework */
#endif /* __APPLE__ */

#ifdef __linux__
    interface_t * nl; /* netlink */

    /*
     * We maintain a map of dynamically created bonjour interfaces, one for each
     * found netdevice
     */
    bonjour_map_t bonjour_map;
#endif /* __linux__ */

#ifdef WITH_EXAMPLE_DUMMY
    interface_t * dummy;
#endif
#ifdef WITH_EXAMPLE_UPDOWN
    interface_t * updown;
#endif
};

int
facemgr_initialize(facemgr_t * facemgr)
{
    int rc;

    rc = interface_map_initialize(&facemgr->interface_map);
    if (rc < 0)
        goto ERR_INTERFACE_MAP;

    rc = facelet_cache_initialize(&facemgr->facelet_cache);
    if (rc < 0)
        goto ERR_FACE_CACHE_PENDING;

#ifdef __linux__
    rc = bonjour_map_initialize(&facemgr->bonjour_map);
    if (rc < 0)
        goto ERR_BJ;
#endif /* __linux */

    facemgr->cfg = facemgr_cfg_create();
    if (!facemgr->cfg)
        goto ERR_CFG;

    return 0;

ERR_CFG:
#ifdef __linux__
    bonjour_map_finalize(&facemgr->bonjour_map);
ERR_BJ:
#endif /* __linux__ */
    facelet_cache_finalize(&facemgr->facelet_cache);
ERR_FACE_CACHE_PENDING:
    interface_map_finalize(&facemgr->interface_map);
ERR_INTERFACE_MAP:
    return -1;
}

int
facemgr_finalize(facemgr_t * facemgr)
{
    int rc;

    /* TODO  Free all interfaces: pass free to map */

    rc = interface_map_finalize(&facemgr->interface_map);
    if (rc < 0)
        goto ERR;

    rc = facelet_cache_finalize(&facemgr->facelet_cache);
    if (rc < 0)
        goto ERR;

#ifdef __linux__
    rc = bonjour_map_finalize(&facemgr->bonjour_map);
    if (rc < 0)
        goto ERR;
#endif /* __linux__ */

    return 0;

ERR:
    return -1;
}

AUTOGENERATE_CREATE_FREE(facemgr);

int
facemgr_set_config(facemgr_t * facemgr, facemgr_cfg_t * cfg)
{
    if (facemgr->cfg) {
        facemgr_cfg_free(facemgr->cfg);
    }
    facemgr->cfg = cfg;
    return 0;
}

int facemgr_reset_config(facemgr_t * facemgr)
{
    assert(facemgr->cfg);
    facemgr_cfg_free(facemgr->cfg);
    facemgr->cfg = facemgr_cfg_create();
    if (!facemgr->cfg)
        return -1;
    return 0;
}

facemgr_t *
facemgr_create_with_config(facemgr_cfg_t * cfg)
{
    facemgr_t * facemgr = facemgr_create();
    if (!facemgr)
        return NULL;
    int rc = facemgr_set_config(facemgr, cfg);
    if (rc < 0) {
        free(facemgr);
        return NULL;
    }
    return facemgr;
}

int facemgr_on_event(facemgr_t * facemgr, facelet_t * facelet);

int
facemgr_create_interface(facemgr_t * facemgr, const char * name, const char * type, void * cfg, interface_t ** pinterface)
{
    int fd, rc;
    void * event = NULL;
    char rand_name[RAND_NAME_LEN+1];
    interface_t * interface;

    if (!name) {
        /*
         * We can manipulate the name on the stack as it will be strdup'ed by
         * interface_create
         */
        rand_str(rand_name, RAND_NAME_LEN);
        name = rand_name;
    }

    INFO("Creating interface %s [%s]...", name, type);
    interface = interface_create(name, type);
    if (!interface) {
        ERROR("Error creating interface %s [%s]", name, type);
        goto ERR_CREATE;
    }
    interface_set_callback(interface, facemgr_on_event, facemgr);

    fd = interface_initialize(interface, cfg);
    if (fd < 0)
        goto ERR_INIT;
    if (fd != 0) {
        event = facemgr->loop_register_fd(facemgr->loop, fd, interface->ops->callback, interface);
        if (event == NULL)
            goto ERR_FD;
    }

    interface_map_data_t * interface_map_data = malloc(sizeof(interface_map_data_t));
    if (!interface_map_data)
        goto ERR_MAP_DATA;


    *interface_map_data = (interface_map_data_t) {
        .interface = interface,
        .event = event,
    };

    rc = interface_map_add(&facemgr->interface_map, interface->name, interface_map_data);
    if (rc < 0)
        goto ERR_MAP_ADD;

    DEBUG("Interface %s created successfully.", name);
    if (pinterface)
        *pinterface = interface;
    return 0;

ERR_MAP_ADD:
    free(interface_map_data);
ERR_MAP_DATA:
    if (fd > 0)
        facemgr->loop_unregister_event(facemgr->loop, interface_map_data->event);
ERR_FD:
    interface_finalize(interface);
ERR_INIT:
    interface_free(interface);
ERR_CREATE:
    if (pinterface)
        *pinterface = NULL;
    return -1;
}

int
facemgr_delete_interface(facemgr_t * facemgr, interface_t * interface)
{
    int rc;

    interface_map_data_t * interface_map_data = NULL;

    DEBUG("Removing interface %s\n", interface->name);
    rc = interface_map_remove(&facemgr->interface_map, interface->name, &interface_map_data);
    if (rc < 0)
        return -1;

    if (!interface_map_data)
        return -1;

    free(interface_map_data);

    rc = facemgr->loop_unregister_event(facemgr->loop, interface_map_data->event);
    if (rc < 0)
        return -1;


    interface_finalize(interface);
    interface_free(interface);

    return 0;
}

#ifdef __linux__
int facemgr_query_bonjour(facemgr_t * facemgr, netdevice_t * netdevice)
{
    interface_t * bj = NULL;

    int rc = bonjour_map_get(&facemgr->bonjour_map, netdevice, &bj);
    if (rc < 0)
        return rc;

    if (!bj) {
        /* Create a new bonjour interface */
        bonjour_cfg_t bj_cfg = {
            .netdevice = *netdevice,
        };
        rc = facemgr_create_interface(facemgr, NULL, "bonjour", &bj_cfg, &bj);
        if (rc < 0) {
            ERROR("Error creating 'Bonjour' interface for '%s'\n", netdevice->name);
            return -1;
        }
    }

    DEBUG("sending event to bonjour interface");

    /* Send an event to the interface (GET ?) */
    return interface_on_event(bj, NULL);
}
#endif /* __linux__ */

#ifdef __ANDROID__
int facemgr_query_android_utility(facemgr_t * facemgr, netdevice_t netdevice)
{
    /* Send an event to the interface */
    facelet_t * facelet = facelet_create();
    if (!facelet)
        goto ERR_MALLOC;

    int rc = facelet_set_netdevice(facelet, netdevice);
    if (rc < 0)
        goto ERR_ND;

    rc = interface_on_event(facemgr->au, facelet);
    if (rc < 0)
        goto ERR_EVENT;

    return 0;

ERR_EVENT:
ERR_ND:
    facelet_free(facelet);
ERR_MALLOC:
    return -1;
}
#endif /* __ANDROID__ */


/**
 * \brief Performs a cache lookup to find matching facelets
 * \param [in] facelet_cache - Facelet cache on which to perform lookup
 * \param [in] facelet - Facelet to lookup
 * \param [out] cached_facelet - Pointer used to return a newly allocated
 *      facelet array corresponding to the result of the cache lookup.
 * \return The number of entries in the array in case of success (positive
 *      value), or -1 in case of error.
 */
int
facelet_cache_lookup(const facelet_cache_t * facelet_cache, facelet_t * facelet,
        facelet_t ***cached_facelets)
{
    /*
     * If the facelet is uniquely identified by its key, it is used to perform
     * an efficient lookup directly...
     */
    if (facelet_has_key(facelet)) {
        facelet_t * found = NULL;
        if (facelet_cache_get(facelet_cache, facelet, &found) < 0) {
            ERROR("[facelet_cache_lookup] Error during cache lookup");
            return -1;
        }
        if (!found)
            return 0;
        *cached_facelets = malloc(sizeof(facelet_t*));
        *cached_facelets[0] = found;
        return 1;
    }

    /* ...otherwise, we iterate over the facelet
     * cache to find matching elements.
     */
    facelet_t ** facelet_array;
    int n = facelet_cache_get_array(facelet_cache, &facelet_array);
    if (n < 0) {
        ERROR("[facelet_cache_lookup] Error during cache match");
        return -1;
    }
    *cached_facelets = malloc(n * sizeof(facelet_t*));

    DEBUG("cache match n = %d", n);

    int num_match = 0;
    for (unsigned i = 0; i < n; i++) {
        char buf[128];
        facelet_snprintf(buf, 128, facelet_array[i]);
        DEBUG("- facelet_array[%d] %s", i, buf);
        facelet_snprintf(buf, 128, facelet);
        DEBUG("  facelet %s", buf);

        DEBUG("match ?");
        if (!facelet_match(facelet_array[i], facelet)) {
            DEBUG("no match");
            continue;
        }
        DEBUG("match!");
        (*cached_facelets)[num_match++] = facelet_array[i];
    }
    free(facelet_array);
    DEBUG("return nummatch=%d", num_match);
    return num_match;
}


/**
 * \brief Checks whether the facelet satisfies face creation rules
 * \param [in] facemgr - Pointer to the face manager instance
 * \param [in] facelet - Pointer to the facelet to process
 * \return 0 in case of success, -2 if we don't have enough information to
 * decide, -3 if the face does not satisfy rules, and -1 in case of error
 */
int
facemgr_facelet_satisfy_rules(facemgr_t * facemgr, facelet_t * facelet)
{
    /* As key, netdevice and family should always be present */
    netdevice_t netdevice = NETDEVICE_EMPTY;
    int rc = facelet_get_netdevice(facelet, &netdevice);
    if (rc < 0) {
        ERROR("[facemgr_facelet_satisfy_rules] Error retrieving netdevice from facelet");
        return -1;
    }

    int family = AF_UNSPEC;
    if (facelet_has_family(facelet)) {
        if (facelet_get_family(facelet, &family) < 0) {
            ERROR("[facemgr_facelet_satisfy_rules] Error retrieving family from facelet");
            return -1;
        }
    }

    netdevice_type_t netdevice_type = NETDEVICE_TYPE_UNDEFINED;
#ifdef __ANDROID__
    /*
     * In addition to netdevice, netdevice_type should be present to correctly
     * apply rules
     */
    rc = facelet_get_netdevice_type(facelet, &netdevice_type);
    if (rc < 0) {
        ERROR("[facemgr_facelet_satisfy_rules] Error retrieving netdevice_type from facelet");
        return -2;
    }
#endif /* __ANDROID__ */

    /* Ignore */
    bool ignore;
    if (facemgr_cfg_get_ignore(facemgr->cfg, &netdevice, netdevice_type,
                &ignore) < 0)
        return -1;
    if (ignore) {
        DEBUG("Ignored interface '%s/%s'...", netdevice.name,
                netdevice_type_str[netdevice_type]);
        return -3;
    }

    /* IPv4 */
    bool ipv4;
    if (facemgr_cfg_get_ipv4(facemgr->cfg, &netdevice, netdevice_type,
                &ipv4) < 0)
        return -1;
    if (!ipv4) {
        DEBUG("Ignored IPv4...");
        return -3;
    }

    /* IPv6 */
    bool ipv6;
    if (facemgr_cfg_get_ipv6(facemgr->cfg, &netdevice, netdevice_type,
                &ipv6) < 0)
        return -1;
    if (!ipv6) {
        DEBUG("Ignored IPv6...");
        return -3;
    }

    return 0;
}

#ifdef __ANDROID__
/**
 * \brief Complements facelet information through Android Utility interface
 * \return 0 if request was successful, -1 in case of error, and -2 if the
 *      interface is not applicable
 *
 * This function returnds _after_ completion.
 */
int
facemgr_complement_facelet_au(facemgr_t * facemgr, facelet_t * facelet)
{

    if (facelet_has_netdevice_type(facelet))
        return -2;

    if (facelet_is_au_done(facelet))
        return -2;

    netdevice_t netdevice = NETDEVICE_EMPTY;
    int rc = facelet_get_netdevice(facelet, &netdevice);
    if (rc < 0) {
        ERROR("[facemgr_complement_facelet_bj] Error retrieving netdevice from facelet");
        return -1;
    }

    DEBUG("Querying android utility...");
    facelet_set_au_done(facelet);

    /* /!\ Synchronous code here /!\ */
    if (facemgr_query_android_utility(facemgr, netdevice) < 0)
        return -1;
    return 0;
}
#endif /* __ANDROID__ */

#ifdef __linux__
/**
 * \brief Complements facelet information through Bonjour interface.
 * \return 0 if request was successful, -1 in case of error, and -2 if the
 *      interface is not applicable
 *
 * This function returnds _before_ completion as bonjour querying is
 * asynchronous.
 */
int
facemgr_complement_facelet_bj(facemgr_t * facemgr, facelet_t * facelet)
{
    netdevice_t netdevice = NETDEVICE_EMPTY;
    int rc = facelet_get_netdevice(facelet, &netdevice);
    if (rc < 0) {
        ERROR("[facemgr_complement_facelet_bj] Error retrieving netdevice from facelet");
        return -1;
    }

    netdevice_type_t netdevice_type = NETDEVICE_TYPE_UNDEFINED;
#ifdef __ANDROID__
    /*
     * In addition to netdevice, netdevice_type should be present to correctly
     * apply rules
     */
    rc = facelet_get_netdevice_type(facelet, &netdevice_type);
    if (rc < 0) {
        ERROR("[facemgr_complement_facelet_bj] Error retrieving netdevice_type from facelet");
        return -2;
    }
#endif /* __ANDROID__ */

    bool discovery;
    if (facemgr_cfg_get_discovery(facemgr->cfg, &netdevice, netdevice_type,
                &discovery) < 0)
        return -2;

    DEBUG("Discovery: %s", discovery ? "ON" : "OFF");

    if (!discovery)
        return -2;

    facemgr_face_type_t face_type = FACEMGR_FACE_TYPE_UNDEFINED;
    if (facelet_get_face_type(facelet, &face_type) < 0) {
        ERROR("[facemgr_complement_facelet_bj] Error retrieving face type from facelet");
        return -1;
    }

    bool discovery_needed = (face_type.layer == FACE_TYPE_LAYER_4) &&
        ((!facelet_has_remote_addr(facelet)) || (!facelet_has_remote_port(facelet)));

    DEBUG("Discovery needed: %s", discovery ? "ON" : "OFF");

    if (!discovery_needed) {
        return -2;
    }

    if (!facelet_has_local_addr(facelet)) {
        DEBUG("No discovery possible without local address");
        return -2;
    }

    if (facelet_is_bj_done(facelet)) {
        DEBUG("Bonjour already queried");
        return -2;
    }

    facelet_set_bj_done(facelet);
    return facemgr_query_bonjour(facemgr, &netdevice);
}
#endif /* __linux__ */

/**
 * \brief Complements facelet information through Manual settings.
 * \return 0 if request was successful, -1 in case of error, and -2 if the
 *      interface is not applicable
 *
 * This function returnds _before_ completion as bonjour querying is
 * asynchronous.
 */
int
facemgr_complement_facelet_manual(facemgr_t * facemgr, facelet_t * facelet)
{

    netdevice_t netdevice = NETDEVICE_EMPTY;
    int rc = facelet_get_netdevice(facelet, &netdevice);
    if (rc < 0) {
        ERROR("[facemgr_complement_facelet_manual] Error retrieving netdevice from facelet");
        return -1;
    }

    netdevice_type_t netdevice_type = NETDEVICE_TYPE_UNDEFINED;
#ifdef __ANDROID__
    /*
     * In addition to netdevice, netdevice_type should be present to correctly
     * apply rules
     */
    rc = facelet_get_netdevice_type(facelet, &netdevice_type);
    if (rc < 0) {
        ERROR("[facemgr_complement_facelet_manual] Error retrieving netdevice_type from facelet");
        return -2;
    }
#endif /* __ANDROID__ */

    int family = AF_UNSPEC;
    if (facelet_has_family(facelet)) {
        if (facelet_get_family(facelet, &family) < 0) {
            ERROR("[facemgr_complement_facelet_manual] Error retrieving family from facelet");
            return -1;
        }
    }

    /* Do not query manual is there is a change to go through bonjour */
    bool discovery;
    if (facemgr_cfg_get_discovery(facemgr->cfg, &netdevice, netdevice_type,
                &discovery) < 0)
        return -2;

    facemgr_face_type_t face_type = FACEMGR_FACE_TYPE_UNDEFINED;
    if (facelet_get_face_type(facelet, &face_type) < 0) {
        ERROR("[facemgr_complement_facelet_manual] Error retrieving face type from facelet");
        return -1;
    }

    bool discovery_needed = (face_type.layer == FACE_TYPE_LAYER_4) &&
        ((!facelet_has_remote_addr(facelet)) || (!facelet_has_remote_port(facelet)));

    if (!discovery_needed) {
        DEBUG("manual settings not considered as no discovery is needed");
        return -2;
    }

    if (discovery && !facelet_is_bj_done(facelet)) {
        DEBUG("manual settings not considered as discovery is enabled and Bonjour has not yet been done");
        return -2;
    }

    DEBUG("Applying manual settings...");
    /*
     * Manual overlay specification (remote addr/port)
     * We never override a result we have obtained through bonjour
     */
    if (!facelet_has_remote_addr(facelet)) {
        ip_address_t remote_addr;
        if (facemgr_cfg_get_overlay_remote_addr(facemgr->cfg,
                &netdevice, netdevice_type, family, &remote_addr) < 0) {
            ERROR("[facemgr_complement_facelet_manual] Error getting remote addr information from cfg");
            return -1;
        }
        if (ip_address_empty(&remote_addr)) {
            ERROR("[facemgr_complement_facelet_manual] Got empty remote addr information from cfg");
        } else {
            DEBUG(" - remote address");
            facelet_set_remote_addr(facelet, remote_addr);
        }
    }

    if (!facelet_has_remote_port(facelet)) {
        uint16_t remote_port;
        int rc = facemgr_cfg_get_overlay_remote_port(facemgr->cfg,
                &netdevice, netdevice_type, family, &remote_port);
        if (rc < 0) {
            ERROR("[facemgr_complement_facelet_manual] Error getting remote port information from cfg");
            return -1;
        }
        DEBUG(" - remote port");
        facelet_set_remote_port(facelet, remote_port);
    }

    /*
     * Complementing local addr/port XXX this should be done somewhere
     * else : manual settings have the lowest priority
     *
     * Local IP address is specific as it allows to override the source
     * address just before creating the face... we would need to check
     * whether this is an address that belong to us... it might be used
     * to arbitrate amongst several IP addresses instead...
     */
    ip_address_t local_addr;
    if (facemgr_cfg_get_overlay_local_addr(facemgr->cfg, &netdevice,
            netdevice_type, family, &local_addr) < 0) {
        ERROR("[facemgr_complement_facelet_manual] Error getting local addr information from cfg");
        return -1;
    }
    if (ip_address_empty(&local_addr)) {
        ERROR("[facemgr_complement_facelet_manual] Got empty local addr information from cfg");
    } else {
        DEBUG(" - local addres");
        facelet_set_local_addr(facelet, local_addr);
    }

    /* Sets a default local port, so far nobody sets it */
    uint16_t local_port;
    if (facemgr_cfg_get_overlay_local_port(facemgr->cfg,
            &netdevice, netdevice_type, family, &local_port) < 0) {
        ERROR("[facemgr_complement_facelet_manual] Error getting local port information from cfg");
        return -1;
    }
    DEBUG(" - local port");
    facelet_set_local_port(facelet, local_port);
    return 0;
}

int
facemgr_complement_facelet(facemgr_t * facemgr, facelet_t * facelet)
{
    int rc;

    if (!facelet_has_key(facelet))
        return -2;

#ifdef __ANDROID__
    rc = facemgr_complement_facelet_au(facemgr, facelet);
    if (rc != -2)
        return rc;
#endif /* __ANDROID__ */

    /* We continue only if the current call was not applicable. In the current
     * setting we have no interface that can be requested in parallel, and no
     * need to. This might evolve in future releases.
     */

#ifdef __linux__
    rc = facemgr_complement_facelet_bj(facemgr, facelet);
    if (rc != -2)
        return rc;
#endif /* __linux__ */

    DEBUG("Complement manual");

    rc = facemgr_complement_facelet_manual(facemgr, facelet);
    if (rc != -2)
        return rc;

    INFO("[facemgr_complement_facelet] No more interfaces to query... incomplete face");
    return 0;
}

/**
 * \brief Process facelet CREATE event
 * \param [in] facemgr - Pointer to the face manager instance
 * \param [in] facelet - Pointer to the facelet event to process
 * \return 0 if everything went correctly, or -1 in case of error.
 */
int
facemgr_process_create(facemgr_t * facemgr, facelet_t * facelet)
{
    /*
     * We create an interface locally, which does not means it should not exist
     * remotely. Once such codepath is enabled, the two facelets will have been
     * merged and we need to handle an eventual update on our side.
     *
     * In the same way, we need to check for the equivalence of face types etc.
     */
    int rc;

    if (facelet_cache_add(&facemgr->facelet_cache, facelet) < 0) {
        ERROR("[facemgr_process_create] Error adding facelet to cache");
        return -1;
    }
    DEBUG("Facelet added to cache");

    /*
     * If the facelet does not satisfy filters, we do not lose any information
     * but do not take any action to complement the face
     */
    rc = facemgr_facelet_satisfy_rules(facemgr, facelet);
    if (rc == -3) {
        /* Does not satisfy rules */
        return 0;
    }

    // FIXME: we should complement a part of the facelet, so that we don't
    // necessarily keep this information if we get more locally. Or at least we
    // should remember that.
    if (rc == -2) {
        /*
         * We don't have equivalent for linux right now, heuristic is only used
         * at the end... might change.
         */
#ifdef __ANDROID__
        /* Priority is given to information that complements a face */
        if (facemgr_complement_facelet_au(facemgr, facelet) < 0) {
            ERROR("[facemgr_process_create] Error while attempting to complement face for fields required by rule application");
            return -1;
        }
        return 0;
#endif /* __ANDROID__ */
    }
    if (rc < 0)
        return -1;

//    netdevice_t netdevice = NETDEVICE_EMPTY;
//    if (facelet_get_netdevice(facelet, &netdevice) < 0) {
//        ERROR("[facemgr_process_create] Error retrieving netdevice from facelet");
//        return -1;
//    }
//
//    netdevice_type_t netdevice_type = NETDEVICE_TYPE_UNDEFINED;
//#ifdef __ANDROID__
//    /*
//     * In addition to netdevice, netdevice_type should be present to correctly
//     * apply rules
//     */
//    if (facelet_get_netdevice_type(facelet, &netdevice_type) < 0) {
//        ERROR("[facemgr_process_create] Error retrieving netdevice_type from facelet");
//        return -2;
//    }
//#endif /* __ANDROID__ */


    char facelet_s[MAXSZ_FACELET];
    facelet_snprintf(facelet_s, MAXSZ_FACELET, facelet);
    DEBUG("---[ FACELET CREATE : %s ] ---", facelet_s);

    /* Do we have enough information about the facelet ? */
    if (!facelet_validate_face(facelet)) {
        if (facemgr_complement_facelet(facemgr, facelet) < 0) {
            ERROR("[facemgr_process_create] Error while attempting to complement face for fields required by face creation");
            return -1;
        }
        // we should not stop after complement_manual but create a face if
        // possible... so we add a second validation
    }

    if (!facelet_validate_face(facelet))
        return 0;

    /*
     * Is the forwarder connected, and has the facelet cache already sync'ed the
     * remote faces ?
     */
    // TODO

    /*
     * Actually create the face on the forwarder
     *
     * FIXME Currently hicn-light is hardcoded
     */
    if (interface_on_event(facemgr->hl, facelet) < 0)
        return -1;
    facelet_set_status(facelet, FACELET_STATUS_CLEAN);
    return 0;
}

/**
 * \brief Process facelet GET event
 * \param [in] facemgr - Pointer to the face manager instance
 * \param [in] facelet - Pointer to the facelet event to process
 * \return 0 if everything went correctly, or -1 in case of error.
 */
int
facemgr_process_get(facemgr_t * facemgr, facelet_t * facelet)
{
    facelet_set_status(facelet, FACELET_STATUS_CLEAN);
    if (facelet_has_netdevice(facelet)) {
        netdevice_t netdevice;
        if (facelet_get_netdevice(facelet, &netdevice) < 0)
            return -1;
        if (!IS_VALID_NETDEVICE(netdevice))
            return 0;
        return facelet_cache_add(&facemgr->facelet_cache, facelet);
    }
    return 0;
}

/**
 * \brief Process facelet UPDATE event
 * \param [in] facemgr - Pointer to the face manager instance
 * \param [in] facelet - Pointer to the facelet event to process
 * \return 0 if everything went correctly, or -1 in case of error.
 */
int
facemgr_process_update(facemgr_t * facemgr, facelet_t * facelet)
{
    /* This is the most complex operation since we have the same problems as in
     * CREATE + the need to manage changes...
     *
     * This might eventually trigger a face deletion...
     */

    /*
     * Update in local does not mean the face should not be created remotely as
     * it might be the first time we have enough information to create it
     */

    char facelet_s[MAXSZ_FACELET];
    facelet_snprintf(facelet_s, MAXSZ_FACELET, facelet);
    DEBUG("---[ FACELET UPDATE : %s ] ---", facelet_s);

    /* Sets face type */
    if (!facelet_has_face_type(facelet)) {

        /* As key, netdevice and family should always be present */
        netdevice_t netdevice = NETDEVICE_EMPTY;
        int rc = facelet_get_netdevice(facelet, &netdevice);
        if (rc < 0) {
            ERROR("[facemgr_facelet_satisfy_rules] Error retrieving netdevice from facelet");
            return -1;
        }

        netdevice_type_t netdevice_type = NETDEVICE_TYPE_UNDEFINED;
#ifdef __ANDROID__
        /*
         * In addition to netdevice, netdevice_type should be present to correctly
         * apply rules
         */
        rc = facelet_get_netdevice_type(facelet, &netdevice_type);
        if (rc < 0) {
            ERROR("[facemgr_facelet_satisfy_rules] Error retrieving netdevice_type from facelet");
            return -2;
        }
#endif /* __ANDROID__ */

        facemgr_face_type_t face_type = FACEMGR_FACE_TYPE_UNDEFINED;
        if (facemgr_cfg_get_face_type(facemgr->cfg, &netdevice, netdevice_type, &face_type) < 0)
            return rc;
        facelet_set_face_type(facelet, face_type);
    }

    /* Process GET/UDPATE... */
    switch(facelet_get_status(facelet)) {
        case FACELET_STATUS_UNDEFINED:
            ERROR("[facemgr_process_update] Unexpected facelet status");
            return -1;

        case FACELET_STATUS_DELETED:
        case FACELET_STATUS_NEW:
            /*
             * If the remote action should be a CREATE, then we need to check
             * whether we have enough information about the face...
             */
            if (!facelet_validate_face(facelet)) {
                if (facemgr_complement_facelet(facemgr, facelet) < 0) {
                    ERROR("[facemgr_process_update] Error while attempting to complement face for fields required by face creation");
                    return -1;
                }
            }
            if (!facelet_validate_face(facelet))
                return 0;

            facelet_set_event(facelet, FACELET_EVENT_CREATE);
            interface_on_event(facemgr->hl, facelet);

            /* This works assuming the call to hicn-light is blocking */
            facelet_set_status(facelet, FACELET_STATUS_CLEAN);
            break;

        case FACELET_STATUS_CLEAN:
            /* Nothing to do */
            break;

        case FACELET_STATUS_DIRTY:
            /*
             * For now we assume only local changes, and proceed to try and
             * update the hICN forwarder.
             *
             * In case of update, the face exists which means we should already
             * have enough information
             */
            if (!facelet_validate_face(facelet)) {
                if (facemgr_complement_facelet(facemgr, facelet) < 0) {
                    ERROR("[facemgr_process_create] Error while attempting to complement face for fields required by face creation");
                    return -1;
                }
            }

            if (!facelet_validate_face(facelet))
                return 0;

            facelet_set_event(facelet, FACELET_EVENT_UPDATE);
            if (interface_on_event(facemgr->hl, facelet) < 0)
                return -1;

            /* This works assuming the call to hicn-light is blocking and we
             * have proceeded to all udpates */
            facelet_set_status(facelet, FACELET_STATUS_CLEAN);
            break;

        case FACELET_STATUS_CONFLICT:
            ERROR("[facemgr_process_update] Conflict resolution (not) yet implemented");
            return -1;
        case FACELET_STATUS_N:
            ERROR("[facemgr_process_update] Facelet in error");
            return -1;
    }
    return 0;
}

/**
 * \brief Process facelet DELETE event
 * \param [in] facemgr - Pointer to the face manager instance
 * \param [in] facelet - Pointer to the facelet event to process
 * \return 0 if everything went correctly, or -1 in case of error.
 */
int
facemgr_process_delete(facemgr_t * facemgr, facelet_t * facelet)
{
    if (interface_on_event(facemgr->hl, facelet) < 0)
        return -1;

    facelet_set_status(facelet, FACELET_STATUS_DELETED);
    //facelet_set_bj_done(facelet, false);

    return 0;
}

/**
 * \brief Process incoming events from interfaces
 *
 * Implementation notes:
 *  - Any event or timeout due to an interface triggers either a local cache
 *  update, as well a face operations needed to resync the state.
 */
int
facemgr_on_event(facemgr_t * facemgr, facelet_t * facelet_in)
{
    int ret = 0;
    assert(facelet_in);

    char facelet_s[MAXSZ_FACELET];
    facelet_snprintf(facelet_s, MAXSZ_FACELET, facelet_in);
    DEBUG("----------------------------------");
    DEBUG("EVENT %s\n", facelet_s);

    facelet_t ** cached_facelets = NULL;
    int n = facelet_cache_lookup(&facemgr->facelet_cache, facelet_in, &cached_facelets);
    if (n < 0) {
        ERROR("[facemgr_on_event] Error during cache lookup");
        goto ERR;
    }
    DEBUG("num matches n=%d", n);
    if (n == 0) {
        /* This is a new facelet...  we expect a CREATE event. */
        switch(facelet_get_event(facelet_in)) {
            case FACELET_EVENT_CREATE:
                if (facemgr_process_create(facemgr, facelet_in) < 0) {
                    ERROR("[facemgr_process_cached_facelet] Error processing CREATE event");
                    goto ERR;
                }
                break;

            case FACELET_EVENT_GET:
                /* Insert new facelet in cached */
                if (facemgr_process_get(facemgr, facelet_in) < 0) {
                    ERROR("[facemgr_process_cached_facelet] Error processing GET event");
                    goto ERR;
                }
                break;

            case FACELET_EVENT_UPDATE:
                /* Might be because we previously ignored the facelet... */
                //ERROR("[facemgr_on_event] Unexpected UPDATE... face does not exist");
                //goto ERR;
                INFO("Ignored UPDATE for non-existing face");
                break;

            case FACELET_EVENT_DELETE:
                ERROR("[facemgr_on_event] Unexpected DELETE... face does not exist");
                goto ERR;

            case FACELET_EVENT_UNDEFINED:
                ERROR("[facemgr_on_event] Unexpected UNDEFINED event.");
                goto ERR;

            default: /* XXX Some events should be deprecated */
                ERROR("[facemgr_on_event] Deprecated event");
                goto ERR;
        }
        goto DUMP_CACHE;
    }

    /*
     * From now on, it should not make any difference whether we have one or
     * more facelet.
     */
    for (unsigned i = 0; i < n; i ++) {
        /*
         * We merge each cached facelet with incoming one, and perform state
         * reconciliation by sending appropriate updates to the forwarder
         */
        facelet_t * facelet = cached_facelets[i];
        DEBUG("... match #%d", i);
        switch(facelet_get_event(facelet_in)) {
            case FACELET_EVENT_CREATE:
                // FIXME, this might occur if the facemgr restarts and we try to
                // re-create existing faces
                ERROR("[facemgr_on_event] CREATE event for a face that already exists...");
                ret = -1;
                continue;

            case FACELET_EVENT_GET: /* should be an INFORM message */
                // FIXME, this might occur if the forwarder restarts and we
                // resync faces...
                ERROR("[facemgr_on_event] GET event for a face that already exists...");
                ret = -1;
                continue;

            case FACELET_EVENT_UPDATE:
                {
                DEBUG("FACELET_EVENT_UPDATE");
                char buf[128];
                facelet_snprintf(buf, 128, facelet_in);
                DEBUG("MERGE %s", buf);
                facelet_snprintf(buf, 128, facelet);
                DEBUG("   ON %s", buf);
                }
                if (facelet_merge(facelet, facelet_in) < 0) {
                    ERROR("[facemgr_on_event] Error merging facelets");
                    continue;
                }
                if (facemgr_process_update(facemgr, facelet) < 0) {
                    ERROR("[facemgr_on_event] Error processing UPDATE event");
                    ret = -1;
                }
                continue;

            case FACELET_EVENT_DELETE:
                if (facelet_merge(facelet, facelet_in) < 0) {
                    ERROR("[facemgr_on_event] Error merging facelets");
                    continue;
                }
                if (facemgr_process_delete(facemgr, facelet) < 0) {
                        ERROR("[facemgr_on_event] Error processing DELETE event");
                    ret = -1;
                }
                continue;

            default: /* XXX Some events should be deprecated */
                ERROR("[facemgr_on_event] Deprecated event");
                ret = -1;
        }

    }
    free(cached_facelets);
    goto DUMP_CACHE;

ERR:
    ret = -1;

DUMP_CACHE:
    DEBUG("    <CACHE>");
    facelet_cache_dump(&facemgr->facelet_cache);
    DEBUG("    </CACHE>");
    DEBUG("</EVENT ret=%d>", ret);
    DEBUG("----------------------------------");
    return ret;
}

int
facemgr_bootstrap(facemgr_t * facemgr)
{
    int rc;

    DEBUG("Registering interfaces...");
    rc = interface_register(&hicn_light_ops);
    if (rc < 0) {
        ERROR("Could not register interfaces");
        goto ERR_REGISTER;
    }

#ifdef __APPLE__
    rc = interface_register(&network_framework_ops);
    if (rc < 0)
        goto ERR_REGISTER;
#endif /* __APPLE__ */

#ifdef __linux__
    rc = interface_register(&netlink_ops);
    if (rc < 0)
        goto ERR_REGISTER;
    rc = interface_register(&bonjour_ops);
    if (rc < 0)
        goto ERR_REGISTER;
#endif /* __linux__ */

#ifdef __ANDROID__
    rc = interface_register(&android_utility_ops);
    if (rc < 0)
        goto ERR_REGISTER;
#endif /* __ANDROID__ */

#ifdef WITH_EXAMPLE_DUMMY
    rc = interface_register(&dummy_ops);
    if (rc < 0)
        goto ERR_REGISTER;
#endif

#ifdef WITH_EXAMPLE_UPDOWN
    rc = interface_register(&updown_ops);
    if (rc < 0)
        goto ERR_REGISTER;
#endif

    rc = facemgr_create_interface(facemgr, "hl", "hicn_light", NULL, &facemgr->hl);
    if (rc < 0) {
        ERROR("Error creating 'hICN forwarder (hicn-light)' interface\n");
        goto ERR_HL_CREATE;
    }

#ifdef __APPLE__
    network_framework_cfg_t nf_cfg = {
        .rules = &facemgr->rules,
    };
    rc = facemgr_create_interface(facemgr, "nf", "network_framework", &nf_cfg, &facemgr->nf);
    if (rc < 0) {
        ERROR("Error creating 'Apple Network Framework' interface\n");
        goto ERR_NF_CREATE;
    }
#endif /* __APPLE__ */

#ifdef __linux__
    rc = facemgr_create_interface(facemgr, "nl", "netlink", NULL, &facemgr->nl);
    if (rc < 0) {
        ERROR("Error creating 'Netlink' interface\n");
        goto ERR_NL_CREATE;
    }
#endif /* __linux__ */

#ifdef __ANDROID__
    android_utility_cfg_t au_cfg = {
        .jvm = facemgr->jvm,
    };
    rc = facemgr_create_interface(facemgr, "au", "android_utility", &au_cfg, &facemgr->au);
    if (rc < 0) {
        ERROR("Error creating 'Android Utility' interface\n");
        goto ERR_AU_CREATE;
    }
#endif /* __ANDROID__ */

#ifdef WITH_EXAMPLE_DUMMY
    rc = facemgr_create_interface(facemgr, "dummy0", "dummy", NULL, &facemgr->dummy);
    if (rc < 0) {
        ERROR("Error creating 'dummy' interface\n");
        goto ERR_DUMMY_CREATE;
    }
#endif

#ifdef WITH_EXAMPLE_UPDOWN
    rc = facemgr_create_interface(facemgr, "updown0", "updown", NULL, &facemgr->updown);
    if (rc < 0) {
        ERROR("Error creating 'updown' interface\n");
        goto ERR_UPDOWN_CREATE;
    }
#endif

    DEBUG("Facemgr successfully initialized...");

    return 0;

    /* FIXME facemgr_delete_interface */
#ifdef WITH_EXAMPLE_UPDOWN
    interface_free(facemgr->updown);
ERR_UPDOWN_CREATE:
#endif
#ifdef WITH_EXAMPLE_DUMMY
    interface_free(facemgr->dummy);
ERR_DUMMY_CREATE:
#endif
#ifdef __ANDROID__
    interface_free(facemgr->au);
ERR_AU_CREATE:
#endif /* __ANDROID__ */
#ifdef __linux__
    interface_free(facemgr->nl);
ERR_NL_CREATE:
#endif /* __linux__ */
#ifdef __APPLE__
    interface_free(facemgr->nf);
ERR_NF_CREATE:
#endif /* __APPLE__ */
    interface_free(facemgr->hl);
ERR_HL_CREATE:
ERR_REGISTER:
    return -1;
}

void facemgr_stop(facemgr_t * facemgr)
{
    // FIXME we should iterate on interface map

#ifdef __APPLE__
    facemgr_delete_interface(facemgr, facemgr->nf);
#endif /* __APPLE__ */


#ifdef __linux__
    facemgr_delete_interface(facemgr, facemgr->nl);

    /* Delete all bonjour interfaces */
    interface_t ** bonjour_array;// = NULL; // NOTE: would allow avoiding tests
    int n = bonjour_map_get_value_array(&facemgr->bonjour_map, &bonjour_array);
    if (n > 0) {
        netdevice_t ** netdevice_array; // = NULL;
        int m = bonjour_map_get_key_array(&facemgr->bonjour_map, &netdevice_array);
        if (m > 0) {
            assert(m == n);
            for (int i = 0; i < n; i++) { /* Fail silently */
                DEBUG("Deleting bonjour interface associated to %s (%p)\n",
                        netdevice_array[i]->name, bonjour_array[i]);
                facemgr_delete_interface(facemgr, bonjour_array[i]);
            }
            free(netdevice_array);
        }
        free(bonjour_array);
    }
#endif /* __linux__ */

#ifdef __ANDROID__
    facemgr_delete_interface(facemgr, facemgr->au);
#endif /* __ANDROID__ */

    facemgr_delete_interface(facemgr, facemgr->hl);

#ifdef WITH_EXAMPLE_DUMMY
    facemgr_delete_interface(facemgr, facemgr->dummy);
#endif

#ifdef WITH_EXAMPLE_UPDOWN
    facemgr_delete_interface(facemgr, facemgr->updown);
#endif
}

#ifdef __ANDROID__
void facemgr_set_jvm(facemgr_t * facemgr, JavaVM *jvm)
{
    facemgr->jvm = jvm;
}
#endif /* __ANDROID__ */

void facemgr_set_event_loop_handler(facemgr_t * facemgr, void * loop, void * loop_register_fd, void * loop_unregister_event)
{
    facemgr->loop = loop;
    facemgr->loop_register_fd = loop_register_fd;
    facemgr->loop_unregister_event = loop_unregister_event;
}

void facemgr_list_faces(facemgr_t * facemgr, facemgr_list_faces_cb_t cb, void * user_data)
{
    //face_cache_iter(&facemgr->face_cache, cb, user_data);
    facelet_cache_dump(&facemgr->facelet_cache);
}