/*
 * Copyright (C) 2019,2020 by Sukchan Lee <acetcom@gmail.com>
 *
 * This file is part of Open5GS.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero 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 <https://www.gnu.org/licenses/>.
 */

#include "sbi-path.h"

static int server_cb(ogs_sbi_request_t *request, void *data)
{
    pcf_event_t *e = NULL;
    int rv;

    ogs_assert(request);
    ogs_assert(data);

    e = pcf_event_new(PCF_EVT_SBI_SERVER);
    ogs_assert(e);

    e->sbi.request = request;
    e->sbi.data = data;

    rv = ogs_queue_push(ogs_app()->queue, e);
    if (rv != OGS_OK) {
        ogs_error("ogs_queue_push() failed:%d", (int)rv);
        ogs_sbi_request_free(request);
        pcf_event_free(e);
        return OGS_ERROR;
    }

    return OGS_OK;
}

static int client_cb(int status, ogs_sbi_response_t *response, void *data)
{
    pcf_event_t *e = NULL;
    int rv;

    if (status != OGS_OK) {
        ogs_log_message(
                status == OGS_DONE ? OGS_LOG_DEBUG : OGS_LOG_WARN, 0,
                "client_cb() failed [%d]", status);
        return OGS_ERROR;
    }

    ogs_assert(response);

    e = pcf_event_new(PCF_EVT_SBI_CLIENT);
    ogs_assert(e);
    e->sbi.response = response;
    e->sbi.data = data;

    rv = ogs_queue_push(ogs_app()->queue, e);
    if (rv != OGS_OK) {
        ogs_error("ogs_queue_push() failed:%d", (int)rv);
        ogs_sbi_response_free(response);
        pcf_event_free(e);
        return OGS_ERROR;
    }

    return OGS_OK;
}

int pcf_sbi_open(void)
{
    ogs_sbi_nf_instance_t *nf_instance = NULL;
    ogs_sbi_nf_service_t *service = NULL;

    /* Add SELF NF instance */
    nf_instance = ogs_sbi_self()->nf_instance;
    ogs_assert(nf_instance);

    /* Build NF instance information. It will be transmitted to NRF. */
    ogs_sbi_nf_instance_build_default(nf_instance, OpenAPI_nf_type_PCF);
    ogs_sbi_nf_instance_add_allowed_nf_type(nf_instance, OpenAPI_nf_type_AMF);
    ogs_sbi_nf_instance_add_allowed_nf_type(nf_instance, OpenAPI_nf_type_SMF);
    ogs_sbi_nf_instance_add_allowed_nf_type(nf_instance, OpenAPI_nf_type_NEF);
    ogs_sbi_nf_instance_add_allowed_nf_type(nf_instance, OpenAPI_nf_type_AF);

    /* Build NF service information. It will be transmitted to NRF. */
    if (ogs_sbi_nf_service_is_available(
                OGS_SBI_SERVICE_NAME_NPCF_AM_POLICY_CONTROL)) {
        service = ogs_sbi_nf_service_build_default(
                    nf_instance, OGS_SBI_SERVICE_NAME_NPCF_AM_POLICY_CONTROL);
        ogs_assert(service);
        ogs_sbi_nf_service_add_version(
                    service, OGS_SBI_API_V1, OGS_SBI_API_V1_0_0, NULL);
        ogs_sbi_nf_service_add_allowed_nf_type(service, OpenAPI_nf_type_AMF);
        ogs_sbi_nf_service_add_allowed_nf_type(service, OpenAPI_nf_type_NEF);
    }

    if (ogs_sbi_nf_service_is_available(
                OGS_SBI_SERVICE_NAME_NPCF_SMPOLICYCONTROL)) {
        service = ogs_sbi_nf_service_build_default(
                    nf_instance, OGS_SBI_SERVICE_NAME_NPCF_SMPOLICYCONTROL);
        ogs_assert(service);
        ogs_sbi_nf_service_add_version(
                    service, OGS_SBI_API_V1, OGS_SBI_API_V1_0_0, NULL);
        ogs_sbi_nf_service_add_allowed_nf_type(service, OpenAPI_nf_type_SMF);
        ogs_sbi_nf_service_add_allowed_nf_type(service, OpenAPI_nf_type_NEF);
    }

    if (ogs_sbi_nf_service_is_available(
                OGS_SBI_SERVICE_NAME_NPCF_POLICYAUTHORIZATION)) {
        service = ogs_sbi_nf_service_build_default(
                    nf_instance, OGS_SBI_SERVICE_NAME_NPCF_POLICYAUTHORIZATION);
        ogs_assert(service);
        ogs_sbi_nf_service_add_version(
                    service, OGS_SBI_API_V1, OGS_SBI_API_V1_0_0, NULL);
        ogs_sbi_nf_service_add_allowed_nf_type(service, OpenAPI_nf_type_AF);
        ogs_sbi_nf_service_add_allowed_nf_type(service, OpenAPI_nf_type_NEF);
    }

    /* Initialize NRF NF Instance */
    ogs_list_for_each(&ogs_sbi_self()->nf_instance_list, nf_instance) {
        if (NF_INSTANCE_IS_NRF(nf_instance)) {
            ogs_sbi_client_t *client = NULL;

            /* Client callback is only used when NF sends to NRF */
            client = nf_instance->client;
            ogs_assert(client);
            client->cb = client_cb;

            /* NFRegister is sent and the response is received
             * by the above client callback. */
            pcf_nf_fsm_init(nf_instance);
        }
    }

    /* Timer expiration handler of client wait timer */
    ogs_sbi_self()->client_wait_expire = pcf_timer_sbi_client_wait_expire;

    /* NF register state in NF state machine */
    ogs_sbi_self()->nf_state_registered =
        (ogs_fsm_handler_t)pcf_nf_state_registered;

    if (ogs_sbi_server_start_all(server_cb) != OGS_OK)
        return OGS_ERROR;

    return OGS_OK;
}

void pcf_sbi_close(void)
{
    ogs_sbi_client_stop_all();
    ogs_sbi_server_stop_all();
}

bool pcf_sbi_send_request(
        ogs_sbi_object_t *sbi_object,
        OpenAPI_nf_type_e target_nf_type,
        void *data)
{
    ogs_sbi_nf_instance_t *nf_instance = NULL;

    nf_instance = OGS_SBI_NF_INSTANCE(sbi_object, target_nf_type);
    if (!nf_instance) {
        pcf_ue_t *pcf_ue = NULL;
        pcf_sess_t *sess = NULL;

        ogs_assert(sbi_object->type > OGS_SBI_OBJ_BASE &&
                    sbi_object->type < OGS_SBI_OBJ_TOP);
        switch(sbi_object->type) {
        case OGS_SBI_OBJ_UE_TYPE:
            pcf_ue = (pcf_ue_t *)sbi_object;
            ogs_assert(pcf_ue);
            ogs_error("[%s] (NF discover) No [%s]", pcf_ue->supi,
                    OpenAPI_nf_type_ToString(target_nf_type));
            break;
        case OGS_SBI_OBJ_SESS_TYPE:
            sess = (pcf_sess_t *)sbi_object;
            ogs_assert(sess);
            ogs_error("[%d] (NF discover) No [%s]", sess->psi,
                    OpenAPI_nf_type_ToString(target_nf_type));
            break;
        default:
            ogs_fatal("(NF discover) Not implemented [%s:%d]",
                OpenAPI_nf_type_ToString(target_nf_type),
                sbi_object->type);
            ogs_assert_if_reached();
        }

        return false;
    }

    return ogs_sbi_send_request(nf_instance, client_cb, data);
}

static bool pcf_sbi_discover_and_send(
        ogs_sbi_object_t *sbi_object,
        OpenAPI_nf_type_e target_nf_type,
        ogs_sbi_discovery_option_t *discovery_option,
        ogs_sbi_build_f build,
        void *context, ogs_sbi_stream_t *stream, void *data)
{
    ogs_sbi_xact_t *xact = NULL;
    OpenAPI_nf_type_e requester_nf_type = OpenAPI_nf_type_NULL;

    ogs_assert(ogs_sbi_self()->nf_instance);
    requester_nf_type = ogs_sbi_self()->nf_instance->nf_type;
    ogs_assert(requester_nf_type);

    ogs_assert(target_nf_type);
    ogs_assert(sbi_object);
    ogs_assert(stream);
    ogs_assert(build);

    xact = ogs_sbi_xact_add(
            sbi_object, target_nf_type, discovery_option,
            build, context, data);
    ogs_expect_or_return_val(xact, false);

    xact->assoc_stream = stream;

    if (ogs_sbi_discover_and_send(
            sbi_object,
            target_nf_type, requester_nf_type, discovery_option,
            client_cb, xact) != true) {
        ogs_error("ogs_sbi_discover_and_send() failed");
        ogs_sbi_xact_remove(xact);
        return false;
    }

    return true;
}

bool pcf_ue_sbi_discover_and_send(
        OpenAPI_nf_type_e target_nf_type,
        ogs_sbi_discovery_option_t *discovery_option,
        ogs_sbi_request_t *(*build)(pcf_ue_t *pcf_ue, void *data),
        pcf_ue_t *pcf_ue, ogs_sbi_stream_t *stream, void *data)
{
    if (pcf_sbi_discover_and_send(
                &pcf_ue->sbi, target_nf_type, discovery_option,
                (ogs_sbi_build_f)build, pcf_ue, stream, data) != true) {
        ogs_error("pcf_ue_sbi_discover_and_send() failed");
        ogs_assert(true ==
            ogs_sbi_server_send_error(stream,
                OGS_SBI_HTTP_STATUS_GATEWAY_TIMEOUT, NULL,
                "Cannot discover", pcf_ue->supi));
        return false;
    }

    return true;
}

bool pcf_sess_sbi_discover_and_send(
        OpenAPI_nf_type_e target_nf_type,
        ogs_sbi_discovery_option_t *discovery_option,
        ogs_sbi_request_t *(*build)(pcf_sess_t *sess, void *data),
        pcf_sess_t *sess, ogs_sbi_stream_t *stream, void *data)
{
    if (pcf_sbi_discover_and_send(
                &sess->sbi, target_nf_type, discovery_option,
                (ogs_sbi_build_f)build, sess, stream, data) != true) {
        ogs_error("pcf_sess_sbi_discover_and_send() failed");
        ogs_assert(true ==
            ogs_sbi_server_send_error(stream,
                OGS_SBI_HTTP_STATUS_GATEWAY_TIMEOUT, NULL,
                "Cannot discover", NULL));
        return false;
    }

    return true;
}

static int client_notify_cb(
        int status, ogs_sbi_response_t *response, void *data)
{
    int rv;
    ogs_sbi_message_t message;

    if (status != OGS_OK) {
        ogs_log_message(
                status == OGS_DONE ? OGS_LOG_DEBUG : OGS_LOG_WARN, 0,
                "client_notify_cb() failed [%d]", status);
        return OGS_ERROR;
    }

    ogs_assert(response);

    rv = ogs_sbi_parse_response(&message, response);
    if (rv != OGS_OK) {
        ogs_error("cannot parse HTTP response");
        ogs_sbi_message_free(&message);
        ogs_sbi_response_free(response);
        return OGS_ERROR;
    }

    if (message.res_status != OGS_SBI_HTTP_STATUS_NO_CONTENT)
        ogs_error("SmContextStatusNotification failed [%d]",
                message.res_status);

    ogs_sbi_message_free(&message);
    ogs_sbi_response_free(response);
    return OGS_OK;
}

static int client_delete_notify_cb(
        int status, ogs_sbi_response_t *response, void *data)
{
    pcf_app_t *app_session = data;

    ogs_assert(app_session);
    client_notify_cb(status, response, data);

    pcf_app_remove(app_session);

    return OGS_OK;
}

bool pcf_sbi_send_am_policy_control_notify(pcf_ue_t *pcf_ue)
{
    ogs_sbi_request_t *request = NULL;
    ogs_sbi_client_t *client = NULL;

    ogs_assert(pcf_ue);
    client = pcf_ue->namf.client;
    ogs_assert(client);

    request = pcf_namf_callback_build_am_policy_control(pcf_ue, NULL);
    ogs_expect_or_return_val(request, false);
    return ogs_sbi_client_send_request(client, client_notify_cb, request, NULL);
}

bool pcf_sbi_send_smpolicycontrol_update_notify(
        pcf_sess_t *sess, OpenAPI_sm_policy_decision_t *SmPolicyDecision)
{
    ogs_sbi_request_t *request = NULL;
    ogs_sbi_client_t *client = NULL;

    ogs_assert(sess);
    client = sess->nsmf.client;
    ogs_assert(client);

    request = pcf_nsmf_callback_build_smpolicycontrol_update(
                sess, SmPolicyDecision);
    ogs_expect_or_return_val(request, false);
    return ogs_sbi_client_send_request(client, client_notify_cb, request, NULL);
}

bool pcf_sbi_send_smpolicycontrol_delete_notify(
        pcf_sess_t *sess, pcf_app_t *app_session,
        OpenAPI_sm_policy_decision_t *SmPolicyDecision)
{
    ogs_sbi_request_t *request = NULL;
    ogs_sbi_client_t *client = NULL;

    ogs_assert(sess);
    client = sess->nsmf.client;
    ogs_assert(client);

    request = pcf_nsmf_callback_build_smpolicycontrol_update(
                sess, SmPolicyDecision);
    ogs_expect_or_return_val(request, false);
    return ogs_sbi_client_send_request(
            client, client_delete_notify_cb, request, app_session);
}

bool pcf_sbi_send_smpolicycontrol_terminate_notify(pcf_sess_t *sess)
{
    ogs_sbi_request_t *request = NULL;
    ogs_sbi_client_t *client = NULL;

    ogs_assert(sess);
    client = sess->nsmf.client;
    ogs_assert(client);

    request = pcf_nsmf_callback_build_smpolicycontrol_terminate(sess, NULL);
    ogs_expect_or_return_val(request, false);
    return ogs_sbi_client_send_request(client, client_notify_cb, request, NULL);
}

bool pcf_sbi_send_policyauthorization_terminate_notify(pcf_app_t *app)
{
    ogs_sbi_request_t *request = NULL;
    ogs_sbi_client_t *client = NULL;

    ogs_assert(app);
    client = app->naf.client;
    ogs_assert(client);

    request = pcf_naf_callback_build_policyauthorization_terminate(app, NULL);
    ogs_expect_or_return_val(request, false);
    return ogs_sbi_client_send_request(client, client_notify_cb, request, NULL);
}