/*
 * Copyright (C) 2019 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 "context.h"
#include "n4-build.h"

ogs_pkbuf_t *smf_n4_build_session_establishment_request(
        uint8_t type, smf_sess_t *sess)
{
    ogs_pfcp_message_t pfcp_message;
    ogs_pfcp_session_establishment_request_t *req = NULL;
    ogs_pkbuf_t *pkbuf = NULL;

    smf_bearer_t *bearer = NULL;

    ogs_pfcp_pdr_t *pdr = NULL;
    ogs_pfcp_far_t *far = NULL;
    ogs_pfcp_urr_t *urr = NULL;
    ogs_pfcp_qer_t *qer = NULL;
    int i;

    ogs_pfcp_node_id_t node_id;
    ogs_pfcp_f_seid_t f_seid;
    int len;

    ogs_debug("Session Establishment Request");
    ogs_assert(sess);

    req = &pfcp_message.pfcp_session_establishment_request;
    memset(&pfcp_message, 0, sizeof(ogs_pfcp_message_t));

    /* Node ID */
    ogs_pfcp_sockaddr_to_node_id(
            ogs_pfcp_self()->pfcp_addr, ogs_pfcp_self()->pfcp_addr6,
            ogs_config()->parameter.prefer_ipv4,
            &node_id, &len);
    req->node_id.presence = 1;
    req->node_id.data = &node_id;
    req->node_id.len = len;

    /* F-SEID */
    ogs_pfcp_sockaddr_to_f_seid(
            ogs_pfcp_self()->pfcp_addr, ogs_pfcp_self()->pfcp_addr6,
            &f_seid, &len);
    f_seid.seid = htobe64(sess->smf_n4_seid);
    req->cp_f_seid.presence = 1;
    req->cp_f_seid.data = &f_seid;
    req->cp_f_seid.len = len;

    ogs_pfcp_pdrbuf_init();

    /* Create PDR */
    i = 0;
    ogs_list_for_each(&sess->bearer_list, bearer) {
        ogs_list_for_each(&bearer->pfcp.pdr_list, pdr) {
            ogs_pfcp_build_create_pdr(&req->create_pdr[i], i, pdr);
            i++;
        }
    }

    /* Create FAR */
    i = 0;
    ogs_list_for_each(&sess->bearer_list, bearer) {
        ogs_list_for_each(&bearer->pfcp.far_list, far) {
            ogs_pfcp_build_create_far(&req->create_far[i], i, far);
            i++;
        }
    }

    /* Create URR */
    i = 0;
    ogs_list_for_each(&sess->bearer_list, bearer) {
        ogs_list_for_each(&bearer->pfcp.urr_list, urr) {
            ogs_pfcp_build_create_urr(&req->create_urr[i], i, urr);
            i++;
        }
    }

    /* Create QER */
    i = 0;
    ogs_list_for_each(&sess->bearer_list, bearer) {
        ogs_list_for_each(&bearer->pfcp.qer_list, qer) {
            ogs_pfcp_build_create_qer(&req->create_qer[i], i, qer);
            i++;
        }
    }

    /* PDN Type */
    req->pdn_type.presence = 1;
    req->pdn_type.u8 = sess->pdn.paa.pdn_type;

    pfcp_message.h.type = type;
    pkbuf = ogs_pfcp_build_msg(&pfcp_message);

    ogs_pfcp_pdrbuf_clear();

    return pkbuf;
}

ogs_pkbuf_t *smf_n4_build_qos_flow_modification_request(
        uint8_t type, smf_bearer_t *qos_flow, uint64_t modify_flags)
{
    ogs_pfcp_message_t pfcp_message;
    ogs_pfcp_session_modification_request_t *req = NULL;
    ogs_pfcp_pdr_t *pdr = NULL;
    ogs_pfcp_far_t *far = NULL;
    ogs_pfcp_qer_t *qer = NULL;
    ogs_pkbuf_t *pkbuf = NULL;
    int i;

    smf_sess_t *sess = NULL;

    ogs_debug("QoS Flow Modification Request");
    ogs_assert(qos_flow);
    sess = qos_flow->sess;
    ogs_assert(sess);
    ogs_assert(modify_flags);

    req = &pfcp_message.pfcp_session_modification_request;
    memset(&pfcp_message, 0, sizeof(ogs_pfcp_message_t));

    if (modify_flags & OGS_PFCP_MODIFY_REMOVE) {
        /* Remove PDR */
        i = 0;
        ogs_list_for_each(&qos_flow->pfcp.pdr_list, pdr) {
            ogs_pfcp_tlv_remove_pdr_t *message = &req->remove_pdr[i];

            message->presence = 1;
            message->pdr_id.presence = 1;
            message->pdr_id.u16 = pdr->id;
            i++;
        }

        /* Remove FAR */
        i = 0;
        ogs_list_for_each(&qos_flow->pfcp.far_list, far) {
            ogs_pfcp_tlv_remove_far_t *message = &req->remove_far[i];

            message->presence = 1;
            message->far_id.presence = 1;
            message->far_id.u32 = far->id;
            i++;
        }

        /* Remove QER */
        i = 0;
        ogs_list_for_each(&qos_flow->pfcp.qer_list, qer) {
            ogs_pfcp_tlv_remove_qer_t *message = &req->remove_qer[i];

            message->presence = 1;
            message->qer_id.presence = 1;
            message->qer_id.u32 = qer->id;
            i++;
        }
    } else {
        if (modify_flags & OGS_PFCP_MODIFY_CREATE) {
            ogs_pfcp_pdrbuf_init();

            /* Create PDR */
            i = 0;
            ogs_list_for_each(&qos_flow->pfcp.pdr_list, pdr) {
                ogs_pfcp_build_create_pdr(&req->create_pdr[i], i, pdr);
                i++;
            }

            /* Create FAR */
            i = 0;
            ogs_list_for_each(&qos_flow->pfcp.far_list, far) {
                ogs_pfcp_build_create_far(&req->create_far[i], i, far);
                i++;
            }

            /* Create QER */
            i = 0;
            ogs_list_for_each(&qos_flow->pfcp.qer_list, qer) {
                ogs_pfcp_build_create_qer(&req->create_qer[i], i, qer);
                i++;
            }
        }
        if (modify_flags & OGS_PFCP_MODIFY_TFT_UPDATE) {
            ogs_pfcp_pdrbuf_init();

            /* Update PDR */
            i = 0;
            ogs_list_for_each(&qos_flow->pfcp.pdr_list, pdr) {
                ogs_pfcp_build_update_pdr(&req->update_pdr[i], i, pdr);
                i++;
            }
        }
        if (modify_flags & OGS_PFCP_MODIFY_ACTIVATE) {
            /* Update FAR - Only DL */
            i = 0;
            ogs_list_for_each(&qos_flow->pfcp.far_list, far) {
                if (far->dst_if == OGS_PFCP_INTERFACE_ACCESS) {

                    if (modify_flags & OGS_PFCP_MODIFY_END_MARKER) {
                        far->smreq_flags.send_end_marker_packets = 1;
                    }

                    ogs_pfcp_build_update_far_activate(
                            &req->update_far[i], i, far);
                    i++;

                    /* Clear all FAR flags */
                    far->smreq_flags.value = 0;
                }
            }
        }
        if (modify_flags & OGS_PFCP_MODIFY_QOS_UPDATE) {
            /* Update QER */
            i = 0;
            ogs_list_for_each(&qos_flow->pfcp.qer_list, qer) {
                ogs_pfcp_build_update_qer(&req->update_qer[i], i, qer);
                i++;
            }
        }
    }

    pfcp_message.h.type = type;
    pkbuf = ogs_pfcp_build_msg(&pfcp_message);

    if (modify_flags & (OGS_PFCP_MODIFY_CREATE|OGS_PFCP_MODIFY_TFT_UPDATE)) {
        ogs_pfcp_pdrbuf_clear();
    }

    return pkbuf;
}

ogs_pkbuf_t *smf_n4_build_session_deletion_request(
        uint8_t type, smf_sess_t *sess)
{
    ogs_pfcp_message_t pfcp_message;

    ogs_debug("Session Deletion Request");
    ogs_assert(sess);

    pfcp_message.h.type = type;
    return ogs_pfcp_build_msg(&pfcp_message);
}

ogs_pkbuf_t *smf_5gc_n4_build_session_modification_request(
        uint8_t type, smf_sess_t *sess, uint64_t modify_flags)
{
    int i;

    ogs_pfcp_message_t pfcp_message;
    ogs_pfcp_session_modification_request_t *req = NULL;
    ogs_pfcp_far_t *far = NULL;
    ogs_pkbuf_t *pkbuf = NULL;
    smf_bearer_t *bearer = NULL;

    ogs_debug("Session Modification Request");
    ogs_assert(sess);
    ogs_assert(modify_flags & OGS_PFCP_MODIFY_DEACTIVATE);

    req = &pfcp_message.pfcp_session_modification_request;
    memset(&pfcp_message, 0, sizeof(ogs_pfcp_message_t));

    i = 0;
    ogs_list_for_each(&sess->bearer_list, bearer) {
        ogs_list_for_each(&bearer->pfcp.far_list, far) {
            /* Update FAR - Only DL */
            if (far->dst_if == OGS_PFCP_INTERFACE_ACCESS) {
                ogs_pfcp_build_update_far_deactivate(
                        &req->update_far[i], i, far);
                i++;
            }
        }
    }

    pfcp_message.h.type = type;
    pkbuf = ogs_pfcp_build_msg(&pfcp_message);

    return pkbuf;
}