#include "facilities.h"
#include "cam.h"
#include "config.h"
#include "denm.h"
#include "infrastructure.h"
#include "requests.h"
#include "cpm.h"

#include <itss-transport/BTPDataRequest.h>
#include <itss-transport/BTPDataIndication.h>
#include <itss-facilities/FacilitiesDataIndication.h>
#include <itss-facilities/FacilitiesDataRequest.h>
#include <itss-facilities/FacilitiesDataResult.h>
#include <itss-security/SecurityIndication.h>
#include <itss-security/SecurityResponse.h>
#include <itss-management/ManagementIndication.h>
#include <itss-management/ManagementRequest.h>

#include <camv2/CAM.h>
#include <denmv2/DENM.h>
#include <ivim/IVIM.h>
#include <cpm/CPM.h>
#include <cpm/INTEGER.h>
#include <cpm/asn_application.h>

#include <zmq.h>
#include <syslog.h>
#include <stdbool.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

#include <it2s-tender/space.h>
#include <it2s-tender/time.h>

#define syslog_info(msg, ...) syslog(LOG_INFO, msg, ##__VA_ARGS__)
#define syslog_emerg(msg, ...) syslog(LOG_EMERG, "%s:%d [" msg "]",  __func__, __LINE__, ##__VA_ARGS__)
#define syslog_err(msg, ...) syslog(LOG_ERR, "%s:%d [" msg "]",  __func__, __LINE__, ##__VA_ARGS__)

#ifndef NDEBUG
#define syslog_debug(msg, ...) syslog(LOG_DEBUG, "%s:%d " msg "", __func__, __LINE__, ##__VA_ARGS__)
#else
#define syslog_debug(msg, ...)
#endif

static int transport_indication(facilities_t *facilities, void* responder, uint8_t *msg, uint32_t msg_len) {
    int rv = 0, code = 0;
    bool handled_msg = false;
    FacilitiesDataIndication_t *fdi = NULL;

    BTPDataIndication_t *bdi = calloc(1, sizeof(BTPDataIndication_t));  

    asn_dec_rval_t dec = oer_decode(NULL, &asn_DEF_BTPDataIndication, (void**) &bdi, msg, msg_len);
    if (dec.code) {
        syslog_err("[facilities]<- invalid bdi received");
        rv = 1;
        code = 1;
        zmq_send(responder, &code, 1, 0);
        goto cleanup;
    }

    zmq_send(responder, &code, 1, 0);
    syslog_debug("[facilities]<- BDI (%ldB)", bdi->data.size);

    // Parse message
    asn_TYPE_descriptor_t *its_msg_descriptor;
    void *its_msg;
    switch (bdi->destinationPort) {
        case Port_cam:
            its_msg_descriptor = &asn_DEF_CAM;
            its_msg = calloc(1, sizeof(CAM_t));
            handled_msg = true;
            break;
        case Port_denm:
            its_msg_descriptor = &asn_DEF_DENM;
            its_msg = calloc(1, sizeof(DENM_t));
            handled_msg = true;
            break;
        case Port_ivim:
            its_msg_descriptor = &asn_DEF_IVIM;
            its_msg = calloc(1, sizeof(IVIM_t));
            handled_msg = true;
            break;
        case Port_cpm:
            its_msg_descriptor = &asn_DEF_CPM;
            its_msg = calloc(1, sizeof(CPM_t));
            handled_msg = true;
            break;

        default:
            syslog_debug("[facilities] messsage with unhandled BTP port received, ignoring");
            goto cleanup;
    }

    dec = uper_decode_complete(NULL, its_msg_descriptor, (void**) &its_msg, bdi->data.buf, bdi->data.size);
    if (dec.code) {
        syslog_debug("[facilities]<- invalid %s received", its_msg_descriptor->name);
        rv = 1;
        goto cleanup;
    }

    // Get permisisons
    uint8_t* ssp = NULL;
    uint16_t ssp_len;
    if (bdi->gnPermissions) {
        ssp = bdi->gnPermissions->ssp.buf;
        ssp_len = bdi->gnPermissions->ssp.size;
    }

    bool fwd = false;
    // Manage message
    switch (bdi->destinationPort) {
        case Port_cam:
            switch (check_cam(facilities, bdi, its_msg, &facilities->epv, ssp, ssp_len)) {
                case CAM_OK:
                    fwd = true;
                    break;
                case CAM_INVALID:
                case CAM_BAD_PERMISSIONS:
                default:
                    break;
            }
            break;

        case Port_denm:
            ;
#ifdef DEBUG
            uint8_t* xml_denm = malloc(32768);
            asn_enc_rval_t rve = xer_encode_to_buffer(xml_denm, 32768, 0x02, &asn_DEF_DENM, its_msg);
            syslog_debug("DENM XER %d: %.*s", (int)rve.encoded, (int)rve.encoded , xml_denm);
            free(xml_denm);
#endif
            int64_t id = -1;
            switch (event_manage(facilities->den, its_msg, &facilities->epv, &id, ssp, ssp_len)) {
                case EVENT_NEW:
                case EVENT_CANCELLATION:
                case EVENT_NEGATION:
                case EVENT_UPDATE:
                case EVENT_NUMBER_EXCEEDED:
                    fwd = true;
                    break;
                case EVENT_INVALID:
                case EVENT_PASSED:
                case EVENT_REPEATED:
                case EVENT_BAD_PERMISSIONS:
                    break;
            }
            break;

        case Port_ivim:
            switch (service_eval(facilities->infrastructure, SERVICE_IVI, its_msg, &facilities->epv, &id, ssp, ssp_len)) {
                case SERVICE_NEW:
                case SERVICE_CANCELLATION:
                case SERVICE_NEGATION:
                case SERVICE_UPDATE:
                case SERVICE_NUMBER_EXCEEDED:
                    fwd = true;
                    break;
                case SERVICE_INVALID:
                case SERVICE_REPEATED:
                case SERVICE_PASSED:
                case SERVICE_BAD_PERMISSIONS:
                default:
                    break;
            }
            break;

        default:
            break;
    }

    // Forward to application
    if (fwd) {
        fdi = calloc(1, sizeof(FacilitiesDataIndication_t));

        fdi->itsMessageType = bdi->destinationPort;

        fdi->data.size = bdi->data.size;
        fdi->data.buf = malloc(bdi->data.size);
        memcpy(fdi->data.buf, bdi->data.buf, bdi->data.size);

        uint8_t buffer[PACKET_MAX_LEN];
        buffer[0] = 4; // Facilities
        asn_enc_rval_t enc = oer_encode_to_buffer(&asn_DEF_FacilitiesDataIndication, NULL, fdi, buffer+1, PACKET_MAX_LEN-1);

        queue_add(facilities->tx_queue, buffer, enc.encoded+1, 5);
        pthread_cond_signal(&facilities->tx_queue->trigger);
    }

cleanup:
    if (handled_msg && bdi->destinationPort != Port_denm && bdi->destinationPort != Port_ivim) {
        ASN_STRUCT_FREE(*its_msg_descriptor, its_msg);
    }
    ASN_STRUCT_FREE(asn_DEF_BTPDataIndication, bdi);
    ASN_STRUCT_FREE(asn_DEF_FacilitiesDataIndication, fdi);

    return rv;
}

static int facilities_request(facilities_t *facilities, void* responder, uint8_t *msg, uint32_t msg_len) {
    int rv = 0;

    FacilitiesDataRequest_t *fdreq = calloc(1, sizeof(FacilitiesDataRequest_t)); 

    asn_dec_rval_t dec = oer_decode(NULL, &asn_DEF_FacilitiesDataRequest, (void**) &fdreq, msg, msg_len);
    if (dec.code) {
        syslog_err("[facilities]<- invalid FDRequest received");
        facilities_request_result_rejected(responder);
        rv = 1;
        goto cleanup;
    }

    switch (fdreq->present) {
        case FacilitiesDataRequest_PR_singleMessage:
            rv = facilities_request_single_message(facilities, responder, fdreq);
            break;

        case FacilitiesDataRequest_PR_activeEvents:
            rv = facilities_request_active_events(facilities, responder, fdreq);
            break;

        case FacilitiesDataRequest_PR_attributeTypes:
            rv = facilities_request_attribute_types(facilities, responder, fdreq);
            break;

        default:
            syslog_err("[facilities] unrecognized FDR type received (%d)", fdreq->present);
            facilities_request_result_rejected(responder);
            rv = 1;
            goto cleanup;
    }

cleanup:
    ASN_STRUCT_FREE(asn_DEF_FacilitiesDataRequest, fdreq);

    return rv;
}


static int security_indication(facilities_t *facilities, void* responder_secured, uint8_t *msg, uint32_t msg_len) {
    int rv = 0;

    SecurityIndication_t* si = calloc(1, sizeof(SecurityIndication_t));
    SecurityResponse_t* sr = calloc(1, sizeof(SecurityResponse_t));

    uint8_t buffer[64];

    asn_enc_rval_t enc;

    asn_dec_rval_t dec = oer_decode(NULL, &asn_DEF_SecurityIndication, (void**) &si, msg, msg_len);
    if (dec.code) {
        syslog_err("[facilities]<- invalid SIndication received");
        rv = 1;
        goto cleanup;
    }

    pthread_mutex_lock(&facilities->id.change.lock);
    if (facilities->id.change.stage == ID_CHANGE_BLOCKED) {
        pthread_mutex_unlock(&facilities->id.change.lock);
        syslog_debug("[facilities] identity change is currently blocked");
        rv = 1;
        goto cleanup;
    }

    if (facilities->id.change.stage == ID_CHANGE_PREPARE &&
            si->choice.idChangeEvent.command != SecurityIdChangeEventType_commit &&
            si->choice.idChangeEvent.command != SecurityIdChangeEventType_abort) {
        pthread_mutex_unlock(&facilities->id.change.lock);
        syslog_debug("[facilities] current identity change state is prepare, but received identity change command is not commit nor abort");
        rv = 1;
        goto cleanup;
    }

    switch (si->choice.idChangeEvent.command) {
        case SecurityIdChangeEventType_prepare:

            facilities->id.change.stage = ID_CHANGE_PREPARE;

            pthread_mutex_lock(&facilities->id.lock);
            pthread_mutex_lock(&facilities->lightship->lock);
            break;

        case SecurityIdChangeEventType_commit:
            ;
            facilities->id.change.stage = ID_CHANGE_COMMIT;

            // Reset lightship
            for (int i = 0; i < facilities->lightship->pos_history_len; ++i) {
                free(facilities->lightship->pos_history[i]);
            }
            facilities->lightship->pos_history_len = 0;

            facilities->lightship->last_cam = 0;
            facilities->lightship->last_cam_lfc = 0;
            facilities->lightship->next_cam_max = 0;
            facilities->lightship->next_cam_min = 0;

            pthread_mutex_unlock(&facilities->lightship->lock);

            // Change Station ID
            facilities->id.value = rand();

            facilities->id.change.stage = ID_CHANGE_INACTIVE;

            pthread_mutex_unlock(&facilities->id.lock);

            break;

        case SecurityIdChangeEventType_abort:
            pthread_mutex_unlock(&facilities->id.lock);
            pthread_mutex_unlock(&facilities->lightship->lock);

            facilities->id.change.stage = ID_CHANGE_INACTIVE;
            break;

        default:
            pthread_mutex_unlock(&facilities->id.change.lock);
            syslog_err("[networking]<- unhandled idChangeEvent command type");
            rv = 1;
            goto cleanup;

    }

    sr->present = SecurityResponse_PR_idChangeEvent;
    sr->choice.idChangeEvent.returnCode = 0;
    enc = oer_encode_to_buffer(&asn_DEF_SecurityResponse, NULL, sr, buffer, 64);
    zmq_send(responder_secured, buffer, enc.encoded, 0);

    if (facilities->id.change.stage == ID_CHANGE_INACTIVE) {
        // Inform management
        ManagementRequest_t* mreq = calloc(1, sizeof(ManagementRequest_t));
        mreq->present = ManagementRequest_PR_attributes;
        mreq->choice.attributes.present = ManagementRequestAttributes_PR_set;
        mreq->choice.attributes.choice.set.stationID = malloc(sizeof(long));
        *mreq->choice.attributes.choice.set.stationID = facilities->id.value;
        uint8_t b_oer[128];
        asn_enc_rval_t enc = asn_encode_to_buffer(NULL, ATS_CANONICAL_OER, &asn_DEF_ManagementRequest, mreq, b_oer, 128);
        if (enc.encoded != -1) {
            int wait_ms = 1000;
            void* management_socket = zmq_socket(facilities->zmq.ctx, ZMQ_REQ);
            zmq_setsockopt(management_socket, ZMQ_RCVTIMEO, &wait_ms, sizeof(int));
            zmq_connect(management_socket, facilities->zmq.management_address);
            zmq_send(management_socket, b_oer, enc.encoded, 0);
            uint8_t code;
            rv = zmq_recv(management_socket, &code, 1, 0);
            if (rv == -1) {syslog_err("[facilities]-> timeout sending MReq set.stationId to ->[management]");}
            zmq_close(management_socket);
        }
        ASN_STRUCT_FREE(asn_DEF_ManagementRequest, mreq);
    }

    pthread_mutex_unlock(&facilities->id.change.lock);

cleanup:
    if (rv) {
        sr->present = SecurityResponse_PR_idChangeEvent;
        sr->choice.idChangeEvent.returnCode = 1;
        enc = oer_encode_to_buffer(&asn_DEF_SecurityResponse, NULL, sr, buffer, 64);
        zmq_send(responder_secured, buffer, enc.encoded, 0);
    }

    pthread_mutex_unlock(&facilities->id.change.lock);
    ASN_STRUCT_FREE(asn_DEF_SecurityResponse, sr);
    ASN_STRUCT_FREE(asn_DEF_SecurityIndication, si);

    return rv;
}

static int management_indication(facilities_t* facilities, void* responder, uint8_t* msg, uint32_t msg_len) {
    int rv = 0;

    uint8_t code = 0;

    ManagementIndication_t* mi = calloc(1, sizeof(ManagementIndication_t));

    asn_dec_rval_t dec = oer_decode(NULL, &asn_DEF_ManagementIndication, (void**) &mi, msg, msg_len);
    if (dec.code) {
        rv = 1;
        code = 1;
        zmq_send(responder, &code, 1, 0);
        goto cleanup;
    }
    zmq_send(responder, &code, 1, 0);

    if (mi->present == ManagementIndication_PR_attributes) {
        it2s_tender_lock_space(&facilities->epv);
        facilities->epv.space.latitude = mi->choice.attributes.coordinates.latitude;
        facilities->epv.space.longitude = mi->choice.attributes.coordinates.longitude;
        facilities->epv.space.speed = mi->choice.attributes.speed.speedValue;
        facilities->epv.space.speed_conf = mi->choice.attributes.speed.speedConfidence;
        facilities->epv.space.heading = mi->choice.attributes.heading.headingValue;
        facilities->epv.space.heading_conf = mi->choice.attributes.heading.headingConfidence;
        facilities->epv.space.altitude = mi->choice.attributes.altitude.altitudeValue;
        facilities->epv.space.altitude_conf = mi->choice.attributes.altitude.altitudeConfidence;
        it2s_tender_unlock_space(&facilities->epv);

        it2s_tender_lock_time(&facilities->epv);
        asn_INTEGER2ulong(&mi->choice.attributes.clock, &facilities->epv.time.clock);
        it2s_tender_unlock_time(&facilities->epv);
    }

cleanup:
    ASN_STRUCT_FREE(asn_DEF_ManagementIndication, mi);

    return rv;
}


void* tx(void* fc) {
    int rv = 0;

    facilities_t *facilities = (facilities_t*) fc;

    queue_t* queue = facilities->tx_queue;

    uint8_t code;
    int wait_ms = 1000;

    void* applications_socket = zmq_socket(facilities->zmq.ctx, ZMQ_REQ);
    zmq_setsockopt(applications_socket, ZMQ_RCVTIMEO, &wait_ms, sizeof(int));
    zmq_connect(applications_socket, facilities->zmq.applications_address);

    void* transport_socket = zmq_socket(facilities->zmq.ctx, ZMQ_REQ);
    zmq_setsockopt(transport_socket, ZMQ_RCVTIMEO, &wait_ms, sizeof(int));
    zmq_connect(transport_socket, facilities->zmq.transport_address);

    queue_t* stream = queue_init();

    while (!facilities->exit) {
        pthread_mutex_lock(&queue->lock);
        while (!queue->len) {
            pthread_cond_wait(&queue->trigger, &queue->lock);
        }
        for (int i = 0; i < queue->len; ++i) {
            memcpy(stream->packet[i], queue->packet[i], queue->packet_len[i]);
            stream->packet_len[i] = queue->packet_len[i];
            stream->destination[i] = queue->destination[i];
        }
        stream->len = queue->len;

        queue->len = 0;
        pthread_mutex_unlock(&queue->lock);

        for (int i = 0; i < stream->len; ++i) {
            switch (stream->destination[i]) {
                case 3:
                    syslog_debug("[facilities]-> sending BDR to ->[transport] (%dB)", stream->packet_len[i]);
                    zmq_send(transport_socket, stream->packet[i], stream->packet_len[i], 0);
                    rv = zmq_recv(transport_socket, &code, 1, 0);
                    if (rv == -1) {syslog_err("[facilities]-> timeout sending BDR to ->[transport]");}
                    break;
                case 5:
                    syslog_debug("[facilities]-> sending FDI to ->[applications] (%dB)", stream->packet_len[i]);
                    zmq_send(applications_socket, stream->packet[i], stream->packet_len[i], 0);
                    rv = zmq_recv(applications_socket, &code, 1, 0);
                    if (rv == -1) {syslog_err("[facilities]-> timeout sending FDI to ->[applications]");}
                    break;
            }
        }
    }

    return NULL;
}

int main() {
    int rv = 0;

    syslog_info("[facilities] starting");

    facilities_t facilities;
    memset(&facilities, 0x00, sizeof(facilities_t));

    facilities.zmq.ctx = zmq_ctx_new();
    facilities.lightship = lightship_init();
    facilities.dissemination = dissemination_init();
    facilities.tx_queue = queue_init();
    facilities.den = calloc(1, sizeof(den_t));
    facilities.infrastructure = calloc(1, sizeof(infrastructure_t));

    time_t t;
    srand((unsigned) time(&t));

    if (facilities_config(&facilities)) return 1;

    facilities.lightship->type = facilities.station_type;

    // Tx
    pthread_create(&facilities.transmitting, NULL, tx, (void*) &facilities);

    // CA
    pthread_create(&facilities.ca_service, NULL, ca_service, (void*) &facilities);

    // DEN
    pthread_create(&facilities.den_service, NULL, den_service, (void*) &facilities);

    // Infrastructure
    pthread_create(&facilities.infrastructure_service, NULL, infrastructure_service, (void*) &facilities);

    // CPM 
    if(facilities.dissemination->active)
        pthread_create(&facilities.cp_service, NULL, cp_service, (void*) &facilities);

    uint8_t buffer[PACKET_MAX_LEN];
    syslog_info("[facilities] listening");
    uint8_t code;
    bool in_idchange;

    while (!facilities.exit) {
        zmq_poll(facilities.zmq.responders, facilities.zmq.n_responders, -1);

        for (int i = 0; i < facilities.zmq.n_responders; ++i) {
            if (facilities.zmq.responders[i].revents) {
                zmq_recv(facilities.zmq.responders[i].socket, buffer, PACKET_MAX_LEN, 0);

                switch (buffer[0]) {
                    case 3:
                        in_idchange = true;
                        pthread_mutex_lock(&facilities.id.change.lock);
                        if (facilities.id.change.stage == ID_CHANGE_INACTIVE) {
                            in_idchange = false;
                            facilities.id.change.stage = ID_CHANGE_BLOCKED;
                        } 
                        pthread_mutex_unlock(&facilities.id.change.lock);

                        if (!in_idchange) {
                            transport_indication(&facilities, facilities.zmq.responders[i].socket, buffer+1, PACKET_MAX_LEN-1);

                            pthread_mutex_lock(&facilities.id.change.lock);
                            facilities.id.change.stage = ID_CHANGE_INACTIVE;
                            pthread_mutex_unlock(&facilities.id.change.lock);
                        } else {
                            code = 1; 
                            zmq_send(facilities.zmq.responders[i].socket, &code, 1, 0);
                        }
                        break;

                    case 5:
                        in_idchange = true;
                        pthread_mutex_lock(&facilities.id.change.lock);
                        if (facilities.id.change.stage == ID_CHANGE_INACTIVE) {
                            in_idchange = false;
                            facilities.id.change.stage = ID_CHANGE_BLOCKED;
                        } 
                        pthread_mutex_unlock(&facilities.id.change.lock);

                        if (!in_idchange) {
                            facilities_request(&facilities, facilities.zmq.responders[i].socket, buffer+1, PACKET_MAX_LEN-1);

                            pthread_mutex_lock(&facilities.id.change.lock);
                            facilities.id.change.stage = ID_CHANGE_INACTIVE;
                            pthread_mutex_unlock(&facilities.id.change.lock);
                        } else {
                            code = 1; 
                            zmq_send(facilities.zmq.responders[i].socket, &code, 1, 0);
                        }

                        break;

                    case 6:
                        management_indication(&facilities, facilities.zmq.responders[i].socket, buffer+1, PACKET_MAX_LEN-1);
                        break;

                    case 7:
                        security_indication(&facilities, facilities.zmq.responders[i].socket, buffer+1, PACKET_MAX_LEN-1);
                        break;

                    default:
                        syslog_debug("[facilities] unrecognized service");
                        code = 1;
                        zmq_send(facilities.zmq.responders[i].socket, &code, 1, 0);
                        continue;
                }
            }
        }
    }

    pthread_join(facilities.transmitting, NULL);
    pthread_join(facilities.ca_service, NULL);
    pthread_join(facilities.den_service, NULL);
    pthread_join(facilities.infrastructure_service, NULL);
    if(facilities.dissemination->active)
        pthread_join(facilities.cp_service, NULL);

    return 0;
}