#include <vanetza/asn1/security_profile.hpp>
#include VANETZA_ASN1_SECURITY_HEADER(Certificate.h)
#include <vanetza/security/hash_algorithm.hpp>
#include <vanetza/security/sha.hpp>
#include <vanetza/security/v3/asn1_conversions.hpp>
#include <vanetza/security/v3/certificate.hpp>
#include <vanetza/security/v3/distance.hpp>
#include <vanetza/security/v3/geometry.hpp>
#include <boost/optional/optional.hpp>
#include <cassert>
#include <cstdlib>
#include <cstring>

namespace vanetza
{
namespace security
{
namespace v3
{

namespace
{
HashAlgorithm digest_hash_algorithm(const asn1::EtsiTs103097Certificate& cert);
bool copy_curve_point(PublicKey& to, const asn1::EccP256CurvePoint& from);
bool copy_curve_point(PublicKey& to, const asn1::EccP384CurvePoint& from);
ByteBuffer fetch_octets(const OCTET_STRING_t& octets);
ByteBuffer get_x_coordinate(const asn1::EccP256CurvePoint& point);
ByteBuffer get_x_coordinate(const asn1::EccP384CurvePoint& point);

bool is_compressed(const Vanetza_Security_EccP256CurvePoint& point);
bool is_compressed(const Vanetza_Security_EccP384CurvePoint& point);
bool is_signature_x_only(const Vanetza_Security_Signature_t& sig);
bool compress(Vanetza_Security_EccP256CurvePoint&);
bool compress(Vanetza_Security_EccP384CurvePoint&);
bool contains_permission(const Vanetza_Security_SequenceOfPsidSspRange_t& permissions, ItsAid aid);
bool equal(const asn1::TwoDLocation& lhs, const asn1::TwoDLocation& rhs);
bool equal(const asn1::RectangularRegion& lhs, const asn1::RectangularRegion& rhs);
bool equal(const asn1::SequenceOfRectangularRegion& lhs, const asn1::SequenceOfRectangularRegion& rhs);
bool is_within(const asn1::GeographicRegion& inner, const asn1::CircularRegion& outer);
bool is_within(const asn1::GeographicRegion& inner, const asn1::SequenceOfRectangularRegion& outer);
bool is_within(const asn1::GeographicRegion& inner, const asn1::PolygonalRegion& outer);
bool is_within(const asn1::GeographicRegion& inner, const asn1::GeographicRegion& outer);
bool make_x_only(Vanetza_Security_EccP256CurvePoint&);
bool make_x_only(Vanetza_Security_EccP384CurvePoint&);
bool make_signature_x_only(Vanetza_Security_Signature_t& sig);

} // namespace

CertificateView::CertificateView(const asn1::EtsiTs103097Certificate* cert) :
    m_cert(cert)
{
}

Certificate::Certificate() :
    Wrapper(asn_DEF_Vanetza_Security_EtsiTs103097Certificate),
    CertificateView { content() }
{
    assert(CertificateView::m_cert == Wrapper::m_struct);
}

Certificate::Certificate(const asn1::EtsiTs103097Certificate& cert) :
    Wrapper(asn_DEF_Vanetza_Security_EtsiTs103097Certificate, &cert),
    CertificateView { content() }
{
    assert(CertificateView::m_cert == Wrapper::m_struct);
}

Certificate::Certificate(const Certificate& other) :
    Wrapper(other), CertificateView(content())
{
    assert(CertificateView::m_cert == Wrapper::m_struct);
}

Certificate& Certificate::operator=(const Certificate& other)
{
    Wrapper::operator=(other);
    CertificateView::m_cert = content();
    assert(CertificateView::m_cert == Wrapper::m_struct);
    return *this;
}

Certificate::Certificate(Certificate&& other) :
    Wrapper(std::move(other)), CertificateView(content())
{
    assert(CertificateView::m_cert == Wrapper::m_struct);
}

Certificate& Certificate::operator=(Certificate&& other)
{
    Wrapper::operator=(std::move(other));
    CertificateView::m_cert = content();
    assert(CertificateView::m_cert == Wrapper::m_struct);
    return *this;
}

boost::optional<HashedId8> CertificateView::calculate_digest() const
{
    return m_cert ? v3::calculate_digest(*m_cert) : boost::none;
}

KeyType CertificateView::get_verification_key_type() const
{
    return m_cert ? v3::get_verification_key_type(*m_cert) : KeyType::Unspecified;
}

bool CertificateView::valid_at_location(const PositionFix& location, const LocationChecker* lc) const
{
    return m_cert ? lc ? lc->valid_at_location(*m_cert, location) : false :  false;
}

bool CertificateView::valid_at_timepoint(const Clock::time_point& timepoint) const
{
    return m_cert ? v3::valid_at_timepoint(*m_cert, timepoint) : false;
}

bool valid_at_timepoint(const asn1::EtsiTs103097Certificate& cert, const Clock::time_point& timepoint)
{
    const asn1::ValidityPeriod& validity = cert.toBeSigned.validityPeriod;
    Clock::time_point start { std::chrono::seconds(validity.start) };
    Clock::time_point end = start;

    switch (validity.duration.present)
    {
        case Vanetza_Security_Duration_PR_microseconds:
            end += std::chrono::microseconds(validity.duration.choice.microseconds);
            break;
        case Vanetza_Security_Duration_PR_milliseconds:
            end += std::chrono::milliseconds(validity.duration.choice.milliseconds);
            break;
        case Vanetza_Security_Duration_PR_seconds:
            end += std::chrono::seconds(validity.duration.choice.seconds);
            break;
        case Vanetza_Security_Duration_PR_minutes:
            end += std::chrono::minutes(validity.duration.choice.minutes);
            break;
        case Vanetza_Security_Duration_PR_hours:
            end += std::chrono::hours(validity.duration.choice.hours);
            break;
        case Vanetza_Security_Duration_PR_sixtyHours:
            end += std::chrono::hours(60) * validity.duration.choice.sixtyHours;
            break;
        case Vanetza_Security_Duration_PR_years:
            // one year is considered 31556952 seconds according to IEEE 1609.2
            end += std::chrono::seconds(31556952) * validity.duration.choice.years;
            break;
        default:
            // leave end at start and thus forming an invalid range
            break;
    }
    
    return timepoint >= start && timepoint < end;
}

bool CertificateView::valid_for_application(ItsAid aid) const
{
    return m_cert ? v3::valid_for_application(*m_cert, aid) : false;
}

bool CertificateView::is_allowed_to_issue(ItsAid aid) const
{
    if (!m_cert) {
        return false;
    }

    if (const auto* seq = m_cert->toBeSigned.certIssuePermissions) {
        for (int i = 0; i < seq->list.count; ++i) {
            const auto* group = seq->list.array[i];
            if (!group) {
                continue;
            }

            const auto& subject_permissions = group->subjectPermissions;
            if (subject_permissions.present == Vanetza_Security_SubjectPermissions_PR_all) {
                return true;
            } else if (
                    subject_permissions.present == Vanetza_Security_SubjectPermissions_PR_explicit &&
                    contains_permission(subject_permissions.choice.Explicit, aid)) {
                return true;
            }
        }
    }

    return false;
}

boost::optional<std::uint8_t> CertificateView::assurance_level() const
{
    if (!m_cert || !m_cert->toBeSigned.assuranceLevel || m_cert->toBeSigned.assuranceLevel->size < 1) {
        return boost::none;
    }

    return m_cert->toBeSigned.assuranceLevel->buf[0];
}

bool CertificateView::region_is_within(const CertificateView& issuer) const
{
    if (!m_cert || !issuer.m_cert) {
        return false;
    }

    const auto* issuer_region = issuer.m_cert->toBeSigned.region;
    const auto* subject_region = m_cert->toBeSigned.region;
    if (!issuer_region) {
        return true;
    } else if (!subject_region) {
        return false;
    } else {
        return is_within(*subject_region, *issuer_region);
    }
}

bool valid_for_application(const asn1::EtsiTs103097Certificate& cert, ItsAid aid)
{
    const asn1::SequenceOfPsidSsp* permissions = cert.toBeSigned.appPermissions;
    if (permissions) {
        for (int i = 0; i < permissions->list.count; ++i) {
            if (permissions->list.array[i]->psid == aid) {
                return true;
            }
        }
    }

    // only explicitly allowed applications are valid
    return false;
}

boost::optional<HashedId8> CertificateView::issuer_digest() const
{
    boost::optional<HashedId8> digest;
    if (m_cert != nullptr) {
        switch (m_cert->issuer.present)
        {
            case Vanetza_Security_IssuerIdentifier_PR_sha256AndDigest:
                digest = create_hashed_id8(m_cert->issuer.choice.sha256AndDigest);
                break;
            case Vanetza_Security_IssuerIdentifier_PR_sha384AndDigest:
                digest = create_hashed_id8(m_cert->issuer.choice.sha384AndDigest);
                break;
            default:
                break;
        }
    }
    return digest;
}

bool CertificateView::issuer_is_self() const
{
    return m_cert->issuer.present == Vanetza_Security_IssuerIdentifier_PR_self;
}

bool CertificateView::has_region_restriction() const
{
    return m_cert ? m_cert->toBeSigned.region != nullptr : false;
}

bool CertificateView::is_ca_certificate() const
{
    return m_cert && m_cert->toBeSigned.certIssuePermissions != nullptr;
}

bool CertificateView::is_at_certificate() const
{
    return m_cert && m_cert->toBeSigned.certIssuePermissions == nullptr && m_cert->toBeSigned.appPermissions != nullptr;
}

bool CertificateView::is_canonical() const
{
    return m_cert ? v3::is_canonical(*m_cert) : false;
}

StartAndEndValidity CertificateView::get_start_and_end_validity() const
{
    StartAndEndValidity start_and_end;
    start_and_end.start_validity = Time32(m_cert->toBeSigned.validityPeriod.start);
    Time32 duration = 0;
    switch (m_cert->toBeSigned.validityPeriod.duration.present)
    {
    case Vanetza_Security_Duration_PR_NOTHING:
        break;
    case Vanetza_Security_Duration_PR_microseconds:
        duration += (int)m_cert->toBeSigned.validityPeriod.duration.choice.microseconds/1000000;
        break;
    case Vanetza_Security_Duration_PR_milliseconds:
        duration += (int)m_cert->toBeSigned.validityPeriod.duration.choice.milliseconds/1000;
        break;
    case Vanetza_Security_Duration_PR_seconds:
        duration += (int)m_cert->toBeSigned.validityPeriod.duration.choice.seconds;
        break;
    case Vanetza_Security_Duration_PR_minutes:
        duration += (int)m_cert->toBeSigned.validityPeriod.duration.choice.minutes*60;
        break;
    case Vanetza_Security_Duration_PR_hours:
        duration += (int)m_cert->toBeSigned.validityPeriod.duration.choice.hours*60*60;
        break;
    case Vanetza_Security_Duration_PR_sixtyHours:
        duration += (int)m_cert->toBeSigned.validityPeriod.duration.choice.sixtyHours*60*60*60;
        break;
    case Vanetza_Security_Duration_PR_years:
        duration += (int)m_cert->toBeSigned.validityPeriod.duration.choice.years*60*60*24*365;
        break;
    default:
        break;
    }
    start_and_end.end_validity = start_and_end.start_validity + duration;
    return start_and_end;
}

bool is_canonical(const asn1::EtsiTs103097Certificate& cert)
{
    bool compressed_point = true;
    const Vanetza_Security_VerificationKeyIndicator& indicator = cert.toBeSigned.verifyKeyIndicator;
    if (indicator.present == Vanetza_Security_VerificationKeyIndicator_PR_verificationKey) {
        const Vanetza_Security_PublicVerificationKey& pubkey = indicator.choice.verificationKey;
        switch (pubkey.present) {
            case Vanetza_Security_PublicVerificationKey_PR_ecdsaNistP256:
                compressed_point = is_compressed(pubkey.choice.ecdsaNistP256);
                break;
            case Vanetza_Security_PublicVerificationKey_PR_ecdsaBrainpoolP256r1:
                compressed_point = is_compressed(pubkey.choice.ecdsaBrainpoolP256r1);
                break;
            case Vanetza_Security_PublicVerificationKey_PR_ecdsaBrainpoolP384r1:
                compressed_point = is_compressed(pubkey.choice.ecdsaBrainpoolP384r1);
                break;
            default:
                break;
        }
    } else if (indicator.present == Vanetza_Security_VerificationKeyIndicator_PR_reconstructionValue) {
        compressed_point = is_compressed(indicator.choice.reconstructionValue);
    }

    if (!compressed_point) {
        return false;
    } else if (cert.signature && !is_signature_x_only(*cert.signature)) {
        return false;
    } else {
        return true;
    }
}

ByteBuffer CertificateView::encode() const
{
    return m_cert ? asn1::encode_oer(asn_DEF_Vanetza_Security_EtsiTs103097Certificate, m_cert) : ByteBuffer {};
}

ByteBuffer Certificate::encode() const
{
    return Wrapper::encode();
}

boost::optional<Certificate> CertificateView::canonicalize() const
{
    return m_cert ? v3::canonicalize(*m_cert) : boost::none;
}

static boost::optional<Certificate> canonicalize(Certificate&& canonical)
{
    bool success = true;

    if (canonical->toBeSigned.verifyKeyIndicator.present == Vanetza_Security_VerificationKeyIndicator_PR_verificationKey) {
        Vanetza_Security_PublicVerificationKey& pubkey = canonical->toBeSigned.verifyKeyIndicator.choice.verificationKey;
        switch (pubkey.present) {
            case Vanetza_Security_PublicVerificationKey_PR_ecdsaNistP256:
                success &= compress(pubkey.choice.ecdsaNistP256);
                break;
            case Vanetza_Security_PublicVerificationKey_PR_ecdsaBrainpoolP256r1:
                success &= compress(pubkey.choice.ecdsaBrainpoolP256r1);
                break;
            case Vanetza_Security_PublicVerificationKey_PR_ecdsaBrainpoolP384r1:
                success &= compress(pubkey.choice.ecdsaBrainpoolP384r1);
                break;
            default:
                break;
        }
    } else if (canonical->toBeSigned.verifyKeyIndicator.present == Vanetza_Security_VerificationKeyIndicator_PR_reconstructionValue) {
        success &= compress(canonical->toBeSigned.verifyKeyIndicator.choice.reconstructionValue);
    }

    if (canonical->toBeSigned.encryptionKey) {
        Vanetza_Security_BasePublicEncryptionKey& pubkey = canonical->toBeSigned.encryptionKey->publicKey;
        switch (pubkey.present) {
            case Vanetza_Security_BasePublicEncryptionKey_PR_eciesNistP256:
                success &= compress(pubkey.choice.eciesNistP256);
                break;
            case Vanetza_Security_BasePublicEncryptionKey_PR_eciesBrainpoolP256r1:
                success &= compress(pubkey.choice.eciesBrainpoolP256r1);
                break;
            default:
                break;
        }
    }

    if (canonical->signature) {
        success &= make_signature_x_only(*canonical->signature);
    }

    if (success) {
        assert(is_canonical(*canonical));
        return canonical;
    } else {
        return boost::none;
    }
}

boost::optional<Certificate> canonicalize(const asn1::EtsiTs103097Certificate& cert)
{
    try {
        Certificate copy { cert };
        return canonicalize(std::move(copy));
    } catch (const std::exception&) {
        return boost::none;
    }
}

boost::optional<HashedId8> calculate_digest_internal(const asn1::EtsiTs103097Certificate& cert, HashAlgorithm hash_algo)
{
    boost::optional<HashedId8> digest;

    try {
        ByteBuffer buffer = asn1::encode_oer(asn_DEF_Vanetza_Security_EtsiTs103097Certificate, &cert);

        switch (hash_algo)
        {
            case HashAlgorithm::SHA256:
                digest = create_hashed_id8(calculate_sha256_digest(buffer.data(), buffer.size()));
                break;
            case HashAlgorithm::SHA384:
                digest = create_hashed_id8(calculate_sha384_digest(buffer.data(), buffer.size()));
                break;
            default:
                break;
        }
    } catch (const std::exception&) {
        // cannot calculate digest of non-encodable certificate
    }

    return digest;
}

boost::optional<HashedId8> calculate_digest(const asn1::EtsiTs103097Certificate& cert)
{
    boost::optional<HashedId8> digest;
    const HashAlgorithm hash_algo = digest_hash_algorithm(cert);
    if (hash_algo != HashAlgorithm::Unspecified) {
        if (is_canonical(cert)) {
            digest = calculate_digest_internal(cert, hash_algo);
        } else {
            auto maybe_canonical_cert = canonicalize(cert);
            if (maybe_canonical_cert) {
                digest = calculate_digest_internal(*maybe_canonical_cert.value(), hash_algo);
            }
        }
    }
    return digest;
}

KeyType get_verification_key_type(const asn1::EtsiTs103097Certificate& cert)
{
    KeyType key_type = KeyType::Unspecified;

    if (cert.toBeSigned.verifyKeyIndicator.present == Vanetza_Security_VerificationKeyIndicator_PR_verificationKey)
    {
        switch (cert.toBeSigned.verifyKeyIndicator.choice.verificationKey.present)
        {
            case Vanetza_Security_PublicVerificationKey_PR_ecdsaNistP256:
                key_type = KeyType::NistP256;
                break;
            case Vanetza_Security_PublicVerificationKey_PR_ecdsaBrainpoolP256r1:
                key_type = KeyType::BrainpoolP256r1;
                break;
            case Vanetza_Security_PublicVerificationKey_PR_ecdsaBrainpoolP384r1:
                key_type = KeyType::BrainpoolP384r1;
                break;
            default:
                break;
        }
    }

    return key_type;
}

boost::optional<PublicKey> get_public_key(const asn1::EtsiTs103097Certificate& cert)
{
  asn1::VerificationKeyIndicator indicator = cert.toBeSigned.verifyKeyIndicator;
    if (indicator.present != Vanetza_Security_VerificationKeyIndicator_PR_verificationKey) {
        return boost::none;
    }

    const asn1::PublicVerificationKey& input = cert.toBeSigned.verifyKeyIndicator.choice.verificationKey;
    PublicKey output;
    switch (input.present) {
        case Vanetza_Security_PublicVerificationKey_PR_ecdsaNistP256:
            output.type = KeyType::NistP256;
            if (copy_curve_point(output, input.choice.ecdsaNistP256)) {
                return output;
            } else {
                return boost::none;
            }
            break;
        case Vanetza_Security_PublicVerificationKey_PR_ecdsaBrainpoolP256r1:
            output.type = KeyType::BrainpoolP256r1;
            if (copy_curve_point(output, input.choice.ecdsaBrainpoolP256r1)) {
                return output;
            } else {
                return boost::none;
            }
            break;
        case Vanetza_Security_PublicVerificationKey_PR_ecdsaBrainpoolP384r1:
            output.type = KeyType::BrainpoolP384r1;
            if (copy_curve_point(output, input.choice.ecdsaBrainpoolP384r1)) {
                return output;
            } else {
                return boost::none;
            }
            break;
        default:
            return boost::none;
            break;
    }
}

boost::optional<PublicKey> get_public_encryption_key(const asn1::EtsiTs103097Certificate& cert)
{
    const asn1::PublicEncryptionKey* enc_key = cert.toBeSigned.encryptionKey;
    if (!enc_key || enc_key->supportedSymmAlg != Vanetza_Security_SymmAlgorithm_aes128Ccm) {
        return boost::none;
    }

    PublicKey output;
    switch (enc_key->publicKey.present) {
        case Vanetza_Security_BasePublicEncryptionKey_PR_eciesNistP256:
            output.type = KeyType::NistP256;
            if (copy_curve_point(output, enc_key->publicKey.choice.eciesNistP256)) {
                return output;
            } else {
                return boost::none;
            }
            break;
        case Vanetza_Security_BasePublicEncryptionKey_PR_eciesBrainpoolP256r1:
            output.type = KeyType::BrainpoolP256r1;
            if (copy_curve_point(output, enc_key->publicKey.choice.eciesBrainpoolP256r1)) {
                return output;
            } else {
                return boost::none;
            }
            break;
        default:
            return boost::none;
            break;
    }
}

boost::optional<Signature> get_signature(const asn1::EtsiTs103097Certificate& cert)
{
    if (!cert.signature) {
        return boost::none;
    }

    const asn1::Signature* asn = cert.signature;
    Signature sig;
    switch (asn->present) {
        case Vanetza_Security_Signature_PR_ecdsaNistP256Signature:
            sig.type = KeyType::NistP256;
            sig.r = get_x_coordinate(asn->choice.ecdsaNistP256Signature.rSig);
            sig.s = fetch_octets(asn->choice.ecdsaNistP256Signature.sSig);
            break;
        case Vanetza_Security_Signature_PR_ecdsaBrainpoolP256r1Signature:
            sig.type = KeyType::BrainpoolP256r1;
            sig.r = get_x_coordinate(asn->choice.ecdsaBrainpoolP256r1Signature.rSig);
            sig.s = fetch_octets(asn->choice.ecdsaBrainpoolP256r1Signature.sSig);
            break;
        case Vanetza_Security_Signature_PR_ecdsaBrainpoolP384r1Signature:
            sig.type = KeyType::BrainpoolP384r1;
            sig.r = get_x_coordinate(asn->choice.ecdsaBrainpoolP384r1Signature.rSig);
            sig.s = fetch_octets(asn->choice.ecdsaBrainpoolP384r1Signature.sSig);
            break;
        default:
            return boost::none;
    }

    return sig;
}

std::list<ItsAid> get_aids(const asn1::EtsiTs103097Certificate& cert)
{
    std::list<ItsAid> aids;
    const asn1::SequenceOfPsidSsp* seq = cert.toBeSigned.appPermissions;
    if (seq) {
        for (int i = 0; i < seq->list.count; ++i) {
            aids.push_back(seq->list.array[i]->psid);
        }
    }
    return aids;
}

ByteBuffer get_app_permissions(const asn1::EtsiTs103097Certificate& cert, ItsAid aid)
{
    ByteBuffer perms;
    const asn1::SequenceOfPsidSsp* seq = cert.toBeSigned.appPermissions;
    if (seq) {
        for (int i = 0; i < seq->list.count; ++i) {
            if (seq->list.array[i]->psid == aid && seq->list.array[i]->ssp != nullptr) {
                const asn1::ServiceSpecificPermissions& ssp = *seq->list.array[i]->ssp;
                if (ssp.present == Vanetza_Security_ServiceSpecificPermissions_PR_bitmapSsp) {
                    const asn1::BitmapSsp& bitmap = ssp.choice.bitmapSsp;
                    perms.assign(bitmap.buf, bitmap.buf + bitmap.size);
                    break;
                } else if (ssp.present == Vanetza_Security_ServiceSpecificPermissions_PR_opaque) {
                    const asn1::Opaque& opaque = ssp.choice.opaque;
                    perms.assign(opaque.buf, opaque.buf + opaque.size);
                    break;
                }
            }
        }
    }
    return perms;
}

void add_psid_group_permission(asn1::PsidGroupPermissions* group_permission, ItsAid aid, const ByteBuffer& ssp, const ByteBuffer& bitmask)
{
    auto psid_range_scr = asn1::allocate<asn1::PsidSspRange>();
    psid_range_scr->psid = aid;
    psid_range_scr->sspRange = asn1::allocate<asn1::SspRange>();
    psid_range_scr->sspRange->present = Vanetza_Security_SspRange_PR_bitmapSspRange;
    OCTET_STRING_fromBuf(
        &psid_range_scr->sspRange->choice.bitmapSspRange.sspValue,
        reinterpret_cast<const char*>(ssp.data()),
        ssp.size()
    );
    OCTET_STRING_fromBuf(
        &psid_range_scr->sspRange->choice.bitmapSspRange.sspBitmask,
        reinterpret_cast<const char*>(bitmask.data()),
        bitmask.size()
    );
    ASN_SEQUENCE_ADD(&group_permission->subjectPermissions.choice.Explicit, psid_range_scr);
}

void Certificate::add_app_permission(ItsAid aid, const ByteBuffer& ssp)
{
    asn1::SequenceOfPsidSsp* seq = m_struct->toBeSigned.appPermissions;
    if (!seq) {
        seq = asn1::allocate<asn1::SequenceOfPsidSsp>();
        m_struct->toBeSigned.appPermissions = seq;
    }

    auto psid_ptr = asn1::allocate<asn1::PsidSsp>();
    psid_ptr->psid = aid;
    if (!ssp.empty()) {
        psid_ptr->ssp = asn1::allocate<asn1::ServiceSpecificPermissions>();
        psid_ptr->ssp->present = Vanetza_Security_ServiceSpecificPermissions_PR_bitmapSsp;
        OCTET_STRING_fromBuf(
            &psid_ptr->ssp->choice.bitmapSsp,
            reinterpret_cast<const char *>(ssp.data()),
            ssp.size()
        );
    }
    ASN_SEQUENCE_ADD(seq, psid_ptr);
}

void Certificate::add_cert_issue_permission(asn1::PsidGroupPermissions* group_permission)
{
    asn1::SequenceOfPsidGroupPermissions* seq = m_struct->toBeSigned.certIssuePermissions;
    if (!seq) {
        seq = asn1::allocate<asn1::SequenceOfPsidGroupPermissions>();
        m_struct->toBeSigned.certIssuePermissions = seq;
    }
    ASN_SEQUENCE_ADD(seq, group_permission);
}

void Certificate::set_signature(const SomeEcdsaSignature& signature)
{
    if (!m_struct->signature) {
        m_struct->signature = asn1::allocate<asn1::Signature>();
    } else {
        asn1::reset(m_struct->signature);
    }

    struct signature_visitor : public boost::static_visitor<>
    {
        asn1::Signature* sig;

        explicit signature_visitor(asn1::Signature* s) : sig(s)
        {
        }

        void operator()(const EcdsaSignature& signature) const
        {
            sig->present = Vanetza_Security_Signature_PR_ecdsaNistP256Signature;
            assign(&sig->choice.ecdsaNistP256Signature.sSig, signature.s);
            sig->choice.ecdsaNistP256Signature.rSig = to_asn1(signature.R);
        }

        void operator()(const EcdsaSignatureFuture& signature) const
        {
            this->operator()(signature.get());
        }
    };

    boost::apply_visitor(signature_visitor(m_struct->signature), signature);
}

Certificate fake_certificate()
{
    Certificate cert;
    cert->issuer.present = Vanetza_Security_IssuerIdentifier_PR_self;
    cert->toBeSigned.id.present = Vanetza_Security_CertificateId_PR_none;
    std::array<char, 3> craca_id = { 0, 0, 0};
    OCTET_STRING_fromBuf(&cert->toBeSigned.cracaId, craca_id.data(), craca_id.size());
    cert->version = 3;
    cert->toBeSigned.crlSeries = 0;
    cert->toBeSigned.validityPeriod.start = 0;
    cert->toBeSigned.validityPeriod.duration.present = Vanetza_Security_Duration_PR_minutes;
    cert->toBeSigned.validityPeriod.duration.choice.minutes = 10080;
    cert->toBeSigned.verifyKeyIndicator.present = Vanetza_Security_VerificationKeyIndicator_PR_verificationKey;
    cert->toBeSigned.verifyKeyIndicator.choice.verificationKey.present = Vanetza_Security_PublicVerificationKey_PR_ecdsaNistP256;
    cert->toBeSigned.verifyKeyIndicator.choice.verificationKey.choice.ecdsaNistP256.present = Vanetza_Security_EccP256CurvePoint_PR_compressed_y_0;
    std::array<char, 32> dummy_r {}; // 32 octets for P256 signature
    OCTET_STRING_fromBuf(
        &cert->toBeSigned.verifyKeyIndicator.choice.verificationKey.choice.ecdsaNistP256.choice.x_only,
        dummy_r.data(), dummy_r.size()
    );
    cert.add_app_permission(aid::CA, ByteBuffer({ 1, 0, 0 }));
    return cert;
}

void serialize(OutputArchive& ar, const Certificate& certificate)
{
    ByteBuffer buffer = certificate.encode();
    ar.save_binary(buffer.data(), buffer.size());
}

namespace
{

bool contains_permission(const Vanetza_Security_SequenceOfPsidSspRange_t& permissions, ItsAid aid)
{
    for (int i = 0; i < permissions.list.count; ++i) {
        const auto* permission = permissions.list.array[i];
        if (permission && permission->psid == aid) {
            return true;
        }
    }

    return false;
}

bool equal(const asn1::TwoDLocation& lhs, const asn1::TwoDLocation& rhs)
{
    return lhs.latitude == rhs.latitude && lhs.longitude == rhs.longitude;
}

bool equal(const asn1::RectangularRegion& lhs, const asn1::RectangularRegion& rhs)
{
    return equal(lhs.northWest, rhs.northWest) && equal(lhs.southEast, rhs.southEast);
}

bool equal(const asn1::SequenceOfRectangularRegion& lhs, const asn1::SequenceOfRectangularRegion& rhs)
{
    if (lhs.list.count != rhs.list.count) {
        return false;
    }

    for (int i = 0; i < lhs.list.count; ++i) {
        if (!lhs.list.array[i] || !rhs.list.array[i] || !equal(*lhs.list.array[i], *rhs.list.array[i])) {
            return false;
        }
    }

    return true;
}

bool is_within(const asn1::GeographicRegion& inner, const asn1::CircularRegion& outer)
{
    if (inner.present != Vanetza_Security_GeographicRegion_PR_circularRegion) {
        return false;
    }

    const auto& circle = inner.choice.circularRegion;
    if (!is_valid(circle.center) || !is_valid(outer.center) || circle.radius < 0 || outer.radius < 0) {
        return false;
    }

    PositionFix inner_center;
    inner_center.latitude = convert_latitude(circle.center.latitude);
    inner_center.longitude = convert_longitude(circle.center.longitude);
    return distance(inner_center, outer.center) + circle.radius * units::si::meter <= outer.radius * units::si::meter;
}

bool is_within(const asn1::GeographicRegion& inner, const asn1::SequenceOfRectangularRegion& outer)
{
    return inner.present == Vanetza_Security_GeographicRegion_PR_rectangularRegion &&
        equal(inner.choice.rectangularRegion, outer);
}

bool is_within(const asn1::GeographicRegion&, const asn1::PolygonalRegion&)
{
    return false;
}

bool is_within(const asn1::GeographicRegion& inner, const asn1::GeographicRegion& outer)
{
    switch (outer.present) {
        case Vanetza_Security_GeographicRegion_PR_circularRegion:
            return is_within(inner, outer.choice.circularRegion);
        case Vanetza_Security_GeographicRegion_PR_rectangularRegion:
            return is_within(inner, outer.choice.rectangularRegion);
        case Vanetza_Security_GeographicRegion_PR_polygonalRegion:
            return is_within(inner, outer.choice.polygonalRegion);
        case Vanetza_Security_GeographicRegion_PR_NOTHING:
            return true;
        default:
            return false;
    }
}

bool copy_curve_point(PublicKey& to, const asn1::EccP256CurvePoint& from)
{
    bool copied = true;
    switch (from.present) {
        case Vanetza_Security_EccP256CurvePoint_PR_compressed_y_0:
            to.compression = KeyCompression::Y0;
            to.x = fetch_octets(from.choice.compressed_y_0);
            break;
        case Vanetza_Security_EccP256CurvePoint_PR_compressed_y_1:
            to.compression = KeyCompression::Y1;
            to.x = fetch_octets(from.choice.compressed_y_1);
            break;
        case Vanetza_Security_EccP256CurvePoint_PR_uncompressedP256:
            to.compression = KeyCompression::NoCompression;
            to.x = fetch_octets(from.choice.uncompressedP256.x);
            to.y = fetch_octets(from.choice.uncompressedP256.y);
            break;
        default:
            copied = false;
            break;
    }

    return copied;
}

bool copy_curve_point(PublicKey& to, const asn1::EccP384CurvePoint& from)
{
    bool copied = true;
    switch (from.present) {
        case Vanetza_Security_EccP384CurvePoint_PR_compressed_y_0:
            to.compression = KeyCompression::Y0;
            to.x = fetch_octets(from.choice.compressed_y_0);
            break;
        case Vanetza_Security_EccP384CurvePoint_PR_compressed_y_1:
            to.compression = KeyCompression::Y1;
            to.x = fetch_octets(from.choice.compressed_y_1);
            break;
        case Vanetza_Security_EccP384CurvePoint_PR_uncompressedP384:
            to.compression = KeyCompression::NoCompression;
            to.x = fetch_octets(from.choice.uncompressedP384.x);
            to.y = fetch_octets(from.choice.uncompressedP384.y);
            break;
        default:
            copied = false;
            break;
    }

    return copied;
}

HashAlgorithm digest_hash_algorithm(const asn1::EtsiTs103097Certificate& cert)
{
    // IEEE 1609.2 clause 6.4.3: hash algorithm depends on the verification key indicator;
    // a reconstruction value (implicit certificate) is always an EccP256CurvePoint and
    // clause 5.3.2 mandates SHA-256 for implicit certificates
    const asn1::VerificationKeyIndicator& indicator = cert.toBeSigned.verifyKeyIndicator;
    switch (indicator.present) {
        case Vanetza_Security_VerificationKeyIndicator_PR_verificationKey:
            switch (indicator.choice.verificationKey.present) {
                case Vanetza_Security_PublicVerificationKey_PR_ecdsaNistP256:
                case Vanetza_Security_PublicVerificationKey_PR_ecdsaBrainpoolP256r1:
                    return HashAlgorithm::SHA256;
                case Vanetza_Security_PublicVerificationKey_PR_ecdsaBrainpoolP384r1:
                    return HashAlgorithm::SHA384;
                default:
                    return HashAlgorithm::Unspecified;
            }
        case Vanetza_Security_VerificationKeyIndicator_PR_reconstructionValue:
            return HashAlgorithm::SHA256;
        default:
            return HashAlgorithm::Unspecified;
    }
}

ByteBuffer fetch_octets(const OCTET_STRING_t& octets)
{
    ByteBuffer buffer(octets.size);
    std::memcpy(buffer.data(), octets.buf, octets.size);
    return buffer;
}

ByteBuffer get_x_coordinate(const asn1::EccP256CurvePoint& point)
{
    switch (point.present) {
        case Vanetza_Security_EccP256CurvePoint_PR_compressed_y_0:
            return fetch_octets(point.choice.compressed_y_0);
        case Vanetza_Security_EccP256CurvePoint_PR_compressed_y_1:
            return fetch_octets(point.choice.compressed_y_1);
        case Vanetza_Security_EccP256CurvePoint_PR_x_only:
            return fetch_octets(point.choice.x_only);
        case Vanetza_Security_EccP256CurvePoint_PR_uncompressedP256:
            return fetch_octets(point.choice.uncompressedP256.x);
        default:
            return ByteBuffer {};
    }
}

ByteBuffer get_x_coordinate(const asn1::EccP384CurvePoint& point)
{
    switch (point.present) {
        case Vanetza_Security_EccP384CurvePoint_PR_compressed_y_0:
            return fetch_octets(point.choice.compressed_y_0);
        case Vanetza_Security_EccP384CurvePoint_PR_compressed_y_1:
            return fetch_octets(point.choice.compressed_y_1);
        case Vanetza_Security_EccP384CurvePoint_PR_x_only:
            return fetch_octets(point.choice.x_only);
        case Vanetza_Security_EccP384CurvePoint_PR_uncompressedP384:
            return fetch_octets(point.choice.uncompressedP384.x);
        default:
            return ByteBuffer {};
    }
}

bool is_compressed(const Vanetza_Security_EccP256CurvePoint& point)
{
    switch (point.present) {
        case Vanetza_Security_EccP256CurvePoint_PR_compressed_y_0:
        case Vanetza_Security_EccP256CurvePoint_PR_compressed_y_1:
            return true;
        default:
            return false;
    }
}

bool is_compressed(const Vanetza_Security_EccP384CurvePoint& point)
{
    switch (point.present) {
        case Vanetza_Security_EccP384CurvePoint_PR_compressed_y_0:
        case Vanetza_Security_EccP384CurvePoint_PR_compressed_y_1:
            return true;
        default:
            return false;
    }
}

bool is_signature_x_only(const Vanetza_Security_Signature_t& sig)
{
    switch (sig.present) {
        case Vanetza_Security_Signature_PR_ecdsaNistP256Signature:
            return sig.choice.ecdsaNistP256Signature.rSig.present == Vanetza_Security_EccP256CurvePoint_PR_x_only;
        case Vanetza_Security_Signature_PR_ecdsaBrainpoolP256r1Signature:
            return sig.choice.ecdsaBrainpoolP256r1Signature.rSig.present == Vanetza_Security_EccP256CurvePoint_PR_x_only;
        case Vanetza_Security_Signature_PR_ecdsaBrainpoolP384r1Signature:
            return sig.choice.ecdsaBrainpoolP384r1Signature.rSig.present == Vanetza_Security_EccP384CurvePoint_PR_x_only;
        default:
            return true; // not an ECDSA signature at all
    }
}

bool compress(Vanetza_Security_EccP256CurvePoint& point)
{
    if (point.present == Vanetza_Security_EccP256CurvePoint_PR_uncompressedP256) {
        auto& unc = point.choice.uncompressedP256;
        const bool y_odd = unc.y.size > 0 && unc.y.buf[unc.y.size - 1] & 0x01;
        asn1::reset(&unc.y);
        std::free(unc._asn_ctx.ptr);
        unc._asn_ctx.ptr = nullptr;
        if (y_odd) {
            assert(&point.choice.uncompressedP256.x == &point.choice.compressed_y_1);
            point.present = Vanetza_Security_EccP256CurvePoint_PR_compressed_y_1;
        } else {
            assert(&point.choice.uncompressedP256.x == &point.choice.compressed_y_0);
            point.present = Vanetza_Security_EccP256CurvePoint_PR_compressed_y_0;
        }
        return true;
    } else if (point.present == Vanetza_Security_EccP256CurvePoint_PR_compressed_y_0 || point.present == Vanetza_Security_EccP256CurvePoint_PR_compressed_y_1) {
        return true;
    } else {
        return false;
    }
}

bool compress(Vanetza_Security_EccP384CurvePoint& point)
{
    if (point.present == Vanetza_Security_EccP384CurvePoint_PR_uncompressedP384) {
        auto& unc = point.choice.uncompressedP384;
        const bool y_odd = unc.y.size > 0 && unc.y.buf[unc.y.size - 1] & 0x01;
        asn1::reset(&unc.y);
        std::free(unc._asn_ctx.ptr);
        unc._asn_ctx.ptr = nullptr;
        if (y_odd) {
            assert(&point.choice.uncompressedP384.x == &point.choice.compressed_y_1);
            point.present = Vanetza_Security_EccP384CurvePoint_PR_compressed_y_1;
        } else {
            assert(&point.choice.uncompressedP384.x == &point.choice.compressed_y_0);
            point.present = Vanetza_Security_EccP384CurvePoint_PR_compressed_y_0;
        }
        return true;
    } else if (point.present == Vanetza_Security_EccP384CurvePoint_PR_compressed_y_0 || point.present == Vanetza_Security_EccP384CurvePoint_PR_compressed_y_1) {
        return true;
    } else {
        return false;
    }
}

bool make_x_only(Vanetza_Security_EccP256CurvePoint& point)
{
    if (point.present == Vanetza_Security_EccP256CurvePoint_PR_uncompressedP256) {
        auto& unc = point.choice.uncompressedP256;
        asn1::reset(&unc.y);
        std::free(unc._asn_ctx.ptr);
        unc._asn_ctx.ptr = nullptr;
        assert(&unc.x == &point.choice.x_only);
        point.present = Vanetza_Security_EccP256CurvePoint_PR_x_only;
        return true;
    } else if (point.present == Vanetza_Security_EccP256CurvePoint_PR_x_only) {
        return true;
    } else {
        return false;
    }
}

bool make_x_only(Vanetza_Security_EccP384CurvePoint& point)
{
    if (point.present == Vanetza_Security_EccP384CurvePoint_PR_uncompressedP384) {
        auto& unc = point.choice.uncompressedP384;
        asn1::reset(&unc.y);
        std::free(unc._asn_ctx.ptr);
        unc._asn_ctx.ptr = nullptr;
        assert(&unc.x == &point.choice.x_only);
        point.present = Vanetza_Security_EccP384CurvePoint_PR_x_only;
        return true;
    } else if (point.present == Vanetza_Security_EccP384CurvePoint_PR_x_only) {
        return true;
    } else {
        return false;
    }
}

bool make_signature_x_only(Vanetza_Security_Signature& sig)
{
    switch (sig.present) {
        case Vanetza_Security_Signature_PR_ecdsaNistP256Signature:
            return make_x_only(sig.choice.ecdsaNistP256Signature.rSig);
            break;
        case Vanetza_Security_Signature_PR_ecdsaBrainpoolP256r1Signature:
            return make_x_only(sig.choice.ecdsaBrainpoolP256r1Signature.rSig);
            break;
        case Vanetza_Security_Signature_PR_ecdsaBrainpoolP384r1Signature:
            return make_x_only(sig.choice.ecdsaBrainpoolP384r1Signature.rSig);
            break;
        default:
            return false;
            break;
    }
}

} // namespace

} // namespace v3
} // namespace security
} // namespace vanetza