#include <vanetza/security/exception.hpp>
#include <vanetza/security/v2/certificate.hpp>
#include <vanetza/security/v2/length_coding.hpp>
#include <vanetza/security/v2/signer_info.hpp>

namespace vanetza
{
namespace security
{
namespace v2
{

SignerInfoType get_type(const SignerInfo& info)
{
    struct SignerInfo_visitor : public boost::static_visitor<SignerInfoType>
    {
        SignerInfoType operator()(const std::nullptr_t)
        {
            return SignerInfoType::Self;
        }
        SignerInfoType operator()(const HashedId8&)
        {
            return SignerInfoType::Certificate_Digest_With_SHA256;
        }
        SignerInfoType operator()(const Certificate&)
        {
            return SignerInfoType::Certificate;
        }
        SignerInfoType operator()(const std::list<Certificate>&)
        {
            return SignerInfoType::Certificate_Chain;
        }
        SignerInfoType operator()(const CertificateDigestWithOtherAlgorithm&)
        {
            return SignerInfoType::Certificate_Digest_With_Other_Algorithm;
        }
    };

    SignerInfo_visitor visit;
    return boost::apply_visitor(visit, info);
}

size_t get_size(const CertificateDigestWithOtherAlgorithm& cert)
{
    size_t size = cert.digest.size();
    size += sizeof(cert.algorithm);
    return size;
}

size_t get_size(const SignerInfo& info)
{
    size_t size = sizeof(SignerInfoType);
    struct SignerInfo_visitor : public boost::static_visitor<size_t>
    {
        size_t operator()(const std::nullptr_t&)
        {
            return 0;
        }
        size_t operator()(const HashedId8& id)
        {
            return id.size();
        }
        size_t operator()(const Certificate& cert)
        {
            return get_size(cert);
        }
        size_t operator()(const std::list<Certificate>& list)
        {
            size_t size = get_size(list);
            size += length_coding_size(size);
            return size;
        }
        size_t operator()(const CertificateDigestWithOtherAlgorithm& cert)
        {
            return get_size(cert);
        }
    };

    SignerInfo_visitor visit;
    size += boost::apply_visitor(visit, info);
    return size;
}

void serialize(OutputArchive& ar, const CertificateDigestWithOtherAlgorithm& cert)
{
    serialize(ar, cert.algorithm);
    for (auto& byte : cert.digest) {
        ar << byte;
    }
}

void serialize(OutputArchive& ar, const SignerInfo& info)
{
    struct SignerInfo_visitor : public boost::static_visitor<>
    {
        SignerInfo_visitor(OutputArchive& ar) :
            m_archive(ar)
        {
        }

        void operator()(const std::nullptr_t)
        {
            // intentionally do nothing
        }

        void operator()(const HashedId8& id)
        {
            for (auto& byte : id) {
                m_archive << byte;
            }
        }

        void operator()(const Certificate& cert)
        {
            serialize(m_archive, cert);
        }

        void operator()(const std::list<Certificate>& list)
        {
            serialize(m_archive, list);
        }

        void operator()(const CertificateDigestWithOtherAlgorithm& cert)
        {
            serialize(m_archive, cert);
        }

        OutputArchive& m_archive;
    };
    SignerInfoType type = get_type(info);
    serialize(ar, type);
    SignerInfo_visitor visit(ar);
    boost::apply_visitor(visit, info);
}

size_t deserialize(InputArchive& ar, CertificateDigestWithOtherAlgorithm& cert)
{
    deserialize(ar, cert.algorithm);
    for (size_t c = 0; c < 8; c++) {
        ar >> cert.digest[c];
    }
    size_t size = cert.digest.size();
    size += sizeof(cert.algorithm);
    return size;
}

size_t deserialize(InputArchive& ar, SignerInfo& info)
{
    SignerInfoType type;
    size_t size = 0;
    deserialize(ar, type);
    size += sizeof(SignerInfoType);
    switch (type) {
        case SignerInfoType::Certificate: {
            Certificate cert;
            size += deserialize(ar, cert);
            info = cert;
            break;
        }
        case SignerInfoType::Certificate_Chain: {
            std::list<Certificate> list;
            size += deserialize(ar, list);
            size += length_coding_size(size);
            info = list;
            break;
        }
        case SignerInfoType::Certificate_Digest_With_SHA256: {
            HashedId8 cert;
            for (size_t c = 0; c < 8; c++) {
                ar >> cert[c];
            }
            info = cert;
            size += sizeof(cert);
            break;
        }
        case SignerInfoType::Certificate_Digest_With_Other_Algorithm: {
            CertificateDigestWithOtherAlgorithm cert;
            size += deserialize(ar, cert);
            info = cert;
            break;
        }
        case SignerInfoType::Self:
            info = nullptr;
            break;
        default:
            throw deserialization_error("Unknown SignerInfoType");
            break;
    }
    return size;
}

size_t deserialize_certificate_signer(InputArchive& ar, SignerInfo& info)
{
    SignerInfoType type;
    size_t size = 0;
    deserialize(ar, type);
    size += sizeof(SignerInfoType);
    switch (type) {
        case SignerInfoType::Certificate:
        case SignerInfoType::Certificate_Chain:
            // TS 103 097 v1.2.1 clause 6.1 forbids these signer info types for certificates
            throw deserialization_error("Illegal SignerInfo for Certificate");
            break;
        case SignerInfoType::Certificate_Digest_With_SHA256: {
            HashedId8 cert;
            for (size_t c = 0; c < 8; c++) {
                ar >> cert[c];
            }
            info = cert;
            size += sizeof(cert);
            break;
        }
        case SignerInfoType::Certificate_Digest_With_Other_Algorithm: {
            CertificateDigestWithOtherAlgorithm cert;
            size += deserialize(ar, cert);
            info = cert;
            break;
        }
        case SignerInfoType::Self:
            info = nullptr;
            break;
        default:
            throw deserialization_error("Unknown SignerInfoType");
            break;
    }
    return size;
}

} // ns v2
} // ns security
} // ns vanetza