#include <chrono>

#include <openssl/ec.h>
#include <openssl/ecdsa.h>

#include "security_services.hh"

#include "EtsiTs103097Codec_ToBeSignedData.hh"
#include "EtsiTs103097Codec_Data.hh"

#include "sha256.hh"
#include "sha384.hh"
#include "ec_keys.hh"

#include "Params.hh"

#include "loggers.hh"

#include "converter.hh"

security_services * security_services::instance = NULL;

security_services::security_services() : _ec_keys(nullptr), _security_db(nullptr) {
  loggers::get_instance().log(">>> security_services::security_services");
} // End of ctor

int security_services::setup(Params& p_params) {
  loggers::get_instance().log("security_services::setup");
  p_params.log();

  _security_db.reset(new security_db(p_params[Params::sec_db_path]));
  if (_security_db.get() == nullptr) { // Memory allocation issue
    return -1;
  }
  
  return 0;
}

int security_services::verify_and_extract_gn_payload(const OCTETSTRING& p_secured_gn_payload, const bool p_verify, OCTETSTRING& p_unsecured_gn_payload, Params& p_params) {
  loggers::get_instance().log_msg(">>> security_services::verify_and_extract_gn_payload: ", p_secured_gn_payload);

  // Sanity checks
  if (p_secured_gn_payload.lengthof() == 0) {
    return -1;
  }
  
  // Decode the secured message (OER encoding)
  IEEE1609dot2::Ieee1609Dot2Data ieee_1609dot2_data;
  EtsiTs103097Codec_Data codec;
  codec.decode(p_secured_gn_payload, ieee_1609dot2_data, &p_params);

  if (!ieee_1609dot2_data.is_bound()) {
    return -1;
  }
  if (p_verify && ((unsigned int)(int)ieee_1609dot2_data.protocolVersion() != security_services::ProtocolVersion)) {
    return -2;
  }

  return process_ieee_dot2_content(ieee_1609dot2_data.content(), p_verify, p_unsecured_gn_payload, p_params);
} // End of method verify_and_extract_gn_payload

int security_services::process_ieee_dot2_content(const IEEE1609dot2::Ieee1609Dot2Content& p_ieee_1609_dot2_content, const bool p_verify, OCTETSTRING& p_unsecured_payload, Params& p_params) {
  loggers::get_instance().log(">>> security_services::process_ieee_dot2_content");
  
  if (!p_ieee_1609_dot2_content.is_bound()) {
    loggers::get_instance().warning("security_services::process_ieee_dot2_content: Unbound value");
    return -1;
  }
  
  return -1;
} // End of method process_ieee_dot2_content

int security_services::secure_gn_payload(const OCTETSTRING& p_unsecured_gn_payload, const bool p_add_certificate, OCTETSTRING& p_secured_gn_payload, Params& p_params) {
  loggers::get_instance().log_msg(">>> security_services::process_ieee_dot2_content: ", p_unsecured_gn_payload);
  p_params.log();

  // Set unsecured data
  IEEE1609dot2::Ieee1609Dot2Content unsecured_data_content;
  unsecured_data_content.unsecuredData() = p_unsecured_gn_payload;
  IEEE1609dot2::Ieee1609Dot2Data unsecured_data(ProtocolVersion, unsecured_data_content);
  // Set hash algorithm
  IEEE1609dot2BaseTypes::HashAlgorithm hashId(IEEE1609dot2BaseTypes::HashAlgorithm::sha256);
  if (p_params[Params::hash].compare("SHA-384") == 0) {
    hashId = IEEE1609dot2BaseTypes::HashAlgorithm::sha384;
  }
  // Set SignedDataPayload
  IEEE1609dot2::SignedDataPayload payload;
  payload.data() = unsecured_data;
  payload.extDataHash().set_to_omit();
  IEEE1609dot2::HeaderInfo header_info;
  header_info.psid() = converter::get_instance().string_to_int(p_params[Params::its_aid]);
  unsigned long long ms = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now().time_since_epoch()).count() - 1072911600000L;  // TODO Add method such as its_tme() & its_time_mod() beacuse it is used also in LibItsCommon_externals
  header_info.generationTime() = ms;
  header_info.expiryTime().set_to_omit();
  header_info.generationLocation().set_to_omit();
  header_info.p2pcdLearningRequest().set_to_omit();
  header_info.missingCrlIdentifier().set_to_omit();
  header_info.encryptionKey().set_to_omit();
  header_info.inlineP2pcdRequest().set_to_omit();
  header_info.requestedCertificate().set_to_omit();

  IEEE1609dot2::ToBeSignedData tbs_data;
  tbs_data.payload() = payload;
  tbs_data.headerInfo() = header_info;
  loggers::get_instance().log_msg("security_services::process_ieee_dot2_content: tbs_data = ", tbs_data);
  // Sign the ToBeSignedData data structure
  IEEE1609dot2BaseTypes::Signature signature;
  if (sign_tbs_data(tbs_data, hashId, signature, p_params) != 0) {
    loggers::get_instance().warning("security_services::process_ieee_dot2_content: Failed to secure payload");
    return -1;
  }
  IEEE1609dot2::SignerIdentifier signer;
  if (!p_add_certificate) {
    OCTETSTRING digest;
    if (_security_db->get_hashed_id(p_params[Params::certificate], digest) != 0) {
      loggers::get_instance().warning("security_services::process_ieee_dot2_content: Failed to secure payload");
    return -1;
    }
    signer.digest() = digest;
  } else { // FIXME Add certifcate case
    OCTETSTRING cert;
    if (_security_db->get_certificate(p_params[Params::certificate], cert) != 0) {
      loggers::get_instance().warning("security_services::process_ieee_dot2_content: Failed to secure payload");
      return -1;
    }
    // FIXME Need to decode certifcate, shall be done once is security_db
  }
  IEEE1609dot2::SignedData signed_data(
                                       hashId,
                                       tbs_data,
                                       signer,
                                       signature
                                       );
  loggers::get_instance().log_msg("security_services::process_ieee_dot2_content: signed_data = ", signed_data);
  IEEE1609dot2::Ieee1609Dot2Content ieee_dot2_content;
  ieee_dot2_content.signedData() = signed_data;
  IEEE1609dot2::Ieee1609Dot2Data ieee_1609dot2_data(
                                                    security_services::ProtocolVersion,
                                                    ieee_dot2_content
                                                    );
  loggers::get_instance().log_msg("security_services::process_ieee_dot2_content: ieee_1609dot2_data = ", ieee_1609dot2_data);
  EtsiTs103097Codec_Data codec;
  codec.encode(ieee_1609dot2_data, p_secured_gn_payload);
  if (!p_secured_gn_payload.is_bound()) {
    loggers::get_instance().warning("security_services::process_ieee_dot2_content: Failed to encode Ieee1609Dot2Data");
    return -1;
  }
  
  return 0;
}

int security_services::sign_tbs_data(const IEEE1609dot2::ToBeSignedData& p_tbs_data, const IEEE1609dot2BaseTypes::HashAlgorithm& p_hashAlgorithm, IEEE1609dot2BaseTypes::Signature& p_signature, Params& p_params) {
  loggers::get_instance().log_msg(">>> security_services::sign_tbs_data: ", p_tbs_data);
  
  // Encode the ToBeSignedData
  EtsiTs103097Codec_ToBeSignedData tbs_data_codec;
  OCTETSTRING os;
  tbs_data_codec.encode(p_tbs_data, os);
  if (os.lengthof() == 0) {
    loggers::get_instance().warning("security_services::sign_tbs_data: Failed to encode ToBeSignedData");
    return -1;
  }
  loggers::get_instance().log_msg("security_services::sign_tbs_data: encoded tbs_data = ", os);
  // Hash ToBeSignedData
  OCTETSTRING hashed_data;
  int result = -1;
  if (p_hashAlgorithm == IEEE1609dot2BaseTypes::HashAlgorithm::sha256) {
    result = hash_sha256(os, hashed_data);
  } else {
    result = hash_sha384(os, hashed_data);
  }
  loggers::get_instance().log_msg("security_services::sign_tbs_data: encoded hashed_data = ", hashed_data);
  if (result != 0) {
    loggers::get_instance().warning("security_services::sign_tbs_data: Failed to create hash");
    return -1;
  }
  // Sign ToBeSignedData
  result = -1;
  loggers::get_instance().log("security_services::sign_tbs_data: encoded Params::signature = '%s'", p_params[Params::signature].c_str());
  loggers::get_instance().log("security_services::sign_tbs_data: encoded Params::certificate = '%s'", p_params[Params::certificate].c_str());
  if (p_params[Params::signature].compare("NISTP-256") == 0) {
    result = sign_ecdsa_nistp256(hashed_data, p_signature, p_params);
  } // FIXME To be continued
  if (result != 0) {
    loggers::get_instance().warning("security_services::sign_tbs_data: Failed to sign payload");
    return -1;
  }
  
  return 0;
}

int security_services::hash_sha256(const OCTETSTRING& p_data, OCTETSTRING& p_hash_data) {
  loggers::get_instance().log_msg(">>> security_services::hash_sha256: ", p_data);
  
  sha256 hash;
  std::vector<unsigned char> tbh(static_cast<const unsigned char *>(p_data), p_data.lengthof() + static_cast<const unsigned char *>(p_data));
  std::vector<unsigned char> hashData;
  hash.generate(tbh, hashData);
  p_hash_data = OCTETSTRING(hashData.size(), hashData.data());

  return 0;
}

int security_services::hash_sha384(const OCTETSTRING& p_data, OCTETSTRING& p_hash_data) {
  loggers::get_instance().log_msg(">>> security_services::hash_sha384: ", p_data);
  
  sha384 hash;
  std::vector<unsigned char> tbh(static_cast<const unsigned char *>(p_data), p_data.lengthof() + static_cast<const unsigned char *>(p_data));
  std::vector<unsigned char> hashData;
  hash.generate(tbh, hashData);
  p_hash_data = OCTETSTRING(hashData.size(), hashData.data());
  
  return 0;
}

int security_services::sign_ecdsa_nistp256(const OCTETSTRING& p_hash, IEEE1609dot2BaseTypes::Signature& p_signature, Params& p_params) {
  loggers::get_instance().log_msg(">>> security_services::sign_ecdsa_nistp256: ", p_hash);
  
  OCTETSTRING pkey;
  if (_security_db->get_private_key(p_params[Params::certificate], pkey) != 0) {
    loggers::get_instance().warning("security_services::sign_ecdsa_nistp256: Failed to get private key");
    return -1;
  }
  std::vector<unsigned char> private_key(static_cast<const unsigned char *>(pkey), static_cast<const unsigned char *>(pkey) + pkey.lengthof());
  OCTETSTRING public_key_x;
  OCTETSTRING public_key_y;
  if (_security_db->get_public_keys(p_params[Params::certificate], public_key_x, public_key_y) != 0) {
    loggers::get_instance().warning("security_services::sign_ecdsa_nistp256: Failed to get public keys");
    return -1;
  }
  
  std::vector<unsigned char> hashed_data(static_cast<const unsigned char *>(p_hash), static_cast<const unsigned char *>(p_hash) + p_hash.lengthof());
  ec_keys k(ec_elliptic_curves::nist_p_256, private_key);
  std::vector<unsigned char> r_sig;
  std::vector<unsigned char> s_sig;
  if (k.sign(hashed_data, r_sig, s_sig) != 0) {
    loggers::get_instance().warning("security_services::sign_ecdsa_nistp256: Failed to sign payload");
    return -1;
  }
  IEEE1609dot2BaseTypes::EccP256CurvePoint ep;
  ep.uncompressedP256() = IEEE1609dot2BaseTypes::EccP256CurvePoint_uncompressedP256(
                                                                                    public_key_x,
                                                                                    public_key_y
                                                                                    );
  p_signature.ecdsaNistP256Signature() = IEEE1609dot2BaseTypes::EcdsaP256Signature(
                                                                                   ep,
                                                                                   OCTETSTRING(r_sig.size(), r_sig.data()) + OCTETSTRING(s_sig.size(), s_sig.data())
                                                                                   );
  loggers::get_instance().log_msg("security_services::sign_ecdsa_nistp256: signature = ", p_signature);
  
  return 0;
}