use deno_core::error::AnyError;
use deno_core::op;
use deno_core::OpState;
use deno_core::ZeroCopyBuf;
use elliptic_curve::pkcs8::der::Decodable as Pkcs8Decodable;
use elliptic_curve::pkcs8::PrivateKeyInfo;
use ring::signature::EcdsaKeyPair;
use rsa::pkcs1::UIntBytes;
use rsa::pkcs8::AlgorithmIdentifier;
use serde::Deserialize;
use serde::Serialize;
use spki::der::Encodable;

use crate::ec_key::ECPrivateKey;
use crate::key::CryptoNamedCurve;
use crate::shared::*;
use crate::OaepPrivateKeyParameters;
use crate::PssPrivateKeyParameters;

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub enum KeyData {
  Spki(ZeroCopyBuf),
  Pkcs8(ZeroCopyBuf),
  Raw(ZeroCopyBuf),
  JwkSecret {
    k: String,
  },
  JwkPublicRsa {
    n: String,
    e: String,
  },
  JwkPrivateRsa {
    n: String,
    e: String,
    d: String,
    p: String,
    q: String,
    dp: String,
    dq: String,
    qi: String,
  },
  JwkPublicEc {
    x: String,
    y: String,
  },
  JwkPrivateEc {
    x: String,
    y: String,
    d: String,
  },
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase", tag = "algorithm")]
pub enum ImportKeyOptions {
  #[serde(rename = "RSASSA-PKCS1-v1_5")]
  RsassaPkcs1v15 { hash: ShaHash },
  #[serde(rename = "RSA-PSS")]
  RsaPss { hash: ShaHash },
  #[serde(rename = "RSA-OAEP")]
  RsaOaep { hash: ShaHash },
  #[serde(rename = "ECDSA", rename_all = "camelCase")]
  Ecdsa { named_curve: EcNamedCurve },
  #[serde(rename = "ECDH", rename_all = "camelCase")]
  Ecdh { named_curve: EcNamedCurve },
  #[serde(rename = "AES", rename_all = "camelCase")]
  Aes {},
  #[serde(rename = "HMAC", rename_all = "camelCase")]
  Hmac {},
}

#[derive(Serialize)]
#[serde(untagged)]
pub enum ImportKeyResult {
  #[serde(rename_all = "camelCase")]
  Rsa {
    raw_data: RawKeyData,
    modulus_length: usize,
    public_exponent: ZeroCopyBuf,
  },
  #[serde(rename_all = "camelCase")]
  Ec { raw_data: RawKeyData },
  #[serde(rename_all = "camelCase")]
  #[allow(dead_code)]
  Aes { raw_data: RawKeyData },
  #[serde(rename_all = "camelCase")]
  Hmac { raw_data: RawKeyData },
}

#[op]
pub fn op_crypto_import_key(
  _state: &mut OpState,
  opts: ImportKeyOptions,
  key_data: KeyData,
) -> Result<ImportKeyResult, AnyError> {
  match opts {
    ImportKeyOptions::RsassaPkcs1v15 { hash } => {
      import_key_rsassa(key_data, hash)
    }
    ImportKeyOptions::RsaPss { hash } => import_key_rsapss(key_data, hash),
    ImportKeyOptions::RsaOaep { hash } => import_key_rsaoaep(key_data, hash),
    ImportKeyOptions::Ecdsa { named_curve }
    | ImportKeyOptions::Ecdh { named_curve } => {
      import_key_ec(key_data, named_curve)
    }
    ImportKeyOptions::Aes {} => import_key_aes(key_data),
    ImportKeyOptions::Hmac {} => import_key_hmac(key_data),
  }
}

const URL_SAFE_FORGIVING: base64::Config =
  base64::URL_SAFE_NO_PAD.decode_allow_trailing_bits(true);

macro_rules! jwt_b64_int_or_err {
  ($name:ident, $b64:expr, $err:expr) => {
    let bytes = base64::decode_config($b64, URL_SAFE_FORGIVING)
      .map_err(|_| data_error($err))?;
    let $name = UIntBytes::new(&bytes).map_err(|_| data_error($err))?;
  };
}

fn import_key_rsa_jwk(
  key_data: KeyData,
) -> Result<ImportKeyResult, deno_core::anyhow::Error> {
  match key_data {
    KeyData::JwkPublicRsa { n, e } => {
      jwt_b64_int_or_err!(modulus, &n, "invalid modulus");
      jwt_b64_int_or_err!(public_exponent, &e, "invalid public exponent");

      let public_key = rsa::pkcs1::RsaPublicKey {
        modulus,
        public_exponent,
      };

      let data = public_key
        .to_vec()
        .map_err(|_| data_error("invalid rsa public key"))?;
      let public_exponent =
        public_key.public_exponent.as_bytes().to_vec().into();
      let modulus_length = public_key.modulus.as_bytes().len() * 8;

      Ok(ImportKeyResult::Rsa {
        raw_data: RawKeyData::Public(data.into()),
        modulus_length,
        public_exponent,
      })
    }
    KeyData::JwkPrivateRsa {
      n,
      e,
      d,
      p,
      q,
      dp,
      dq,
      qi,
    } => {
      jwt_b64_int_or_err!(modulus, &n, "invalid modulus");
      jwt_b64_int_or_err!(public_exponent, &e, "invalid public exponent");
      jwt_b64_int_or_err!(private_exponent, &d, "invalid private exponent");
      jwt_b64_int_or_err!(prime1, &p, "invalid first prime factor");
      jwt_b64_int_or_err!(prime2, &q, "invalid second prime factor");
      jwt_b64_int_or_err!(exponent1, &dp, "invalid first CRT exponent");
      jwt_b64_int_or_err!(exponent2, &dq, "invalid second CRT exponent");
      jwt_b64_int_or_err!(coefficient, &qi, "invalid CRT coefficient");

      let private_key = rsa::pkcs1::RsaPrivateKey {
        version: rsa::pkcs1::Version::TwoPrime,
        modulus,
        public_exponent,
        private_exponent,
        prime1,
        prime2,
        exponent1,
        exponent2,
        coefficient,
      };

      let data = private_key
        .to_vec()
        .map_err(|_| data_error("invalid rsa private key"))?;

      let public_exponent =
        private_key.public_exponent.as_bytes().to_vec().into();
      let modulus_length = private_key.modulus.as_bytes().len() * 8;

      Ok(ImportKeyResult::Rsa {
        raw_data: RawKeyData::Private(data.into()),
        modulus_length,
        public_exponent,
      })
    }
    _ => unreachable!(),
  }
}

fn validate_mask_gen(
  mask_gen_algorithm: &AlgorithmIdentifier,
  hash_algorithm: &AlgorithmIdentifier,
) -> Result<(), deno_core::anyhow::Error> {
  if mask_gen_algorithm.oid != ID_MFG1 {
    return Err(not_supported_error("unsupported mask gen algorithm"));
  }

  let parameters = mask_gen_algorithm
    .parameters_any()
    .map_err(|_| not_supported_error("unsupported parameters"))?;
  let mgf1_hash_identifier = AlgorithmIdentifier::try_from(parameters)
    .map_err(|_| not_supported_error("unsupported parameters"))?;

  // The hash function on which MGF1 is based.
  mgf1_hash_identifier
    .assert_algorithm_oid(hash_algorithm.oid)
    .map_err(|_| not_supported_error("unsupported parameters"))?;

  Ok(())
}

fn import_key_rsassa(
  key_data: KeyData,
  hash: ShaHash,
) -> Result<ImportKeyResult, deno_core::anyhow::Error> {
  match key_data {
    KeyData::Spki(data) => {
      // 2-3.
      let pk_info = spki::SubjectPublicKeyInfo::from_der(&data)
        .map_err(|e| data_error(e.to_string()))?;

      // 4-5.
      let alg = pk_info.algorithm.oid;

      // 6.
      let pk_hash = match alg {
        // rsaEncryption
        RSA_ENCRYPTION_OID => None,
        // sha1WithRSAEncryption
        SHA1_RSA_ENCRYPTION_OID => Some(ShaHash::Sha1),
        // sha256WithRSAEncryption
        SHA256_RSA_ENCRYPTION_OID => Some(ShaHash::Sha256),
        // sha384WithRSAEncryption
        SHA384_RSA_ENCRYPTION_OID => Some(ShaHash::Sha384),
        // sha512WithRSAEncryption
        SHA512_RSA_ENCRYPTION_OID => Some(ShaHash::Sha512),
        _ => return Err(data_error("unsupported algorithm")),
      };

      // 7.
      if let Some(pk_hash) = pk_hash {
        if pk_hash != hash {
          return Err(data_error("hash mismatch"));
        }
      }

      // 8-9.
      let public_key =
        rsa::pkcs1::RsaPublicKey::from_der(pk_info.subject_public_key)
          .map_err(|e| data_error(e.to_string()))?;

      let bytes_consumed = public_key
        .encoded_len()
        .map_err(|e| data_error(e.to_string()))?;

      if bytes_consumed
        != spki::der::Length::new(pk_info.subject_public_key.len() as u16)
      {
        return Err(data_error("public key is invalid (too long)"));
      }

      let data = pk_info.subject_public_key.to_vec().into();
      let public_exponent =
        public_key.public_exponent.as_bytes().to_vec().into();
      let modulus_length = public_key.modulus.as_bytes().len() * 8;

      Ok(ImportKeyResult::Rsa {
        raw_data: RawKeyData::Public(data),
        modulus_length,
        public_exponent,
      })
    }
    KeyData::Pkcs8(data) => {
      // 2-3.
      let pk_info = PrivateKeyInfo::from_der(&data)
        .map_err(|e| data_error(e.to_string()))?;

      // 4-5.
      let alg = pk_info.algorithm.oid;

      // 6.
      let pk_hash = match alg {
        // rsaEncryption
        RSA_ENCRYPTION_OID => None,
        // sha1WithRSAEncryption
        SHA1_RSA_ENCRYPTION_OID => Some(ShaHash::Sha1),
        // sha256WithRSAEncryption
        SHA256_RSA_ENCRYPTION_OID => Some(ShaHash::Sha256),
        // sha384WithRSAEncryption
        SHA384_RSA_ENCRYPTION_OID => Some(ShaHash::Sha384),
        // sha512WithRSAEncryption
        SHA512_RSA_ENCRYPTION_OID => Some(ShaHash::Sha512),
        _ => return Err(data_error("unsupported algorithm")),
      };

      // 7.
      if let Some(pk_hash) = pk_hash {
        if pk_hash != hash {
          return Err(data_error("hash mismatch"));
        }
      }

      // 8-9.
      let private_key =
        rsa::pkcs1::RsaPrivateKey::from_der(pk_info.private_key)
          .map_err(|e| data_error(e.to_string()))?;

      let bytes_consumed = private_key
        .encoded_len()
        .map_err(|e| data_error(e.to_string()))?;

      if bytes_consumed
        != spki::der::Length::new(pk_info.private_key.len() as u16)
      {
        return Err(data_error("private key is invalid (too long)"));
      }

      let data = pk_info.private_key.to_vec().into();
      let public_exponent =
        private_key.public_exponent.as_bytes().to_vec().into();
      let modulus_length = private_key.modulus.as_bytes().len() * 8;

      Ok(ImportKeyResult::Rsa {
        raw_data: RawKeyData::Private(data),
        modulus_length,
        public_exponent,
      })
    }
    KeyData::JwkPublicRsa { .. } | KeyData::JwkPrivateRsa { .. } => {
      import_key_rsa_jwk(key_data)
    }
    _ => Err(unsupported_format()),
  }
}

fn import_key_rsapss(
  key_data: KeyData,
  hash: ShaHash,
) -> Result<ImportKeyResult, deno_core::anyhow::Error> {
  match key_data {
    KeyData::Spki(data) => {
      // 2-3.
      let pk_info = spki::SubjectPublicKeyInfo::from_der(&data)
        .map_err(|e| data_error(e.to_string()))?;

      // 4-5.
      let alg = pk_info.algorithm.oid;

      // 6.
      let pk_hash = match alg {
        // rsaEncryption
        RSA_ENCRYPTION_OID => None,
        // id-RSASSA-PSS
        RSASSA_PSS_OID => {
          let params = PssPrivateKeyParameters::try_from(
            pk_info
              .algorithm
              .parameters
              .ok_or_else(|| data_error("malformed parameters"))?,
          )
          .map_err(|_| data_error("malformed parameters"))?;

          let hash_alg = params.hash_algorithm;
          let hash = match hash_alg.oid {
            // id-sha1
            ID_SHA1_OID => Some(ShaHash::Sha1),
            // id-sha256
            ID_SHA256_OID => Some(ShaHash::Sha256),
            // id-sha384
            ID_SHA384_OID => Some(ShaHash::Sha384),
            // id-sha256
            ID_SHA512_OID => Some(ShaHash::Sha512),
            _ => return Err(data_error("unsupported hash algorithm")),
          };

          if params.mask_gen_algorithm.oid != ID_MFG1 {
            return Err(not_supported_error("unsupported hash algorithm"));
          }

          validate_mask_gen(&params.mask_gen_algorithm, &hash_alg)?;
          hash
        }
        _ => return Err(data_error("unsupported algorithm")),
      };

      // 7.
      if let Some(pk_hash) = pk_hash {
        if pk_hash != hash {
          return Err(data_error("hash mismatch"));
        }
      }

      // 8-9.
      let public_key =
        rsa::pkcs1::RsaPublicKey::from_der(pk_info.subject_public_key)
          .map_err(|e| data_error(e.to_string()))?;

      let bytes_consumed = public_key
        .encoded_len()
        .map_err(|e| data_error(e.to_string()))?;

      if bytes_consumed
        != spki::der::Length::new(pk_info.subject_public_key.len() as u16)
      {
        return Err(data_error("public key is invalid (too long)"));
      }

      let data = pk_info.subject_public_key.to_vec().into();
      let public_exponent =
        public_key.public_exponent.as_bytes().to_vec().into();
      let modulus_length = public_key.modulus.as_bytes().len() * 8;

      Ok(ImportKeyResult::Rsa {
        raw_data: RawKeyData::Public(data),
        modulus_length,
        public_exponent,
      })
    }
    KeyData::Pkcs8(data) => {
      // 2-3.
      let pk_info = PrivateKeyInfo::from_der(&data)
        .map_err(|e| data_error(e.to_string()))?;

      // 4-5.
      let alg = pk_info.algorithm.oid;

      // 6.
      // 6.
      let pk_hash = match alg {
        // rsaEncryption
        RSA_ENCRYPTION_OID => None,
        // id-RSASSA-PSS
        RSASSA_PSS_OID => {
          let params = PssPrivateKeyParameters::try_from(
            pk_info
              .algorithm
              .parameters
              .ok_or_else(|| not_supported_error("malformed parameters"))?,
          )
          .map_err(|_| not_supported_error("malformed parameters"))?;

          let hash_alg = params.hash_algorithm;
          let hash = match hash_alg.oid {
            // id-sha1
            ID_SHA1_OID => Some(ShaHash::Sha1),
            // id-sha256
            ID_SHA256_OID => Some(ShaHash::Sha256),
            // id-sha384
            ID_SHA384_OID => Some(ShaHash::Sha384),
            // id-sha256
            ID_SHA512_OID => Some(ShaHash::Sha512),
            _ => return Err(data_error("unsupported hash algorithm")),
          };

          validate_mask_gen(&params.mask_gen_algorithm, &hash_alg)?;
          hash
        }
        _ => return Err(data_error("unsupported algorithm")),
      };

      // 7.
      if let Some(pk_hash) = pk_hash {
        if pk_hash != hash {
          return Err(data_error("hash mismatch"));
        }
      }

      // 8-9.
      let private_key =
        rsa::pkcs1::RsaPrivateKey::from_der(pk_info.private_key)
          .map_err(|e| data_error(e.to_string()))?;

      let bytes_consumed = private_key
        .encoded_len()
        .map_err(|e| data_error(e.to_string()))?;

      if bytes_consumed
        != spki::der::Length::new(pk_info.private_key.len() as u16)
      {
        return Err(data_error("private key is invalid (too long)"));
      }

      let data = pk_info.private_key.to_vec().into();
      let public_exponent =
        private_key.public_exponent.as_bytes().to_vec().into();
      let modulus_length = private_key.modulus.as_bytes().len() * 8;

      Ok(ImportKeyResult::Rsa {
        raw_data: RawKeyData::Private(data),
        modulus_length,
        public_exponent,
      })
    }
    KeyData::JwkPublicRsa { .. } | KeyData::JwkPrivateRsa { .. } => {
      import_key_rsa_jwk(key_data)
    }
    _ => Err(unsupported_format()),
  }
}

fn import_key_rsaoaep(
  key_data: KeyData,
  hash: ShaHash,
) -> Result<ImportKeyResult, deno_core::anyhow::Error> {
  match key_data {
    KeyData::Spki(data) => {
      // 2-3.
      let pk_info = spki::SubjectPublicKeyInfo::from_der(&data)
        .map_err(|e| data_error(e.to_string()))?;

      // 4-5.
      let alg = pk_info.algorithm.oid;

      // 6.
      let pk_hash = match alg {
        // rsaEncryption
        RSA_ENCRYPTION_OID => None,
        // id-RSAES-OAEP
        RSAES_OAEP_OID => {
          let params = OaepPrivateKeyParameters::try_from(
            pk_info
              .algorithm
              .parameters
              .ok_or_else(|| data_error("malformed parameters"))?,
          )
          .map_err(|_| data_error("malformed parameters"))?;

          let hash_alg = params.hash_algorithm;
          let hash = match hash_alg.oid {
            // id-sha1
            ID_SHA1_OID => Some(ShaHash::Sha1),
            // id-sha256
            ID_SHA256_OID => Some(ShaHash::Sha256),
            // id-sha384
            ID_SHA384_OID => Some(ShaHash::Sha384),
            // id-sha256
            ID_SHA512_OID => Some(ShaHash::Sha512),
            _ => return Err(data_error("unsupported hash algorithm")),
          };

          validate_mask_gen(&params.mask_gen_algorithm, &hash_alg)?;
          hash
        }
        _ => return Err(data_error("unsupported algorithm")),
      };

      // 7.
      if let Some(pk_hash) = pk_hash {
        if pk_hash != hash {
          return Err(data_error("hash mismatch"));
        }
      }

      // 8-9.
      let public_key =
        rsa::pkcs1::RsaPublicKey::from_der(pk_info.subject_public_key)
          .map_err(|e| data_error(e.to_string()))?;

      let bytes_consumed = public_key
        .encoded_len()
        .map_err(|e| data_error(e.to_string()))?;

      if bytes_consumed
        != spki::der::Length::new(pk_info.subject_public_key.len() as u16)
      {
        return Err(data_error("public key is invalid (too long)"));
      }

      let data = pk_info.subject_public_key.to_vec().into();
      let public_exponent =
        public_key.public_exponent.as_bytes().to_vec().into();
      let modulus_length = public_key.modulus.as_bytes().len() * 8;

      Ok(ImportKeyResult::Rsa {
        raw_data: RawKeyData::Public(data),
        modulus_length,
        public_exponent,
      })
    }
    KeyData::Pkcs8(data) => {
      // 2-3.
      let pk_info = PrivateKeyInfo::from_der(&data)
        .map_err(|e| data_error(e.to_string()))?;

      // 4-5.
      let alg = pk_info.algorithm.oid;

      // 6.
      // 6.
      let pk_hash = match alg {
        // rsaEncryption
        RSA_ENCRYPTION_OID => None,
        // id-RSAES-OAEP
        RSAES_OAEP_OID => {
          let params = OaepPrivateKeyParameters::try_from(
            pk_info
              .algorithm
              .parameters
              .ok_or_else(|| not_supported_error("malformed parameters"))?,
          )
          .map_err(|_| not_supported_error("malformed parameters"))?;

          let hash_alg = params.hash_algorithm;
          let hash = match hash_alg.oid {
            // id-sha1
            ID_SHA1_OID => Some(ShaHash::Sha1),
            // id-sha256
            ID_SHA256_OID => Some(ShaHash::Sha256),
            // id-sha384
            ID_SHA384_OID => Some(ShaHash::Sha384),
            // id-sha256
            ID_SHA512_OID => Some(ShaHash::Sha512),
            _ => return Err(data_error("unsupported hash algorithm")),
          };
          validate_mask_gen(&params.mask_gen_algorithm, &hash_alg)?;
          hash
        }
        _ => return Err(data_error("unsupported algorithm")),
      };

      // 7.
      if let Some(pk_hash) = pk_hash {
        if pk_hash != hash {
          return Err(data_error("hash mismatch"));
        }
      }

      // 8-9.
      let private_key =
        rsa::pkcs1::RsaPrivateKey::from_der(pk_info.private_key)
          .map_err(|e| data_error(e.to_string()))?;

      let bytes_consumed = private_key
        .encoded_len()
        .map_err(|e| data_error(e.to_string()))?;

      if bytes_consumed
        != spki::der::Length::new(pk_info.private_key.len() as u16)
      {
        return Err(data_error("private key is invalid (too long)"));
      }

      let data = pk_info.private_key.to_vec().into();
      let public_exponent =
        private_key.public_exponent.as_bytes().to_vec().into();
      let modulus_length = private_key.modulus.as_bytes().len() * 8;

      Ok(ImportKeyResult::Rsa {
        raw_data: RawKeyData::Private(data),
        modulus_length,
        public_exponent,
      })
    }
    KeyData::JwkPublicRsa { .. } | KeyData::JwkPrivateRsa { .. } => {
      import_key_rsa_jwk(key_data)
    }
    _ => Err(unsupported_format()),
  }
}

fn decode_b64url_to_field_bytes<C: elliptic_curve::Curve>(
  b64: &str,
) -> Result<elliptic_curve::FieldBytes<C>, deno_core::anyhow::Error> {
  jwt_b64_int_or_err!(val, b64, "invalid b64 coordinate");

  let mut bytes = elliptic_curve::FieldBytes::<C>::default();
  let val = val.as_bytes();
  if val.len() != bytes.len() {
    return Err(data_error("invalid b64 coordinate"));
  }
  bytes.copy_from_slice(val);

  Ok(bytes)
}

fn import_key_ec_jwk_to_point(
  x: String,
  y: String,
  named_curve: EcNamedCurve,
) -> Result<Vec<u8>, deno_core::anyhow::Error> {
  let point_bytes = match named_curve {
    EcNamedCurve::P256 => {
      let x = decode_b64url_to_field_bytes::<p256::NistP256>(&x)?;
      let y = decode_b64url_to_field_bytes::<p256::NistP256>(&y)?;

      p256::EncodedPoint::from_affine_coordinates(&x, &y, false).to_bytes()
    }
    EcNamedCurve::P384 => {
      let x = decode_b64url_to_field_bytes::<p384::NistP384>(&x)?;
      let y = decode_b64url_to_field_bytes::<p384::NistP384>(&y)?;

      p384::EncodedPoint::from_affine_coordinates(&x, &y, false).to_bytes()
    }
    _ => return Err(not_supported_error("Unsupported named curve")),
  };

  Ok(point_bytes.to_vec())
}

fn import_key_ec_jwk(
  key_data: KeyData,
  named_curve: EcNamedCurve,
) -> Result<ImportKeyResult, deno_core::anyhow::Error> {
  match key_data {
    KeyData::JwkPublicEc { x, y } => {
      let point_bytes = import_key_ec_jwk_to_point(x, y, named_curve)?;

      Ok(ImportKeyResult::Ec {
        raw_data: RawKeyData::Public(point_bytes.into()),
      })
    }
    KeyData::JwkPrivateEc { d, x, y } => {
      let point_bytes = import_key_ec_jwk_to_point(x, y, named_curve)?;

      jwt_b64_int_or_err!(private_d, &d, "invalid JWK private key");

      let pkcs8_der = match named_curve {
        EcNamedCurve::P256 => {
          let d = decode_b64url_to_field_bytes::<p256::NistP256>(&d)?;

          let pk =
            ECPrivateKey::<p256::NistP256>::from_private_and_public_bytes(
              d,
              &point_bytes,
            );

          pk.to_pkcs8_der()?
        }
        EcNamedCurve::P384 => {
          let d = decode_b64url_to_field_bytes::<p384::NistP384>(&d)?;

          let pk =
            ECPrivateKey::<p384::NistP384>::from_private_and_public_bytes(
              d,
              &point_bytes,
            );

          pk.to_pkcs8_der()?
        }
        EcNamedCurve::P521 => {
          return Err(data_error("Unsupported named curve"))
        }
      };

      // Import using ring, to validate key
      let key_alg = match named_curve {
        EcNamedCurve::P256 => CryptoNamedCurve::P256.try_into()?,
        EcNamedCurve::P384 => CryptoNamedCurve::P256.try_into()?,
        EcNamedCurve::P521 => {
          return Err(data_error("Unsupported named curve"))
        }
      };

      let _key_pair = EcdsaKeyPair::from_private_key_and_public_key(
        key_alg,
        private_d.as_bytes(),
        point_bytes.as_ref(),
      );

      Ok(ImportKeyResult::Ec {
        raw_data: RawKeyData::Private(pkcs8_der.as_ref().to_vec().into()),
      })
    }
    _ => unreachable!(),
  }
}

pub struct ECParametersSpki {
  pub named_curve_alg: spki::der::asn1::ObjectIdentifier,
}

impl<'a> TryFrom<spki::der::asn1::Any<'a>> for ECParametersSpki {
  type Error = spki::der::Error;

  fn try_from(
    any: spki::der::asn1::Any<'a>,
  ) -> spki::der::Result<ECParametersSpki> {
    let x = any.oid()?;

    Ok(Self { named_curve_alg: x })
  }
}

fn import_key_ec(
  key_data: KeyData,
  named_curve: EcNamedCurve,
) -> Result<ImportKeyResult, AnyError> {
  match key_data {
    KeyData::Raw(data) => {
      // The point is parsed and validated, ultimately the original data is
      // returned though.
      match named_curve {
        EcNamedCurve::P256 => {
          // 1-2.
          let point = p256::EncodedPoint::from_bytes(&data)
            .map_err(|_| data_error("invalid P-256 eliptic curve point"))?;
          // 3.
          if point.is_identity() {
            return Err(data_error("invalid P-256 eliptic curve point"));
          }
        }
        EcNamedCurve::P384 => {
          // 1-2.
          let point = p384::EncodedPoint::from_bytes(&data)
            .map_err(|_| data_error("invalid P-384 eliptic curve point"))?;
          // 3.
          if point.is_identity() {
            return Err(data_error("invalid P-384 eliptic curve point"));
          }
        }
        _ => return Err(not_supported_error("Unsupported named curve")),
      };
      Ok(ImportKeyResult::Ec {
        raw_data: RawKeyData::Public(data),
      })
    }
    KeyData::Pkcs8(data) => {
      // 2-7
      // Deserialize PKCS8 - validate structure, extracts named_curve
      let named_curve_alg = match named_curve {
        EcNamedCurve::P256 => {
          let pk = ECPrivateKey::<p256::NistP256>::try_from(data.as_ref())?;

          pk.named_curve_oid().unwrap()
        }
        EcNamedCurve::P384 => {
          let pk = ECPrivateKey::<p384::NistP384>::try_from(data.as_ref())?;

          pk.named_curve_oid().unwrap()
        }
        EcNamedCurve::P521 => {
          return Err(data_error("Unsupported named curve"))
        }
      };

      // 8-9.
      let pk_named_curve = match named_curve_alg {
        // id-secp256r1
        ID_SECP256R1_OID => Some(EcNamedCurve::P256),
        // id-secp384r1
        ID_SECP384R1_OID => Some(EcNamedCurve::P384),
        // id-secp521r1
        ID_SECP521R1_OID => Some(EcNamedCurve::P521),
        _ => None,
      };

      // 10.
      if let Some(pk_named_curve) = pk_named_curve {
        let signing_alg = match pk_named_curve {
          EcNamedCurve::P256 => CryptoNamedCurve::P256.try_into()?,
          EcNamedCurve::P384 => CryptoNamedCurve::P384.try_into()?,
          EcNamedCurve::P521 => {
            return Err(data_error("Unsupported named curve"))
          }
        };

        // deserialize pkcs8 using ring crate, to VALIDATE public key
        let _private_key = EcdsaKeyPair::from_pkcs8(signing_alg, &data)?;

        // 11.
        if named_curve != pk_named_curve {
          return Err(data_error("curve mismatch"));
        }
      } else {
        return Err(data_error("Unsupported named curve"));
      }

      Ok(ImportKeyResult::Ec {
        raw_data: RawKeyData::Private(data),
      })
    }
    KeyData::Spki(data) => {
      // 2-3.
      let pk_info = spki::SubjectPublicKeyInfo::from_der(&data)
        .map_err(|e| data_error(e.to_string()))?;

      // 4.
      let alg = pk_info.algorithm.oid;
      // id-ecPublicKey
      if alg != elliptic_curve::ALGORITHM_OID {
        return Err(data_error("unsupported algorithm"));
      }

      // 5-7.
      let params = ECParametersSpki::try_from(
        pk_info
          .algorithm
          .parameters
          .ok_or_else(|| data_error("malformed parameters"))?,
      )
      .map_err(|_| data_error("malformed parameters"))?;

      // 8-9.
      let named_curve_alg = params.named_curve_alg;
      let pk_named_curve = match named_curve_alg {
        // id-secp256r1
        ID_SECP256R1_OID => Some(EcNamedCurve::P256),
        // id-secp384r1
        ID_SECP384R1_OID => Some(EcNamedCurve::P384),
        // id-secp521r1
        ID_SECP521R1_OID => Some(EcNamedCurve::P521),
        _ => None,
      };

      // 10.
      let encoded_key;

      if let Some(pk_named_curve) = pk_named_curve {
        let pk = pk_info.subject_public_key;

        encoded_key = pk.to_vec();

        let bytes_consumed = match named_curve {
          EcNamedCurve::P256 => {
            let point =
              p256::EncodedPoint::from_bytes(&*encoded_key).map_err(|_| {
                data_error("invalid P-256 eliptic curve SPKI data")
              })?;

            if point.is_identity() {
              return Err(data_error("invalid P-256 eliptic curve point"));
            }

            point.as_bytes().len()
          }
          EcNamedCurve::P384 => {
            let point =
              p384::EncodedPoint::from_bytes(&*encoded_key).map_err(|_| {
                data_error("invalid P-384 eliptic curve SPKI data")
              })?;

            if point.is_identity() {
              return Err(data_error("invalid P-384 eliptic curve point"));
            }

            point.as_bytes().len()
          }
          _ => return Err(not_supported_error("Unsupported named curve")),
        };

        if bytes_consumed != pk_info.subject_public_key.len() {
          return Err(data_error("public key is invalid (too long)"));
        }

        // 11.
        if named_curve != pk_named_curve {
          return Err(data_error("curve mismatch"));
        }
      } else {
        return Err(data_error("Unsupported named curve"));
      }

      Ok(ImportKeyResult::Ec {
        raw_data: RawKeyData::Public(encoded_key.to_vec().into()),
      })
    }
    KeyData::JwkPublicEc { .. } | KeyData::JwkPrivateEc { .. } => {
      import_key_ec_jwk(key_data, named_curve)
    }
    _ => Err(unsupported_format()),
  }
}

fn import_key_aes(key_data: KeyData) -> Result<ImportKeyResult, AnyError> {
  Ok(match key_data {
    KeyData::JwkSecret { k } => {
      let data = base64::decode_config(k, URL_SAFE_FORGIVING)
        .map_err(|_| data_error("invalid key data"))?;
      ImportKeyResult::Hmac {
        raw_data: RawKeyData::Secret(data.into()),
      }
    }
    _ => return Err(unsupported_format()),
  })
}

fn import_key_hmac(key_data: KeyData) -> Result<ImportKeyResult, AnyError> {
  Ok(match key_data {
    KeyData::JwkSecret { k } => {
      let data = base64::decode_config(k, URL_SAFE_FORGIVING)
        .map_err(|_| data_error("invalid key data"))?;
      ImportKeyResult::Hmac {
        raw_data: RawKeyData::Secret(data.into()),
      }
    }
    _ => return Err(unsupported_format()),
  })
}