import { sm2Curve } from './curve';
import { base58, base64url } from './encoding';
import {
  JsonWebKey2020,
  Sm2VerificationKey2019,
  Sm2VerificationKey2020,
} from './types';

import { getMultibaseFingerprintFromPublicKeyBytes } from './getMultibaseFingerprintFromPublicKeyBytes';

export const toJsonWebKey2020 = (
  id: string,
  controller: string,
  publicKey: Uint8Array,
  privateKey?: Uint8Array,
  _alg?: string
) => {
  const { px, py } = sm2Curve.ProjectivePoint.fromHex(publicKey);
  const publicKeyJwk = {
    kty: 'EC',
    crv: 'SM2',
    x: base64url.encode(Buffer.from(px.toString(16), 'hex')),
    y: base64url.encode(Buffer.from(py.toString(16), 'hex')),
  };
  const k: JsonWebKey2020 = {
    id: id,
    type: 'JsonWebKey2020',
    controller: controller,
    publicKeyJwk,
  };
  if (privateKey) {
    k.privateKeyJwk = {
      ...publicKeyJwk,
      d: base64url.encode(privateKey),
    };
  }
  return k;
};

export const toSm2VerificationKey2019 = (
  id: string,
  controller: string,
  publicKey: Uint8Array,
  privateKey?: Uint8Array
) => {
  const k: Sm2VerificationKey2019 = {
    id: id,
    type: 'Sm2VerificationKey2019',
    controller: controller,
    publicKeyBase58: base58.encode(publicKey),
  };
  if (privateKey) {
    k.privateKeyBase58 = base58.encode(privateKey);
  }
  return k;
};

export const toSm2VerificationKey2020 = (
  id: string,
  controller: string,
  publicKey: Uint8Array,
  privateKey?: Uint8Array
) => {
  const k: Sm2VerificationKey2020 = {
    id: id,
    type: 'Sm2VerificationKey2020',
    controller: controller,
    publicKeyMultibase: getMultibaseFingerprintFromPublicKeyBytes(publicKey),
  };
  if (privateKey) {
    throw new Error(
      'Unable to represent sm2 private key in multibase. See https://github.com/multiformats/multicodec/pull/210'
    );
  }
  return k;
};

export const exportableTypes = {
  JsonWebKey2020: toJsonWebKey2020,
  Sm2VerificationKey2020: toSm2VerificationKey2020,
  Sm2VerificationKey2019: toSm2VerificationKey2019,
};