import Aes256Gcm from "@app/components/utilities/cryptography/aes-256-gcm";
import { deriveArgonKey } from "@app/components/utilities/cryptography/crypto";

/**
 * @param {Object} obj
 * @param {Number} obj.encryptionVersion
 * @param {String} obj.encryptedPrivateKey
 * @param {String} obj.iv
 * @param {String} obj.tag
 * @param {String} obj.password
 * @param {String} obj.salt
 * @param {String} obj.protectedKey
 * @param {String} obj.protectedKeyIV
 * @param {String} obj.protectedKeyTag
 */
const decryptPrivateKeyHelper = async ({
  encryptionVersion,
  encryptedPrivateKey,
  iv,
  tag,
  password,
  salt,
  protectedKey,
  protectedKeyIV,
  protectedKeyTag
}: {
  encryptionVersion: number;
  encryptedPrivateKey: string;
  iv: string;
  tag: string;
  password: string;
  salt: string;
  protectedKey?: string;
  protectedKeyIV?: string;
  protectedKeyTag?: string;
}) => {
  let privateKey;
  try {
    if (encryptionVersion === 1) {
      privateKey = Aes256Gcm.decrypt({
        ciphertext: encryptedPrivateKey,
        iv,
        tag,
        secret: password
          .slice(0, 32)
          .padStart(32 + (password.slice(0, 32).length - new Blob([password]).size), "0")
      });
    } else if (encryptionVersion === 2 && protectedKey && protectedKeyIV && protectedKeyTag) {
      const derivedKey = await deriveArgonKey({
        password,
        salt,
        mem: 65536,
        time: 3,
        parallelism: 1,
        hashLen: 32
      });

      if (!derivedKey) throw new Error("Failed to generate derived key");

      const key = Aes256Gcm.decrypt({
        ciphertext: protectedKey,
        iv: protectedKeyIV,
        tag: protectedKeyTag,
        secret: Buffer.from(derivedKey.hash)
      });

      // decrypt back the private key
      privateKey = Aes256Gcm.decrypt({
        ciphertext: encryptedPrivateKey,
        iv,
        tag,
        secret: Buffer.from(key, "hex")
      });
    } else {
      throw new Error("Insufficient details to decrypt private key");
    }
  } catch {
    throw new Error("Failed to decrypt private key");
  }

  return privateKey;
};

export { decryptPrivateKeyHelper };