const { randomBytes, pbkdf2Sync } = require("crypto");
const argon2 = require("@node-rs/argon2");
/**
 * Password hash utils
 * using MocoBaas logic and flow
 */
const pwdHash = {
  hashPassword: (pwd) => {
    const salt = randomBytes(16).toString("hex");
    const hash = pbkdf2Sync(pwd, salt, 2048, 32, "sha512").toString("hex");

    return [salt, hash].join("$");
  },

  verifyPassword: (pwd, storedPwd) => {
    if (!storedPwd) return false;

    // if the hash started with $ sign, it's hash v2 (argon2id)
    // we need to remove base64 padding
    if (storedPwd.startsWith("$")) {
      // remove base64 padding from salt and hash
      // reference: https://github.com/P-H-C/phc-string-format/blob/master/phc-sf-spec.md
      const fields = storedPwd.split("$");
      fields[4] = fields[4].replace(/=+$/, "");
      fields[5] = fields[5].replace(/=+$/, "");
      storedPwd = fields.join("$");

      return argon2.verifySync(storedPwd, pwd);
    }

    const [salt, originalHash] = storedPwd.split("$");
    const hash = pbkdf2Sync(pwd, salt, 2048, 32, "sha512").toString("hex");

    return hash === originalHash;
  },
};

module.exports = pwdHash;