class JwtService
  SECRET_KEY = Rails.application.secret_key_base
  ALGORITHM = "HS256"
  EXPIRATION = 7.days

  def self.encode(payload)
    payload[:exp] = EXPIRATION.from_now.to_i if payload[:exp] == nil
    JWT.encode(payload, SECRET_KEY, ALGORITHM)
  end

  def self.decode(token)
    decoded = JWT.decode(token, SECRET_KEY, true, { algorithm: ALGORITHM }).first
    HashWithIndifferentAccess.new(decoded).slice(:user_id, :exp)
  rescue JWT::DecodeError, JWT::ExpiredSignature
    nil
  end
end