@type flow_data() :: %{
  optional(:after_completion) => flow_data_after_completion() | nil,
  optional(:subscription_cancel) => flow_data_subscription_cancel() | nil,
  optional(:subscription_update) => flow_data_subscription_update() | nil,
  optional(:subscription_update_confirm) =>
    flow_data_subscription_update_confirm() | nil,
  optional(:type) => String.t() | nil,
  optional(String.t()) => term()
}

@type flow_data_after_completion() :: %{
  optional(:hosted_confirmation) =>
    flow_data_after_completion_hosted_confirmation() | nil,
  optional(:redirect) => flow_data_after_completion_redirect() | nil,
  optional(:type) => String.t() | nil,
  optional(String.t()) => term()
}

@type flow_data_after_completion_hosted_confirmation() :: %{
  optional(:custom_message) => String.t() | nil,
  optional(String.t()) => term()
}

@type flow_data_after_completion_redirect() :: %{
  optional(:return_url) => String.t() | nil,
  optional(String.t()) => term()
}

@type flow_data_subscription_cancel() :: %{
  optional(:retention) => flow_data_subscription_cancel_retention() | nil,
  optional(:subscription) => String.t() | nil,
  optional(String.t()) => term()
}

@type flow_data_subscription_cancel_retention() :: %{
  optional(:coupon_offer) =>
    flow_data_subscription_cancel_retention_coupon_offer() | nil,
  optional(:type) => String.t() | nil,
  optional(String.t()) => term()
}

@type flow_data_subscription_cancel_retention_coupon_offer() :: %{
  optional(:coupon) => String.t() | nil,
  optional(String.t()) => term()
}

@type flow_data_subscription_update() :: %{
  optional(:subscription) => String.t() | nil,
  optional(String.t()) => term()
}

@type flow_data_subscription_update_confirm() :: %{
  optional(:discounts) =>
    [flow_data_subscription_update_confirm_discounts()] | nil,
  optional(:items) => [flow_data_subscription_update_confirm_items()] | nil,
  optional(:subscription) => String.t() | nil,
  optional(String.t()) => term()
}

@type flow_data_subscription_update_confirm_discounts() :: %{
  optional(:coupon) => String.t() | nil,
  optional(:promotion_code) => String.t() | nil,
  optional(String.t()) => term()
}

@type flow_data_subscription_update_confirm_items() :: %{
  optional(:id) => String.t() | nil,
  optional(:price) => String.t() | nil,
  optional(:quantity) => integer() | nil,
  optional(String.t()) => term()
}

@type t() :: %Stripe.Params.BillingPortal.SessionCreateParams{
  configuration: String.t() | nil,
  customer: String.t() | nil,
  customer_account: String.t() | nil,
  expand: [String.t()] | nil,
  flow_data: flow_data() | nil,
  locale: String.t() | nil,
  on_behalf_of: String.t() | nil,
  return_url: String.t() | nil
}