+use io;
+use prelude::*;
+use core::time::Duration;
+use core::ops::Deref;
+
+/// Some information provided on receipt of payment depends on whether the payment received is a
+/// spontaneous payment or a "conventional" lightning payment that's paying an invoice.
+#[derive(Clone, Debug)]
+pub enum PaymentPurpose {
+ /// Information for receiving a payment that we generated an invoice for.
+ InvoicePayment {
+ /// The preimage to the payment_hash, if the payment hash (and secret) were fetched via
+ /// [`ChannelManager::create_inbound_payment`]. If provided, this can be handed directly to
+ /// [`ChannelManager::claim_funds`].
+ ///
+ /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
+ /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
+ payment_preimage: Option<PaymentPreimage>,
+ /// The "payment secret". This authenticates the sender to the recipient, preventing a
+ /// number of deanonymization attacks during the routing process.
+ /// It is provided here for your reference, however its accuracy is enforced directly by
+ /// [`ChannelManager`] using the values you previously provided to
+ /// [`ChannelManager::create_inbound_payment`] or
+ /// [`ChannelManager::create_inbound_payment_for_hash`].
+ ///
+ /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
+ /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
+ /// [`ChannelManager::create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
+ payment_secret: PaymentSecret,
+ /// This is the `user_payment_id` which was provided to
+ /// [`ChannelManager::create_inbound_payment_for_hash`] or
+ /// [`ChannelManager::create_inbound_payment`]. It has no meaning inside of LDK and is
+ /// simply copied here. It may be used to correlate PaymentReceived events with invoice
+ /// metadata stored elsewhere.
+ ///
+ /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
+ /// [`ChannelManager::create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
+ user_payment_id: u64,
+ },
+ /// Because this is a spontaneous payment, the payer generated their own preimage rather than us
+ /// (the payee) providing a preimage.
+ SpontaneousPayment(PaymentPreimage),
+}