+/// The context of an inbound payment, which is included in a [`BlindedPath`] via [`ReceiveTlvs`]
+/// and surfaced in [`PaymentPurpose`].
+///
+/// [`BlindedPath`]: crate::blinded_path::BlindedPath
+/// [`PaymentPurpose`]: crate::events::PaymentPurpose
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub enum PaymentContext {
+ /// The payment context was unknown.
+ Unknown(UnknownPaymentContext),
+}
+
+/// An unknown payment context.
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct UnknownPaymentContext(());
+
+impl PaymentContext {
+ pub(crate) fn unknown() -> Self {
+ PaymentContext::Unknown(UnknownPaymentContext(()))
+ }
+}
+
+impl TryFrom<CounterpartyForwardingInfo> for PaymentRelay {
+ type Error = ();
+
+ fn try_from(info: CounterpartyForwardingInfo) -> Result<Self, ()> {
+ let CounterpartyForwardingInfo {
+ fee_base_msat, fee_proportional_millionths, cltv_expiry_delta
+ } = info;
+
+ // Avoid exposing esoteric CLTV expiry deltas
+ let cltv_expiry_delta = match cltv_expiry_delta {
+ 0..=40 => 40,
+ 41..=80 => 80,
+ 81..=144 => 144,
+ 145..=216 => 216,
+ _ => return Err(()),
+ };
+
+ Ok(Self { cltv_expiry_delta, fee_proportional_millionths, fee_base_msat })
+ }
+}
+