From f89a55e3a8453f1163ac589fc334e66389fc9187 Mon Sep 17 00:00:00 2001 From: Jeffrey Czyz Date: Mon, 22 Jan 2024 15:34:27 -0600 Subject: [PATCH] Add BOLT 12 Offers section to ChannelManager docs --- lightning/src/ln/channelmanager.rs | 101 +++++++++++++++++++++++++++++ 1 file changed, 101 insertions(+) diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs index df7fb2d7fe1..ec0b80f3130 100644 --- a/lightning/src/ln/channelmanager.rs +++ b/lightning/src/ln/channelmanager.rs @@ -1486,6 +1486,103 @@ where /// # } /// ``` /// +/// ## BOLT 12 Offers +/// +/// The [`offers`] module is useful for creating BOLT 12 offers. An [`Offer`] is a precursor to a +/// [`Bolt12Invoice`], which must first be requested by the payer. The interchange of these messages +/// as defined in the specification is handled by [`ChannelManager`] and its implementation of +/// [`OffersMessageHandler`]. However, this only works with an [`Offer`] created using a builder +/// returned by [`create_offer_builder`]. With this approach, offers are stateless just as they are +/// with BOLT 11 invoices. +/// +/// ``` +/// # use lightning::events::{Event, EventsProvider, PaymentPurpose}; +/// # use lightning::ln::channelmanager::AChannelManager; +/// # use lightning::offers::parse::Bolt12SemanticError; +/// # +/// # fn example(channel_manager: T) -> Result<(), Bolt12SemanticError> { +/// # let channel_manager = channel_manager.get_cm(); +/// let offer = channel_manager +/// .create_offer_builder("coffee".to_string())? +/// .amount_msats(10_000_000) +/// .build()?; +/// let bech32_offer = offer.to_string(); +/// +/// // On the event processing thread +/// channel_manager.process_pending_events(&|event| match event { +/// Event::PaymentClaimable { payment_hash, purpose, .. } => match purpose { +/// PaymentPurpose::InvoicePayment { payment_preimage: Some(payment_preimage), .. } => { +/// println!("Claiming payment {}", payment_hash); +/// channel_manager.claim_funds(payment_preimage); +/// }, +/// PaymentPurpose::InvoicePayment { payment_preimage: None, .. } => { +/// println!("Unknown payment hash: {}", payment_hash); +/// }, +/// // ... +/// # _ => {}, +/// }, +/// Event::PaymentClaimed { payment_hash, amount_msat, .. } => { +/// println!("Claimed {} msats", amount_msat); +/// }, +/// // ... +/// # _ => {}, +/// }); +/// # Ok(()) +/// # } +/// ``` +/// +/// Use [`pay_for_offer`] to initiated payment, which sends an [`InvoiceRequest`] for an [`Offer`] +/// and pays the [`Bolt12Invoice`] response. In addition to success and failure events, +/// [`ChannelManager`] may also generate an [`Event::InvoiceRequestFailed`]. +/// +/// ``` +/// # use core::time::Duration; +/// # use lightning::events::{Event, EventsProvider}; +/// # use lightning::ln::channelmanager::{AChannelManager, PaymentId, RecentPaymentDetails, Retry}; +/// # use lightning::offers::offer::Offer; +/// # +/// # fn example( +/// # channel_manager: T, offer: &Offer, quantity: Option, amount_msats: Option, +/// # payer_note: Option, max_total_routing_fee_msat: Option +/// # ) { +/// # let channel_manager = channel_manager.get_cm(); +/// let payment_id = PaymentId([42; 32]); +/// let retry = Retry::Timeout(Duration::from_secs(60)); +/// match channel_manager.pay_for_offer( +/// offer, quantity, amount_msats, payer_note, payment_id, retry, max_total_routing_fee_msat +/// ) { +/// Ok(()) => println!("Requesting invoice for offer"), +/// Err(e) => println!("Unable to request invoice for offer: {:?}", e), +/// } +/// +/// // First the payment will be waiting on an invoice +/// let expected_payment_id = payment_id; +/// assert!( +/// channel_manager.list_recent_payments().iter().find(|details| matches!( +/// details, +/// RecentPaymentDetails::AwaitingInvoice { payment_id: expected_payment_id } +/// )).is_some() +/// ); +/// +/// // Once the invoice is received, a payment will be sent +/// assert!( +/// channel_manager.list_recent_payments().iter().find(|details| matches!( +/// details, +/// RecentPaymentDetails::Pending { payment_id: expected_payment_id, .. } +/// )).is_some() +/// ); +/// +/// // On the event processing thread +/// channel_manager.process_pending_events(&|event| match event { +/// Event::PaymentSent { payment_id: Some(payment_id), .. } => println!("Paid {}", payment_id), +/// Event::PaymentFailed { payment_id, .. } => println!("Failed paying {}", payment_id), +/// Event::InvoiceRequestFailed { payment_id, .. } => println!("Failed paying {}", payment_id), +/// // ... +/// # _ => {}, +/// }); +/// # } +/// ``` +/// /// # Persistence /// /// Implements [`Writeable`] to write out all channel state to disk. Implies [`peer_disconnected`] for @@ -1561,6 +1658,10 @@ where /// [`create_inbound_payment_for_hash`]: Self::create_inbound_payment_for_hash /// [`claim_funds`]: Self::claim_funds /// [`send_payment`]: Self::send_payment +/// [`offers`]: crate::offers +/// [`create_offer_builder`]: Self::create_offer_builder +/// [`pay_for_offer`]: Self::pay_for_offer +/// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest /// [`peer_disconnected`]: msgs::ChannelMessageHandler::peer_disconnected /// [`funding_created`]: msgs::FundingCreated /// [`funding_transaction_generated`]: Self::funding_transaction_generated