+ * ## Opening Channels
+ *
+ * To an open a channel with a peer, call [`create_channel`]. This will initiate the process of
+ * opening an outbound channel, which requires self-funding when handling
+ * [`Event::FundingGenerationReady`].
+ *
+ * ```
+ * # use bitcoin::{ScriptBuf, Transaction};
+ * # use bitcoin::secp256k1::PublicKey;
+ * # use lightning::ln::channelmanager::AChannelManager;
+ * # use lightning::events::{Event, EventsProvider};
+ * #
+ * # trait Wallet {
+ * # fn create_funding_transaction(
+ * # &self, _amount_sats: u64, _output_script: ScriptBuf
+ * # ) -> Transaction;
+ * # }
+ * #
+ * # fn example<T: AChannelManager, W: Wallet>(channel_manager: T, wallet: W, peer_id: PublicKey) {
+ * # let channel_manager = channel_manager.get_cm();
+ * let value_sats = 1_000_000;
+ * let push_msats = 10_000_000;
+ * match channel_manager.create_channel(peer_id, value_sats, push_msats, 42, None, None) {
+ * Ok(channel_id) => println!(\"Opening channel {}\", channel_id),
+ * Err(e) => println!(\"Error opening channel: {:?}\", e),
+ * }
+ *
+ * // On the event processing thread once the peer has responded
+ * channel_manager.process_pending_events(&|event| match event {
+ * Event::FundingGenerationReady {
+ * temporary_channel_id, counterparty_node_id, channel_value_satoshis, output_script,
+ * user_channel_id, ..
+ * } => {
+ * assert_eq!(user_channel_id, 42);
+ * let funding_transaction = wallet.create_funding_transaction(
+ * channel_value_satoshis, output_script
+ * );
+ * match channel_manager.funding_transaction_generated(
+ * &temporary_channel_id, &counterparty_node_id, funding_transaction
+ * ) {
+ * Ok(()) => println!(\"Funding channel {}\", temporary_channel_id),
+ * Err(e) => println!(\"Error funding channel {}: {:?}\", temporary_channel_id, e),
+ * }
+ * },
+ * Event::ChannelPending { channel_id, user_channel_id, former_temporary_channel_id, .. } => {
+ * assert_eq!(user_channel_id, 42);
+ * println!(
+ * \"Channel {} now {} pending (funding transaction has been broadcasted)\", channel_id,
+ * former_temporary_channel_id.unwrap()
+ * );
+ * },
+ * Event::ChannelReady { channel_id, user_channel_id, .. } => {
+ * assert_eq!(user_channel_id, 42);
+ * println!(\"Channel {} ready\", channel_id);
+ * },
+ * // ...
+ * # _ => {},
+ * });
+ * # }
+ * ```
+ *
+ * ## Accepting Channels
+ *
+ * Inbound channels are initiated by peers and are automatically accepted unless [`ChannelManager`]
+ * has [`UserConfig::manually_accept_inbound_channels`] set. In that case, the channel may be
+ * either accepted or rejected when handling [`Event::OpenChannelRequest`].
+ *
+ * ```
+ * # use bitcoin::secp256k1::PublicKey;
+ * # use lightning::ln::channelmanager::AChannelManager;
+ * # use lightning::events::{Event, EventsProvider};
+ * #
+ * # fn is_trusted(counterparty_node_id: PublicKey) -> bool {
+ * # // ...
+ * # unimplemented!()
+ * # }
+ * #
+ * # fn example<T: AChannelManager>(channel_manager: T) {
+ * # let channel_manager = channel_manager.get_cm();
+ * channel_manager.process_pending_events(&|event| match event {
+ * Event::OpenChannelRequest { temporary_channel_id, counterparty_node_id, .. } => {
+ * if !is_trusted(counterparty_node_id) {
+ * match channel_manager.force_close_without_broadcasting_txn(
+ * &temporary_channel_id, &counterparty_node_id
+ * ) {
+ * Ok(()) => println!(\"Rejecting channel {}\", temporary_channel_id),
+ * Err(e) => println!(\"Error rejecting channel {}: {:?}\", temporary_channel_id, e),
+ * }
+ * return;
+ * }
+ *
+ * let user_channel_id = 43;
+ * match channel_manager.accept_inbound_channel(
+ * &temporary_channel_id, &counterparty_node_id, user_channel_id
+ * ) {
+ * Ok(()) => println!(\"Accepting channel {}\", temporary_channel_id),
+ * Err(e) => println!(\"Error accepting channel {}: {:?}\", temporary_channel_id, e),
+ * }
+ * },
+ * // ...
+ * # _ => {},
+ * });
+ * # }
+ * ```
+ *
+ * ## Closing Channels
+ *
+ * There are two ways to close a channel: either cooperatively using [`close_channel`] or
+ * unilaterally using [`force_close_broadcasting_latest_txn`]. The former is ideal as it makes for
+ * lower fees and immediate access to funds. However, the latter may be necessary if the
+ * counterparty isn't behaving properly or has gone offline. [`Event::ChannelClosed`] is generated
+ * once the channel has been closed successfully.
+ *
+ * ```
+ * # use bitcoin::secp256k1::PublicKey;
+ * # use lightning::ln::types::ChannelId;
+ * # use lightning::ln::channelmanager::AChannelManager;
+ * # use lightning::events::{Event, EventsProvider};
+ * #
+ * # fn example<T: AChannelManager>(
+ * # channel_manager: T, channel_id: ChannelId, counterparty_node_id: PublicKey
+ * # ) {
+ * # let channel_manager = channel_manager.get_cm();
+ * match channel_manager.close_channel(&channel_id, &counterparty_node_id) {
+ * Ok(()) => println!(\"Closing channel {}\", channel_id),
+ * Err(e) => println!(\"Error closing channel {}: {:?}\", channel_id, e),
+ * }
+ *
+ * // On the event processing thread
+ * channel_manager.process_pending_events(&|event| match event {
+ * Event::ChannelClosed { channel_id, user_channel_id, .. } => {
+ * assert_eq!(user_channel_id, 42);
+ * println!(\"Channel {} closed\", channel_id);
+ * },
+ * // ...
+ * # _ => {},
+ * });
+ * # }
+ * ```
+ *
+ * # Payments
+ *
+ * [`ChannelManager`] is responsible for sending, forwarding, and receiving payments through its
+ * channels. A payment is typically initiated from a [BOLT 11] invoice or a [BOLT 12] offer, though
+ * spontaneous (i.e., keysend) payments are also possible. Incoming payments don't require
+ * maintaining any additional state as [`ChannelManager`] can reconstruct the [`PaymentPreimage`]
+ * from the [`PaymentSecret`]. Sending payments, however, require tracking in order to retry failed
+ * HTLCs.
+ *
+ * After a payment is initiated, it will appear in [`list_recent_payments`] until a short time
+ * after either an [`Event::PaymentSent`] or [`Event::PaymentFailed`] is handled. Failed HTLCs
+ * for a payment will be retried according to the payment's [`Retry`] strategy or until
+ * [`abandon_payment`] is called.
+ *
+ * ## BOLT 11 Invoices
+ *
+ * The [`lightning-invoice`] crate is useful for creating BOLT 11 invoices. Specifically, use the
+ * functions in its `utils` module for constructing invoices that are compatible with
+ * [`ChannelManager`]. These functions serve as a convenience for building invoices with the
+ * [`PaymentHash`] and [`PaymentSecret`] returned from [`create_inbound_payment`]. To provide your
+ * own [`PaymentHash`], use [`create_inbound_payment_for_hash`] or the corresponding functions in
+ * the [`lightning-invoice`] `utils` module.
+ *
+ * [`ChannelManager`] generates an [`Event::PaymentClaimable`] once the full payment has been
+ * received. Call [`claim_funds`] to release the [`PaymentPreimage`], which in turn will result in
+ * an [`Event::PaymentClaimed`].
+ *
+ * ```
+ * # use lightning::events::{Event, EventsProvider, PaymentPurpose};
+ * # use lightning::ln::channelmanager::AChannelManager;
+ * #
+ * # fn example<T: AChannelManager>(channel_manager: T) {
+ * # let channel_manager = channel_manager.get_cm();
+ * // Or use utils::create_invoice_from_channelmanager
+ * let known_payment_hash = match channel_manager.create_inbound_payment(
+ * Some(10_000_000), 3600, None
+ * ) {
+ * Ok((payment_hash, _payment_secret)) => {
+ * println!(\"Creating inbound payment {}\", payment_hash);
+ * payment_hash
+ * },
+ * Err(()) => panic!(\"Error creating inbound payment\"),
+ * };
+ *
+ * // On the event processing thread
+ * channel_manager.process_pending_events(&|event| match event {
+ * Event::PaymentClaimable { payment_hash, purpose, .. } => match purpose {
+ * PaymentPurpose::Bolt11InvoicePayment { payment_preimage: Some(payment_preimage), .. } => {
+ * assert_eq!(payment_hash, known_payment_hash);
+ * println!(\"Claiming payment {}\", payment_hash);
+ * channel_manager.claim_funds(payment_preimage);
+ * },
+ * PaymentPurpose::Bolt11InvoicePayment { payment_preimage: None, .. } => {
+ * println!(\"Unknown payment hash: {}\", payment_hash);
+ * },
+ * PaymentPurpose::SpontaneousPayment(payment_preimage) => {
+ * assert_ne!(payment_hash, known_payment_hash);
+ * println!(\"Claiming spontaneous payment {}\", payment_hash);
+ * channel_manager.claim_funds(payment_preimage);
+ * },
+ * // ...
+ * # _ => {},
+ * },
+ * Event::PaymentClaimed { payment_hash, amount_msat, .. } => {
+ * assert_eq!(payment_hash, known_payment_hash);
+ * println!(\"Claimed {} msats\", amount_msat);
+ * },
+ * // ...
+ * # _ => {},
+ * });
+ * # }
+ * ```
+ *
+ * For paying an invoice, [`lightning-invoice`] provides a `payment` module with convenience
+ * functions for use with [`send_payment`].
+ *
+ * ```
+ * # use lightning::events::{Event, EventsProvider};
+ * # use lightning::ln::types::PaymentHash;
+ * # use lightning::ln::channelmanager::{AChannelManager, PaymentId, RecentPaymentDetails, RecipientOnionFields, Retry};
+ * # use lightning::routing::router::RouteParameters;
+ * #
+ * # fn example<T: AChannelManager>(
+ * # channel_manager: T, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
+ * # route_params: RouteParameters, retry: Retry
+ * # ) {
+ * # let channel_manager = channel_manager.get_cm();
+ * // let (payment_hash, recipient_onion, route_params) =
+ * // payment::payment_parameters_from_invoice(&invoice);
+ * let payment_id = PaymentId([42; 32]);
+ * match channel_manager.send_payment(
+ * payment_hash, recipient_onion, payment_id, route_params, retry
+ * ) {
+ * Ok(()) => println!(\"Sending payment with hash {}\", payment_hash),
+ * Err(e) => println!(\"Failed sending payment with hash {}: {:?}\", payment_hash, e),
+ * }
+ *
+ * let expected_payment_id = payment_id;
+ * let expected_payment_hash = payment_hash;
+ * assert!(
+ * channel_manager.list_recent_payments().iter().find(|details| matches!(
+ * details,
+ * RecentPaymentDetails::Pending {
+ * payment_id: expected_payment_id,
+ * payment_hash: expected_payment_hash,
+ * ..
+ * }
+ * )).is_some()
+ * );
+ *
+ * // On the event processing thread
+ * channel_manager.process_pending_events(&|event| match event {
+ * Event::PaymentSent { payment_hash, .. } => println!(\"Paid {}\", payment_hash),
+ * Event::PaymentFailed { payment_hash, .. } => println!(\"Failed paying {}\", payment_hash),
+ * // ...
+ * # _ => {},
+ * });
+ * # }
+ * ```
+ *
+ * ## 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, BOLT 12 offers and invoices are
+ * stateless just as BOLT 11 invoices are.
+ *
+ * ```
+ * # use lightning::events::{Event, EventsProvider, PaymentPurpose};
+ * # use lightning::ln::channelmanager::AChannelManager;
+ * # use lightning::offers::parse::Bolt12SemanticError;
+ * #
+ * # fn example<T: AChannelManager>(channel_manager: T) -> Result<(), Bolt12SemanticError> {
+ * # let channel_manager = channel_manager.get_cm();
+ * let offer = channel_manager
+ * .create_offer_builder()?
+ * # ;
+ * # // Needed for compiling for c_bindings
+ * # let builder: lightning::offers::offer::OfferBuilder<_, _> = offer.into();
+ * # let offer = builder
+ * .description(\"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::Bolt12OfferPayment { payment_preimage: Some(payment_preimage), .. } => {
+ * println!(\"Claiming payment {}\", payment_hash);
+ * channel_manager.claim_funds(payment_preimage);
+ * },
+ * PaymentPurpose::Bolt12OfferPayment { 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 lightning::events::{Event, EventsProvider};
+ * # use lightning::ln::channelmanager::{AChannelManager, PaymentId, RecentPaymentDetails, Retry};
+ * # use lightning::offers::offer::Offer;
+ * #
+ * # fn example<T: AChannelManager>(
+ * # channel_manager: T, offer: &Offer, quantity: Option<u64>, amount_msats: Option<u64>,
+ * # payer_note: Option<String>, retry: Retry, max_total_routing_fee_msat: Option<u64>
+ * # ) {
+ * # let channel_manager = channel_manager.get_cm();
+ * let payment_id = PaymentId([42; 32]);
+ * 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),
+ * // ...
+ * # _ => {},
+ * });
+ * # }
+ * ```
+ *
+ * ## BOLT 12 Refunds
+ *
+ * A [`Refund`] is a request for an invoice to be paid. Like *paying* for an [`Offer`], *creating*
+ * a [`Refund`] involves maintaining state since it represents a future outbound payment.
+ * Therefore, use [`create_refund_builder`] when creating one, otherwise [`ChannelManager`] will
+ * refuse to pay any corresponding [`Bolt12Invoice`] that it receives.
+ *
+ * ```
+ * # use core::time::Duration;
+ * # use lightning::events::{Event, EventsProvider};
+ * # use lightning::ln::channelmanager::{AChannelManager, PaymentId, RecentPaymentDetails, Retry};
+ * # use lightning::offers::parse::Bolt12SemanticError;
+ * #
+ * # fn example<T: AChannelManager>(
+ * # channel_manager: T, amount_msats: u64, absolute_expiry: Duration, retry: Retry,
+ * # max_total_routing_fee_msat: Option<u64>
+ * # ) -> Result<(), Bolt12SemanticError> {
+ * # let channel_manager = channel_manager.get_cm();
+ * let payment_id = PaymentId([42; 32]);
+ * let refund = channel_manager
+ * .create_refund_builder(
+ * amount_msats, absolute_expiry, payment_id, retry, max_total_routing_fee_msat
+ * )?
+ * # ;
+ * # // Needed for compiling for c_bindings
+ * # let builder: lightning::offers::refund::RefundBuilder<_> = refund.into();
+ * # let refund = builder
+ * .description(\"coffee\".to_string())
+ * .payer_note(\"refund for order 1234\".to_string())
+ * .build()?;
+ * let bech32_refund = refund.to_string();
+ *
+ * // 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),
+ * // ...
+ * # _ => {},
+ * });
+ * # Ok(())
+ * # }
+ * ```
+ *
+ * Use [`request_refund_payment`] to send a [`Bolt12Invoice`] for receiving the refund. Similar to
+ * *creating* an [`Offer`], this is stateless as it represents an inbound payment.
+ *
+ * ```
+ * # use lightning::events::{Event, EventsProvider, PaymentPurpose};
+ * # use lightning::ln::channelmanager::AChannelManager;
+ * # use lightning::offers::refund::Refund;
+ * #
+ * # fn example<T: AChannelManager>(channel_manager: T, refund: &Refund) {
+ * # let channel_manager = channel_manager.get_cm();
+ * let known_payment_hash = match channel_manager.request_refund_payment(refund) {
+ * Ok(invoice) => {
+ * let payment_hash = invoice.payment_hash();
+ * println!(\"Requesting refund payment {}\", payment_hash);
+ * payment_hash
+ * },
+ * Err(e) => panic!(\"Unable to request payment for refund: {:?}\", e),
+ * };
+ *
+ * // On the event processing thread
+ * channel_manager.process_pending_events(&|event| match event {
+ * Event::PaymentClaimable { payment_hash, purpose, .. } => match purpose {
+ * \tPaymentPurpose::Bolt12RefundPayment { payment_preimage: Some(payment_preimage), .. } => {
+ * assert_eq!(payment_hash, known_payment_hash);
+ * println!(\"Claiming payment {}\", payment_hash);
+ * channel_manager.claim_funds(payment_preimage);
+ * },
+ * \tPaymentPurpose::Bolt12RefundPayment { payment_preimage: None, .. } => {
+ * println!(\"Unknown payment hash: {}\", payment_hash);
+ * \t},
+ * // ...
+ * # _ => {},
+ * },
+ * Event::PaymentClaimed { payment_hash, amount_msat, .. } => {
+ * assert_eq!(payment_hash, known_payment_hash);
+ * println!(\"Claimed {} msats\", amount_msat);
+ * },
+ * // ...
+ * # _ => {},
+ * });
+ * # }
+ * ```
+ *
+ * # Persistence