From 7c10fbed18701426fcce4307b2fb74194686b715 Mon Sep 17 00:00:00 2001
From: G8XSU <3442979+G8XSU@users.noreply.github.com>
Date: Mon, 14 Oct 2024 19:04:33 -0700
Subject: [PATCH] Add impl for UpdateChannelConfig Api.

---
 server/src/api/mod.rs                   |  2 +
 server/src/api/update_channel_config.rs | 77 +++++++++++++++++++++++++
 server/src/service.rs                   |  2 +
 3 files changed, 81 insertions(+)
 create mode 100644 server/src/api/update_channel_config.rs

diff --git a/server/src/api/mod.rs b/server/src/api/mod.rs
index c1079f2..3f6a577 100644
--- a/server/src/api/mod.rs
+++ b/server/src/api/mod.rs
@@ -10,3 +10,5 @@ pub(crate) mod list_payments;
 pub(crate) mod onchain_receive;
 pub(crate) mod onchain_send;
 pub(crate) mod open_channel;
+
+pub(crate) mod update_channel_config;
diff --git a/server/src/api/update_channel_config.rs b/server/src/api/update_channel_config.rs
new file mode 100644
index 0000000..46e45b2
--- /dev/null
+++ b/server/src/api/update_channel_config.rs
@@ -0,0 +1,77 @@
+use ldk_node::bitcoin::secp256k1::PublicKey;
+use ldk_node::{ChannelConfig, Node, UserChannelId};
+use protos::channel_config::MaxDustHtlcExposure;
+use protos::{UpdateChannelConfigRequest, UpdateChannelConfigResponse};
+use std::str::FromStr;
+use std::sync::Arc;
+
+pub(crate) const UPDATE_CHANNEL_CONFIG_PATH: &str = "UpdateChannelConfig";
+
+pub(crate) fn handle_update_channel_config_request(
+	node: Arc<Node>, request: UpdateChannelConfigRequest,
+) -> Result<UpdateChannelConfigResponse, ldk_node::NodeError> {
+	let user_channel_id: u128 =
+		request.user_channel_id.parse().map_err(|_| ldk_node::NodeError::InvalidChannelId)?;
+
+	let channel_config = proto_to_channel_config(&request.channel_config.unwrap());
+
+	let counterparty_node_id = PublicKey::from_str(&request.counterparty_node_id)
+		.map_err(|_| ldk_node::NodeError::InvalidPublicKey)?;
+	node.update_channel_config(
+		&UserChannelId(user_channel_id),
+		counterparty_node_id,
+		Arc::new(channel_config),
+	)
+	.map_err(ldk_node::NodeError::from)?;
+
+	Ok(UpdateChannelConfigResponse {})
+}
+
+fn proto_to_channel_config(proto_channel_config: &protos::ChannelConfig) -> ChannelConfig {
+	let channel_config = ChannelConfig::new();
+
+	match proto_channel_config.forwarding_fee_proportional_millionths {
+		Some(forwarding_fee_proportional_millionths) => channel_config
+			.set_forwarding_fee_proportional_millionths(forwarding_fee_proportional_millionths),
+		None => {},
+	}
+
+	match proto_channel_config.forwarding_fee_base_msat {
+		Some(forwarding_fee_base_msat) => {
+			channel_config.set_forwarding_fee_base_msat(forwarding_fee_base_msat)
+		},
+		None => {},
+	}
+
+	match proto_channel_config.cltv_expiry_delta {
+		Some(cltv_expiry_delta) => channel_config.set_cltv_expiry_delta(cltv_expiry_delta as u16),
+		None => {},
+	}
+
+	match proto_channel_config.force_close_avoidance_max_fee_satoshis {
+		Some(force_close_avoidance_max_fee_satoshis) => channel_config
+			.set_force_close_avoidance_max_fee_satoshis(force_close_avoidance_max_fee_satoshis),
+		None => {},
+	}
+
+	match proto_channel_config.accept_underpaying_htlcs {
+		Some(accept_underpaying_htlcs) => {
+			channel_config.set_accept_underpaying_htlcs(accept_underpaying_htlcs)
+		},
+		None => {},
+	}
+
+	match &proto_channel_config.max_dust_htlc_exposure {
+		Some(max_dust_htlc_exposure) => match max_dust_htlc_exposure {
+			&MaxDustHtlcExposure::FixedLimitMsat(limit) => {
+				channel_config.set_max_dust_htlc_exposure_from_fixed_limit(limit)
+			},
+			&MaxDustHtlcExposure::FeeRateMultiplier(multiplier) => {
+				channel_config.set_max_dust_htlc_exposure_from_fee_rate_multiplier(multiplier)
+			},
+		},
+		None => {},
+	}
+	// FIXME: set max_dust_htlc_exposure
+	channel_config
+}
diff --git a/server/src/service.rs b/server/src/service.rs
index 510131d..03c76f5 100644
--- a/server/src/service.rs
+++ b/server/src/service.rs
@@ -21,6 +21,7 @@ use crate::api::get_payment_details::{
 	handle_get_payment_details_request, GET_PAYMENT_DETAILS_PATH,
 };
 use crate::api::list_channels::{handle_list_channels_request, LIST_CHANNELS_PATH};
+use crate::api::update_channel_config::{handle_update_channel_config_request, UPDATE_CHANNEL_CONFIG_PATH};
 use crate::api::list_payments::{handle_list_payments_request, LIST_PAYMENTS_PATH};
 use crate::api::onchain_receive::{handle_onchain_receive_request, ONCHAIN_RECEIVE_PATH};
 use crate::api::onchain_send::{handle_onchain_send_request, ONCHAIN_SEND_PATH};
@@ -62,6 +63,7 @@ impl Service<Request<Incoming>> for NodeService {
 			OPEN_CHANNEL_PATH => Box::pin(handle_request(node, req, handle_open_channel)),
 			CLOSE_CHANNEL_PATH => Box::pin(handle_request(node, req, handle_close_channel_request)),
 			LIST_CHANNELS_PATH => Box::pin(handle_request(node, req, handle_list_channels_request)),
+			UPDATE_CHANNEL_CONFIG_PATH => Box::pin(handle_request(node, req, handle_update_channel_config_request)),
 			GET_PAYMENT_DETAILS_PATH => {
 				Box::pin(handle_request(node, req, handle_get_payment_details_request))
 			},