Actually remember the order state in `ChannelOrder`

diff --git a/lightning-liquidity/src/lsps1/peer_state.rs b/lightning-liquidity/src/lsps1/peer_state.rs
index 8f7c5a9..a3d2000 100644
--- a/lightning-liquidity/src/lsps1/peer_state.rs
+++ b/lightning-liquidity/src/lsps1/peer_state.rs
@@ -9,7 +9,10 @@
 
 //! Contains peer state objects that are used by `LSPS1ServiceHandler`.
 
-use super::msgs::{LSPS1OrderId, LSPS1OrderParams, LSPS1PaymentInfo, LSPS1Request};
+use super::msgs::{
+	LSPS1ChannelInfo, LSPS1OrderId, LSPS1OrderParams, LSPS1OrderState, LSPS1PaymentInfo,
+	LSPS1Request,
+};
 
 use crate::lsps0::ser::{LSPSDateTime, LSPSRequestId};
 use crate::prelude::HashMap;
@@ -26,13 +29,31 @@ impl PeerState {
 	pub(super) fn new_order(
 		&mut self, order_id: LSPS1OrderId, order_params: LSPS1OrderParams,
 		created_at: LSPSDateTime, payment_details: LSPS1PaymentInfo,
-	) {
-		let channel_order = ChannelOrder { order_params, created_at, payment_details };
-		self.outbound_channels_by_order_id.insert(order_id, channel_order);
+	) -> ChannelOrder {
+		let order_state = LSPS1OrderState::Created;
+		let channel_details = None;
+		let channel_order = ChannelOrder {
+			order_params,
+			order_state,
+			created_at,
+			payment_details,
+			channel_details,
+		};
+		self.outbound_channels_by_order_id.insert(order_id, channel_order.clone());
+		channel_order
 	}
 
-	pub(super) fn get_order<'a>(&'a self, order_id: &LSPS1OrderId) -> Option<&'a ChannelOrder> {
-		self.outbound_channels_by_order_id.get(order_id)
+	pub(super) fn update_order<'a>(
+		&'a mut self, order_id: &LSPS1OrderId, order_state: LSPS1OrderState,
+		channel_details: Option<LSPS1ChannelInfo>,
+	) -> Result<&'a ChannelOrder, PeerStateError> {
+		let order = self
+			.outbound_channels_by_order_id
+			.get_mut(order_id)
+			.ok_or(PeerStateError::UnknownOrderId)?;
+		order.order_state = order_state;
+		order.channel_details = channel_details;
+		Ok(order)
 	}
 
 	pub(super) fn register_request(
@@ -60,6 +81,7 @@ impl PeerState {
 pub(super) enum PeerStateError {
 	UnknownRequestId,
 	DuplicateRequestId,
+	UnknownOrderId,
 }
 
 impl fmt::Display for PeerStateError {
@@ -67,12 +89,16 @@ impl fmt::Display for PeerStateError {
 		match self {
 			Self::UnknownRequestId => write!(f, "unknown request id"),
 			Self::DuplicateRequestId => write!(f, "duplicate request id"),
+			Self::UnknownOrderId => write!(f, "unknown order id"),
 		}
 	}
 }
 
+#[derive(Debug, Clone)]
 pub(super) struct ChannelOrder {
 	pub(super) order_params: LSPS1OrderParams,
+	pub(super) order_state: LSPS1OrderState,
 	pub(super) created_at: LSPSDateTime,
 	pub(super) payment_details: LSPS1PaymentInfo,
+	pub(super) channel_details: Option<LSPS1ChannelInfo>,
 }
diff --git a/lightning-liquidity/src/lsps1/service.rs b/lightning-liquidity/src/lsps1/service.rs
index a75db34..52d9715 100644
--- a/lightning-liquidity/src/lsps1/service.rs
+++ b/lightning-liquidity/src/lsps1/service.rs
@@ -181,7 +181,7 @@ where
 	/// [`LSPS1ServiceEvent::RequestForPaymentDetails`]: crate::lsps1::event::LSPS1ServiceEvent::RequestForPaymentDetails
 	pub fn send_payment_details(
 		&self, request_id: LSPSRequestId, counterparty_node_id: &PublicKey,
-		payment: LSPS1PaymentInfo, created_at: LSPSDateTime,
+		payment_details: LSPS1PaymentInfo, created_at: LSPSDateTime,
 	) -> Result<(), APIError> {
 		let mut message_queue_notifier = self.pending_messages.notifier();
 
@@ -198,23 +198,21 @@ where
 				match request {
 					LSPS1Request::CreateOrder(params) => {
 						let order_id = self.generate_order_id();
-						peer_state_lock.new_order(
+						let order = peer_state_lock.new_order(
 							order_id.clone(),
-							params.order.clone(),
+							params.order,
 							created_at,
-							payment.clone(),
+							payment_details,
 						);
 
 						let response = LSPS1Response::CreateOrder(LSPS1CreateOrderResponse {
-							order: params.order,
+							order: order.order_params,
 							order_id,
 
-							// TODO, we need to set this in the peer/channel state, and send the
-							// set value here:
-							order_state: LSPS1OrderState::Created,
-							created_at,
-							payment,
-							channel: None,
+							order_state: order.order_state,
+							created_at: order.created_at,
+							payment: order.payment_details,
+							channel: order.channel_details,
 						});
 						let msg = LSPS1Message::Response(request_id, response).into();
 						message_queue_notifier.enqueue(counterparty_node_id, msg);
@@ -284,7 +282,7 @@ where
 	/// [`LSPS1ServiceEvent::CheckPaymentConfirmation`]: crate::lsps1::event::LSPS1ServiceEvent::CheckPaymentConfirmation
 	pub fn update_order_status(
 		&self, request_id: LSPSRequestId, counterparty_node_id: PublicKey, order_id: LSPS1OrderId,
-		order_state: LSPS1OrderState, channel: Option<LSPS1ChannelInfo>,
+		order_state: LSPS1OrderState, channel_details: Option<LSPS1ChannelInfo>,
 	) -> Result<(), APIError> {
 		let mut message_queue_notifier = self.pending_messages.notifier();
 
@@ -292,22 +290,20 @@ where
 
 		match outer_state_lock.get(&counterparty_node_id) {
 			Some(inner_state_lock) => {
-				let peer_state_lock = inner_state_lock.lock().unwrap();
-				let order =
-					peer_state_lock.get_order(&order_id).ok_or(APIError::APIMisuseError {
-						err: format!("Channel with order_id {} not found", order_id.0),
-					})?;
-
-				// FIXME: we need to actually remember the order state (and eventually persist it)
-				// here.
+				let mut peer_state_lock = inner_state_lock.lock().unwrap();
+				let order = peer_state_lock
+					.update_order(&order_id, order_state, channel_details)
+					.map_err(|e| APIError::APIMisuseError {
+					err: format!("Failed to update order: {:?}", e),
+				})?;
 
 				let response = LSPS1Response::GetOrder(LSPS1CreateOrderResponse {
 					order_id,
 					order: order.order_params.clone(),
-					order_state,
+					order_state: order.order_state.clone(),
 					created_at: order.created_at.clone(),
 					payment: order.payment_details.clone(),
-					channel,
+					channel: order.channel_details.clone(),
 				});
 				let msg = LSPS1Message::Response(request_id, response).into();
 				message_queue_notifier.enqueue(&counterparty_node_id, msg);