From e9d77a3a7197e6c2c163a2a1d236991beaeed8e6 Mon Sep 17 00:00:00 2001
From: user <benalleng@gmail.com>
Date: Fri, 7 Nov 2025 16:03:11 -0500
Subject: [PATCH] Add bip21 receive display support

This adds the scaffolding for the receiver to display bip21 QR codes
when a payjoin or other bip21 receive format is required.
---
 liana-gui/src/app/state/receive.rs | 35 ++++++++++++++++++++++++------
 liana-gui/src/app/view/message.rs  |  2 +-
 liana-gui/src/app/view/receive.rs  |  6 +++--
 3 files changed, 33 insertions(+), 10 deletions(-)

diff --git a/liana-gui/src/app/state/receive.rs b/liana-gui/src/app/state/receive.rs
index 4df5012f7..f256b6cad 100644
--- a/liana-gui/src/app/state/receive.rs
+++ b/liana-gui/src/app/state/receive.rs
@@ -1,4 +1,5 @@
 use std::collections::{HashMap, HashSet};
+use std::str::FromStr;
 use std::sync::Arc;
 
 use iced::{widget::qr_code, Subscription, Task};
@@ -286,9 +287,21 @@ impl State for ReceivePanel {
                     Task::none()
                 }
             }
-            Message::View(view::Message::ShowQrCode(i)) => {
-                if let (Some(address), Some(index)) = (self.address(i), self.derivation_index(i)) {
-                    if let Some(modal) = ShowQrCodeModal::new(address, *index) {
+            Message::View(view::Message::ShowQrCode(i, bip21)) => {
+                if let Some(address) = self.address(i) {
+                    if bip21.is_some() {
+                        if let Some(modal) =
+                            ShowQrCodeModal::new(&bip21.clone().unwrap_or(address.to_string()))
+                        {
+                            self.modal = Modal::ShowQrCode(modal);
+                        } else {
+                            tracing::error!(
+                                "Failed to create QR modal for BIP21 '{:?}' (address {})",
+                                bip21,
+                                address
+                            );
+                        }
+                    } else if let Some(modal) = ShowQrCodeModal::new(&address.to_string()) {
                         self.modal = Modal::ShowQrCode(modal);
                     }
                 }
@@ -420,13 +433,21 @@ pub struct ShowQrCodeModal {
 }
 
 impl ShowQrCodeModal {
-    pub fn new(address: &Address, index: ChildNumber) -> Option<Self> {
-        qr_code::Data::new(format!("bitcoin:{}?index={}", address, index))
-            .ok()
-            .map(|qr_code| Self {
+    pub fn new(address: &str) -> Option<Self> {
+        if Address::from_str(address).is_ok() {
+            qr_code::Data::new(format!("bitcoin:{}", address))
+                .ok()
+                .map(|qr_code| Self {
+                    qr_code,
+                    address: address.to_string(),
+                })
+        } else {
+            // Already in bip21 format
+            qr_code::Data::new(address).ok().map(|qr_code| Self {
                 qr_code,
                 address: address.to_string(),
             })
+        }
     }
 
     fn view(&self) -> Element<view::Message> {
diff --git a/liana-gui/src/app/view/message.rs b/liana-gui/src/app/view/message.rs
index dd874bacf..b317b1593 100644
--- a/liana-gui/src/app/view/message.rs
+++ b/liana-gui/src/app/view/message.rs
@@ -32,7 +32,7 @@ pub enum Message {
     Previous,
     SelectHardwareWallet(usize),
     CreateRbf(CreateRbfMessage),
-    ShowQrCode(usize),
+    ShowQrCode(usize, Option<String>),
     ImportExport(ImportExportMessage),
     HideRescanWarning,
     ExportPsbt,
diff --git a/liana-gui/src/app/view/receive.rs b/liana-gui/src/app/view/receive.rs
index fd015901a..b4506a328 100644
--- a/liana-gui/src/app/view/receive.rs
+++ b/liana-gui/src/app/view/receive.rs
@@ -37,6 +37,7 @@ use super::message::Message;
 fn address_card<'a>(
     row_index: usize,
     address: &'a bitcoin::Address,
+    maybe_bip21: Option<String>,
     labels: &'a HashMap<String, String>,
     labels_editing: &'a HashMap<String, form::Value<String>>,
 ) -> Container<'a, Message> {
@@ -83,7 +84,7 @@ fn address_card<'a>(
                     .push(Space::with_width(Length::Fill))
                     .push(
                         button::secondary(None, "Show QR Code")
-                            .on_press(Message::ShowQrCode(row_index)),
+                            .on_press(Message::ShowQrCode(row_index, maybe_bip21)),
                     ),
             )
             .spacing(10),
@@ -129,7 +130,7 @@ pub fn receive<'a>(
                     Column::new().spacing(10).width(Length::Fill),
                     |col, (i, address)| {
                         addresses_count += 1;
-                        col.push(address_card(i, address, labels, labels_editing))
+                        col.push(address_card(i, address, None, labels, labels_editing))
                     },
                 )),
         )
@@ -229,6 +230,7 @@ pub fn receive<'a>(
                         Button::new(address_card(
                             addresses_count + i,
                             address,
+                            None,
                             prev_labels,
                             labels_editing,
                         ))