From 7d914961322f7c206fd298f2e749a7b7c09f357c Mon Sep 17 00:00:00 2001
From: MoCipher <info@mocipher.com>
Date: Fri, 20 Feb 2026 09:58:56 +0100
Subject: [PATCH] feat(uniffi): add UniFFI bridge functions + tests
 (generate_mnemonic, first_receive_address, create_psbt, sign_psbt)

---
 core/src/lib.rs                   |  3 +++
 core/src/uniffi.rs                | 44 +++++++++++++++++++++++++++++++
 core/tests/uniffi_bridge_tests.rs | 20 ++++++++++++++
 3 files changed, 67 insertions(+)
 create mode 100644 core/src/uniffi.rs
 create mode 100644 core/tests/uniffi_bridge_tests.rs

diff --git a/core/src/lib.rs b/core/src/lib.rs
index beb1683..435aba0 100644
--- a/core/src/lib.rs
+++ b/core/src/lib.rs
@@ -30,6 +30,9 @@ pub use swap_manager::SwapOffer;
 pub use swap_sim::SwapSimulation;
 pub use wallet_manager::{register_decrypted_db, close_decrypted_db, register_inmemory_db, close_inmemory_db, close_all, list_handles};
 
+mod uniffi;
+pub use uniffi::{generate_mnemonic, first_receive_address, create_psbt, sign_psbt};
+
 /// WalletCore: minimal demonstrative API
 pub struct WalletCore {
     // In a real implementation, secrets should be stored in a secure enclave or encrypted storage
diff --git a/core/src/uniffi.rs b/core/src/uniffi.rs
new file mode 100644
index 0000000..7d3265c
--- /dev/null
+++ b/core/src/uniffi.rs
@@ -0,0 +1,44 @@
+use crate::bip39::Mnemonic as LocalMnemonic;
+use crate::wallet_bdk::{BdkWallet, PersistentBdkWallet};
+use bitcoin::Network;
+
+/// UniFFI-compatible thin bridge functions consumed by mobile/native bindings.
+/// These mirror the `cryptec.udl` UDL surface and delegate to existing core logic.
+
+/// Generate a BIP39 mnemonic (wordlist phrase)
+pub fn generate_mnemonic(strength: u32) -> String {
+    // Accept strengths like 128, 160, 192, 224, 256
+    let s = match strength {
+        128 | 160 | 192 | 224 | 256 => strength as usize,
+        _ => 128,
+    };
+    let m = LocalMnemonic::generate(s);
+    m.phrase
+}
+
+/// Return the first (external 0) receive address for the given mnemonic (Testnet)
+pub fn first_receive_address(mnemonic: &str) -> String {
+    // Reuse the BDK wallet helper which already derives descriptors/addresses
+    let w = match BdkWallet::new_from_mnemonic(mnemonic, "", Network::Testnet) {
+        Ok(x) => x,
+        Err(_) => return String::new(),
+    };
+    match w.get_new_address() {
+        Ok(a) => a,
+        Err(_) => String::new(),
+    }
+}
+
+/// Create a PSBT (base64) using the mnemonic (Testnet)
+pub fn create_psbt(mnemonic: &str, to_address: &str, satoshis: u64) -> String {
+    let w = BdkWallet::new_from_mnemonic(mnemonic, "", Network::Testnet)
+        .expect("create wallet");
+    w.create_psbt(to_address, satoshis).expect("create psbt")
+}
+
+/// Sign a PSBT (base64) with the wallet's internal keys (Testnet)
+pub fn sign_psbt(mnemonic: &str, psbt_b64: &str) -> String {
+    let w = BdkWallet::new_from_mnemonic(mnemonic, "", Network::Testnet)
+        .expect("create wallet");
+    w.sign_psbt_base64(psbt_b64).expect("sign psbt")
+}
diff --git a/core/tests/uniffi_bridge_tests.rs b/core/tests/uniffi_bridge_tests.rs
new file mode 100644
index 0000000..d20b7c0
--- /dev/null
+++ b/core/tests/uniffi_bridge_tests.rs
@@ -0,0 +1,20 @@
+use crate::uniffi::{generate_mnemonic, first_receive_address, create_psbt, sign_psbt};
+
+#[test]
+fn uniffi_generate_and_address() {
+    let m = generate_mnemonic(128);
+    assert!(!m.is_empty());
+    let addr = first_receive_address(&m);
+    assert!(!addr.is_empty());
+}
+
+#[test]
+fn uniffi_psbt_roundtrip_mock() {
+    let m = generate_mnemonic(128);
+    let addr = first_receive_address(&m);
+    assert!(!addr.is_empty());
+    let psbt = create_psbt(&m, &addr, 1000);
+    assert!(!psbt.is_empty());
+    let signed = sign_psbt(&m, &psbt);
+    assert!(!signed.is_empty());
+}