From 8519e91f6d4d176c220091d432069c7a18d44286 Mon Sep 17 00:00:00 2001
From: Dr Maxim Orlovsky <orlovsky@lnp-bp.org>
Date: Sun, 30 Jul 2023 12:57:02 +0200
Subject: [PATCH] descriptor: add set of standard descriptors

---
 std/src/derive.rs      |  7 +++++++
 std/src/descriptors.rs | 30 ++++++++++++++++++++++++------
 std/src/lib.rs         |  4 ++--
 std/src/wallet.rs      |  6 ++++--
 4 files changed, 37 insertions(+), 10 deletions(-)

diff --git a/std/src/derive.rs b/std/src/derive.rs
index 41e45ab..66c70d1 100644
--- a/std/src/derive.rs
+++ b/std/src/derive.rs
@@ -20,6 +20,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use bc::secp256k1::PublicKey;
 use bc::{InternalPk, ScriptPubkey};
 
 use crate::{Address, AddressNetwork, ComprPubkey, Idx, NormalIndex};
@@ -88,3 +89,9 @@ pub trait DeriveSpk: Derive<Derived = ScriptPubkey> {
     }
 }
 impl<T: Derive<Derived = ScriptPubkey>> DeriveSpk for T {}
+
+pub trait DeriveSet {
+    type Base: Derive<Derived = PublicKey>;
+    type Compr: DeriveCompr<Derived = ComprPubkey>;
+    type XOnly: DeriveXOnly<Derived = InternalPk>;
+}
diff --git a/std/src/descriptors.rs b/std/src/descriptors.rs
index e12205e..0cee5d6 100644
--- a/std/src/descriptors.rs
+++ b/std/src/descriptors.rs
@@ -22,10 +22,17 @@
 
 use bc::ScriptPubkey;
 
-use crate::{Derive, DeriveXOnly, NormalIndex};
+use crate::{Derive, DeriveSet, DeriveSpk, DeriveXOnly, NormalIndex};
 
 pub struct TrKey<K: DeriveXOnly>(K);
 
+/*
+pub struct TrScript<K: DeriveXOnly> {
+    internal_key: K,
+    tap_tree: TapTree<Policy<K>>,
+}
+*/
+
 impl<K: DeriveXOnly> Derive for TrKey<K> {
     type Derived = ScriptPubkey;
 
@@ -39,9 +46,20 @@ impl<K: DeriveXOnly> Derive for TrKey<K> {
     }
 }
 
-/*
-pub struct TrScript<K: DeriveXOnly> {
-    internal_key: K,
-    tap_tree: TapTree<Policy<K>>,
+pub enum DescriptorStd<S: DeriveSet> {
+    TrKey(TrKey<S::XOnly>),
+}
+
+impl<S: DeriveSet> Derive for DescriptorStd<S> {
+    type Derived = ScriptPubkey;
+
+    fn derive(
+        &self,
+        change: impl Into<NormalIndex>,
+        index: impl Into<NormalIndex>,
+    ) -> Self::Derived {
+        match self {
+            DescriptorStd::TrKey(d) => d.derive(change, index),
+        }
+    }
 }
-*/
diff --git a/std/src/lib.rs b/std/src/lib.rs
index 388fd1e..5576ad7 100644
--- a/std/src/lib.rs
+++ b/std/src/lib.rs
@@ -44,8 +44,8 @@ pub use address::{
 };
 pub use bc::{secp256k1, *};
 pub use chain::{AddrInfo, BlockInfo, MiningInfo, TxInInfo, TxInfo, TxOutInfo, TxStatus, UtxoInfo};
-pub use derive::{Derive, DeriveCompr, DeriveSpk, DeriveXOnly};
-pub use descriptors::TrKey;
+pub use derive::{Derive, DeriveCompr, DeriveSet, DeriveSpk, DeriveXOnly};
+pub use descriptors::{DescriptorStd, TrKey};
 pub use index::{
     DerivationIndex, HardenedIndex, Idx, IndexError, IndexParseError, NormalIndex,
     HARDENED_INDEX_BOUNDARY,
diff --git a/std/src/wallet.rs b/std/src/wallet.rs
index 42168b0..219f244 100644
--- a/std/src/wallet.rs
+++ b/std/src/wallet.rs
@@ -25,7 +25,7 @@ use std::collections::{BTreeMap, BTreeSet, HashMap};
 use std::num::NonZeroU32;
 use std::ops::Deref;
 
-use bc::{Outpoint, ScriptPubkey, Txid};
+use bc::{Chain, Outpoint, ScriptPubkey, Txid};
 
 use crate::chain::BlockHeight;
 use crate::derive::DeriveSpk;
@@ -37,6 +37,8 @@ where D: DeriveSpk
 {
     script_pubkey: D,
     keychains: BTreeSet<NormalIndex>,
+    #[getter(as_copy)]
+    chain: Chain,
 }
 
 impl<D: DeriveSpk> Deref for WalletDescr<D> {
@@ -63,7 +65,7 @@ pub struct WalletCache {
     max_known: HashMap<NormalIndex, NormalIndex>,
 }
 
-pub struct Wallet<D: DeriveSpk, L2 = ()> {
+pub struct Wallet<D: DeriveSpk, L2: Default = ()> {
     descr: WalletDescr<D>,
     data: WalletData,
     cache: WalletCache,