Multi Descriptor Wallet API [MVP Refactoring]

crates/bdk/src/types.rs

@@ -166,8 +166,6 @@ pub struct LocalUtxo {
     pub outpoint: OutPoint,
     /// Transaction output
     pub txout: TxOut,
-    /// Type of keychain
-    pub keychain: KeychainKind,
     /// Whether this UTXO is spent or not
     pub is_spent: bool,
     /// The derivation index for the script pubkey in the wallet
@@ -268,6 +266,56 @@ impl Ord for TransactionDetails {
     }
 }
 
+#[derive(Debug, PartialEq, Eq, Clone, Default)]
+pub struct Balance {
+    /// All coinbase outputs not yet matured
+    pub immature: u64,
+    /// Unconfirmed UTXOs generated by a wallet tx
+    pub trusted_pending: u64,
+    /// Unconfirmed UTXOs received from an external wallet
+    pub untrusted_pending: u64,
+    /// Confirmed and immediately spendable balance
+    pub confirmed: u64,
+}
+
+impl Balance {
+    /// Get sum of trusted_pending and confirmed coins.
+    ///
+    /// This is the balance you can spend right now that shouldn't get cancelled via another party
+    /// double spending it.
+    pub fn trusted_spendable(&self) -> u64 {
+        self.confirmed + self.trusted_pending
+    }
+
+    /// Get the whole balance visible to the wallet.
+    pub fn total(&self) -> u64 {
+        self.confirmed + self.trusted_pending + self.untrusted_pending + self.immature
+    }
+}
+
+impl core::fmt::Display for Balance {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        write!(
+            f,
+            "{{ immature: {}, trusted_pending: {}, untrusted_pending: {}, confirmed: {} }}",
+            self.immature, self.trusted_pending, self.untrusted_pending, self.confirmed
+        )
+    }
+}
+
+impl core::ops::Add for Balance {
+    type Output = Self;
+
+    fn add(self, other: Self) -> Self {
+        Self {
+            immature: self.immature + other.immature,
+            trusted_pending: self.trusted_pending + other.trusted_pending,
+            untrusted_pending: self.untrusted_pending + other.untrusted_pending,
+            confirmed: self.confirmed + other.confirmed,
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

crates/bdk/src/wallet/coin_selection.rs

@@ -712,7 +712,6 @@ mod test {
                     value,
                     script_pubkey: Script::new(),
                 },
-                keychain: KeychainKind::External,
                 is_spent: false,
                 derivation_index: 42,
                 confirmation_time,
@@ -771,7 +770,6 @@ mod test {
                         value: rng.gen_range(0..200000000),
                         script_pubkey: Script::new(),
                     },
-                    keychain: KeychainKind::External,
                     is_spent: false,
                     derivation_index: rng.next_u32(),
                     confirmation_time: if rng.gen_bool(0.5) {
@@ -800,7 +798,6 @@ mod test {
                     value: utxos_value,
                     script_pubkey: Script::new(),
                 },
-                keychain: KeychainKind::External,
                 is_spent: false,
                 derivation_index: 42,
                 confirmation_time: ConfirmationTime::Unconfirmed,

crates/bdk/src/wallet/export.rs

@@ -118,6 +118,7 @@ impl FullyNodedExport {
     ) -> Result<Self, &'static str> {
         let descriptor = wallet
             .get_descriptor_for_keychain(KeychainKind::External)
+            .expect("external descriptor is always expected for default wallet")
             .to_string_with_secret(
                 &wallet
                     .get_signers(KeychainKind::External)
@@ -147,6 +148,7 @@ impl FullyNodedExport {
             true => {
                 let descriptor = wallet
                     .get_descriptor_for_keychain(KeychainKind::Internal)
+                    .expect("we ensured that public descriptor exists at this point")
                     .to_string_with_secret(
                         &wallet
                             .get_signers(KeychainKind::Internal)