refactor: use macros for ChainPosition

Author: rustaceanrob

bdk-ffi/src/bdk.udl

@@ -307,17 +307,7 @@ dictionary LocalOutput {
 
 typedef dictionary TxOut;
 
-/// Represents the observed position of some chain data.
-[Enum]
-interface ChainPosition {
-  /// The chain data is confirmed as it is anchored in the best chain by `A`.
-  Confirmed(ConfirmationBlockTime confirmation_block_time, string? transitively);
-
-  /// The chain data is not confirmed and last seen in the mempool at this timestamp.
-  Unconfirmed(u64? timestamp);
-};
-
-typedef dictionary ConfirmationBlockTime;
+typedef enum ChainPosition;
 
 dictionary CanonicalTx {
   Transaction transaction;

bdk-ffi/src/lib.rs

@@ -47,7 +47,6 @@ use crate::types::AddressInfo;
 use crate::types::CanonicalTx;
 use crate::types::ChainPosition;
 use crate::types::Condition;
-use crate::types::ConfirmationBlockTime;
 use crate::types::FullScanRequest;
 use crate::types::FullScanRequestBuilder;
 use crate::types::FullScanScriptInspector;

bdk-ffi/src/types.rs

@@ -42,15 +42,19 @@ pub enum KeychainKind {
     Internal = 1,
 }
 
-#[derive(Debug)]
+/// Represents the observed position of some chain data.
+#[derive(Debug, uniffi::Enum)]
 pub enum ChainPosition {
+    /// The chain data is confirmed as it is anchored in the best chain by `A`.
     Confirmed {
         confirmation_block_time: ConfirmationBlockTime,
+        /// A child transaction that has been confirmed. Due to incomplete information,
+        /// it is only known that this transaction is confirmed at a chain height less than
+        /// or equal to this child TXID.
         transitively: Option<String>,
     },
-    Unconfirmed {
-        timestamp: Option<u64>,
-    },
+    /// The transaction was last seen in the mempool at this timestamp.
+    Unconfirmed { timestamp: Option<u64> },
 }
 
 impl From<BdkChainPosition<BdkConfirmationBlockTime>> for ChainPosition {