From cd566b91af07a53f9651c034ef4da95a8a033c56 Mon Sep 17 00:00:00 2001
From: Antoine Poinsot <darosior@protonmail.com>
Date: Thu, 23 Mar 2023 16:23:31 +0100
Subject: [PATCH] descriptors: rename LianaDescInfo into LianaPolicy

What this really represents is a spending policy. We'll extend it to be
able to infer it from a descriptor and to create a descriptor from it.
---
 src/descriptors/analysis.rs | 11 +++++------
 src/descriptors/mod.rs      | 14 +++++++-------
 2 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/src/descriptors/analysis.rs b/src/descriptors/analysis.rs
index 749e6937..5a725f69 100644
--- a/src/descriptors/analysis.rs
+++ b/src/descriptors/analysis.rs
@@ -200,17 +200,16 @@ impl PathInfo {
     }
 }
 
-/// Information about the descriptor: how many keys are present in each path, what's the timelock
-/// of the recovery path, what's the threshold if there are multiple keys, etc..
+/// A Liana spending policy.
 #[derive(Debug, Eq, PartialEq, Clone, Ord, PartialOrd, Hash)]
-pub struct LianaDescInfo {
+pub struct LianaPolicy {
     pub(super) primary_path: PathInfo,
     pub(super) recovery_path: (u16, PathInfo),
 }
 
-impl LianaDescInfo {
-    pub(super) fn new(primary_path: PathInfo, recovery_path: (u16, PathInfo)) -> LianaDescInfo {
-        LianaDescInfo {
+impl LianaPolicy {
+    pub(super) fn new(primary_path: PathInfo, recovery_path: (u16, PathInfo)) -> LianaPolicy {
+        LianaPolicy {
             primary_path,
             recovery_path,
         }
diff --git a/src/descriptors/mod.rs b/src/descriptors/mod.rs
index 5037b6ca..e14494be 100644
--- a/src/descriptors/mod.rs
+++ b/src/descriptors/mod.rs
@@ -291,8 +291,8 @@ impl MultipathDescriptor {
         &self.change_desc
     }
 
-    /// Parse information about this descriptor
-    pub fn info(&self) -> LianaDescInfo {
+    /// Get the spending policy of this descriptor.
+    pub fn policy(&self) -> LianaPolicy {
         // Get the Miniscript
         let wsh_desc = match &self.multi_desc {
             descriptor::Descriptor::Wsh(desc) => desc,
@@ -338,13 +338,13 @@ impl MultipathDescriptor {
         let reco_path = PathInfo::from_recovery_path(reco_path_sub)
             .expect("The recovery path policy must always be a timelock along with a set of keys.");
 
-        LianaDescInfo::new(primary_path, reco_path)
+        LianaPolicy::new(primary_path, reco_path)
     }
 
     /// Get the value (in blocks) of the relative timelock for the heir's spending path.
     pub fn timelock_value(&self) -> u32 {
         // TODO: make it return a u16
-        self.info().recovery_path.0 as u32
+        self.policy().recovery_path.0 as u32
     }
 
     /// Get the maximum size in WU of a satisfaction for this descriptor.
@@ -390,7 +390,7 @@ impl MultipathDescriptor {
         // Determine the structure of the descriptor. Then compute the spend info for the primary
         // and recovery paths. Only provide the spend info for the recovery path if it is available
         // (ie if the nSequence is >= to the chosen CSV value).
-        let desc_info = self.info();
+        let desc_info = self.policy();
         let primary_path = desc_info.primary_path.spend_info(pubkeys_signed.clone());
         let recovery_path = if txin.sequence.is_height_locked()
             && txin.sequence.0 >= desc_info.recovery_path.0 as u32
@@ -772,7 +772,7 @@ mod tests {
     fn partial_spend_info() {
         // A simple descriptor with 1 keys as primary path and 1 recovery key.
         let desc = MultipathDescriptor::from_str("wsh(or_d(pk([f5acc2fd]tpubD6NzVbkrYhZ4YgUx2ZLNt2rLYAMTdYysCRzKoLu2BeSHKvzqPaBDvf17GeBPnExUVPkuBpx4kniP964e2MxyzzazcXLptxLXModSVCVEV1T/<0;1>/*),and_v(v:pkh([8a64f2a9]tpubD6NzVbkrYhZ4WmzFjvQrp7sDa4ECUxTi9oby8K4FZkd3XCBtEdKwUiQyYJaxiJo5y42gyDWEczrFpozEjeLxMPxjf2WtkfcbpUdfvNnozWF/<0;1>/*),older(10))))#d72le4dr").unwrap();
-        let desc_info = desc.info();
+        let desc_info = desc.policy();
         let prim_key_origin = (
             bip32::Fingerprint::from_str("f5acc2fd").unwrap(),
             Vec::new().into(),
@@ -949,7 +949,7 @@ mod tests {
         assert!(info.recovery_path.is_none());
 
         let desc = MultipathDescriptor::from_str("wsh(or_d(multi(2,[636adf3f/48'/1'/0'/2']tpubDEE9FvWbG4kg4gxDNrALgrWLiHwNMXNs8hk6nXNPw4VHKot16xd2251vwi2M6nsyQTkak5FJNHVHkCcuzmvpSbWHdumX3DxpDm89iTfSBaL/<0;1>/*,[ffd63c8d/48'/1'/0'/2']tpubDExA3EC3iAsPxPhFn4j6gMiVup6V2eH3qKyk69RcTc9TTNRfFYVPad8bJD5FCHVQxyBT4izKsvr7Btd2R4xmQ1hZkvsqGBaeE82J71uTK4N/<0;1>/*),and_v(v:multi(2,[636adf3f/48'/1'/1'/2']tpubDDvF2khuoBBj8vcSjQfa7iKaxsQZE7YjJ7cJL8A8eaneadMPKbHSpoSr4JD1F5LUvWD82HCxdtSppGfrMUmiNbFxrA2EHEVLnrdCFNFe75D/<0;1>/*,[ffd63c8d/48'/1'/1'/2']tpubDFMs44FD4kFt3M7Z317cFh5tdKEGN8tyQRY6Q5gcSha4NtxZfGmTVRMbsD1bWN469LstXU4aVSARDxrvxFCUjHeegfEY2cLSazMBkNCmDPD/<0;1>/*),older(2))))#xcf6jr2r").unwrap();
-        let info = desc.info();
+        let info = desc.policy();
         assert_eq!(info.primary_path, PathInfo::Multi(
             2,
             vec![