From d43923c38155fdadad3837d79c19a84c9d2d7f50 Mon Sep 17 00:00:00 2001
From: Andrew Chow <achow101-github@achow101.com>
Date: Mon, 12 Jul 2021 17:04:46 -0400
Subject: [PATCH] Add TaprootBuilder::GetTreeTuples

GetTreeTuples returns the leaves in DFS order as tuples of depth, leaf
version, and script. This is a representation of the tree that can be
serialized.
---
 src/script/standard.cpp | 16 ++++++++++++++++
 src/script/standard.h   |  2 ++
 2 files changed, 18 insertions(+)

diff --git a/src/script/standard.cpp b/src/script/standard.cpp
index e25155d3dd7..063e149d36c 100644
--- a/src/script/standard.cpp
+++ b/src/script/standard.cpp
@@ -642,3 +642,19 @@ std::optional<std::vector<std::tuple<int, CScript, int>>> InferTaprootTree(const
 
     return ret;
 }
+
+std::vector<std::tuple<uint8_t, uint8_t, CScript>> TaprootBuilder::GetTreeTuples() const
+{
+    assert(IsComplete());
+    std::vector<std::tuple<uint8_t, uint8_t, CScript>> tuples;
+    if (m_branch.size()) {
+        const auto& leaves = m_branch[0]->leaves;
+        for (const auto& leaf : leaves) {
+            assert(leaf.merkle_branch.size() <= TAPROOT_CONTROL_MAX_NODE_COUNT);
+            uint8_t depth = (uint8_t)leaf.merkle_branch.size();
+            uint8_t leaf_ver = (uint8_t)leaf.leaf_version;
+            tuples.push_back(std::make_tuple(depth, leaf_ver, leaf.script));
+        }
+    }
+    return tuples;
+}
diff --git a/src/script/standard.h b/src/script/standard.h
index 6a15ba4e3d5..448fdff0109 100644
--- a/src/script/standard.h
+++ b/src/script/standard.h
@@ -322,6 +322,8 @@ public:
     static bool ValidDepths(const std::vector<int>& depths);
     /** Compute spending data (after Finalize()). */
     TaprootSpendData GetSpendData() const;
+    /** Returns a vector of tuples representing the depth, leaf version, and script */
+    std::vector<std::tuple<uint8_t, uint8_t, CScript>> GetTreeTuples() const;
 };
 
 /** Given a TaprootSpendData and the output key, reconstruct its script tree.