From a73c70df07025e9349cb6b0ddf59e644e6e680bc Mon Sep 17 00:00:00 2001
From: panleone <alessandrorezzi2000@gmail.com>
Date: Fri, 7 Apr 2023 12:02:12 +0200
Subject: [PATCH] Return a vector of stakable shield notes

---
 src/sapling/saplingscriptpubkeyman.cpp | 44 ++++++++++++++++++++++++++
 src/sapling/saplingscriptpubkeyman.h   |  3 ++
 2 files changed, 47 insertions(+)

diff --git a/src/sapling/saplingscriptpubkeyman.cpp b/src/sapling/saplingscriptpubkeyman.cpp
index d0b9009a5e54b6..36f3243612518f 100644
--- a/src/sapling/saplingscriptpubkeyman.cpp
+++ b/src/sapling/saplingscriptpubkeyman.cpp
@@ -6,6 +6,7 @@
 #include "sapling/saplingscriptpubkeyman.h"
 
 #include "chain.h" // for CBlockIndex
+#include "saplingscriptpubkeyman.h"
 #include "validation.h" // for ReadBlockFromDisk()
 
 void SaplingScriptPubKeyMan::AddToSaplingSpends(const uint256& nullifier, const uint256& wtxid)
@@ -540,6 +541,49 @@ void SaplingScriptPubKeyMan::GetFilteredNotes(
         }
     }
 }
+void SaplingScriptPubKeyMan::GetStakableNotes(std::vector<CShieldStake>& shieldInputs, int minDepth)
+{
+    LOCK(wallet->cs_wallet);
+    for (auto& p : wallet->mapWallet) {
+        const CWalletTx& wtx = p.second;
+        // Filter coinbase/coinstakes transactions that don't have Sapling outputs
+        if ((wtx.IsCoinBase() || wtx.IsCoinStake()) && wtx.mapSaplingNoteData.empty()) {
+            continue;
+        }
+        // Filter the transactions before checking for notes
+        const int depth = wtx.GetDepthInMainChain();
+        if (!IsFinalTx(wtx.tx, wallet->GetLastBlockHeight() + 1, GetAdjustedTime()) ||
+            depth < minDepth) {
+            continue;
+        }
+        for (const auto& it : wtx.mapSaplingNoteData) {
+            const SaplingOutPoint& op = it.first;
+            const SaplingNoteData& nd = it.second;
+
+            // skip sent notes
+            if (!nd.IsMyNote()) continue;
+
+            // recover plaintext and address
+            auto optNotePtAndAddress = wtx.DecryptSaplingNote(op);
+            assert(static_cast<bool>(optNotePtAndAddress));
+
+            const libzcash::SaplingIncomingViewingKey& ivk = *(nd.ivk);
+            const libzcash::SaplingNotePlaintext& notePt = optNotePtAndAddress->first;
+            const libzcash::SaplingPaymentAddress& pa = optNotePtAndAddress->second;
+            auto note = notePt.note(ivk).get();
+
+            // skip notes which cannot be spent
+            if (!HaveSpendingKeyForPaymentAddress(pa)) {
+                continue;
+            }
+
+            if (nd.nullifier && IsSaplingSpent(*nd.nullifier)) {
+                continue;
+            }
+            shieldInputs.emplace_back(CShieldStake(note.value(), *nd.nullifier));
+        }
+    }
+}
 
 /* Return list of available notes grouped by sapling address. */
 std::map<libzcash::SaplingPaymentAddress, std::vector<SaplingNoteEntry>> SaplingScriptPubKeyMan::ListNotes() const
diff --git a/src/sapling/saplingscriptpubkeyman.h b/src/sapling/saplingscriptpubkeyman.h
index 5462e58a0ab7ab..830826da33d95f 100644
--- a/src/sapling/saplingscriptpubkeyman.h
+++ b/src/sapling/saplingscriptpubkeyman.h
@@ -294,6 +294,9 @@ class SaplingScriptPubKeyMan {
                           bool requireSpendingKey=true,
                           bool ignoreLocked=true) const;
 
+    /* Return a list of notes that are stakable */
+    void GetStakableNotes(std::vector<CShieldStake>& shieldInputs, int minDepth);
+
     /* Return list of available notes grouped by sapling address. */
     std::map<libzcash::SaplingPaymentAddress, std::vector<SaplingNoteEntry>> ListNotes() const;