Closes #2910. Add z_listunspent RPC call.

src/wallet/wallet.cpp

@@ -3758,3 +3758,80 @@ void CWallet::GetFilteredNotes(
         }
     }
 }
+
+
+/* Find unspent notes filtered by payment address, min depth and max depth */
+void CWallet::GetUnspentFilteredNotes(
+    std::vector<CUnspentNotePlaintextEntry>& outEntries,
+    std::set<PaymentAddress>& filterAddresses,
+    int minDepth,
+    int maxDepth,
+    bool requireSpendingKey)
+{
+    LOCK2(cs_main, cs_wallet);
+
+    for (auto & p : mapWallet) {
+        CWalletTx wtx = p.second;
+
+        // Filter the transactions before checking for notes
+        if (!CheckFinalTx(wtx) || wtx.GetBlocksToMaturity() > 0 || wtx.GetDepthInMainChain() < minDepth || wtx.GetDepthInMainChain() > maxDepth) {
+            continue;
+        }
+
+        if (wtx.mapNoteData.size() == 0) {
+            continue;
+        }
+
+        for (auto & pair : wtx.mapNoteData) {
+            JSOutPoint jsop = pair.first;
+            CNoteData nd = pair.second;
+            PaymentAddress pa = nd.address;
+
+            // skip notes which belong to a different payment address in the wallet
+            if (!(filterAddresses.empty() || filterAddresses.count(pa))) {
+                continue;
+            }
+
+            // skip note which has been spent
+            if (nd.nullifier && IsSpent(*nd.nullifier)) {
+                continue;
+            }
+
+            // skip notes where the spending key is not available
+            if (requireSpendingKey && !HaveSpendingKey(pa)) {
+                continue;
+            }
+
+            int i = jsop.js; // Index into CTransaction.vjoinsplit
+            int j = jsop.n; // Index into JSDescription.ciphertexts
+
+            // Get cached decryptor
+            ZCNoteDecryption decryptor;
+            if (!GetNoteDecryptor(pa, decryptor)) {
+                // Note decryptors are created when the wallet is loaded, so it should always exist
+                throw std::runtime_error(strprintf("Could not find note decryptor for payment address %s", CZCPaymentAddress(pa).ToString()));
+            }
+
+            // determine amount of funds in the note
+            auto hSig = wtx.vjoinsplit[i].h_sig(*pzcashParams, wtx.joinSplitPubKey);
+            try {
+                NotePlaintext plaintext = NotePlaintext::decrypt(
+                        decryptor,
+                        wtx.vjoinsplit[i].ciphertexts[j],
+                        wtx.vjoinsplit[i].ephemeralKey,
+                        hSig,
+                        (unsigned char) j);
+
+                outEntries.push_back(CUnspentNotePlaintextEntry{jsop, pa, plaintext, wtx.GetDepthInMainChain()});
+
+            } catch (const note_decryption_failed &err) {
+                // Couldn't decrypt with this spending key
+                throw std::runtime_error(strprintf("Could not decrypt note for payment address %s", CZCPaymentAddress(pa).ToString()));
+            } catch (const std::exception &exc) {
+                // Unexpected failure
+                throw std::runtime_error(strprintf("Error while decrypting note for payment address %s: %s", CZCPaymentAddress(pa).ToString(), exc.what()));
+            }
+        }
+    }
+}
+