From 02a26751bb51cf6a576790c487872a21b5beccb5 Mon Sep 17 00:00:00 2001
From: Duke <duke@hush.is>
Date: Mon, 13 Oct 2025 15:06:42 -0400
Subject: [PATCH] WIP donation

---
 src/wallet/asyncrpcoperation_shieldcoinbase.cpp | 11 ++++++++++-
 src/wallet/asyncrpcoperation_shieldcoinbase.h   |  2 +-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/wallet/asyncrpcoperation_shieldcoinbase.cpp b/src/wallet/asyncrpcoperation_shieldcoinbase.cpp
index ce4da86fe..dfb1932a1 100644
--- a/src/wallet/asyncrpcoperation_shieldcoinbase.cpp
+++ b/src/wallet/asyncrpcoperation_shieldcoinbase.cpp
@@ -54,6 +54,7 @@ AsyncRPCOperation_shieldcoinbase::AsyncRPCOperation_shieldcoinbase(
         std::vector<ShieldCoinbaseUTXO> inputs,
         std::string toAddress,
         CAmount fee,
+        CAmount donation,
         UniValue contextInfo) :
         builder_(builder), tx_(contextualTx), inputs_(inputs), fee_(fee), contextinfo_(contextInfo)
 {
@@ -214,6 +215,13 @@ bool ShieldToAddress::operator()(const libzcash::SaplingPaymentAddress &zaddr) c
         }
     }
 
+    //TODO: randomly select from a set
+    auto dzaddr         = "zs1...";
+    auto donationZaddr = DecodePaymentAddress(dzaddr);
+    if (!IsValidPaymentAddress(donationZaddr)) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, string("Unknown address format: ") + dzaddr);
+    }
+
     //TODO: if donation==true, send X% of value to zaddr and Y% of of value to donatezaddr
     // Send all value to the target z-addr
     if(donation) {
@@ -222,7 +230,8 @@ bool ShieldToAddress::operator()(const libzcash::SaplingPaymentAddress &zaddr) c
 
         CAmount donationAmount = 0; //TODO calculate exact donation amount in puposhis
         // donation recipient as second output
-        m_op->builder_.AddSaplingOutput(ovk, donationZaddr, donationAmount);
+        auto donationZout   = boost::get<libzcash::SaplingPaymentAddress>(donationZaddr);
+        m_op->builder_.AddSaplingOutput(ovk, donationZout, donationAmount);
     
         // zdust as third output, so donation txs are indistinguishable from
         // non-donation z_shieldcoinbase txs
diff --git a/src/wallet/asyncrpcoperation_shieldcoinbase.h b/src/wallet/asyncrpcoperation_shieldcoinbase.h
index ce8de1c4d..c07b638fb 100644
--- a/src/wallet/asyncrpcoperation_shieldcoinbase.h
+++ b/src/wallet/asyncrpcoperation_shieldcoinbase.h
@@ -49,7 +49,7 @@ public:
         std::vector<ShieldCoinbaseUTXO> inputs,
         std::string toAddress,
         CAmount fee = SHIELD_COINBASE_DEFAULT_MINERS_FEE,
-        CAmount donation,
+        CAmount donation = 0,
         UniValue contextInfo = NullUniValue);
     virtual ~AsyncRPCOperation_shieldcoinbase();