From e7f14d76c00165f9af018b5a4d96b9e1f3545890cd2a244f6867365e0ac82a40 Mon Sep 17 00:00:00 2001
From: Minimons <morten.g.hermansen@gmail.com>
Date: Fri, 26 Jun 2026 20:44:01 +0200
Subject: [PATCH] 17: Implement AnchorIdlJupiterPerpsCustodyDecoder

---
 .../AnchorIdlJupiterPerpsCustodyDecoder.tjava | 49 +++++++++++++++++++
 .../AnchorIdlJupiterPerpsServiceImpl.tjava    | 27 +++++++---
 2 files changed, 70 insertions(+), 6 deletions(-)
 create mode 100644 src/main/tjava/com/r35157/libs/jupiter/perps/impl/anchoridl/AnchorIdlJupiterPerpsCustodyDecoder.tjava

diff --git a/src/main/tjava/com/r35157/libs/jupiter/perps/impl/anchoridl/AnchorIdlJupiterPerpsCustodyDecoder.tjava b/src/main/tjava/com/r35157/libs/jupiter/perps/impl/anchoridl/AnchorIdlJupiterPerpsCustodyDecoder.tjava
new file mode 100644
index 0000000..fc2ceb9
--- /dev/null
+++ b/src/main/tjava/com/r35157/libs/jupiter/perps/impl/anchoridl/AnchorIdlJupiterPerpsCustodyDecoder.tjava
@@ -0,0 +1,49 @@
+package com.r35157.libs.jupiter.perps.impl.anchoridl;
+
+import com.r35157.libs.solana.SolanaAccountInfo;
+import org.apache.commons.codec.binary.Base58;
+
+import java.util.Base64;
+
+class AnchorIdlJupiterPerpsCustodyDecoder {
+
+    ΩSPLMintAddressΩ decodeMint(
+            SolanaAccountInfo custodyAccountInfo
+    ) {
+        byte[] data = Base64.getDecoder().decode(custodyAccountInfo.dataBase64());
+
+        if (data.length < MINT_OFFSET + PUBLIC_KEY_LENGTH) {
+            throw new IllegalArgumentException(
+                    "Jupiter Perps custody account data is too short: " + data.length
+            );
+        }
+
+        return readPublicKey(data, MINT_OFFSET);
+    }
+
+    private ΩSPLMintAddressΩ readPublicKey(
+            byte[] data,
+            int offset
+    ) {
+        byte[] publicKeyBytes = new byte[PUBLIC_KEY_LENGTH];
+
+        System.arraycopy(
+                data,
+                offset,
+                publicKeyBytes,
+                0,
+                PUBLIC_KEY_LENGTH
+        );
+
+        return base58.encode(publicKeyBytes);
+    }
+
+    private static final int ANCHOR_DISCRIMINATOR_LENGTH = 8;
+    private static final int PUBLIC_KEY_LENGTH = 32;
+
+    private static final int MINT_OFFSET =
+            ANCHOR_DISCRIMINATOR_LENGTH
+                    + PUBLIC_KEY_LENGTH; // pool
+
+    private static final Base58 base58 = Base58.getInstance();
+}
\ No newline at end of file
diff --git a/src/main/tjava/com/r35157/libs/jupiter/perps/impl/anchoridl/AnchorIdlJupiterPerpsServiceImpl.tjava b/src/main/tjava/com/r35157/libs/jupiter/perps/impl/anchoridl/AnchorIdlJupiterPerpsServiceImpl.tjava
index c7b8640..78a718a 100644
--- a/src/main/tjava/com/r35157/libs/jupiter/perps/impl/anchoridl/AnchorIdlJupiterPerpsServiceImpl.tjava
+++ b/src/main/tjava/com/r35157/libs/jupiter/perps/impl/anchoridl/AnchorIdlJupiterPerpsServiceImpl.tjava
@@ -34,9 +34,9 @@ public class AnchorIdlJupiterPerpsServiceImpl implements JupiterPerpsService {
             );
         }
 
-        ΩSPLMintAddressΩ tradedTokenMint = "";
-
+        ΩSPLMintAddressΩ tradedTokenMint = getTradedTokenMint(accountInfo);
         JupiterPerpsPosition pos = positionDecoder.decode(positionAccount, accountInfo, tradedTokenMint);
+
         return pos;
     }
 
@@ -63,16 +63,31 @@ public class AnchorIdlJupiterPerpsServiceImpl implements JupiterPerpsService {
                 throw new IllegalArgumentException(errorMsg);
             }
 
-            JupiterPerpsPosition position = positionDecoder.decode(
-                    address,
-                    accountInfo
-            );
+            ΩSPLMintAddressΩ tradedTokenMint = getTradedTokenMint(accountInfo);
+
+            JupiterPerpsPosition position = positionDecoder.decode(address, accountInfo, tradedTokenMint);
             positions.add(position);
         }
 
         return Set.copyOf(positions);
     }
 
+    private ΩSPLMintAddressΩ getTradedTokenMint(SolanaAccountInfo positionAccountInfo)
+            throws IOException, InterruptedException
+    {
+        ΩSolanaAddressΩ custodyAccount = positionDecoder.decodeCustodyAccount(positionAccountInfo);
+        SolanaAccountInfo custodyAccountInfo = solanaBlockChain.getAccountInfo(custodyAccount);
+
+        if (custodyAccountInfo == null) {
+            throw new IllegalArgumentException(
+                    "Jupiter Perps custody account does not exist: " + custodyAccount
+            );
+        }
+
+        ΩSPLMintAddressΩ mintAddress = custodyDecoder.decodeMint(custodyAccountInfo);
+        return mintAddress;
+    }
+
     private static final ΩJupiterPerpsProgramIdΩ JUPITER_PERPS_PROGRAM_ID =
             "PERPHjGBqRHArX4DySjwM6UJHiR3sWAatqfdBS2qQJu";
     private static final int POSITION_OWNER_OFFSET = 8;