program: add explanation for borrow (#772)

* program: add explanation for borrow

* CHANGELOG

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Features
 
+- program: add borrow explanation to DepositRecords ([#772](https://github.com/drift-labs/protocol-v2/pull/772))
 - sdk: OrderSubscriber has resync option ([#780](https://github.com/drift-labs/protocol-v2/pull/780))
 - program: only consider recent last_active_slot in qualifies_for_withdraw_feen ([#756](https://github.com/drift-labs/protocol-v2/pull/756))
 - program: amm can use reference price offset from oracle price based on clamped inventory and persist market premiums ([#681](https://github.com/drift-labs/protocol-v2/pull/681))

programs/drift/src/instructions/user.rs

@@ -531,6 +531,15 @@ pub fn handle_withdraw(
     let mut spot_market = spot_market_map.get_ref_mut(&market_index)?;
     let oracle_price = oracle_map.get_price_data(&spot_market.oracle)?.price;
 
+    let is_borrow = user
+        .get_spot_position(market_index)
+        .map_or(false, |pos| pos.is_borrow());
+    let deposit_explanation = if is_borrow {
+        DepositExplanation::Borrow
+    } else {
+        DepositExplanation::None
+    };
+
     let deposit_record_id = get_then_update_id!(spot_market, next_deposit_record_id);
     let deposit_record = DepositRecord {
         ts: now,
@@ -547,7 +556,7 @@ pub fn handle_withdraw(
         market_cumulative_borrow_interest: spot_market.cumulative_borrow_interest,
         total_deposits_after: user.total_deposits,
         total_withdraws_after: user.total_withdraws,
-        explanation: DepositExplanation::None,
+        explanation: deposit_explanation,
         transfer_user: None,
     };
     emit!(deposit_record);

programs/drift/src/state/events.rs

@@ -44,6 +44,7 @@ pub struct DepositRecord {
 pub enum DepositExplanation {
     None,
     Transfer,
+    Borrow,
 }
 
 impl Default for DepositExplanation {

programs/drift/src/state/user.rs

@@ -674,6 +674,10 @@ impl SpotPosition {
 
         Ok([bid_simulation, ask_simulation])
     }
+
+    pub fn is_borrow(&self) -> bool {
+        self.scaled_balance > 0 && self.balance_type == SpotBalanceType::Borrow
+    }
 }
 
 #[zero_copy(unsafe)]

sdk/src/idl/drift.json

@@ -8244,6 +8244,9 @@
           },
           {
             "name": "Transfer"
+          },
+          {
+            "name": "Borrow"
           }
         ]
       }

sdk/src/types.ts

@@ -182,6 +182,7 @@ export class SpotFulfillmentStatus {
 export class DepositExplanation {
 	static readonly NONE = { none: {} };
 	static readonly TRANSFER = { transfer: {} };
+	static readonly BORROW = { borrow: {} };
 }
 
 export class SettlePnlExplanation {