update unified balance if user deposits or withdraws through resize

custody.go

@@ -287,7 +287,7 @@ func (c *Custody) handleBlockChainEvent(l types.Log) {
 			return nil
 		})
 		if err != nil {
-			log.Printf("[Closed] Error closing channel in database: %v", err)
+			log.Printf("[Closed] Error closing channel: %v", err)
 			return
 		}
 		c.sendBalanceUpdate(channel.Participant)
@@ -296,33 +296,59 @@ func (c *Custody) handleBlockChainEvent(l types.Log) {
 	case custodyAbi.Events["Resized"].ID:
 		ev, err := c.custody.ParseResized(l)
 		if err != nil {
-			log.Println("error parsing ChannelResized event:", err)
+			log.Println("error parsing Resized event:", err)
 			return
 		}
 		log.Printf("Resized event data: %+v\n", ev)
 
-		channelID := common.BytesToHash(ev.ChannelId[:])
-
 		var channel Channel
-		result := c.db.Where("channel_id = ?", channelID.Hex()).First(&channel)
-		if result.Error != nil {
-			log.Println("error finding channel:", result.Error)
-			return
-		}
+		err = c.db.Transaction(func(tx *gorm.DB) error {
+			channelID := common.BytesToHash(ev.ChannelId[:]).Hex()
+			result := c.db.Where("channel_id = ?", channelID).First(&channel)
+			if result.Error != nil {
+				return fmt.Errorf("error finding channel: %w", result.Error)
+			}
 
-		newAmount := int64(channel.Amount)
-		for _, change := range ev.DeltaAllocations {
-			newAmount += change.Int64()
-		}
+			newAmount := int64(channel.Amount)
+			for _, change := range ev.DeltaAllocations {
+				newAmount += change.Int64()
+			}
+
+			channel.Amount = uint64(newAmount)
+			channel.UpdatedAt = time.Now()
+			channel.Version++
+			if err := c.db.Save(&channel).Error; err != nil {
+				return fmt.Errorf("[Resized] Error saving channel in database: %w", err)
+			}
 
-		channel.Amount = uint64(newAmount)
-		channel.UpdatedAt = time.Now()
-		channel.Version++
-		if err := c.db.Save(&channel).Error; err != nil {
-			log.Printf("[Resized] Error saving channel in database: %v", err)
+			resizeAmount := ev.DeltaAllocations[0] // Participant deposits or withdraws.
+			if resizeAmount.Cmp(big.NewInt(0)) != 0 {
+				asset, err := GetAssetByToken(tx, channel.Token, c.chainID)
+				if err != nil {
+					return fmt.Errorf("DB error fetching asset: %w", err)
+				}
+
+				if asset == nil {
+					return fmt.Errorf("Asset not found in database for token: %s", channel.Token)
+				}
+
+				amount := decimal.NewFromBigInt(resizeAmount, -int32(asset.Decimals))
+				ledger := GetParticipantLedger(tx, channel.Participant)
+				if err := ledger.Record(channel.Participant, asset.Symbol, amount); err != nil {
+					log.Printf("[Resized] Error recording balance update for participant: %v", err)
+					return err
+				}
+			}
+
+			return nil
+		})
+
+		if err != nil {
+			log.Printf("[Resized] Error resizing channel: %v", err)
 			return
 		}
 
+		c.sendBalanceUpdate(channel.Participant)
 		c.sendChannelUpdate(channel)
 	default:
 		log.Println("Unknown event ID:", eventID.Hex())