feat: add cost statistics

Author: mgpai22

internal/api/api.go

@@ -28,6 +28,8 @@ import (
 // @tag.description Object Queries
 // @tag.name     system
 // @tag.description System status and health monitoring endpoints
+// @tag.name     statistics
+// @tag.description Statistics and analytics endpoints
 // @schemes      http https
 
 var scalarHTML []byte
@@ -94,6 +96,9 @@ func Start(
 	router.GET("/objects", handleGetAllObjectIDs)
 	router.GET("/objects/:id", handleGetObjectByID)
 
+	// Statistics endpoints
+	router.GET("/statistics/costs", handleGetCostStatistics)
+
 	// Setup metrics endpoint
 	router.GET("/metrics", gin.WrapH(promhttp.Handler()))
 
@@ -340,6 +345,27 @@ func handleGetAllObjectIDs(c *gin.Context) {
 	c.JSON(http.StatusOK, result)
 }
 
+// handleGetCostStatistics godoc
+// @Summary      Get Cost Statistics
+// @Description  Retrieves transaction fee statistics including total fees, averages, min/max values, and slot information.
+// @Tags         statistics
+// @Accept       json
+// @Produce      json
+// @Success      200  {object}  database.CostStatistics "Cost statistics"
+// @Failure      500  {object}  map[string]string "Internal server error"
+// @Router       /statistics/costs [get]
+func handleGetCostStatistics(c *gin.Context) {
+	db := c.MustGet("db").(*database.Database)
+
+	stats, err := db.GetCostStatistics(c.Request.Context())
+	if err != nil {
+		ServerError(c, fmt.Errorf("failed to get cost statistics: %w", err))
+		return
+	}
+
+	c.JSON(http.StatusOK, stats)
+}
+
 func ServerError(c *gin.Context, err error) {
 	logging.GetLogger().
 		Error("server error", "error", err, "path", c.Request.URL.Path)

internal/database/operation.go

@@ -33,6 +33,8 @@ type ApplyBatchParams struct {
 	PreviousMerkleRoot    *string
 	BlockchainConfirmedAt *time.Time
 	Slot                  int64
+	TxID                  string
+	TxFee                 uint32
 	Entries               []Entry
 }
 
@@ -50,6 +52,9 @@ func (d *Database) ApplyOracleFile(
 	if p.Slot <= 0 {
 		return nil, nil, errors.New("slot must be > 0")
 	}
+	if p.TxID == "" {
+		return nil, nil, errors.New("txid is required")
+	}
 
 	var outFile OracleFile
 	var outTrie Trie
@@ -110,6 +115,8 @@ func (d *Database) ApplyOracleFile(
 			TrieLibrary:           p.TrieLibrary,
 			BlockchainConfirmedAt: p.BlockchainConfirmedAt,
 			Slot:                  p.Slot,
+			TxID:                  p.TxID,
+			TxFee:                 p.TxFee,
 		}
 		if err := tx.Create(tr).Error; err != nil {
 			return err
@@ -608,3 +615,39 @@ func (d *Database) GetObjectValuesAtTimestamp(
 	}
 	return out, nil
 }
+
+type CostStatistics struct {
+	TotalFees         uint64  `json:"totalFees"`
+	AverageFee        float64 `json:"averageFee"`
+	MinFee            uint32  `json:"minFee"`
+	MaxFee            uint32  `json:"maxFee"`
+	TotalTransactions int64   `json:"totalTransactions"`
+	LatestSlot        int64   `json:"latestSlot"`
+	EarliestSlot      int64   `json:"earliestSlot"`
+}
+
+// GetCostStatistics returns transaction fee statistics from the trie table
+func (d *Database) GetCostStatistics(
+	ctx context.Context,
+) (*CostStatistics, error) {
+	var stats CostStatistics
+
+	err := d.db.WithContext(ctx).
+		Model(&Trie{}).
+		Select(`
+			COALESCE(SUM(tx_fee), 0) as total_fees,
+			COALESCE(AVG(tx_fee), 0) as average_fee,
+			COALESCE(MIN(tx_fee), 0) as min_fee,
+			COALESCE(MAX(tx_fee), 0) as max_fee,
+			COUNT(*) as total_transactions,
+			COALESCE(MAX(slot), 0) as latest_slot,
+			COALESCE(MIN(slot), 0) as earliest_slot
+		`).
+		Scan(&stats).Error
+
+	if err != nil {
+		return nil, fmt.Errorf("failed to get cost statistics: %w", err)
+	}
+
+	return &stats, nil
+}

internal/database/oracle.go

@@ -45,6 +45,8 @@ type Trie struct {
 	TrieLibrary           *string    `gorm:"column:trie_library"`
 	BlockchainConfirmedAt *time.Time `gorm:"column:blockchain_confirmed_at;index:trie_confirmed_idx"`
 	Slot                  int64      `gorm:"column:slot;not null;index:trie_slot_idx"`
+	TxID                  string     `gorm:"column:txid;not null;uniqueIndex"`
+	TxFee                 uint32     `gorm:"column:tx_fee;not null"`
 	CreatedAt             time.Time  `gorm:"column:created_at;not null;default:now()"`
 
 	// belongs to OracleFile (ON DELETE CASCADE)

internal/strategy/chain_event_processor_strategy.go

@@ -1458,7 +1458,11 @@ func (s *ChainEventProcessorActor) processTransactionEvent(
 			PreviousMerkleRoot:    prevRootPtr,
 			BlockchainConfirmedAt: &txEvent.EventTimestamp,
 			Slot:                  int64(txEvent.EventContext.SlotNumber),
-			Entries:               entries,
+			TxID:                  txHash,
+			TxFee: uint32(
+				txEvent.EventTransaction.Transaction.Fee(),
+			),
+			Entries: entries,
 		}
 
 		if _, _, err := s.db.ApplyOracleFile(context.Background(), params); err != nil {