going full courtside

backend-go/internal/handlers/status.go

@@ -1,8 +1,13 @@
 package handlers
 
 import (
+	"context"
+	"log"
 	"net/http"
 	"time"
+
+	"github.com/kjannette/koin-ping/backend-go/internal/models"
+	"github.com/kjannette/koin-ping/backend-go/internal/protocols/ethereum"
 )
 
 func HealthCheck(w http.ResponseWriter, r *http.Request) {
@@ -13,11 +18,62 @@ func HealthCheck(w http.ResponseWriter, r *http.Request) {
 	})
 }
 
-func SystemStatus(w http.ResponseWriter, r *http.Request) {
+type StatusHandler struct {
+	eth         ethereum.EthereumObserver
+	checkpoints *models.CheckpointModel
+}
+
+func NewStatusHandler(eth ethereum.EthereumObserver, checkpoints *models.CheckpointModel) *StatusHandler {
+	return &StatusHandler{eth: eth, checkpoints: checkpoints}
+}
+
+func (h *StatusHandler) SystemStatus(w http.ResponseWriter, r *http.Request) {
+	ctx, cancel := context.WithTimeout(r.Context(), 10*time.Second)
+	defer cancel()
+
+	status := "healthy"
+
+	if h.eth == nil {
+		writeJSON(w, http.StatusOK, map[string]interface{}{
+			"latestBlock":      0,
+			"lag":              0,
+			"trackedAddresses": 0,
+			"status":           "no_rpc",
+			"timestamp":        time.Now().UTC().Format(time.RFC3339),
+		})
+		return
+	}
+
+	latestBlock, err := h.eth.GetLatestBlockNumber(ctx)
+	if err != nil {
+		log.Printf("Failed to get latest block: %v", err)
+		status = "degraded"
+		latestBlock = 0
+	}
+
+	lag := 0
+	checkpoints, err := h.checkpoints.ListAll(ctx)
+	if err != nil {
+		log.Printf("Failed to list checkpoints: %v", err)
+	} else if len(checkpoints) > 0 && latestBlock > 0 {
+		minChecked := checkpoints[0].LastCheckedBlock
+		for _, cp := range checkpoints[1:] {
+			if cp.LastCheckedBlock < minChecked {
+				minChecked = cp.LastCheckedBlock
+			}
+		}
+		lag = latestBlock - minChecked
+	}
+
+	if lag > 50 {
+		status = "syncing"
+	}
+
 	writeJSON(w, http.StatusOK, map[string]interface{}{
-		"latestBlock": 0,
-		"lag":         0,
-		"status":      "healthy",
-		"timestamp":   time.Now().UTC().Format(time.RFC3339),
+		"latestBlock":      latestBlock,
+		"lag":              lag,
+		"trackedAddresses": len(checkpoints),
+		"status":           status,
+		"timestamp":        time.Now().UTC().Format(time.RFC3339),
 	})
 }