add Cloudflare R2 storage integration and update bug report handling

internal/middleware/timing.go

@@ -0,0 +1,62 @@
+package middleware
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+	"strings"
+	"time"
+
+	"emly-api-go/internal/timing"
+)
+
+// Timing is a middleware that measures per-request step durations.
+//
+// It injects a *timing.Timer into the request context so that handlers can
+// record named checkpoints with timing.Mark(r.Context(), "step_name").
+// After the handler returns, it logs a single line of the form:
+//
+//	[TIMING] METHOD /path  step1=1.2ms  step2=18ms  total=20ms
+//
+// Each step duration is measured from the previous checkpoint (or request
+// start for the first one), so the values add up to the total.
+func Timing(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		ctx, t := timing.NewContext(r.Context())
+		next.ServeHTTP(w, r.WithContext(ctx))
+
+		total := time.Since(t.Start)
+		checkpoints := t.Checkpoints()
+
+		if len(checkpoints) == 0 {
+			// No checkpoints: just log the total so every request is visible.
+			log.Printf("[TIMING] %s %s  total=%s", r.Method, r.URL.Path, round(total))
+			return
+		}
+
+		parts := make([]string, 0, len(checkpoints)+1)
+		prev := t.Start
+		for _, cp := range checkpoints {
+			parts = append(parts, fmt.Sprintf("%s=%s", cp.Name, round(cp.At.Sub(prev))))
+			prev = cp.At
+		}
+		// Remainder after the last checkpoint.
+		if tail := total - prev.Sub(t.Start); tail > 0 {
+			parts = append(parts, fmt.Sprintf("response=%s", round(tail)))
+		}
+		parts = append(parts, fmt.Sprintf("total=%s", round(total)))
+
+		log.Printf("[TIMING] %s %s  %s", r.Method, r.URL.Path, strings.Join(parts, "  "))
+	})
+}
+
+func round(d time.Duration) string {
+	switch {
+	case d < time.Microsecond:
+		return fmt.Sprintf("%dns", d.Nanoseconds())
+	case d < time.Millisecond:
+		return fmt.Sprintf("%.2fµs", float64(d.Nanoseconds())/1e3)
+	default:
+		return fmt.Sprintf("%.2fms", float64(d.Nanoseconds())/1e6)
+	}
+}