refactor

internal/infrastructure/metrics/prometheus.go

@@ -0,0 +1,103 @@
+package metrics
+
+import (
+	"net/http"
+	"strconv"
+	"time"
+
+	"github.com/gin-gonic/gin"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+// MetricsService interface defines the contract for metrics operations
+type MetricsService interface {
+	RecordHTTPRequest(method, path string, statusCode int, duration time.Duration)
+	RecordDBOperation(operation, table string)
+	RecordAuthAttempt(action, result string)
+	StartMetricsServer(port string)
+	MetricsMiddleware() gin.HandlerFunc
+}
+
+// PrometheusMetricsService implements MetricsService using Prometheus
+type PrometheusMetricsService struct {
+	httpRequestsTotal   *prometheus.CounterVec
+	httpRequestDuration *prometheus.HistogramVec
+	dbOperationsTotal   *prometheus.CounterVec
+	authAttemptsTotal   *prometheus.CounterVec
+}
+
+// NewPrometheusMetricsService creates a new Prometheus metrics service
+func NewPrometheusMetricsService() MetricsService {
+	return &PrometheusMetricsService{
+		httpRequestsTotal: promauto.NewCounterVec(
+			prometheus.CounterOpts{
+				Name: "http_requests_total",
+				Help: "Total number of HTTP requests",
+			},
+			[]string{"method", "path", "status"},
+		),
+		httpRequestDuration: promauto.NewHistogramVec(
+			prometheus.HistogramOpts{
+				Name:    "http_request_duration_seconds",
+				Help:    "HTTP request duration in seconds",
+				Buckets: prometheus.DefBuckets,
+			},
+			[]string{"method", "path"},
+		),
+		dbOperationsTotal: promauto.NewCounterVec(
+			prometheus.CounterOpts{
+				Name: "db_operations_total",
+				Help: "Total number of database operations",
+			},
+			[]string{"operation", "table"},
+		),
+		authAttemptsTotal: promauto.NewCounterVec(
+			prometheus.CounterOpts{
+				Name: "auth_attempts_total",
+				Help: "Total number of authentication attempts",
+			},
+			[]string{"action", "result"},
+		),
+	}
+}
+
+// RecordHTTPRequest records an HTTP request
+func (m *PrometheusMetricsService) RecordHTTPRequest(method, path string, statusCode int, duration time.Duration) {
+	status := strconv.Itoa(statusCode)
+	m.httpRequestsTotal.WithLabelValues(method, path, status).Inc()
+	m.httpRequestDuration.WithLabelValues(method, path).Observe(duration.Seconds())
+}
+
+// RecordDBOperation records a database operation
+func (m *PrometheusMetricsService) RecordDBOperation(operation, table string) {
+	m.dbOperationsTotal.WithLabelValues(operation, table).Inc()
+}
+
+// RecordAuthAttempt records an authentication attempt
+func (m *PrometheusMetricsService) RecordAuthAttempt(action, result string) {
+	m.authAttemptsTotal.WithLabelValues(action, result).Inc()
+}
+
+// StartMetricsServer starts the Prometheus metrics server
+func (m *PrometheusMetricsService) StartMetricsServer(port string) {
+	http.Handle("/metrics", promhttp.Handler())
+	go func() {
+		if err := http.ListenAndServe(":"+port, nil); err != nil {
+			// Log error but don't fail the application
+		}
+	}()
+}
+
+// MetricsMiddleware creates a Gin middleware for HTTP metrics
+func (m *PrometheusMetricsService) MetricsMiddleware() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		start := time.Now()
+
+		c.Next()
+
+		duration := time.Since(start)
+		m.RecordHTTPRequest(c.Request.Method, c.FullPath(), c.Writer.Status(), duration)
+	}
+}