first commit

internal/httpx/context.go

@@ -0,0 +1,14 @@
+package httpx
+
+import "context"
+
+type userIDKey struct{}
+
+func WithUserID(ctx context.Context, userID int64) context.Context {
+	return context.WithValue(ctx, userIDKey{}, userID)
+}
+
+func UserID(ctx context.Context) (int64, bool) {
+	v, ok := ctx.Value(userIDKey{}).(int64)
+	return v, ok
+}

internal/httpx/middleware.go

@@ -0,0 +1,119 @@
+package httpx
+
+import (
+	"net/http"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/golang-jwt/jwt/v5"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+type Middleware struct {
+	jwtSecret []byte
+	limit     int
+	mu        sync.Mutex
+	buckets   map[string]*bucket
+	requests  *prometheus.CounterVec
+	duration  *prometheus.HistogramVec
+}
+
+type bucket struct {
+	count int
+	reset time.Time
+}
+
+func NewMiddleware(jwtSecret string, rpm int, requests *prometheus.CounterVec, duration *prometheus.HistogramVec) *Middleware {
+	return &Middleware{jwtSecret: []byte(jwtSecret), limit: rpm, buckets: map[string]*bucket{}, requests: requests, duration: duration}
+}
+
+func (m *Middleware) Chain(next http.Handler) http.Handler {
+	return m.Metrics(m.RateLimit(next))
+}
+
+func (m *Middleware) Auth(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		header := r.Header.Get("Authorization")
+		if !strings.HasPrefix(header, "Bearer ") {
+			WriteError(w, http.StatusUnauthorized, "missing token")
+			return
+		}
+		token, err := jwt.Parse(strings.TrimPrefix(header, "Bearer "), func(t *jwt.Token) (any, error) {
+			return m.jwtSecret, nil
+		})
+		if err != nil || !token.Valid {
+			WriteError(w, http.StatusUnauthorized, "invalid token")
+			return
+		}
+		claims, ok := token.Claims.(jwt.MapClaims)
+		if !ok {
+			WriteError(w, http.StatusUnauthorized, "invalid claims")
+			return
+		}
+		sub, err := claims.GetSubject()
+		if err != nil {
+			if f, ok := claims["sub"].(float64); ok {
+				sub = strconv.FormatInt(int64(f), 10)
+			}
+		}
+		id, err := strconv.ParseInt(sub, 10, 64)
+		if err != nil {
+			WriteError(w, http.StatusUnauthorized, "invalid subject")
+			return
+		}
+		next.ServeHTTP(w, r.WithContext(WithUserID(r.Context(), id)))
+	})
+}
+
+func (m *Middleware) RateLimit(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		key := r.RemoteAddr
+		if id, ok := UserID(r.Context()); ok {
+			key = strconv.FormatInt(id, 10)
+		}
+		if !m.allow(key) {
+			WriteError(w, http.StatusTooManyRequests, "rate limit exceeded")
+			return
+		}
+		next.ServeHTTP(w, r)
+	})
+}
+
+func (m *Middleware) Metrics(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		start := time.Now()
+		rec := &statusRecorder{ResponseWriter: w, status: 200}
+		next.ServeHTTP(rec, r)
+		code := strconv.Itoa(rec.status)
+		m.requests.WithLabelValues(r.Method, r.URL.Path, code).Inc()
+		m.duration.WithLabelValues(r.Method, r.URL.Path).Observe(time.Since(start).Seconds())
+	})
+}
+
+func (m *Middleware) allow(key string) bool {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	now := time.Now()
+	b := m.buckets[key]
+	if b == nil || now.After(b.reset) {
+		m.buckets[key] = &bucket{count: 1, reset: now.Add(time.Minute)}
+		return true
+	}
+	if b.count >= m.limit {
+		return false
+	}
+	b.count++
+	return true
+}
+
+type statusRecorder struct {
+	http.ResponseWriter
+	status int
+}
+
+func (r *statusRecorder) WriteHeader(code int) {
+	r.status = code
+	r.ResponseWriter.WriteHeader(code)
+}

internal/httpx/response.go

@@ -0,0 +1,36 @@
+package httpx
+
+import (
+	"encoding/json"
+	"errors"
+	"net/http"
+
+	"secunda-test/internal/service"
+)
+
+func WriteJSON(w http.ResponseWriter, status int, v any) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(status)
+	_ = json.NewEncoder(w).Encode(v)
+}
+
+func WriteError(w http.ResponseWriter, status int, message string) {
+	WriteJSON(w, status, map[string]string{"error": message})
+}
+
+func StatusFromError(err error) int {
+	switch {
+	case errors.Is(err, service.ErrUnauthorized):
+		return http.StatusUnauthorized
+	case errors.Is(err, service.ErrForbidden):
+		return http.StatusForbidden
+	case errors.Is(err, service.ErrNotFound):
+		return http.StatusNotFound
+	case errors.Is(err, service.ErrBadRequest):
+		return http.StatusBadRequest
+	case errors.Is(err, service.ErrConflict):
+		return http.StatusConflict
+	default:
+		return http.StatusInternalServerError
+	}
+}