refactor: migrate from raw pgx to GORM, unify ErrNoRows, cleanup auth

internal/middleware/ratelimit.go

@@ -0,0 +1,87 @@
+package middleware
+
+import (
+	"net/http"
+	"sync"
+	"time"
+
+	"github.com/gin-gonic/gin"
+)
+
+type visitor struct {
+	count    int
+	lastSeen time.Time
+}
+
+type RateLimiter struct {
+	mu       sync.Mutex
+	visitors map[string]*visitor
+	rate     int
+	window   time.Duration
+	done     chan struct{}
+}
+
+func NewRateLimiter(rate int, window time.Duration) *RateLimiter {
+	rl := &RateLimiter{
+		visitors: make(map[string]*visitor),
+		rate:     rate,
+		window:   window,
+		done:     make(chan struct{}),
+	}
+	go rl.cleanup()
+	return rl
+}
+
+func (rl *RateLimiter) Stop() {
+	close(rl.done)
+}
+
+func (rl *RateLimiter) cleanup() {
+	ticker := time.NewTicker(10 * time.Minute)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-rl.done:
+			return
+		case <-ticker.C:
+			rl.mu.Lock()
+			now := time.Now()
+			for ip, v := range rl.visitors {
+				if now.Sub(v.lastSeen) > rl.window*2 {
+					delete(rl.visitors, ip)
+				}
+			}
+			rl.mu.Unlock()
+		}
+	}
+}
+
+func (rl *RateLimiter) Middleware() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		ip := c.ClientIP()
+
+		rl.mu.Lock()
+		v, exists := rl.visitors[ip]
+		now := time.Now()
+
+		if !exists || now.Sub(v.lastSeen) > rl.window {
+			rl.visitors[ip] = &visitor{count: 1, lastSeen: now}
+			rl.mu.Unlock()
+			c.Next()
+			return
+		}
+
+		v.count++
+		v.lastSeen = now
+
+		if v.count > rl.rate {
+			rl.mu.Unlock()
+			c.JSON(http.StatusTooManyRequests, gin.H{"error": "too many requests, try again later"})
+			c.Abort()
+			return
+		}
+
+		rl.mu.Unlock()
+		c.Next()
+	}
+}