init

internal/middleware/rate_limit.go

@@ -0,0 +1,69 @@
+package middleware
+
+import (
+	"sync"
+	"time"
+
+	"github.com/gin-gonic/gin"
+)
+
+type RateLimiter struct {
+	requests map[string][]time.Time
+	mutex    sync.RWMutex
+	limit    int
+	window   time.Duration
+}
+
+func NewRateLimiter(limit int, window time.Duration) *RateLimiter {
+	return &RateLimiter{
+		requests: make(map[string][]time.Time),
+		limit:    limit,
+		window:   window,
+	}
+}
+
+func (rl *RateLimiter) Allow(key string) bool {
+	rl.mutex.Lock()
+	defer rl.mutex.Unlock()
+
+	now := time.Now()
+	windowStart := now.Add(-rl.window)
+
+	// Clean old requests
+	if times, exists := rl.requests[key]; exists {
+		var validTimes []time.Time
+		for _, t := range times {
+			if t.After(windowStart) {
+				validTimes = append(validTimes, t)
+			}
+		}
+		rl.requests[key] = validTimes
+	}
+
+	// Check if limit exceeded
+	if len(rl.requests[key]) >= rl.limit {
+		return false
+	}
+
+	// Add current request
+	rl.requests[key] = append(rl.requests[key], now)
+	return true
+}
+
+func RateLimit() gin.HandlerFunc {
+	limiter := NewRateLimiter(100, time.Minute) // 100 requests per minute
+
+	return gin.HandlerFunc(func(c *gin.Context) {
+		clientIP := c.ClientIP()
+
+		if !limiter.Allow(clientIP) {
+			c.JSON(429, gin.H{
+				"error": "Rate limit exceeded",
+			})
+			c.Abort()
+			return
+		}
+
+		c.Next()
+	})
+}