2 files changed, 100 insertions, 0 deletions
diff --git a/internal/utils/key_generator.go b/internal/utils/key_generator.go
new file mode 100644
index 0000000..1f88be9
--- /dev/null
+++ b/internal/utils/key_generator.go
@@ -0,0 +1,28 @@
+package utils
+
+import (
+	"encoding/base64"
+
+	crand "crypto/rand"
+
+	"donetick.com/core/logging"
+	"github.com/gin-gonic/gin"
+)
+
+func GenerateInviteCode(c *gin.Context) string {
+	logger := logging.FromContext(c)
+	// Define the length of the token (in bytes). For example, 32 bytes will result in a 44-character base64-encoded token.
+	tokenLength := 12
+
+	// Generate a random byte slice.
+	tokenBytes := make([]byte, tokenLength)
+	_, err := crand.Read(tokenBytes)
+	if err != nil {
+		logger.Errorw("utility.GenerateEmailResetToken failed to generate random bytes", "err", err)
+	}
+
+	// Encode the byte slice to a base64 string.
+	token := base64.URLEncoding.EncodeToString(tokenBytes)
+
+	return token
+}
diff --git a/internal/utils/middleware.go b/internal/utils/middleware.go
new file mode 100644
index 0000000..f31184b
--- /dev/null
+++ b/internal/utils/middleware.go
@@ -0,0 +1,72 @@
+package utils
+
+import (
+	"context"
+	"net/http"
+	"strconv"
+	"time"
+
+	"donetick.com/core/config"
+	"github.com/gin-gonic/gin"
+	"github.com/ulule/limiter/v3"
+	"github.com/ulule/limiter/v3/drivers/store/memory"
+)
+
+const (
+	XRequestIdKey = "X-Request-ID" // request id header key
+)
+
+func NewRateLimiter(cfg *config.Config) *limiter.Limiter {
+
+	store := memory.NewStore()
+
+	// rate, err := limiter.NewRateFromFormatted("10-H")
+	rate := limiter.Rate{
+		Period: cfg.Server.RatePeriod,
+		Limit:  int64(cfg.Server.RateLimit),
+	}
+
+	// Then, create the limiter instance which takes the store and the rate as arguments.
+	// Now, you can give this instance to any supported middleware.
+	return limiter.New(store, rate)
+
+}
+
+// wrapper ratelimiter and have it as a middkewatr function:
+func RateLimitMiddleware(limiter *limiter.Limiter) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		// Use the IP as the key, which is the client IP.
+		// And set the expiration time to 10 seconds.
+		context, err := limiter.Get(c.Request.Context(), c.ClientIP())
+		if err != nil {
+			panic(err) // perhaps handle this nicer
+		}
+		// Check if the client is ratelimited.
+		if context.Reached {
+			c.AbortWithStatusJSON(http.StatusTooManyRequests, gin.H{"message": "Too many requests"})
+			return
+		}
+		// Add a header in response to inform the current quota.
+		c.Header("X-RateLimit-Limit", strconv.FormatInt(context.Limit, 10))
+		// Add a header in response to inform the remaining quota.
+		c.Header("X-RateLimit-Remaining", strconv.FormatInt(context.Remaining, 10))
+		// Add a header in response to inform the time to wait before retry.
+		c.Header("X-RateLimit-Reset", strconv.FormatInt(context.Reset, 10))
+		c.Next()
+	}
+}
+
+func TimeoutMiddleware(timeout time.Duration) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		ctx, cancel := context.WithTimeout(c.Request.Context(), timeout)
+
+		defer func() {
+			if ctx.Err() == context.DeadlineExceeded {
+				c.AbortWithStatus(http.StatusGatewayTimeout)
+			}
+			cancel()
+		}()
+		c.Request = c.Request.WithContext(ctx)
+		c.Next()
+	}
+}