Add admin config page and runtime-tunable upload/rate-limit settings

internal/file/upload_multi.go

@@ -1,6 +1,7 @@
 package file
 
 import (
+	"ResendIt/internal/config"
 	"net/http"
 	"strconv"
 	"time"
@@ -26,11 +27,27 @@ func (h *Handler) UploadMulti(c *gin.Context) {
 		c.JSON(http.StatusBadRequest, gin.H{"error": "missing files"})
 		return
 	}
-	if len(files) > 50 {
-		c.JSON(http.StatusBadRequest, gin.H{"error": "too many files (max 50)"})
+	maxFiles := h.configService.GetIntDefault(config.KeyUploadMultiMaxFiles, config.DefaultUploadMultiMaxFiles)
+	if len(files) > maxFiles {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "too many files"})
 		return
 	}
 
+	maxSize := h.configService.GetInt64Default(config.KeyUploadMaxFileSizeBytes, config.DefaultUploadMaxFileSizeBytes)
+	var total int64
+	for _, fh := range files {
+		if fh.Size > maxSize {
+			c.JSON(http.StatusRequestEntityTooLarge, gin.H{"error": "file too large"})
+			return
+		}
+		total += fh.Size
+		if total > maxSize {
+			// crude guard against huge bundles; you can add a separate config later.
+			c.JSON(http.StatusRequestEntityTooLarge, gin.H{"error": "bundle too large"})
+			return
+		}
+	}
+
 	once := c.PostForm("once") == "true"
 
 	durationStr := c.PostForm("duration")
@@ -38,6 +55,10 @@ func (h *Handler) UploadMulti(c *gin.Context) {
 	if err != nil || hours <= 0 {
 		hours = 24
 	}
+	maxHours := h.configService.GetIntDefault(config.KeyUploadMaxHours, config.DefaultUploadMaxHours)
+	if hours > maxHours {
+		hours = maxHours
+	}
 	duration := time.Duration(hours) * time.Hour
 
 	record, err := h.service.UploadBundle(files, once, duration)