feat: Add pagination to getRules endpoint

hub/route/rules.go

@@ -2,6 +2,7 @@ package route
 
 import (
 	"net/http"
+	"strconv"
 
 	"github.com/MerlinKodo/clash-rev/constant"
 
@@ -25,9 +26,44 @@ type Rule struct {
 }
 
 func getRules(w http.ResponseWriter, r *http.Request) {
+	pageStr := r.URL.Query().Get("page")
+	sizeStr := r.URL.Query().Get("size")
+
+	var page, size, start, end int
+	var errPage, errSize error
+	paginate := true
+
+	if pageStr != "" && sizeStr != "" {
+		page, errPage = strconv.Atoi(pageStr)
+		size, errSize = strconv.Atoi(sizeStr)
+
+		if errPage != nil || errSize != nil || page <= 0 || size <= 0 {
+			render.Status(r, http.StatusBadRequest)
+			render.JSON(w, r, render.M{"error": "Invalid page or size number"})
+			return
+		}
+
+		start = (page - 1) * size
+		end = start + size
+	} else {
+		paginate = false
+	}
+
 	rawRules := tunnel.Rules()
+	totalRules := len(rawRules)
+
+	if !paginate {
+		start = 0
+		end = totalRules
+	} else if start >= totalRules {
+		start = totalRules
+		end = totalRules
+	} else if end > totalRules {
+		end = totalRules
+	}
+
 	rules := []Rule{}
-	for _, rule := range rawRules {
+	for _, rule := range rawRules[start:end] {
 		r := Rule{
 			Type:    rule.RuleType().String(),
 			Payload: rule.Payload(),
@@ -38,7 +74,6 @@ func getRules(w http.ResponseWriter, r *http.Request) {
 			r.Size = rule.(constant.RuleGroup).GetRecodeSize()
 		}
 		rules = append(rules, r)
-
 	}
 
 	render.JSON(w, r, render.M{