feat: merge default proxy groups of all subscription

internal/corecfg/merge.go

@@ -1,5 +1,7 @@
 package corecfg
 
+import "gitea.epss.net.cn/klesh/ss/internal/automation"
+
 // deepMerge merges dict2 into dict1 in place and returns dict1, mirroring
 // corecfg_manager.py's module-level deep_merge(): nested maps recurse,
 // matching lists are concatenated, everything else is overwritten by dict2.
@@ -25,3 +27,74 @@ func deepMerge(dict1, dict2 map[string]interface{}) map[string]interface{} {
 	}
 	return dict1
 }
+
+// popFirstProxyGroup removes and returns data["proxy-groups"]' first entry —
+// by convention a subscription's default selector group, the one its own
+// rules point at — so mergeProxySelection can fold every subscription's
+// default selector into one combined group. Returns nil if there is none.
+func popFirstProxyGroup(data map[string]interface{}) map[string]interface{} {
+	groupsRaw, ok := data["proxy-groups"].([]interface{})
+	if !ok || len(groupsRaw) == 0 {
+		return nil
+	}
+
+	group, ok := groupsRaw[0].(map[string]interface{})
+	if !ok {
+		return nil
+	}
+
+	data["proxy-groups"] = groupsRaw[1:]
+	return group
+}
+
+// selectionGroupName is the name given to the proxy-group produced by
+// folding every merged subscription's default selector group together.
+const selectionGroupName = "Proxy Selection"
+
+// mergeProxySelection collapses each subscription's default selector group
+// (already popped off by popFirstProxyGroup) into a single combined group
+// named selectionGroupName, covering every subscription's proxies, and
+// rewrites every rule/group reference to the old per-subscription groups so
+// they point at it instead.
+func mergeProxySelection(combined map[string]interface{}, groups []map[string]interface{}) {
+	if len(groups) == 0 {
+		return
+	}
+
+	rename := make(map[string]string, len(groups))
+	seen := make(map[string]bool)
+	var groupType interface{}
+	var mergedProxies []interface{}
+
+	for _, group := range groups {
+		if name, ok := group["name"].(string); ok {
+			rename[name] = selectionGroupName
+		}
+		if groupType == nil {
+			groupType = group["type"]
+		}
+		if list, ok := group["proxies"].([]interface{}); ok {
+			for _, p := range list {
+				name, ok := p.(string)
+				if ok && seen[name] {
+					continue
+				}
+				if ok {
+					seen[name] = true
+				}
+				mergedProxies = append(mergedProxies, p)
+			}
+		}
+	}
+
+	merged := map[string]interface{}{
+		"name":    selectionGroupName,
+		"type":    groupType,
+		"proxies": mergedProxies,
+	}
+
+	existing, _ := combined["proxy-groups"].([]interface{})
+	combined["proxy-groups"] = append([]interface{}{merged}, existing...)
+
+	automation.RewriteReferences(combined, rename)
+}