feat: add NodeController with list, getConfig, and updateConfig endpoints

Expose node management API endpoints for the cluster feature:
- GET /node/list — returns connected nodes with online status
- GET /node/config — returns current node + DB configuration
- POST /node/config — validates and persists node settings to x-ui.json

web/controller/node.go

@@ -0,0 +1,170 @@
+package controller
+
+import (
+	"os"
+	"strconv"
+	"time"
+
+	"github.com/mhsanaei/3x-ui/v2/config"
+	"github.com/mhsanaei/3x-ui/v2/database"
+
+	"github.com/gin-gonic/gin"
+)
+
+// NodeController handles node management API endpoints.
+type NodeController struct {
+	BaseController
+}
+
+// NewNodeController creates a new NodeController and initializes its routes.
+func NewNodeController(g *gin.RouterGroup) *NodeController {
+	a := &NodeController{}
+	a.initRouter(g)
+	return a
+}
+
+// initRouter sets up the routes for node management.
+func (a *NodeController) initRouter(g *gin.RouterGroup) {
+	g.GET("/list", a.list)
+	g.GET("/config", a.getConfig)
+	g.POST("/config", a.updateConfig)
+}
+
+// NodeView is the JSON shape returned to the frontend for each node.
+type NodeView struct {
+	NodeID          string `json:"nodeId"`
+	NodeRole        string `json:"nodeRole"`
+	Online          bool   `json:"online"`
+	LastHeartbeatAt int64  `json:"lastHeartbeatAt"`
+	LastSyncAt      int64  `json:"lastSyncAt"`
+	LastSeenVersion int64  `json:"lastSeenVersion"`
+	LastError       string `json:"lastError"`
+}
+
+// list returns connected nodes. Master sees all workers; worker sees the master.
+func (a *NodeController) list(c *gin.Context) {
+	nodeCfg := config.GetNodeConfigFromJSON()
+	states, err := database.GetNodeStates()
+	if err != nil {
+		jsonMsg(c, "get node states", err)
+		return
+	}
+
+	syncInterval := nodeCfg.SyncIntervalSeconds
+	if syncInterval <= 0 {
+		syncInterval = 30
+	}
+	offlineThreshold := int64(syncInterval * 2)
+	now := time.Now().Unix()
+
+	var nodes []NodeView
+	for _, s := range states {
+		// Master shows workers; worker shows master
+		if nodeCfg.Role == config.NodeRoleMaster && s.NodeRole != string(config.NodeRoleWorker) {
+			continue
+		}
+		if nodeCfg.Role == config.NodeRoleWorker && s.NodeRole != string(config.NodeRoleMaster) {
+			continue
+		}
+		online := (now - s.LastHeartbeatAt) < offlineThreshold
+		nodes = append(nodes, NodeView{
+			NodeID:          s.NodeID,
+			NodeRole:        s.NodeRole,
+			Online:          online,
+			LastHeartbeatAt: s.LastHeartbeatAt,
+			LastSyncAt:      s.LastSyncAt,
+			LastSeenVersion: s.LastSeenVersion,
+			LastError:       s.LastError,
+		})
+	}
+	if nodes == nil {
+		nodes = []NodeView{}
+	}
+
+	jsonObj(c, nodes, nil)
+}
+
+// NodeConfigView is the JSON shape for node configuration.
+type NodeConfigView struct {
+	Role                 string `json:"role"`
+	NodeID               string `json:"nodeId"`
+	SyncInterval         int    `json:"syncInterval"`
+	TrafficFlushInterval int    `json:"trafficFlushInterval"`
+	DBType               string `json:"dbType"`
+	DBHost               string `json:"dbHost"`
+	DBPort               string `json:"dbPort"`
+	DBUser               string `json:"dbUser"`
+	DBPass               string `json:"dbPass"`
+	DBName               string `json:"dbName"`
+}
+
+// getConfig returns the current node configuration.
+func (a *NodeController) getConfig(c *gin.Context) {
+	nodeCfg := config.GetNodeConfigFromJSON()
+	dbCfg := config.GetDBConfigFromJSON()
+
+	jsonObj(c, NodeConfigView{
+		Role:                 string(nodeCfg.Role),
+		NodeID:               nodeCfg.NodeID,
+		SyncInterval:         nodeCfg.SyncIntervalSeconds,
+		TrafficFlushInterval: nodeCfg.TrafficFlushSeconds,
+		DBType:               dbCfg.Type,
+		DBHost:               dbCfg.Host,
+		DBPort:               dbCfg.Port,
+		DBUser:               dbCfg.User,
+		DBPass:               dbCfg.Password,
+		DBName:               dbCfg.Name,
+	}, nil)
+}
+
+// updateConfigRequest is the JSON body for updating node config.
+type updateConfigRequest struct {
+	SyncInterval         int    `json:"syncInterval"`
+	TrafficFlushInterval int    `json:"trafficFlushInterval"`
+	DBType               string `json:"dbType"`
+	DBHost               string `json:"dbHost"`
+	DBPort               string `json:"dbPort"`
+	DBUser               string `json:"dbUser"`
+	DBPass               string `json:"dbPass"`
+	DBName               string `json:"dbName"`
+}
+
+// updateConfig updates the node configuration in x-ui.json.
+func (a *NodeController) updateConfig(c *gin.Context) {
+	var req updateConfigRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		jsonMsg(c, "invalid request", err)
+		return
+	}
+
+	// Validate
+	if req.SyncInterval <= 0 {
+		jsonMsg(c, "syncInterval must be positive", os.ErrInvalid)
+		return
+	}
+	if req.TrafficFlushInterval <= 0 {
+		jsonMsg(c, "trafficFlushInterval must be positive", os.ErrInvalid)
+		return
+	}
+
+	// Write each setting to JSON config
+	settings := map[string]string{
+		"syncInterval":         strconv.Itoa(req.SyncInterval),
+		"trafficFlushInterval": strconv.Itoa(req.TrafficFlushInterval),
+		"dbType":               req.DBType,
+		"dbHost":               req.DBHost,
+		"dbPort":               req.DBPort,
+		"dbUser":               req.DBUser,
+		"dbPassword":           req.DBPass,
+		"dbName":               req.DBName,
+	}
+
+	for key, value := range settings {
+		if err := config.WriteSettingToJSON(key, value); err != nil {
+			jsonMsg(c, "save "+key, err)
+			return
+		}
+	}
+
+	jsonMsg(c, I18nWeb(c, "pages.nodes.saveSuccess"), nil)
+}