3x-ui/sub/subService.go

package sub

import (
	"crypto/sha256"
	"encoding/base64"
	"encoding/hex"
	"fmt"
	"maps"
	"net"
	"net/url"
	"slices"
	"strings"
	"time"

	"github.com/gin-gonic/gin"
	"github.com/goccy/go-json"

	"github.com/mhsanaei/3x-ui/v3/database"
	"github.com/mhsanaei/3x-ui/v3/database/model"
	"github.com/mhsanaei/3x-ui/v3/logger"
	"github.com/mhsanaei/3x-ui/v3/util/common"
	"github.com/mhsanaei/3x-ui/v3/util/random"
	"github.com/mhsanaei/3x-ui/v3/web/service"
	"github.com/mhsanaei/3x-ui/v3/xray"
)

// SubService provides business logic for generating subscription links and managing subscription data.
type SubService struct {
	address        string
	showInfo       bool
	remarkModel    string
	datepicker     string
	emailInRemark  bool
	inboundService service.InboundService
	settingService service.SettingService
	// nodesByID is populated per request from the Node table so
	// resolveInboundAddress can return the node's address for any
	// inbound whose NodeID is set. Keeps the per-link host derivation
	// O(1) instead of O(N) DB hits.
	nodesByID map[int]*model.Node
}

// NewSubService creates a new subscription service with the given configuration.
func NewSubService(showInfo bool, remarkModel string) *SubService {
	return &SubService{
		showInfo:    showInfo,
		remarkModel: remarkModel,
	}
}

// PrepareForRequest sets per-request state (host + nodes map) on the
// shared SubService. Called by every entry point — GetSubs, GetJson,
// GetClash — so resolveInboundAddress sees the right host and the
// freshly-loaded node map regardless of which sub flavour the client
// hit.
func (s *SubService) PrepareForRequest(host string) {
	if !isRoutableHost(host) {
		if d := s.configuredPublicHost(); d != "" {
			host = d
		} else if isLoopbackHost(host) {
			host = "localhost"
		}
	}
	s.address = host
	s.loadNodes()
}

func (s *SubService) configuredPublicHost() string {
	if d, err := s.settingService.GetSubDomain(); err == nil && d != "" {
		return d
	}
	if d, err := s.settingService.GetWebDomain(); err == nil && d != "" {
		return d
	}
	return ""
}

func isRoutableHost(host string) bool {
	if host == "" {
		return false
	}
	if ip := net.ParseIP(strings.Trim(host, "[]")); ip != nil {
		return !ip.IsLoopback() && !ip.IsUnspecified()
	}
	return true
}

func isLoopbackHost(host string) bool {
	ip := net.ParseIP(strings.Trim(host, "[]"))
	return ip != nil && ip.IsLoopback()
}

// listenIsInternalOnly reports whether a bind address is reachable only from
// the same host — a loopback IP or a unix-domain socket. Such an inbound can't
// be dialed directly by a remote client, so when it is the child side of a
// fallback its share link must be projected through the master. A public or
// wildcard listen (""/0.0.0.0/::) is reachable on its own port and advertises
// itself.
func listenIsInternalOnly(listen string) bool {
	if listen == "" {
		return false
	}
	if listen[0] == '@' || listen[0] == '/' {
		return true
	}
	return isLoopbackHost(listen)
}

// GetSubs retrieves subscription links for a given subscription ID and host.
func (s *SubService) GetSubs(subId string, host string) ([]string, []string, int64, xray.ClientTraffic, error) {
	s.PrepareForRequest(host)
	var result []string
	var emails []string
	var traffic xray.ClientTraffic
	var hasEnabledClient bool
	inbounds, err := s.getInboundsBySubId(subId)
	if err != nil {
		return nil, nil, 0, traffic, err
	}

	if len(inbounds) == 0 {
		return nil, nil, 0, traffic, nil
	}

	s.datepicker, err = s.settingService.GetDatepicker()
	if err != nil {
		s.datepicker = "gregorian"
	}

	s.emailInRemark, err = s.settingService.GetSubEmailInRemark()
	if err != nil {
		s.emailInRemark = true
	}

	seenEmails := make(map[string]struct{})
	for _, inbound := range inbounds {
		clients, err := s.inboundService.GetClients(inbound)
		if err != nil {
			logger.Error("SubService - GetClients: Unable to get clients from inbound")
		}
		if clients == nil {
			continue
		}
		s.projectThroughFallbackMaster(inbound)
		for _, client := range clients {
			if client.SubID == subId {
				if client.Enable {
					hasEnabledClient = true
				}
				result = append(result, s.GetLink(inbound, client.Email))
				emails = append(emails, client.Email)
				seenEmails[client.Email] = struct{}{}
			}
		}
	}

	uniqueEmails := make([]string, 0, len(seenEmails))
	for e := range seenEmails {
		uniqueEmails = append(uniqueEmails, e)
	}
	traffic, lastOnline := s.AggregateTrafficByEmails(uniqueEmails)
	traffic.Enable = hasEnabledClient
	return result, emails, lastOnline, traffic, nil
}

// AggregateTrafficByEmails resolves traffic for every email in one
// query and folds the rows into a single ClientTraffic + lastOnline.
// xray.ClientTraffic.Email is globally unique, so a multi-inbound
// client's single row is attached to exactly one inbound — iterating
// per-inbound ClientStats would miss it on the others. Used by GetSubs,
// SubClashService.GetClash, and SubJsonService.GetJson to keep the
// sub-info header consistent across all three formats.
func (s *SubService) AggregateTrafficByEmails(emails []string) (xray.ClientTraffic, int64) {
	var agg xray.ClientTraffic
	var lastOnline int64
	if len(emails) == 0 {
		return agg, 0
	}
	db := database.GetDB()
	var rows []xray.ClientTraffic
	if err := db.
		Model(&xray.ClientTraffic{}).
		Where("email IN ?", emails).
		Find(&rows).Error; err != nil {
		logger.Warning("SubService - AggregateTrafficByEmails: load by email:", err)
		return agg, 0
	}

	// total/expiry are configured limits owned by the clients table, not the
	// runtime traffic rows. In a multi-node setup the node snapshot can reset
	// client_traffics.total/expiry_time to 0, so fall back to the clients
	// table to keep the Subscription-Userinfo header in sync with the UI (#4645).
	limits := make(map[string][2]int64, len(emails))
	var records []model.ClientRecord
	if err := db.Model(&model.ClientRecord{}).Where("email IN ?", emails).Find(&records).Error; err != nil {
		logger.Warning("SubService - AggregateTrafficByEmails: load client limits:", err)
	} else {
		for _, r := range records {
			limits[r.Email] = [2]int64{r.TotalGB, r.ExpiryTime}
		}
	}

	now := time.Now().UnixMilli()
	first := true
	for _, ct := range rows {
		if ct.LastOnline > lastOnline {
			lastOnline = ct.LastOnline
		}
		total, expiry := ct.Total, ct.ExpiryTime
		if lim, ok := limits[ct.Email]; ok {
			if total == 0 {
				total = lim[0]
			}
			if expiry == 0 {
				expiry = lim[1]
			}
		}
		if first {
			agg.Up = ct.Up
			agg.Down = ct.Down
			agg.Total = total
			agg.ExpiryTime = subscriptionExpiryFromClient(now, expiry)
			first = false
			continue
		}
		agg.Up += ct.Up
		agg.Down += ct.Down
		if agg.Total == 0 || total == 0 {
			agg.Total = 0
		} else {
			agg.Total += total
		}
		normalized := subscriptionExpiryFromClient(now, expiry)
		if normalized != agg.ExpiryTime {
			agg.ExpiryTime = 0
		}
	}
	return agg, lastOnline
}

func subscriptionExpiryFromClient(nowMs, expiryTime int64) int64 {
	if expiryTime > 0 {
		return expiryTime
	}
	if expiryTime < 0 {
		return nowMs + (-expiryTime)
	}
	return 0
}

func (s *SubService) getInboundsBySubId(subId string) ([]*model.Inbound, error) {
	db := database.GetDB()
	var inbounds []*model.Inbound
	err := db.Model(model.Inbound{}).Preload("ClientStats").Where(`id in (
		SELECT DISTINCT inbounds.id
		FROM inbounds
		JOIN client_inbounds ON client_inbounds.inbound_id = inbounds.id
		JOIN clients ON clients.id = client_inbounds.client_id
		WHERE
			inbounds.protocol in ('vmess','vless','trojan','shadowsocks','hysteria')
			AND clients.sub_id = ? AND inbounds.enable = ?
	)`, subId, true).Find(&inbounds).Error
	if err != nil {
		return nil, err
	}
	return inbounds, nil
}

// projectThroughFallbackMaster mutates the inbound in place so its
// Listen/Port/StreamSettings reflect the externally reachable master
// when applicable. Covers both fallback mechanisms:
//   - panel-tracked: an inbound_fallbacks row where child_id = inbound.Id
//   - legacy unix-socket: inbound.Listen begins with "@" and some VLESS/
//     Trojan inbound's settings.fallbacks references that listen address
//
// Returns true when a projection happened; sub services call this before
// generating links so a child VLESS-WS bound to 127.0.0.1 emits the
// master's :443 + TLS state instead of its own loopback endpoint.
//
// Projection only applies to a child that is not directly reachable on its
// own listen (loopback or a unix-domain socket). An inbound on a public or
// wildcard listen is reachable on its own port, so it advertises its own
// port + security even when a stale fallback rule still names it as a child —
// otherwise its share link would leak the master's port and Reality/TLS
// settings (#4987).
func (s *SubService) projectThroughFallbackMaster(inbound *model.Inbound) bool {
	if inbound == nil {
		return false
	}
	if !listenIsInternalOnly(inbound.Listen) {
		return false
	}
	db := database.GetDB()
	var master *model.Inbound

	var rule model.InboundFallback
	if err := db.Where("child_id = ?", inbound.Id).
		Order("sort_order ASC, id ASC").
		First(&rule).Error; err == nil {
		var m model.Inbound
		if err := db.Where("id = ?", rule.MasterId).First(&m).Error; err == nil {
			master = &m
		}
	}

	if master == nil && len(inbound.Listen) > 0 && inbound.Listen[0] == '@' {
		var m model.Inbound
		if err := db.Model(model.Inbound{}).
			Where("JSON_TYPE(settings, '$.fallbacks') = 'array'").
			Where("EXISTS (SELECT * FROM json_each(settings, '$.fallbacks') WHERE json_extract(value, '$.dest') = ?)", inbound.Listen).
			First(&m).Error; err == nil {
			master = &m
		}
	}

	if master == nil {
		return false
	}
	inbound.StreamSettings = mergeStreamFromMaster(inbound.StreamSettings, master.StreamSettings)
	inbound.Listen = master.Listen
	inbound.Port = master.Port
	return true
}

// mergeStreamFromMaster copies the master's security + tlsSettings +
// realitySettings + externalProxy onto the child's stream so the child's
// link advertises the master's TLS / Reality state. Transport (network
// + ws/grpc/etc. settings) stays the child's.
func mergeStreamFromMaster(childStream, masterStream string) string {
	var stream map[string]any
	json.Unmarshal([]byte(childStream), &stream)
	if stream == nil {
		stream = map[string]any{}
	}
	var mst map[string]any
	json.Unmarshal([]byte(masterStream), &mst)
	if mst == nil {
		return childStream
	}
	stream["security"] = mst["security"]
	if v, ok := mst["tlsSettings"]; ok {
		stream["tlsSettings"] = v
	} else {
		delete(stream, "tlsSettings")
	}
	if v, ok := mst["realitySettings"]; ok {
		stream["realitySettings"] = v
	} else {
		delete(stream, "realitySettings")
	}
	if v, ok := mst["externalProxy"]; ok {
		stream["externalProxy"] = v
	}
	out, err := json.MarshalIndent(stream, "", "  ")
	if err != nil {
		return childStream
	}
	return string(out)
}

// GetLink dispatches to the protocol-specific generator for one (inbound, client)
// pair. Returns "" when the inbound's protocol doesn't produce a subscription URL
// (socks, http, mixed, wireguard, dokodemo, tunnel). The returned string may
// contain multiple `\n`-separated URLs when the inbound has externalProxy set.
func (s *SubService) GetLink(inbound *model.Inbound, email string) string {
	switch inbound.Protocol {
	case "vmess":
		return s.genVmessLink(inbound, email)
	case "vless":
		return s.genVlessLink(inbound, email)
	case "trojan":
		return s.genTrojanLink(inbound, email)
	case "shadowsocks":
		return s.genShadowsocksLink(inbound, email)
	case "hysteria":
		return s.genHysteriaLink(inbound, email)
	case "mtproto":
		return s.genMtprotoLink(inbound, email)
	}
	return ""
}

// genMtprotoLink builds a Telegram proxy deep link for an mtproto inbound:
// tg://proxy?server=<addr>&port=<port>&secret=<ee FakeTLS secret>.
func (s *SubService) genMtprotoLink(inbound *model.Inbound, email string) string {
	if inbound.Protocol != model.MTProto {
		return ""
	}
	settings := map[string]any{}
	json.Unmarshal([]byte(inbound.Settings), &settings)
	secret, _ := settings["secret"].(string)
	if secret == "" {
		if healed, ok := model.HealMtprotoSecret(inbound.Settings); ok {
			_ = json.Unmarshal([]byte(healed), &settings)
			secret, _ = settings["secret"].(string)
		}
	}
	if secret == "" {
		return ""
	}
	params := map[string]string{
		"server": s.resolveInboundAddress(inbound),
		"port":   fmt.Sprintf("%d", inbound.Port),
		"secret": secret,
	}
	return buildLinkWithParams("tg://proxy", params, s.genRemark(inbound, email, ""))
}

// Protocol link generators are intentionally ordered as:
// vmess -> vless -> trojan -> shadowsocks -> hysteria.
func (s *SubService) genVmessLink(inbound *model.Inbound, email string) string {
	if inbound.Protocol != model.VMESS {
		return ""
	}
	address := s.resolveInboundAddress(inbound)
	obj := map[string]any{
		"v":    "2",
		"add":  address,
		"port": inbound.Port,
		"type": "none",
	}
	stream := unmarshalStreamSettings(inbound.StreamSettings)
	network, _ := stream["network"].(string)
	applyVmessNetworkParams(stream, network, obj)
	if finalmask, ok := stream["finalmask"].(map[string]any); ok {
		applyFinalMaskObj(finalmask, obj)
	}
	security, _ := stream["security"].(string)
	obj["tls"] = security
	if security == "tls" {
		applyVmessTLSParams(stream, obj)
	}

	clients, _ := s.inboundService.GetClients(inbound)
	clientIndex := findClientIndex(clients, email)
	obj["id"] = clients[clientIndex].ID
	obj["scy"] = clients[clientIndex].Security

	externalProxies, _ := stream["externalProxy"].([]any)

	if len(externalProxies) > 0 {
		return s.buildVmessExternalProxyLinks(externalProxies, obj, inbound, email)
	}

	obj["ps"] = s.genRemark(inbound, email, "")
	return buildVmessLink(obj)
}

func (s *SubService) genVlessLink(inbound *model.Inbound, email string) string {
	if inbound.Protocol != model.VLESS {
		return ""
	}
	address := s.resolveInboundAddress(inbound)
	stream := unmarshalStreamSettings(inbound.StreamSettings)
	clients, _ := s.inboundService.GetClients(inbound)
	clientIndex := findClientIndex(clients, email)
	uuid := clients[clientIndex].ID
	port := inbound.Port
	streamNetwork := stream["network"].(string)
	params := make(map[string]string)
	params["type"] = streamNetwork

	// Add encryption parameter for VLESS from inbound settings
	var settings map[string]any
	json.Unmarshal([]byte(inbound.Settings), &settings)
	if encryption, ok := settings["encryption"].(string); ok {
		params["encryption"] = encryption
	}

	applyShareNetworkParams(stream, streamNetwork, params)
	if finalmask, ok := stream["finalmask"].(map[string]any); ok {
		applyFinalMaskParams(finalmask, params)
	}
	security, _ := stream["security"].(string)
	switch security {
	case "tls":
		applyShareTLSParams(stream, params)
		if streamNetwork == "tcp" && len(clients[clientIndex].Flow) > 0 {
			params["flow"] = clients[clientIndex].Flow
		}
	case "reality":
		applyShareRealityParams(stream, params)
		if streamNetwork == "tcp" && len(clients[clientIndex].Flow) > 0 {
			params["flow"] = clients[clientIndex].Flow
		}
	default:
		params["security"] = "none"
	}

	externalProxies, _ := stream["externalProxy"].([]any)

	if len(externalProxies) > 0 {
		return s.buildExternalProxyURLLinks(
			externalProxies,
			params,
			security,
			func(dest string, port int) string {
				return fmt.Sprintf("vless://%s@%s:%d", uuid, dest, port)
			},
			func(ep map[string]any) string {
				return s.genRemark(inbound, email, ep["remark"].(string))
			},
		)
	}

	link := fmt.Sprintf("vless://%s@%s:%d", uuid, address, port)
	return buildLinkWithParams(link, params, s.genRemark(inbound, email, ""))
}

func (s *SubService) genTrojanLink(inbound *model.Inbound, email string) string {
	if inbound.Protocol != model.Trojan {
		return ""
	}
	address := s.resolveInboundAddress(inbound)
	stream := unmarshalStreamSettings(inbound.StreamSettings)
	clients, _ := s.inboundService.GetClients(inbound)
	clientIndex := findClientIndex(clients, email)
	password := encodeUserinfo(clients[clientIndex].Password)
	port := inbound.Port
	streamNetwork := stream["network"].(string)
	params := make(map[string]string)
	params["type"] = streamNetwork

	applyShareNetworkParams(stream, streamNetwork, params)
	if finalmask, ok := stream["finalmask"].(map[string]any); ok {
		applyFinalMaskParams(finalmask, params)
	}
	security, _ := stream["security"].(string)
	switch security {
	case "tls":
		applyShareTLSParams(stream, params)
	case "reality":
		applyShareRealityParams(stream, params)
		if streamNetwork == "tcp" && len(clients[clientIndex].Flow) > 0 {
			params["flow"] = clients[clientIndex].Flow
		}
	default:
		params["security"] = "none"
	}

	externalProxies, _ := stream["externalProxy"].([]any)

	if len(externalProxies) > 0 {
		return s.buildExternalProxyURLLinks(
			externalProxies,
			params,
			security,
			func(dest string, port int) string {
				return fmt.Sprintf("trojan://%s@%s:%d", password, dest, port)
			},
			func(ep map[string]any) string {
				return s.genRemark(inbound, email, ep["remark"].(string))
			},
		)
	}

	link := fmt.Sprintf("trojan://%s@%s:%d", password, address, port)
	return buildLinkWithParams(link, params, s.genRemark(inbound, email, ""))
}

// encodeUserinfo percent-encodes a userinfo (password/auth) value so it
// can be safely embedded in a `scheme://<value>@host:port` URL. RFC 3986
// allows `=` in userinfo as a sub-delim, but several Trojan and Hysteria
// clients reject share-links where the password contains literal `/`
// or `=` (notably the common base64-with-padding shape produced by the
// panel). Encode them too — this matches encodeURIComponent() on the
// frontend and round-trips cleanly through net/url's parser.
func encodeUserinfo(s string) string {
	return strings.ReplaceAll(url.QueryEscape(s), "+", "%20")
}

func (s *SubService) genShadowsocksLink(inbound *model.Inbound, email string) string {
	if inbound.Protocol != model.Shadowsocks {
		return ""
	}
	address := s.resolveInboundAddress(inbound)
	stream := unmarshalStreamSettings(inbound.StreamSettings)
	clients, _ := s.inboundService.GetClients(inbound)

	var settings map[string]any
	json.Unmarshal([]byte(inbound.Settings), &settings)
	inboundPassword := settings["password"].(string)
	method := settings["method"].(string)
	clientIndex := findClientIndex(clients, email)
	streamNetwork := stream["network"].(string)
	params := make(map[string]string)
	params["type"] = streamNetwork

	applyShareNetworkParams(stream, streamNetwork, params)
	if finalmask, ok := stream["finalmask"].(map[string]any); ok {
		applyFinalMaskParams(finalmask, params)
	}

	security, _ := stream["security"].(string)
	if security == "tls" {
		applyShareTLSParams(stream, params)
	}

	encPart := fmt.Sprintf("%s:%s", method, clients[clientIndex].Password)
	if method[0] == '2' {
		encPart = fmt.Sprintf("%s:%s:%s", method, inboundPassword, clients[clientIndex].Password)
	}

	externalProxies, _ := stream["externalProxy"].([]any)

	if len(externalProxies) > 0 {
		proxyParams := cloneStringMap(params)
		proxyParams["security"] = security
		return s.buildExternalProxyURLLinks(
			externalProxies,
			proxyParams,
			security,
			func(dest string, port int) string {
				return fmt.Sprintf("ss://%s@%s:%d", base64.RawURLEncoding.EncodeToString([]byte(encPart)), dest, port)
			},
			func(ep map[string]any) string {
				return s.genRemark(inbound, email, ep["remark"].(string))
			},
		)
	}

	link := fmt.Sprintf("ss://%s@%s:%d", base64.RawURLEncoding.EncodeToString([]byte(encPart)), address, inbound.Port)
	return buildLinkWithParams(link, params, s.genRemark(inbound, email, ""))
}

func (s *SubService) genHysteriaLink(inbound *model.Inbound, email string) string {
	if inbound.Protocol != model.Hysteria {
		return ""
	}
	var stream map[string]any
	json.Unmarshal([]byte(inbound.StreamSettings), &stream)
	clients, _ := s.inboundService.GetClients(inbound)
	clientIndex := -1
	for i, client := range clients {
		if client.Email == email {
			clientIndex = i
			break
		}
	}
	auth := encodeUserinfo(clients[clientIndex].Auth)
	params := make(map[string]string)

	params["security"] = "tls"
	tlsSetting, _ := stream["tlsSettings"].(map[string]any)
	alpns, _ := tlsSetting["alpn"].([]any)
	var alpn []string
	for _, a := range alpns {
		alpn = append(alpn, a.(string))
	}
	if len(alpn) > 0 {
		params["alpn"] = strings.Join(alpn, ",")
	}
	if sniValue, ok := searchKey(tlsSetting, "serverName"); ok {
		params["sni"], _ = sniValue.(string)
	}

	tlsSettings, _ := searchKey(tlsSetting, "settings")
	if tlsSetting != nil {
		if fpValue, ok := searchKey(tlsSettings, "fingerprint"); ok {
			params["fp"], _ = fpValue.(string)
		}
		if echValue, ok := searchKey(tlsSettings, "echConfigList"); ok {
			if ech, _ := echValue.(string); ech != "" {
				params["ech"] = ech
			}
		}
		if pins, ok := pinnedSha256List(tlsSettings); ok {
			for i, p := range pins {
				pins[i] = hysteriaPinHex(p)
			}
			params["pinSHA256"] = strings.Join(pins, ",")
		}
	}

	// salamander obfs (Hysteria2). The panel-side link generator already
	// emits these; keep the subscription output in sync so a client has
	// the obfs password to match the server.
	if finalmask, ok := stream["finalmask"].(map[string]any); ok {
		applyFinalMaskParams(finalmask, params)
		if udpMasks, ok := finalmask["udp"].([]any); ok {
			for _, m := range udpMasks {
				mask, _ := m.(map[string]any)
				if mask == nil || mask["type"] != "salamander" {
					continue
				}
				settings, _ := mask["settings"].(map[string]any)
				if pw, ok := settings["password"].(string); ok && pw != "" {
					params["obfs"] = "salamander"
					params["obfs-password"] = pw
					break
				}
			}
		}
	}

	var settings map[string]any
	json.Unmarshal([]byte(inbound.Settings), &settings)
	version, _ := settings["version"].(float64)
	protocol := "hysteria2"
	if int(version) == 1 {
		protocol = "hysteria"
	}

	// Fan out one link per External Proxy entry if any. Previously this
	// generator ignored `externalProxy` entirely, so the link kept the
	// server's own IP/port even when the admin configured an alternate
	// endpoint (e.g. a CDN hostname + port that forwards to the node).
	// Matches the behaviour of genVlessLink / genTrojanLink / ….
	externalProxies, _ := stream["externalProxy"].([]any)
	if len(externalProxies) > 0 {
		links := make([]string, 0, len(externalProxies))
		for _, externalProxy := range externalProxies {
			ep, ok := externalProxy.(map[string]any)
			if !ok {
				continue
			}
			dest, _ := ep["dest"].(string)
			portF, okPort := ep["port"].(float64)
			if dest == "" || !okPort {
				continue
			}
			epRemark, _ := ep["remark"].(string)

			epParams := cloneStringMap(params)
			applyExternalProxyHysteriaParams(ep, epParams)

			link := fmt.Sprintf("%s://%s@%s:%d", protocol, auth, dest, int(portF))
			links = append(links, buildLinkWithParams(link, epParams, s.genRemark(inbound, email, epRemark)))
		}
		return strings.Join(links, "\n")
	}

	// No external proxy configured — use the inbound's resolved address so
	// node-managed inbounds get the node's host instead of the central panel's.
	if hopPorts := hysteriaHopPorts(stream); hopPorts != "" {
		params["mport"] = hopPorts
	}
	link := fmt.Sprintf("%s://%s@%s:%d", protocol, auth, s.resolveInboundAddress(inbound), inbound.Port)
	return buildLinkWithParams(link, params, s.genRemark(inbound, email, ""))
}

// hysteriaHopPorts returns the configured Hysteria2 UDP port-hopping range
// (finalmask.quicParams.udpHop.ports), or "" when port hopping is off. The
// range is emitted as the v2rayN-compatible `mport` query param; the URL port
// field stays numeric so .NET-Uri-based importers (v2rayN) can parse the link.
func hysteriaHopPorts(stream map[string]any) string {
	finalmask, _ := stream["finalmask"].(map[string]any)
	quicParams, _ := finalmask["quicParams"].(map[string]any)
	udpHop, _ := quicParams["udpHop"].(map[string]any)
	ports, _ := udpHop["ports"].(string)
	return strings.TrimSpace(ports)
}

// loadNodes refreshes nodesByID from the DB. Called once per request so
// the per-inbound resolveInboundAddress lookups are pure map reads.
// We filter to address != ” so a half-configured node row doesn't
// accidentally produce a useless host like "https://:2053".
func (s *SubService) loadNodes() {
	db := database.GetDB()
	var nodes []*model.Node
	if err := db.Model(&model.Node{}).Where("address != ''").Find(&nodes).Error; err != nil {
		logger.Warning("subscription: load nodes failed:", err)
		s.nodesByID = nil
		return
	}
	m := make(map[int]*model.Node, len(nodes))
	for _, n := range nodes {
		m[n.Id] = n
	}
	s.nodesByID = m
}

// resolveInboundAddress picks the host an external client should connect to:
//  1. node-managed inbound -> the node's address
//  2. an explicit, client-reachable bind Listen -> that Listen
//  3. otherwise the subscriber's request host (s.address)
//
// A loopback/wildcard bind or a unix-domain-socket listen is a server-side
// detail and is never advertised; External Proxy remains the way to advertise
// an arbitrary endpoint. Mirrors the frontend's resolveAddr so the panel QR and
// the subscription agree.
func (s *SubService) resolveInboundAddress(inbound *model.Inbound) string {
	if inbound.NodeID != nil && s.nodesByID != nil {
		if n, ok := s.nodesByID[*inbound.NodeID]; ok && n.Address != "" {
			return n.Address
		}
	}
	if listen := inbound.Listen; listen != "" && listen[0] != '@' && listen[0] != '/' && isRoutableHost(listen) {
		return listen
	}
	return s.address
}

func findClientIndex(clients []model.Client, email string) int {
	for i, client := range clients {
		if client.Email == email {
			return i
		}
	}
	return -1
}

func unmarshalStreamSettings(streamSettings string) map[string]any {
	var stream map[string]any
	json.Unmarshal([]byte(streamSettings), &stream)
	return stream
}

func applyPathAndHostParams(settings map[string]any, params map[string]string) {
	params["path"] = settings["path"].(string)
	if host, ok := settings["host"].(string); ok && len(host) > 0 {
		params["host"] = host
	} else {
		headers, _ := settings["headers"].(map[string]any)
		params["host"] = searchHost(headers)
	}
}

func applyPathAndHostObj(settings map[string]any, obj map[string]any) {
	obj["path"] = settings["path"].(string)
	if host, ok := settings["host"].(string); ok && len(host) > 0 {
		obj["host"] = host
	} else {
		headers, _ := settings["headers"].(map[string]any)
		obj["host"] = searchHost(headers)
	}
}

func applyShareNetworkParams(stream map[string]any, streamNetwork string, params map[string]string) {
	switch streamNetwork {
	case "tcp":
		tcp, _ := stream["tcpSettings"].(map[string]any)
		header, _ := tcp["header"].(map[string]any)
		typeStr, _ := header["type"].(string)
		if typeStr == "http" {
			request := header["request"].(map[string]any)
			requestPath, _ := request["path"].([]any)
			params["path"] = requestPath[0].(string)
			host := ""
			if response, ok := header["response"].(map[string]any); ok {
				if respHeaders, ok := response["headers"].(map[string]any); ok {
					host = searchHost(respHeaders)
				}
			}
			if host == "" {
				headers, _ := request["headers"].(map[string]any)
				host = searchHost(headers)
			}
			params["host"] = host
			params["headerType"] = "http"
		}
	case "kcp":
		applyKcpShareParams(stream, params)
	case "ws":
		ws, _ := stream["wsSettings"].(map[string]any)
		applyPathAndHostParams(ws, params)
	case "grpc":
		grpc, _ := stream["grpcSettings"].(map[string]any)
		params["serviceName"] = grpc["serviceName"].(string)
		params["authority"], _ = grpc["authority"].(string)
		if grpc["multiMode"].(bool) {
			params["mode"] = "multi"
		}
	case "httpupgrade":
		httpupgrade, _ := stream["httpupgradeSettings"].(map[string]any)
		applyPathAndHostParams(httpupgrade, params)
	case "xhttp":
		xhttp, _ := stream["xhttpSettings"].(map[string]any)
		applyXhttpExtraParams(xhttp, params)
	}
}

// applyXhttpExtraObj copies the bidirectional xhttp settings into the
// VMess base64 JSON link object. VMess supports arbitrary keys, so we
// flatten the SplitHTTPConfig "extra" fields directly onto obj.
func applyXhttpExtraObj(xhttp map[string]any, obj map[string]any) {
	if xpb, ok := xhttp["xPaddingBytes"].(string); ok && len(xpb) > 0 {
		obj["x_padding_bytes"] = xpb
	}
	maps.Copy(obj, buildXhttpExtra(xhttp))
}

func applyVmessNetworkParams(stream map[string]any, network string, obj map[string]any) {
	obj["net"] = network
	switch network {
	case "tcp":
		tcp, _ := stream["tcpSettings"].(map[string]any)
		header, _ := tcp["header"].(map[string]any)
		typeStr, _ := header["type"].(string)
		obj["type"] = typeStr
		if typeStr == "http" {
			request := header["request"].(map[string]any)
			requestPath, _ := request["path"].([]any)
			obj["path"] = requestPath[0].(string)
			host := ""
			if response, ok := header["response"].(map[string]any); ok {
				if respHeaders, ok := response["headers"].(map[string]any); ok {
					host = searchHost(respHeaders)
				}
			}
			if host == "" {
				headers, _ := request["headers"].(map[string]any)
				host = searchHost(headers)
			}
			obj["host"] = host
		}
	case "kcp":
		applyKcpShareObj(stream, obj)
	case "ws":
		ws, _ := stream["wsSettings"].(map[string]any)
		applyPathAndHostObj(ws, obj)
	case "grpc":
		grpc, _ := stream["grpcSettings"].(map[string]any)
		obj["path"] = grpc["serviceName"].(string)
		obj["authority"] = grpc["authority"].(string)
		if grpc["multiMode"].(bool) {
			obj["type"] = "multi"
		}
	case "httpupgrade":
		httpupgrade, _ := stream["httpupgradeSettings"].(map[string]any)
		applyPathAndHostObj(httpupgrade, obj)
	case "xhttp":
		xhttp, _ := stream["xhttpSettings"].(map[string]any)
		applyPathAndHostObj(xhttp, obj)
		if mode, ok := xhttp["mode"].(string); ok {
			obj["mode"] = mode
		}
		applyXhttpExtraObj(xhttp, obj)
	}
}

func applyShareTLSParams(stream map[string]any, params map[string]string) {
	params["security"] = "tls"
	tlsSetting, _ := stream["tlsSettings"].(map[string]any)
	alpns, _ := tlsSetting["alpn"].([]any)
	var alpn []string
	for _, a := range alpns {
		alpn = append(alpn, a.(string))
	}
	if len(alpn) > 0 {
		params["alpn"] = strings.Join(alpn, ",")
	}
	if sniValue, ok := searchKey(tlsSetting, "serverName"); ok {
		params["sni"], _ = sniValue.(string)
	}

	tlsSettings, _ := searchKey(tlsSetting, "settings")
	if tlsSetting != nil {
		if fpValue, ok := searchKey(tlsSettings, "fingerprint"); ok {
			params["fp"], _ = fpValue.(string)
		}
		if echValue, ok := searchKey(tlsSettings, "echConfigList"); ok {
			if ech, _ := echValue.(string); ech != "" {
				params["ech"] = ech
			}
		}
		if pins, ok := pinnedSha256List(tlsSettings); ok {
			params["pcs"] = strings.Join(pins, ",")
		}
	}
}

func applyVmessTLSParams(stream map[string]any, obj map[string]any) {
	tlsSetting, _ := stream["tlsSettings"].(map[string]any)
	alpns, _ := tlsSetting["alpn"].([]any)
	if len(alpns) > 0 {
		var alpn []string
		for _, a := range alpns {
			alpn = append(alpn, a.(string))
		}
		obj["alpn"] = strings.Join(alpn, ",")
	}
	if sniValue, ok := searchKey(tlsSetting, "serverName"); ok {
		obj["sni"], _ = sniValue.(string)
	}

	tlsSettings, _ := searchKey(tlsSetting, "settings")
	if tlsSetting != nil {
		if fpValue, ok := searchKey(tlsSettings, "fingerprint"); ok {
			obj["fp"], _ = fpValue.(string)
		}
		if echValue, ok := searchKey(tlsSettings, "echConfigList"); ok {
			if ech, _ := echValue.(string); ech != "" {
				obj["ech"] = ech
			}
		}
		if pins, ok := pinnedSha256List(tlsSettings); ok {
			obj["pcs"] = strings.Join(pins, ",")
		}
	}
}

// pinnedSha256List extracts tlsSettings.settings.pinnedPeerCertSha256 as a
// []string. The field is panel-only (stripped before the run-config reaches
// xray-core via web/service/xray.go) but flows into share links so clients
// can pin the server's certificate hash.
func pinnedSha256List(tlsClientSettings any) ([]string, bool) {
	raw, ok := searchKey(tlsClientSettings, "pinnedPeerCertSha256")
	if !ok {
		return nil, false
	}
	arr, ok := raw.([]any)
	if !ok || len(arr) == 0 {
		return nil, false
	}
	out := make([]string, 0, len(arr))
	for _, v := range arr {
		s, ok := v.(string)
		if !ok || s == "" {
			continue
		}
		out = append(out, s)
	}
	if len(out) == 0 {
		return nil, false
	}
	return out, true
}

// hysteriaPinHex normalises a pinnedPeerCertSha256 entry into the 64-character
// lowercase hex form that Xray-core's Hysteria2 pinSHA256 parser requires.
//
// The panel stores pins in several shapes: base64 (xray-core's native TLS
// format, used by the generate button and the JSON subscription) and hex —
// either bare or colon-separated as `openssl x509 -fingerprint -sha256` emits
// it. Hysteria2 clients hex-decode pinSHA256 and crash on a base64 value, so
// each entry is coerced to bare hex here. Anything that is neither a 32-byte
// hex nor a 32-byte base64 SHA-256 is returned unchanged so unexpected data is
// not silently dropped. Mirrors decodeCertPin in web/service/node.go.
func hysteriaPinHex(pin string) string {
	pin = strings.TrimSpace(pin)
	if h := strings.ReplaceAll(pin, ":", ""); len(h) == hex.EncodedLen(sha256.Size) {
		if _, err := hex.DecodeString(h); err == nil {
			return strings.ToLower(h)
		}
	}
	for _, enc := range []*base64.Encoding{
		base64.StdEncoding,
		base64.RawStdEncoding,
		base64.URLEncoding,
		base64.RawURLEncoding,
	} {
		if b, err := enc.DecodeString(pin); err == nil && len(b) == sha256.Size {
			return hex.EncodeToString(b)
		}
	}
	return pin
}

func applyShareRealityParams(stream map[string]any, params map[string]string) {
	params["security"] = "reality"
	realitySetting, _ := stream["realitySettings"].(map[string]any)
	realitySettings, _ := searchKey(realitySetting, "settings")
	if realitySetting != nil {
		if sniValue, ok := searchKey(realitySetting, "serverNames"); ok {
			sNames, _ := sniValue.([]any)
			params["sni"] = sNames[random.Num(len(sNames))].(string)
		}
		if pbkValue, ok := searchKey(realitySettings, "publicKey"); ok {
			params["pbk"], _ = pbkValue.(string)
		}
		if sidValue, ok := searchKey(realitySetting, "shortIds"); ok {
			shortIds, _ := sidValue.([]any)
			params["sid"] = shortIds[random.Num(len(shortIds))].(string)
		}
		if fpValue, ok := searchKey(realitySettings, "fingerprint"); ok {
			if fp, ok := fpValue.(string); ok && len(fp) > 0 {
				params["fp"] = fp
			}
		}
		if pqvValue, ok := searchKey(realitySettings, "mldsa65Verify"); ok {
			if pqv, ok := pqvValue.(string); ok && len(pqv) > 0 {
				params["pqv"] = pqv
			}
		}
		params["spx"] = "/" + random.Seq(15)
	}
}

func buildVmessLink(obj map[string]any) string {
	jsonStr, _ := json.MarshalIndent(obj, "", "  ")
	return "vmess://" + base64.StdEncoding.EncodeToString(jsonStr)
}

func cloneVmessShareObj(baseObj map[string]any, newSecurity string) map[string]any {
	newObj := map[string]any{}
	for key, value := range baseObj {
		if !(newSecurity == "none" && (key == "alpn" || key == "sni" || key == "fp" || key == "pcs")) {
			newObj[key] = value
		}
	}
	return newObj
}

func applyExternalProxyTLSObj(ep map[string]any, obj map[string]any, security string) {
	if security != "tls" {
		return
	}
	if sni, ok := externalProxySNI(ep); ok {
		obj["sni"] = sni
	}
	if fp, ok := ep["fingerprint"].(string); ok && fp != "" {
		obj["fp"] = fp
	}
	if alpn, ok := externalProxyALPN(ep["alpn"]); ok {
		obj["alpn"] = alpn
	}
	if pins, ok := externalProxyPins(ep["pinnedPeerCertSha256"]); ok {
		obj["pcs"] = joinAnyStrings(pins)
	}
	if ech, ok := ep["echConfigList"].(string); ok && ech != "" {
		obj["ech"] = ech
	}
}

func applyExternalProxyTLSParams(ep map[string]any, params map[string]string, security string) {
	if security != "tls" {
		return
	}
	if sni, ok := externalProxySNI(ep); ok {
		params["sni"] = sni
	}
	if fp, ok := ep["fingerprint"].(string); ok && fp != "" {
		params["fp"] = fp
	}
	if alpn, ok := externalProxyALPN(ep["alpn"]); ok {
		params["alpn"] = alpn
	}
	if pins, ok := externalProxyPins(ep["pinnedPeerCertSha256"]); ok {
		params["pcs"] = joinAnyStrings(pins)
	}
	if ech, ok := ep["echConfigList"].(string); ok && ech != "" {
		params["ech"] = ech
	}
}

// applyExternalProxyHysteriaParams overrides the cert pin for a single
// external-proxy entry on a Hysteria link. Hysteria carries the pin as a hex
// `pinSHA256` (not the `pcs` the URL-param protocols use), so each entry is
// coerced through hysteriaPinHex like the main pin. sni/fp/alpn are left as
// the inbound's own — Hysteria external proxies are typically alternate
// endpoints (port-hop / CDN) fronting the same certificate.
func applyExternalProxyHysteriaParams(ep map[string]any, params map[string]string) {
	pins, ok := externalProxyPins(ep["pinnedPeerCertSha256"])
	if !ok {
		return
	}
	hexPins := make([]string, 0, len(pins))
	for _, p := range pins {
		if s, ok := p.(string); ok {
			hexPins = append(hexPins, hysteriaPinHex(s))
		}
	}
	params["pinSHA256"] = strings.Join(hexPins, ",")
}

// cloneStreamForExternalProxy returns a shallow clone of stream with
// tlsSettings (and its nested settings map) deep-copied. The external
// proxy loop mutates tlsSettings per iteration, so without isolating
// those maps each proxy's SNI/fingerprint/ALPN would leak into the next.
func cloneStreamForExternalProxy(stream map[string]any) map[string]any {
	out := cloneMap(stream)
	ts, ok := out["tlsSettings"].(map[string]any)
	if !ok || ts == nil {
		return out
	}
	clonedTs := cloneMap(ts)
	if inner, ok := clonedTs["settings"].(map[string]any); ok && inner != nil {
		clonedTs["settings"] = cloneMap(inner)
	}
	out["tlsSettings"] = clonedTs
	return out
}

func applyExternalProxyTLSToStream(ep map[string]any, stream map[string]any, security string) {
	if security != "tls" {
		return
	}
	tlsSettings, _ := stream["tlsSettings"].(map[string]any)
	if tlsSettings == nil {
		tlsSettings = map[string]any{}
		stream["tlsSettings"] = tlsSettings
	}
	if sni, ok := externalProxySNI(ep); ok {
		tlsSettings["serverName"] = sni
	}
	if fp, ok := ep["fingerprint"].(string); ok && fp != "" {
		tlsSettings["fingerprint"] = fp
		settings, _ := tlsSettings["settings"].(map[string]any)
		if settings == nil {
			settings = map[string]any{}
			tlsSettings["settings"] = settings
		}
		settings["fingerprint"] = fp
	}
	if alpn, ok := externalProxyALPNList(ep["alpn"]); ok {
		tlsSettings["alpn"] = alpn
	}
	if pins, ok := externalProxyPins(ep["pinnedPeerCertSha256"]); ok {
		settings, _ := tlsSettings["settings"].(map[string]any)
		if settings == nil {
			settings = map[string]any{}
			tlsSettings["settings"] = settings
		}
		settings["pinnedPeerCertSha256"] = pins
	}
	if ech, ok := ep["echConfigList"].(string); ok && ech != "" {
		settings, _ := tlsSettings["settings"].(map[string]any)
		if settings == nil {
			settings = map[string]any{}
			tlsSettings["settings"] = settings
		}
		settings["echConfigList"] = ech
	}
}

func externalProxySNI(ep map[string]any) (string, bool) {
	if sni, ok := ep["sni"].(string); ok && sni != "" {
		return sni, true
	}
	return "", false
}

func externalProxyALPN(value any) (string, bool) {
	switch v := value.(type) {
	case string:
		return v, v != ""
	case []string:
		if len(v) == 0 {
			return "", false
		}
		return strings.Join(v, ","), true
	case []any:
		alpn := make([]string, 0, len(v))
		for _, item := range v {
			if s, ok := item.(string); ok && s != "" {
				alpn = append(alpn, s)
			}
		}
		if len(alpn) == 0 {
			return "", false
		}
		return strings.Join(alpn, ","), true
	default:
		return "", false
	}
}

func externalProxyALPNList(value any) ([]any, bool) {
	switch v := value.(type) {
	case string:
		if v == "" {
			return nil, false
		}
		parts := strings.Split(v, ",")
		out := make([]any, 0, len(parts))
		for _, part := range parts {
			if part = strings.TrimSpace(part); part != "" {
				out = append(out, part)
			}
		}
		return out, len(out) > 0
	case []string:
		out := make([]any, 0, len(v))
		for _, item := range v {
			if item != "" {
				out = append(out, item)
			}
		}
		return out, len(out) > 0
	case []any:
		out := make([]any, 0, len(v))
		for _, item := range v {
			if s, ok := item.(string); ok && s != "" {
				out = append(out, s)
			}
		}
		return out, len(out) > 0
	default:
		return nil, false
	}
}

// externalProxyPins extracts an external-proxy entry's pinnedPeerCertSha256
// as a []any of non-empty strings. The []any element type matches what the
// JSON/Clash sub builders expect when reading the value back off the cloned
// stream's tlsSettings.settings.
func externalProxyPins(value any) ([]any, bool) {
	switch v := value.(type) {
	case []string:
		out := make([]any, 0, len(v))
		for _, item := range v {
			if item != "" {
				out = append(out, item)
			}
		}
		return out, len(out) > 0
	case []any:
		out := make([]any, 0, len(v))
		for _, item := range v {
			if s, ok := item.(string); ok && s != "" {
				out = append(out, s)
			}
		}
		return out, len(out) > 0
	default:
		return nil, false
	}
}

func joinAnyStrings(items []any) string {
	parts := make([]string, 0, len(items))
	for _, item := range items {
		if s, ok := item.(string); ok {
			parts = append(parts, s)
		}
	}
	return strings.Join(parts, ",")
}

func (s *SubService) buildVmessExternalProxyLinks(externalProxies []any, baseObj map[string]any, inbound *model.Inbound, email string) string {
	var links strings.Builder
	for index, externalProxy := range externalProxies {
		ep, _ := externalProxy.(map[string]any)
		newSecurity, _ := ep["forceTls"].(string)
		securityToApply := baseObj["tls"].(string)
		if newSecurity != "same" {
			securityToApply = newSecurity
		}
		newObj := cloneVmessShareObj(baseObj, newSecurity)
		newObj["ps"] = s.genRemark(inbound, email, ep["remark"].(string))
		newObj["add"] = ep["dest"].(string)
		newObj["port"] = int(ep["port"].(float64))

		if newSecurity != "same" {
			newObj["tls"] = newSecurity
		}
		applyExternalProxyTLSObj(ep, newObj, securityToApply)
		if index > 0 {
			links.WriteString("\n")
		}
		links.WriteString(buildVmessLink(newObj))
	}
	return links.String()
}

// buildLinkWithParams appends ?query and #fragment to a pre-built
// scheme://userinfo@host:port string without re-parsing it. The caller
// has already escaped userinfo via encodeUserinfo (or chosen a base64
// alphabet with no reserved chars); a url.Parse + .String() round-trip
// would silently decode that escaping because Go's userinfo emitter
// leaves sub-delims (=, +, ;) literal, which breaks Trojan/Hysteria/SS
// clients that reject those chars in the password.
func buildLinkWithParams(link string, params map[string]string, fragment string) string {
	return appendQueryAndFragment(link, params, fragment, "", false)
}

// buildLinkWithParamsAndSecurity is buildLinkWithParams plus an
// external-proxy override: the `security` key in params is replaced with
// the supplied value, and TLS hint fields (alpn/sni/fp/pcs) are stripped
// when the override is `none`.
func buildLinkWithParamsAndSecurity(link string, params map[string]string, fragment, security string, omitTLSFields bool) string {
	return appendQueryAndFragment(link, params, fragment, security, omitTLSFields)
}

func appendQueryAndFragment(link string, params map[string]string, fragment, securityOverride string, omitTLSFields bool) string {
	var sb strings.Builder
	sb.WriteString(link)

	if len(params) > 0 {
		q := url.Values{}
		for k, v := range params {
			if securityOverride != "" && k == "security" {
				v = securityOverride
			}
			if omitTLSFields && (k == "alpn" || k == "sni" || k == "fp" || k == "pcs") {
				continue
			}
			q.Set(k, v)
		}
		encoded := q.Encode()
		if encoded != "" {
			if strings.Contains(link, "?") {
				sb.WriteByte('&')
			} else {
				sb.WriteByte('?')
			}
			sb.WriteString(encoded)
		}
	}

	if fragment != "" {
		sb.WriteByte('#')
		// Match the frontend's encodeURIComponent(remark): spaces become
		// %20 (not + as in query strings).
		sb.WriteString(strings.ReplaceAll(url.QueryEscape(fragment), "+", "%20"))
	}
	return sb.String()
}

func (s *SubService) buildExternalProxyURLLinks(
	externalProxies []any,
	params map[string]string,
	baseSecurity string,
	makeLink func(dest string, port int) string,
	makeRemark func(ep map[string]any) string,
) string {
	links := make([]string, 0, len(externalProxies))
	for _, externalProxy := range externalProxies {
		ep, _ := externalProxy.(map[string]any)
		newSecurity, _ := ep["forceTls"].(string)
		dest, _ := ep["dest"].(string)
		port := int(ep["port"].(float64))

		securityToApply := baseSecurity
		if newSecurity != "same" {
			securityToApply = newSecurity
		}

		nextParams := cloneStringMap(params)
		applyExternalProxyTLSParams(ep, nextParams, securityToApply)

		links = append(
			links,
			buildLinkWithParamsAndSecurity(
				makeLink(dest, port),
				nextParams,
				makeRemark(ep),
				securityToApply,
				newSecurity == "none",
			),
		)
	}
	return strings.Join(links, "\n")
}

func cloneStringMap(source map[string]string) map[string]string {
	cloned := make(map[string]string, len(source))
	maps.Copy(cloned, source)
	return cloned
}

func (s *SubService) genRemark(inbound *model.Inbound, email string, extra string) string {
	separationChar := string(s.remarkModel[0])
	orderChars := s.remarkModel[1:]
	orders := map[byte]string{
		'i': "",
		'e': "",
		'o': "",
	}
	if len(email) > 0 && s.emailInRemark {
		orders['e'] = email
	}
	if len(inbound.Remark) > 0 {
		orders['i'] = inbound.Remark
	}
	if len(extra) > 0 {
		orders['o'] = extra
	}

	var remark []string
	for i := 0; i < len(orderChars); i++ {
		char := orderChars[i]
		order, exists := orders[char]
		if exists && order != "" {
			remark = append(remark, order)
		}
	}

	if s.showInfo {
		statsExist := false
		var stats xray.ClientTraffic
		for _, clientStat := range inbound.ClientStats {
			if clientStat.Email == email {
				stats = clientStat
				statsExist = true
				break
			}
		}

		// Get remained days
		if statsExist {
			if !stats.Enable {
				return fmt.Sprintf("⛔️N/A%s%s", separationChar, strings.Join(remark, separationChar))
			}
			if vol := stats.Total - (stats.Up + stats.Down); vol > 0 {
				remark = append(remark, fmt.Sprintf("%s%s", common.FormatTraffic(vol), "📊"))
			}
			now := time.Now().Unix()
			switch exp := stats.ExpiryTime / 1000; {
			case exp > 0:
				remainingSeconds := exp - now
				days := remainingSeconds / 86400
				hours := (remainingSeconds % 86400) / 3600
				minutes := (remainingSeconds % 3600) / 60
				if days > 0 {
					if hours > 0 {
						remark = append(remark, fmt.Sprintf("%dD,%dH⏳", days, hours))
					} else {
						remark = append(remark, fmt.Sprintf("%dD⏳", days))
					}
				} else if hours > 0 {
					remark = append(remark, fmt.Sprintf("%dH⏳", hours))
				} else {
					remark = append(remark, fmt.Sprintf("%dM⏳", minutes))
				}
			case exp < 0:
				days := exp / -86400
				hours := (exp % -86400) / 3600
				minutes := (exp % -3600) / 60
				if days > 0 {
					if hours > 0 {
						remark = append(remark, fmt.Sprintf("%dD,%dH⏳", days, hours))
					} else {
						remark = append(remark, fmt.Sprintf("%dD⏳", days))
					}
				} else if hours > 0 {
					remark = append(remark, fmt.Sprintf("%dH⏳", hours))
				} else {
					remark = append(remark, fmt.Sprintf("%dM⏳", minutes))
				}
			}
		}
	}
	return strings.Join(remark, separationChar)
}

func searchKey(data any, key string) (any, bool) {
	switch val := data.(type) {
	case map[string]any:
		for k, v := range val {
			if k == key {
				return v, true
			}
			if result, ok := searchKey(v, key); ok {
				return result, true
			}
		}
	case []any:
		for _, v := range val {
			if result, ok := searchKey(v, key); ok {
				return result, true
			}
		}
	}
	return nil, false
}

// buildXhttpExtra walks an xhttpSettings map and returns the JSON blob
// that goes into the URL's `extra` param (or, for VMess, the link
// object). Carries ONLY the bidirectional fields from xray-core's
// SplitHTTPConfig — i.e. the ones the server enforces and the client
// must match. Strictly one-sided fields are excluded:
//
//   - server-only (noSSEHeader, scMaxBufferedPosts, scStreamUpServerSecs,
//     serverMaxHeaderBytes) — client wouldn't read them, so emitting
//     them just bloats the URL.
//   - client-only values are included only when present in the inbound
//     JSON. Some deployments/imported configs carry them there, and the
//     subscription link is the only place clients can receive them.
//
// Truthy-only guards keep default inbounds emitting the same compact URL
// they did before this helper grew.
func buildXhttpExtra(xhttp map[string]any) map[string]any {
	if xhttp == nil {
		return nil
	}
	extra := map[string]any{}

	if xpb, ok := xhttp["xPaddingBytes"].(string); ok && len(xpb) > 0 {
		extra["xPaddingBytes"] = xpb
	}
	if obfs, ok := xhttp["xPaddingObfsMode"].(bool); ok && obfs {
		extra["xPaddingObfsMode"] = true
		for _, field := range []string{"xPaddingKey", "xPaddingHeader", "xPaddingPlacement", "xPaddingMethod"} {
			if v, ok := xhttp[field].(string); ok && len(v) > 0 {
				extra[field] = v
			}
		}
	}

	stringFields := []string{
		"uplinkHTTPMethod",
		"sessionPlacement", "sessionKey",
		"seqPlacement", "seqKey",
		"uplinkDataPlacement", "uplinkDataKey",
		"scMaxEachPostBytes", "scMinPostsIntervalMs",
	}
	for _, field := range stringFields {
		if v, ok := xhttp[field].(string); ok && len(v) > 0 {
			extra[field] = v
		}
	}

	for _, field := range []string{"uplinkChunkSize"} {
		if v, ok := nonZeroShareValue(xhttp[field]); ok {
			extra[field] = v
		}
	}

	for _, field := range []string{"noGRPCHeader"} {
		if v, ok := xhttp[field].(bool); ok && v {
			extra[field] = v
		}
	}

	for _, field := range []string{"xmux", "downloadSettings"} {
		if v, ok := nonEmptyShareObject(xhttp[field]); ok {
			extra[field] = v
		}
	}

	// Headers — emitted as the {name: value} map upstream's struct
	// expects. The server runtime ignores this field, but the client
	// (consuming the share link) honors it. Drop any "host" entry —
	// host already wins as a top-level URL param.
	if rawHeaders, ok := xhttp["headers"].(map[string]any); ok && len(rawHeaders) > 0 {
		out := map[string]any{}
		for k, v := range rawHeaders {
			if strings.EqualFold(k, "host") {
				continue
			}
			out[k] = v
		}
		if len(out) > 0 {
			extra["headers"] = out
		}
	}

	if len(extra) == 0 {
		return nil
	}
	return extra
}

func nonZeroShareValue(v any) (any, bool) {
	switch value := v.(type) {
	case string:
		return value, value != ""
	case int:
		return value, value != 0
	case int32:
		return value, value != 0
	case int64:
		return value, value != 0
	case float32:
		return value, value != 0
	case float64:
		return value, value != 0
	default:
		return nil, false
	}
}

func nonEmptyShareObject(v any) (any, bool) {
	switch value := v.(type) {
	case map[string]any:
		return value, len(value) > 0
	case map[string]string:
		return value, len(value) > 0
	case []any:
		return value, len(value) > 0
	default:
		return nil, false
	}
}

// applyXhttpExtraParams emits the full xhttp config into the URL query
// params of a vless:// / trojan:// / ss:// link. Sets path/host/mode at
// top level (xray's Build() always lets these win over `extra`) and packs
// everything else into a JSON `extra` param. Also writes the flat
// `x_padding_bytes` param sing-box-family clients understand.
//
// Without this, the admin's custom xPaddingBytes / sessionKey / etc. never
// reach the client and handshakes are silently rejected with
// `invalid padding (...) length: 0` — the client-visible symptom is
// "xhttp doesn't connect" on OpenWRT / sing-box.
//
// Two encodings are written so every popular client can read at least one:
//
//   - x_padding_bytes=<range>  — flat param, understood by sing-box and its
//     derivatives (Podkop, OpenWRT sing-box, Karing, NekoBox, …).
//   - extra=<url-encoded-json> — full xhttp settings blob, which is how
//     xray-core clients (v2rayNG, Happ, Furious, Exclave, …) pick up the
//     bidirectional fields beyond path/host/mode.
func applyXhttpExtraParams(xhttp map[string]any, params map[string]string) {
	if xhttp == nil {
		return
	}
	applyPathAndHostParams(xhttp, params)
	if mode, ok := xhttp["mode"].(string); ok {
		params["mode"] = mode
	}

	if xpb, ok := xhttp["xPaddingBytes"].(string); ok && len(xpb) > 0 {
		params["x_padding_bytes"] = xpb
	}

	extra := buildXhttpExtra(xhttp)
	if extra != nil {
		if b, err := json.Marshal(extra); err == nil {
			params["extra"] = string(b)
		}
	}
}

var kcpMaskToHeaderType = map[string]string{
	"dns":       "dns",
	"dtls":      "dtls",
	"srtp":      "srtp",
	"utp":       "utp",
	"wechat":    "wechat-video",
	"wireguard": "wireguard",
}

var validFinalMaskUDPTypes = map[string]struct{}{
	"salamander":    {},
	"mkcp-legacy":   {},
	"xdns":          {},
	"xicmp":         {},
	"noise":         {},
	"header-custom": {},
	"realm":         {},
}

var validFinalMaskTCPTypes = map[string]struct{}{
	"header-custom": {},
	"fragment":      {},
	"sudoku":        {},
}

// applyKcpShareParams reconstructs legacy KCP share-link fields from either
// the historical kcpSettings.header/seed shape or the current finalmask model.
// This keeps subscription output compatible while avoiding panics when older
// keys are absent from modern inbounds.
func applyKcpShareParams(stream map[string]any, params map[string]string) {
	extractKcpShareFields(stream).applyToParams(params)
}

func applyKcpShareObj(stream map[string]any, obj map[string]any) {
	extractKcpShareFields(stream).applyToObj(obj)
}

type kcpShareFields struct {
	headerType string
	seed       string
	mtu        int
	tti        int
}

func (f kcpShareFields) applyToParams(params map[string]string) {
	if f.headerType != "" && f.headerType != "none" {
		params["headerType"] = f.headerType
	}
	setStringParam(params, "seed", f.seed)
	setIntParam(params, "mtu", f.mtu)
	setIntParam(params, "tti", f.tti)
}

func (f kcpShareFields) applyToObj(obj map[string]any) {
	if f.headerType != "" && f.headerType != "none" {
		obj["type"] = f.headerType
	}
	setStringField(obj, "path", f.seed)
	setIntField(obj, "mtu", f.mtu)
	setIntField(obj, "tti", f.tti)
}

func extractKcpShareFields(stream map[string]any) kcpShareFields {
	fields := kcpShareFields{headerType: "none"}

	if kcp, ok := stream["kcpSettings"].(map[string]any); ok {
		if header, ok := kcp["header"].(map[string]any); ok {
			if value, ok := header["type"].(string); ok && value != "" {
				fields.headerType = value
			}
		}
		if value, ok := kcp["seed"].(string); ok && value != "" {
			fields.seed = value
		}
		if value, ok := readPositiveInt(kcp["mtu"]); ok {
			fields.mtu = value
		}
		if value, ok := readPositiveInt(kcp["tti"]); ok {
			fields.tti = value
		}
	}

	for _, rawMask := range normalizedFinalMaskUDPMasks(stream["finalmask"]) {
		mask, _ := rawMask.(map[string]any)
		if mask == nil {
			continue
		}
		if maskType, _ := mask["type"].(string); maskType != "mkcp-legacy" {
			continue
		}

		settings, _ := mask["settings"].(map[string]any)
		header, _ := settings["header"].(string)
		value, _ := settings["value"].(string)
		if header == "" {
			fields.seed = value
			continue
		}
		if mapped, ok := kcpMaskToHeaderType[header]; ok {
			fields.headerType = mapped
		}
	}

	return fields
}

func readPositiveInt(value any) (int, bool) {
	switch number := value.(type) {
	case int:
		return number, number > 0
	case int32:
		return int(number), number > 0
	case int64:
		return int(number), number > 0
	case float32:
		parsed := int(number)
		return parsed, parsed > 0
	case float64:
		parsed := int(number)
		return parsed, parsed > 0
	default:
		return 0, false
	}
}

func setStringParam(params map[string]string, key, value string) {
	if value == "" {
		delete(params, key)
		return
	}
	params[key] = value
}

func setIntParam(params map[string]string, key string, value int) {
	if value <= 0 {
		delete(params, key)
		return
	}
	params[key] = fmt.Sprintf("%d", value)
}

func setStringField(obj map[string]any, key, value string) {
	if value == "" {
		delete(obj, key)
		return
	}
	obj[key] = value
}

func setIntField(obj map[string]any, key string, value int) {
	if value <= 0 {
		delete(obj, key)
		return
	}
	obj[key] = value
}

// applyFinalMaskParams exports the finalmask payload as the compact
// `fm=<json>` share-link field used by v2rayN-compatible clients.
func applyFinalMaskParams(finalmask map[string]any, params map[string]string) {
	if fm, ok := marshalFinalMask(finalmask); ok {
		params["fm"] = fm
	}
}

func applyFinalMaskObj(finalmask map[string]any, obj map[string]any) {
	if fm, ok := marshalFinalMask(finalmask); ok {
		obj["fm"] = fm
	}
}

func marshalFinalMask(finalmask map[string]any) (string, bool) {
	normalized := normalizeFinalMask(finalmask)
	if !hasFinalMaskContent(normalized) {
		return "", false
	}
	b, err := json.Marshal(normalized)
	if err != nil || len(b) == 0 || string(b) == "null" {
		return "", false
	}
	return string(b), true
}

func normalizeFinalMask(finalmask map[string]any) map[string]any {
	tcpMasks := normalizedFinalMaskTCPMasks(finalmask)
	udpMasks := normalizedFinalMaskUDPMasks(finalmask)
	quicParams, hasQuicParams := finalmask["quicParams"].(map[string]any)

	if len(tcpMasks) == 0 && len(udpMasks) == 0 && !hasQuicParams {
		return nil
	}

	result := map[string]any{}
	if len(tcpMasks) > 0 {
		result["tcp"] = tcpMasks
	}
	if len(udpMasks) > 0 {
		result["udp"] = udpMasks
	}
	if hasQuicParams && len(quicParams) > 0 {
		result["quicParams"] = quicParams
	}
	return result
}

func normalizedFinalMaskTCPMasks(value any) []any {
	finalmask, _ := value.(map[string]any)
	if finalmask == nil {
		return nil
	}
	rawMasks, _ := finalmask["tcp"].([]any)
	if len(rawMasks) == 0 {
		return nil
	}

	normalized := make([]any, 0, len(rawMasks))
	for _, rawMask := range rawMasks {
		mask, _ := rawMask.(map[string]any)
		if mask == nil {
			continue
		}
		maskType, _ := mask["type"].(string)
		if _, ok := validFinalMaskTCPTypes[maskType]; !ok || maskType == "" {
			continue
		}

		normalizedMask := map[string]any{"type": maskType}
		if settings, ok := mask["settings"].(map[string]any); ok && len(settings) > 0 {
			normalizedMask["settings"] = settings
		}
		normalized = append(normalized, normalizedMask)
	}

	if len(normalized) == 0 {
		return nil
	}
	return normalized
}

func normalizedFinalMaskUDPMasks(value any) []any {
	finalmask, _ := value.(map[string]any)
	if finalmask == nil {
		return nil
	}
	rawMasks, _ := finalmask["udp"].([]any)
	if len(rawMasks) == 0 {
		return nil
	}

	normalized := make([]any, 0, len(rawMasks))
	for _, rawMask := range rawMasks {
		mask, _ := rawMask.(map[string]any)
		if mask == nil {
			continue
		}
		maskType, _ := mask["type"].(string)
		if _, ok := validFinalMaskUDPTypes[maskType]; !ok || maskType == "" {
			continue
		}

		normalizedMask := map[string]any{"type": maskType}
		if settings, ok := mask["settings"].(map[string]any); ok && len(settings) > 0 {
			normalizedMask["settings"] = settings
		}
		normalized = append(normalized, normalizedMask)
	}

	if len(normalized) == 0 {
		return nil
	}
	return normalized
}

func hasFinalMaskContent(value any) bool {
	switch v := value.(type) {
	case nil:
		return false
	case string:
		return len(v) > 0
	case map[string]any:
		for _, item := range v {
			if hasFinalMaskContent(item) {
				return true
			}
		}
		return false
	case []any:
		return slices.ContainsFunc(v, hasFinalMaskContent)
	default:
		return true
	}
}

func searchHost(headers any) string {
	data, _ := headers.(map[string]any)
	for k, v := range data {
		if strings.EqualFold(k, "host") {
			switch v.(type) {
			case []any:
				hosts, _ := v.([]any)
				if len(hosts) > 0 {
					return hosts[0].(string)
				} else {
					return ""
				}
			case any:
				return v.(string)
			}
		}
	}

	return ""
}

// PageData is a view model for subpage.html
// PageData contains data for rendering the subscription information page.
type PageData struct {
	Host          string
	BasePath      string
	SId           string
	Enabled       bool
	Download      string
	Upload        string
	Total         string
	Used          string
	Remained      string
	Expire        int64
	LastOnline    int64
	Datepicker    string
	DownloadByte  int64
	UploadByte    int64
	TotalByte     int64
	SubUrl        string
	SubJsonUrl    string
	SubClashUrl   string
	SubTitle      string
	SubSupportUrl string
	Result        []string
	Emails        []string
}

// ResolveRequest extracts scheme and host info from request/headers consistently.
// ResolveRequest extracts scheme, host, and header information from an HTTP request.
func (s *SubService) ResolveRequest(c *gin.Context) (scheme string, host string, hostWithPort string, hostHeader string) {
	// scheme
	scheme = "http"
	if c.Request.TLS != nil || strings.EqualFold(c.GetHeader("X-Forwarded-Proto"), "https") {
		scheme = "https"
	}

	// base host (no port)
	if h, err := getHostFromXFH(c.GetHeader("X-Forwarded-Host")); err == nil && h != "" {
		host = h
	}
	if host == "" {
		host = c.GetHeader("X-Real-IP")
	}
	if host == "" {
		var err error
		host, _, err = net.SplitHostPort(c.Request.Host)
		if err != nil {
			host = c.Request.Host
		}
	}

	// host:port for URLs
	hostWithPort = c.GetHeader("X-Forwarded-Host")
	if hostWithPort == "" {
		hostWithPort = c.Request.Host
	}
	if hostWithPort == "" {
		hostWithPort = host
	}

	// header display host
	hostHeader = c.GetHeader("X-Forwarded-Host")
	if hostHeader == "" {
		hostHeader = c.GetHeader("X-Real-IP")
	}
	if hostHeader == "" {
		hostHeader = host
	}
	return
}

// BuildURLs constructs absolute subscription and JSON subscription URLs for a given subscription ID.
// It prioritizes configured URIs, then individual settings, and finally falls back to request-derived components.
func (s *SubService) BuildURLs(subPath, subJsonPath, subClashPath, subId string) (subURL, subJsonURL, subClashURL string) {
	if subId == "" {
		return "", "", ""
	}

	configuredSubURI, _ := s.settingService.GetSubURI()
	configuredSubJsonURI, _ := s.settingService.GetSubJsonURI()
	configuredSubClashURI, _ := s.settingService.GetSubClashURI()

	// Same base as the panel's Client Information page; s.address is the
	// subscriber's host already normalized away from any loopback/bind IP.
	base := s.settingService.BuildSubURIBase(s.address)

	subURL = s.buildSingleURL(configuredSubURI, base, subPath, subId)
	subJsonURL = s.buildSingleURL(configuredSubJsonURI, base, subJsonPath, subId)
	subClashURL = s.buildSingleURL(configuredSubClashURI, base, subClashPath, subId)

	return subURL, subJsonURL, subClashURL
}

// buildSingleURL constructs a single URL using configured URI or base components
func (s *SubService) buildSingleURL(configuredURI, base, basePath, subId string) string {
	if configuredURI != "" {
		return s.joinPathWithID(configuredURI, subId)
	}
	return s.joinPathWithID(base+basePath, subId)
}

// joinPathWithID safely joins a base path with a subscription ID
func (s *SubService) joinPathWithID(basePath, subId string) string {
	if strings.HasSuffix(basePath, "/") {
		return basePath + subId
	}
	return basePath + "/" + subId
}

// BuildPageData parses header and prepares the template view model.
// BuildPageData constructs page data for rendering the subscription information page.
func (s *SubService) BuildPageData(subId string, hostHeader string, traffic xray.ClientTraffic, lastOnline int64, subs []string, emails []string, subURL, subJsonURL, subClashURL string, basePath string, subTitle string, subSupportUrl string) PageData {
	download := common.FormatTraffic(traffic.Down)
	upload := common.FormatTraffic(traffic.Up)
	total := "∞"
	used := common.FormatTraffic(traffic.Up + traffic.Down)
	remained := ""
	if traffic.Total > 0 {
		total = common.FormatTraffic(traffic.Total)
		left := max(traffic.Total-(traffic.Up+traffic.Down), 0)
		remained = common.FormatTraffic(left)
	}

	datepicker := s.datepicker
	if datepicker == "" {
		datepicker = "gregorian"
	}

	return PageData{
		Host:          hostHeader,
		BasePath:      basePath,
		SId:           subId,
		Enabled:       traffic.Enable,
		Download:      download,
		Upload:        upload,
		Total:         total,
		Used:          used,
		Remained:      remained,
		Expire:        traffic.ExpiryTime / 1000,
		LastOnline:    lastOnline,
		Datepicker:    datepicker,
		DownloadByte:  traffic.Down,
		UploadByte:    traffic.Up,
		TotalByte:     traffic.Total,
		SubUrl:        subURL,
		SubJsonUrl:    subJsonURL,
		SubClashUrl:   subClashURL,
		SubTitle:      subTitle,
		SubSupportUrl: subSupportUrl,
		Result:        subs,
		Emails:        emails,
	}
}

func getHostFromXFH(s string) (string, error) {
	if strings.Contains(s, ":") {
		realHost, _, err := net.SplitHostPort(s)
		if err != nil {
			return "", err
		}
		return realHost, nil
	}
	return s, nil
}