package core

import (
	"context"
	"errors"
	"fmt"
	"io"
	"net"
	"net/http"
	"net/url"
	"os"
	"strings"
	"sync"
	"time"

	"vpnclient/internal/config"
	"vpnclient/internal/corebin"
	"vpnclient/internal/linknorm"
	"vpnclient/internal/protocols/awg"
	"vpnclient/internal/protocols/hysteria2"
	"vpnclient/internal/protocols/naive"
	"vpnclient/internal/protocols/xray"
	"vpnclient/internal/subscription"
	"vpnclient/internal/sysproxy"
)

// Manager orchestrates protocol engines and OS system proxy.
type Manager struct {
	mu       sync.Mutex
	cfgPath  string
	cfg      *config.Config
	engine   Engine
	sys      sysproxy.Controller
	profile  *config.Profile
	stderr   io.Writer
	binDir   string
	// lastStop tracks in-flight engine.Stop so Connect waits for ports to free.
	lastStop sync.WaitGroup

	lastError       string
	unexpectedDrop  bool
	watchGeneration uint64
}

func NewManager(cfgPath string, cfg *config.Config, stderr io.Writer) (*Manager, error) {
	if stderr == nil {
		stderr = os.Stderr
	}
	binDir, err := config.ResolveBinDir(cfgPath, cfg.BinDir)
	if err != nil {
		return nil, err
	}
	m := &Manager{
		cfgPath: cfgPath,
		cfg:     cfg,
		sys:     sysproxy.New(),
		stderr:  stderr,
		binDir:  binDir,
	}
	m.RecoverSystemProxy()
	return m, nil
}

// RecoverSystemProxy clears a system proxy left on after an unclean exit.
func (m *Manager) RecoverSystemProxy() {
	if m == nil || m.sys == nil {
		return
	}
	if !sysproxy.HasSentinel(m.cfgPath) {
		return
	}
	if err := m.sys.ForceDisable(); err != nil {
		fmt.Fprintf(m.stderr, "recover system proxy: %v\n", err)
	}
	sysproxy.ClearSentinel(m.cfgPath)
}

func (m *Manager) waitEngineStopped() {
	m.lastStop.Wait()
}

func (m *Manager) Connect(ctx context.Context, profileName string) error {
	// Wait outside the lock so a slow Disconnect can finish freeing :1080/:1081.
	m.waitEngineStopped()

	m.mu.Lock()
	if m.engine != nil && m.engine.Running() {
		m.mu.Unlock()
		return fmt.Errorf("already connected; disconnect first")
	}
	if m.engine != nil {
		m.engine = nil
		m.profile = nil
	}
	if profileName != "" {
		m.cfg.Active = profileName
	}
	profile, err := m.cfg.ActiveProfile()
	if err != nil {
		m.mu.Unlock()
		return err
	}
	profileCopy := *profile
	binDir := m.binDir
	wantSysProxy := m.cfg.SystemProxy
	cfgPath := m.cfgPath
	sys := m.sys
	stderr := m.stderr
	m.mu.Unlock()

	engine, err := m.newEngine(profileCopy.Protocol)
	if err != nil {
		return err
	}
	if err := engine.Start(ctx, profileCopy, binDir); err != nil {
		return err
	}

	m.mu.Lock()
	if m.engine != nil && m.engine.Running() {
		_ = engine.Stop()
		m.mu.Unlock()
		return fmt.Errorf("already connected; disconnect first")
	}

	if wantSysProxy {
		httpProxy, ok := engine.LocalHTTPProxy()
		if !ok {
			m.mu.Unlock()
			_ = engine.Stop()
			return fmt.Errorf("system_proxy requires an http:// listen address in the profile")
		}
		if err := sys.Enable(httpProxy); err != nil {
			if errors.Is(err, sysproxy.ErrUnsupported) {
				fmt.Fprintf(stderr, "system proxy unsupported on this OS; local SOCKS/HTTP still up\n")
			} else {
				m.mu.Unlock()
				_ = engine.Stop()
				return fmt.Errorf("enable system proxy: %w", err)
			}
		} else {
			sysproxy.WriteSentinel(cfgPath, httpProxy)
		}
	}

	m.engine = engine
	m.profile = &profileCopy
	m.lastError = ""
	m.unexpectedDrop = false
	m.watchGeneration++
	gen := m.watchGeneration
	m.mu.Unlock()
	go m.watchEngine(gen, engine)
	return nil
}

// LastError returns the last connection / core failure message.
func (m *Manager) LastError() string {
	m.mu.Lock()
	defer m.mu.Unlock()
	return m.lastError
}

// SetLastError stores a UI-facing error string.
func (m *Manager) SetLastError(msg string) {
	m.mu.Lock()
	m.lastError = strings.TrimSpace(msg)
	m.mu.Unlock()
}

// TakeUnexpectedDrop reports and clears a crash-driven disconnect.
func (m *Manager) TakeUnexpectedDrop() bool {
	m.mu.Lock()
	defer m.mu.Unlock()
	if !m.unexpectedDrop {
		return false
	}
	m.unexpectedDrop = false
	return true
}

func (m *Manager) watchEngine(gen uint64, eng Engine) {
	if eng == nil {
		return
	}
	for {
		time.Sleep(800 * time.Millisecond)
		m.mu.Lock()
		if m.watchGeneration != gen || m.engine != eng {
			m.mu.Unlock()
			return
		}
		if eng.Running() {
			m.mu.Unlock()
			continue
		}
		// Core died without Disconnect().
		m.engine = nil
		m.profile = nil
		m.lastError = "процесс ядра завершился неожиданно"
		m.unexpectedDrop = true
		sys := m.sys
		cfgPath := m.cfgPath
		m.mu.Unlock()

		if sys != nil && (sys.Enabled() || sysproxy.HasSentinel(cfgPath)) {
			_ = sys.ForceDisable()
			sysproxy.ClearSentinel(cfgPath)
			fmt.Fprintf(m.stderr, "core exited: system proxy cleared\n")
		}
		return
	}
}

func (m *Manager) Disconnect() error {
	m.mu.Lock()
	sys := m.sys
	engine := m.engine
	m.engine = nil
	m.profile = nil
	m.watchGeneration++ // stop watcher
	m.unexpectedDrop = false
	if engine != nil {
		m.lastStop.Add(1)
	}
	m.mu.Unlock()

	var first error
	if sys != nil && (sys.Enabled() || sysproxy.HasSentinel(m.cfgPath)) {
		var err error
		if sys.Enabled() {
			err = sys.Disable()
		} else {
			err = sys.ForceDisable()
		}
		if err != nil {
			if err2 := sys.ForceDisable(); err2 != nil && first == nil {
				first = err2
			} else if first == nil {
				first = err
			}
		}
		sysproxy.ClearSentinel(m.cfgPath)
	}
	if engine != nil {
		done := make(chan error, 1)
		go func() {
			defer m.lastStop.Done()
			done <- engine.Stop()
		}()
		select {
		case err := <-done:
			if err != nil && first == nil {
				first = err
			}
		case <-time.After(3 * time.Second):
			// Stop continues in background; Connect will wait on lastStop.
			if first == nil {
				first = fmt.Errorf("отключение заняло слишком много времени")
			}
		}
	}
	return first
}

func (m *Manager) Status() Status {
	m.mu.Lock()
	defer m.mu.Unlock()

	st := Status{SystemProxy: m.sys.Enabled()}
	if m.engine == nil || !m.engine.Running() {
		return st
	}
	st.Connected = true
	if m.profile != nil {
		st.Profile = m.profile.Name
		st.Protocol = m.profile.Protocol
	}
	if hp, ok := m.engine.LocalHTTPProxy(); ok {
		st.HTTPProxy = hp
	}
	if sp, ok := m.engine.LocalSOCKSProxy(); ok {
		st.SOCKSProxy = sp
	}
	return st
}

// Probe fetches url via the local HTTP or SOCKS proxy to verify the tunnel.
func (m *Manager) Probe(ctx context.Context, testURL string) error {
	m.mu.Lock()
	engine := m.engine
	m.mu.Unlock()
	if engine == nil || !engine.Running() {
		return fmt.Errorf("not connected")
	}
	if testURL == "" {
		testURL = "https://www.google.com/generate_204"
	}

	var proxyURL *url.URL
	if hp, ok := engine.LocalHTTPProxy(); ok {
		proxyURL, _ = url.Parse("http://" + hp)
	} else if sp, ok := engine.LocalSOCKSProxy(); ok {
		proxyURL, _ = url.Parse("socks5://" + sp)
	} else {
		return fmt.Errorf("no local proxy listen address")
	}

	transport := &http.Transport{
		Proxy: http.ProxyURL(proxyURL),
		DialContext: (&net.Dialer{
			Timeout: 15 * time.Second,
		}).DialContext,
		TLSHandshakeTimeout: 15 * time.Second,
		ForceAttemptHTTP2:   true,
	}
	client := &http.Client{
		Transport: transport,
		Timeout:   30 * time.Second,
		CheckRedirect: func(req *http.Request, via []*http.Request) error {
			return http.ErrUseLastResponse
		},
	}
	req, err := http.NewRequestWithContext(ctx, http.MethodGet, testURL, nil)
	if err != nil {
		return err
	}
	resp, err := client.Do(req)
	if err != nil {
		return fmt.Errorf("probe via %s: %w", proxyURL.String(), err)
	}
	defer resp.Body.Close()
	if resp.StatusCode >= 400 {
		return fmt.Errorf("probe unexpected status %d", resp.StatusCode)
	}
	return nil
}

func (m *Manager) BinDir() string { return m.binDir }

func (m *Manager) ConfigPath() string { return m.cfgPath }

// Config returns a deep snapshot for UI reads. Mutations must go through Manager methods.
func (m *Manager) Config() *config.Config {
	m.mu.Lock()
	defer m.mu.Unlock()
	if m.cfg == nil {
		return &config.Config{}
	}
	return m.cfg.Clone()
}

// UIPoll is a cheap manager snapshot for GUI polling (no JSON deep-clone of all proxies).
type UIPoll struct {
	Status          Status
	Active          string
	SystemProxy     bool
	Subscription    string
	ActiveProxy     string
	ActiveProtocol  config.Protocol
	Profiles        []config.ProfileInfo
	Hy2             Hy2Options
	BinDir          string
	LastError       string
	ConnectOnLaunch bool
	AutoReconnect   bool
}

// PollUI gathers status + profile list under one lock without Config().Clone().
func (m *Manager) PollUI(includeSecrets bool) UIPoll {
	m.mu.Lock()
	defer m.mu.Unlock()

	out := UIPoll{
		Status:       Status{SystemProxy: m.sys.Enabled()},
		BinDir:       m.binDir,
		SystemProxy:  false,
		Subscription: "",
		Hy2:          Hy2Options{Congestion: "bbr", BBRProfile: "standard"},
		LastError:    m.lastError,
	}
	if m.cfg != nil {
		out.Active = m.cfg.Active
		out.SystemProxy = m.cfg.SystemProxy
		out.Subscription = m.cfg.SubscriptionURL
		out.ConnectOnLaunch = m.cfg.ConnectOnLaunch
		out.AutoReconnect = m.cfg.AutoReconnect
		if includeSecrets {
			out.Profiles = m.cfg.ListProfiles()
		} else {
			out.Profiles = m.cfg.ListProfilesForPoll()
		}
		if p, err := m.cfg.ActiveProfile(); err == nil {
			out.Active = p.Name
			out.ActiveProxy = p.Proxy
			out.ActiveProtocol = p.Protocol
			out.Hy2 = Hy2Options{
				Congestion:    p.Hy2Congestion,
				BBRProfile:    p.Hy2BBRProfile,
				BandwidthUp:   p.Hy2BandwidthUp,
				BandwidthDown: p.Hy2BandwidthDown,
				Obfs:          p.Hy2Obfs,
				ObfsPassword:  p.Hy2ObfsPassword,
				SNI:           p.Hy2SNI,
				Insecure:      p.Hy2Insecure,
				PinSHA256:     p.Hy2PinSHA256,
				FastOpen:      p.Hy2FastOpen,
				Lazy:          p.Hy2Lazy,
				HopInterval:   p.Hy2HopInterval,
			}
		}
	}
	if m.engine != nil && m.engine.Running() {
		out.Status.Connected = true
		if m.profile != nil {
			out.Status.Profile = m.profile.Name
			out.Status.Protocol = m.profile.Protocol
		}
		if hp, ok := m.engine.LocalHTTPProxy(); ok {
			out.Status.HTTPProxy = hp
		}
		if sp, ok := m.engine.LocalSOCKSProxy(); ok {
			out.Status.SOCKSProxy = sp
		}
	}
	return out
}

func (m *Manager) SetSystemProxy(enabled bool) {
	m.mu.Lock()
	defer m.mu.Unlock()
	m.cfg.SystemProxy = enabled
}

// Prefs are GUI toggles persisted in config.json.
type Prefs struct {
	ConnectOnLaunch bool `json:"connect_on_launch"`
	AutoReconnect   bool `json:"auto_reconnect"`
	SystemProxy     bool `json:"system_proxy"`
}

func (m *Manager) Prefs() Prefs {
	m.mu.Lock()
	defer m.mu.Unlock()
	if m.cfg == nil {
		return Prefs{}
	}
	return Prefs{
		ConnectOnLaunch: m.cfg.ConnectOnLaunch,
		AutoReconnect:   m.cfg.AutoReconnect,
		SystemProxy:     m.cfg.SystemProxy,
	}
}

func (m *Manager) SavePrefs(p Prefs) error {
	m.mu.Lock()
	defer m.mu.Unlock()
	if m.cfg == nil {
		return fmt.Errorf("no config")
	}
	m.cfg.ConnectOnLaunch = p.ConnectOnLaunch
	m.cfg.AutoReconnect = p.AutoReconnect
	m.cfg.SystemProxy = p.SystemProxy
	return config.Save(m.cfgPath, *m.cfg)
}

func (m *Manager) UpdateProxyURI(proxy string) error {
	m.mu.Lock()
	defer m.mu.Unlock()
	active, err := m.cfg.ActiveProfile()
	if err != nil {
		return err
	}
	normalized, proto, _, err := linknorm.Normalize(active.Protocol, proxy)
	if err != nil {
		return err
	}
	if err := m.cfg.SetActiveProxy(normalized); err != nil {
		return err
	}
	if proto != "" {
		_ = m.cfg.UpsertProfileWithProtocol(m.cfg.Active, normalized, proto)
	}
	return config.Save(m.cfgPath, *m.cfg)
}

func (m *Manager) SetActiveProfile(name string) error {
	m.mu.Lock()
	defer m.mu.Unlock()
	if m.engine != nil && m.engine.Running() {
		return fmt.Errorf("сначала отключитесь")
	}
	if err := m.cfg.SetActive(name); err != nil {
		return err
	}
	return config.Save(m.cfgPath, *m.cfg)
}

func (m *Manager) SaveProfile(name, proxy string) error {
	m.mu.Lock()
	defer m.mu.Unlock()
	name = strings.TrimSpace(name)
	if name == "" {
		return fmt.Errorf("имя профиля пустое")
	}
	connected := m.engine != nil && m.engine.Running()
	if connected && name == m.cfg.Active {
		return fmt.Errorf("сначала отключитесь, чтобы изменить активный профиль")
	}
	proxy = strings.TrimSpace(proxy)
	var proto config.Protocol
	if proxy != "" {
		normalized, detected, _, err := linknorm.Normalize("", proxy)
		if err != nil {
			return err
		}
		proxy = normalized
		proto = detected
	}
	var err error
	if connected {
		err = m.cfg.UpsertProfileKeepActive(name, proxy, proto)
	} else {
		err = m.cfg.UpsertProfileWithProtocol(name, proxy, proto)
	}
	if err != nil {
		return err
	}
	if p, err := m.cfg.ActiveProfile(); err == nil {
		hysteria2.EnrichProfile(p)
	}
	return config.Save(m.cfgPath, *m.cfg)
}

// SaveActiveProfile updates the current profile (rename if needed) and proxy URI.
func (m *Manager) SaveActiveProfile(name, proxy string) error {
	m.mu.Lock()
	defer m.mu.Unlock()
	if m.engine != nil && m.engine.Running() {
		return fmt.Errorf("сначала отключитесь")
	}
	name = strings.TrimSpace(name)
	if name == "" {
		return fmt.Errorf("имя профиля пустое")
	}
	proxy = strings.TrimSpace(proxy)
	var proto config.Protocol
	if proxy != "" {
		activeProto := config.Protocol("")
		if p, err := m.cfg.ActiveProfile(); err == nil {
			activeProto = p.Protocol
		}
		normalized, detected, _, err := linknorm.Normalize(activeProto, proxy)
		if err != nil {
			return err
		}
		proxy = normalized
		proto = detected
	}

	active := m.cfg.Active
	if name != active {
		exists := false
		for _, p := range m.cfg.Profiles {
			if p.Name == name {
				exists = true
				break
			}
		}
		if exists {
			if err := m.cfg.SetActive(name); err != nil {
				return err
			}
		} else if err := m.cfg.RenameProfile(active, name); err != nil {
			return err
		}
	}
	if err := m.cfg.UpsertProfileWithProtocol(name, proxy, proto); err != nil {
		return err
	}
	if p, err := m.cfg.ActiveProfile(); err == nil {
		hysteria2.EnrichProfile(p)
	}
	return config.Save(m.cfgPath, *m.cfg)
}

func (m *Manager) DeleteProfile(name string) error {
	m.mu.Lock()
	defer m.mu.Unlock()
	if m.engine != nil && m.engine.Running() {
		return fmt.Errorf("сначала отключитесь")
	}
	if err := m.cfg.DeleteProfile(name); err != nil {
		return err
	}
	return config.Save(m.cfgPath, *m.cfg)
}

func (m *Manager) Profiles() []config.ProfileInfo {
	m.mu.Lock()
	defer m.mu.Unlock()
	return m.cfg.ListProfiles()
}

// Hy2Options are editable Hysteria 2 extras for the active profile.
type Hy2Options struct {
	Congestion    string `json:"congestion"`
	BBRProfile    string `json:"bbr_profile"`
	BandwidthUp   string `json:"bandwidth_up"`
	BandwidthDown string `json:"bandwidth_down"`
	Obfs          string `json:"obfs"`
	ObfsPassword  string `json:"obfs_password"`
	SNI           string `json:"sni"`
	Insecure      bool   `json:"insecure"`
	PinSHA256     string `json:"pin_sha256"`
	FastOpen      bool   `json:"fast_open"`
	Lazy          bool   `json:"lazy"`
	HopInterval   string `json:"hop_interval"`
}

func (m *Manager) ActiveHy2Options() Hy2Options {
	m.mu.Lock()
	defer m.mu.Unlock()
	p, err := m.cfg.ActiveProfile()
	if err != nil {
		return Hy2Options{Congestion: "bbr", BBRProfile: "standard"}
	}
	return Hy2Options{
		Congestion:    p.Hy2Congestion,
		BBRProfile:    p.Hy2BBRProfile,
		BandwidthUp:   p.Hy2BandwidthUp,
		BandwidthDown: p.Hy2BandwidthDown,
		Obfs:          p.Hy2Obfs,
		ObfsPassword:  p.Hy2ObfsPassword,
		SNI:           p.Hy2SNI,
		Insecure:      p.Hy2Insecure,
		PinSHA256:     p.Hy2PinSHA256,
		FastOpen:      p.Hy2FastOpen,
		Lazy:          p.Hy2Lazy,
		HopInterval:   p.Hy2HopInterval,
	}
}

func (m *Manager) SaveHy2Options(opts Hy2Options) error {
	m.mu.Lock()
	defer m.mu.Unlock()
	if m.engine != nil && m.engine.Running() {
		return fmt.Errorf("сначала отключитесь")
	}
	p, err := m.cfg.ActiveProfile()
	if err != nil {
		return err
	}
	p.Protocol = config.ProtocolHysteria2
	p.Hy2Congestion = strings.TrimSpace(opts.Congestion)
	p.Hy2BBRProfile = strings.TrimSpace(opts.BBRProfile)
	p.Hy2BandwidthUp = strings.TrimSpace(opts.BandwidthUp)
	p.Hy2BandwidthDown = strings.TrimSpace(opts.BandwidthDown)
	p.Hy2Obfs = strings.TrimSpace(opts.Obfs)
	p.Hy2ObfsPassword = strings.TrimSpace(opts.ObfsPassword)
	p.Hy2SNI = strings.TrimSpace(opts.SNI)
	p.Hy2Insecure = opts.Insecure
	p.Hy2PinSHA256 = strings.TrimSpace(opts.PinSHA256)
	p.Hy2FastOpen = opts.FastOpen
	p.Hy2Lazy = opts.Lazy
	p.Hy2HopInterval = strings.TrimSpace(opts.HopInterval)
	return config.Save(m.cfgPath, *m.cfg)
}

func (m *Manager) SubscriptionURL() string {
	m.mu.Lock()
	defer m.mu.Unlock()
	return m.cfg.SubscriptionURL
}

func (m *Manager) ImportSubscription(rawURL string) (int, error) {
	ctx, cancel := context.WithTimeout(context.Background(), 45*time.Second)
	defer cancel()
	items, err := subscription.Fetch(ctx, rawURL)
	if err != nil {
		return 0, err
	}
	if len(items) == 0 {
		return 0, fmt.Errorf("в подписке нет поддерживаемых ссылок (naive / hysteria2 / awg / vless / vmess / trojan)")
	}

	m.mu.Lock()
	defer m.mu.Unlock()
	if m.engine != nil && m.engine.Running() {
		return 0, fmt.Errorf("сначала отключитесь")
	}
	m.cfg.SubscriptionURL = strings.TrimSpace(rawURL)

	newNames := make([]string, 0, len(items))
	seen := map[string]struct{}{}
	for _, it := range items {
		name := strings.TrimSpace(it.Name)
		if name == "" {
			continue
		}
		_ = m.cfg.UpsertProfileKeepActive(name, it.URI, it.Protocol)
		for i := range m.cfg.Profiles {
			if m.cfg.Profiles[i].Name == name {
				hysteria2.EnrichProfile(&m.cfg.Profiles[i])
				break
			}
		}
		if _, ok := seen[name]; !ok {
			seen[name] = struct{}{}
			newNames = append(newNames, name)
		}
	}

	prev := map[string]struct{}{}
	for _, n := range m.cfg.SubscriptionNames {
		prev[n] = struct{}{}
	}
	// Prune profiles that came from the previous subscription sync but are gone now.
	if len(prev) > 0 {
		kept := make([]config.Profile, 0, len(m.cfg.Profiles))
		for _, p := range m.cfg.Profiles {
			if _, wasSub := prev[p.Name]; wasSub {
				if _, still := seen[p.Name]; !still {
					continue
				}
			}
			kept = append(kept, p)
		}
		if len(kept) == 0 {
			// Safety: never wipe all profiles.
			kept = append([]config.Profile(nil), m.cfg.Profiles...)
		} else {
			m.cfg.Profiles = kept
		}
		activeOK := false
		for _, p := range m.cfg.Profiles {
			if p.Name == m.cfg.Active {
				activeOK = true
				break
			}
		}
		if !activeOK && len(m.cfg.Profiles) > 0 {
			m.cfg.Active = m.cfg.Profiles[0].Name
		}
	}
	m.cfg.SubscriptionNames = newNames

	if err := config.Save(m.cfgPath, *m.cfg); err != nil {
		return 0, err
	}
	return len(newNames), nil
}

func (m *Manager) SaveConfig() error {
	m.mu.Lock()
	defer m.mu.Unlock()
	return config.Save(m.cfgPath, *m.cfg)
}

func (m *Manager) Reload() error {
	m.mu.Lock()
	defer m.mu.Unlock()
	if m.engine != nil && m.engine.Running() {
		return fmt.Errorf("disconnect before reloading config")
	}
	cfg, err := config.Load(m.cfgPath)
	if err != nil {
		return err
	}
	binDir, err := config.ResolveBinDir(m.cfgPath, cfg.BinDir)
	if err != nil {
		return err
	}
	m.cfg = cfg
	m.binDir = binDir
	return nil
}

func (m *Manager) newEngine(p config.Protocol) (Engine, error) {
	switch p {
	case config.ProtocolNaive, "":
		return naive.New(m.stderr), nil
	case config.ProtocolHysteria2:
		return hysteria2.New(m.stderr), nil
	case config.ProtocolAWG:
		return awg.New(m.stderr), nil
	case config.ProtocolVLESS, config.ProtocolVMess, config.ProtocolTrojan:
		return xray.New(m.stderr), nil
	default:
		return nil, fmt.Errorf("unsupported protocol %q", p)
	}
}

// EnsureCore downloads the binary required by the active (or given) protocol.
func (m *Manager) EnsureCore(proto config.Protocol) (string, error) {
	m.mu.Lock()
	binDir := m.binDir
	if proto == "" {
		if p, err := m.cfg.ActiveProfile(); err == nil {
			proto = p.Protocol
		}
	}
	m.mu.Unlock()

	var (
		path string
		err  error
	)
	switch proto {
	case config.ProtocolHysteria2:
		path, err = hysteria2.EnsureBinary(binDir)
	case config.ProtocolAWG:
		path, err = awg.EnsureBinary(binDir)
	case config.ProtocolVLESS, config.ProtocolVMess, config.ProtocolTrojan:
		path, err = xray.EnsureBinary(binDir)
	default:
		path, err = naive.EnsureBinary(binDir)
		proto = config.ProtocolNaive
	}
	if err != nil {
		return "", err
	}
	corebin.Set(corebin.CacheKey(binDir, corebin.ProtoKey(string(proto))), path)
	return path, nil
}

// EnsureAllCores installs naive + hysteria2 + xray cores (AWG is embedded).
// Downloads run in parallel (one goroutine per core) to use multiple CPU cores / network.
func (m *Manager) EnsureAllCores() (map[string]string, error) {
	m.mu.Lock()
	binDir := m.binDir
	m.mu.Unlock()

	corebin.Invalidate()

	type item struct {
		key  string
		path string
		err  error
	}
	jobs := []struct {
		key string
		fn  func() (string, error)
	}{
		{"naive", func() (string, error) { return naive.EnsureBinary(binDir) }},
		{"hysteria2", func() (string, error) { return hysteria2.EnsureBinary(binDir) }},
		{"awg", func() (string, error) { return awg.EnsureBinary(binDir) }},
		{"xray", func() (string, error) { return xray.EnsureBinary(binDir) }},
	}
	ch := make(chan item, len(jobs))
	for _, j := range jobs {
		j := j
		go func() {
			path, err := j.fn()
			ch <- item{key: j.key, path: path, err: err}
		}()
	}
	out := map[string]string{}
	var first error
	for range jobs {
		it := <-ch
		if it.err != nil {
			if first == nil {
				first = fmt.Errorf("%s: %w", it.key, it.err)
			}
			continue
		}
		out[it.key] = it.path
		corebin.Set(corebin.CacheKey(binDir, it.key), it.path)
	}
	return out, first
}