package main

import (
	"bufio"
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
	"runtime/debug"
	"strconv"
	"strings"
	"sync"
	"time"

	wailsruntime "github.com/wailsapp/wails/v2/pkg/runtime"
)

// pi 默认 Web UI 端口
const piPort = 30141

// App is the Wails application backend.
type App struct {
	ctx context.Context

	mu        sync.Mutex
	piCmd     *exec.Cmd
	piURL     string
	startedAt time.Time
	running   bool
}

// NewApp creates a new App application struct.
func NewApp() *App {
	initCrashLog()
	// 在进程启动时预先初始化 npm prefix 缓存,后续 buildChildEnv 直接读缓存。
	// 这步可能 exec npm 子命令(限 2s 超时),但不会和 buildChildEnv 互相递归。
	initNpmPrefix()
	return &App{}
}

// initNpmPrefix triggers the cached npm prefix lookup exactly once.
// 必须在启动早期(且不依赖 buildChildEnv)调用,避免 buildChildEnv → cachedNpmPrefix
// 第一次执行时栈还未充分展开导致后续路径无法解析。
func initNpmPrefix() {
	_, _ = cachedNpmPrefix()
}

// initCrashLog wires a panic logger that writes to ~/Library/Logs/pi-launcher.log.
// macOS GUI 进程 stderr 没终端,panic 信息看不到,落盘最稳。
var crashLogOnce sync.Once

func initCrashLog() {
	crashLogOnce.Do(func() {
		home, _ := os.UserHomeDir()
		logPath := filepath.Join(home, "Library", "Logs", "pi-launcher.log")
		_ = os.MkdirAll(filepath.Dir(logPath), 0o755)
		f, err := os.OpenFile(logPath, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0o644)
		if err != nil {
			return
		}
		log.SetOutput(f)
		log.SetFlags(log.LstdFlags | log.Lmicroseconds | log.Lshortfile)
	})
}

// safeGo wraps a goroutine with recover so a panic in any background
// task can't take down the whole Wails app.
func safeGo(name string, fn func()) {
	go func() {
		defer func() {
			if r := recover(); r != nil {
				log.Printf("[panic:%s] %v\n%s", name, r, debugStack())
			}
		}()
		fn()
	}()
}

func debugStack() string {
	return string(debug.Stack())
}

// startup is called when the app starts.
func (a *App) startup(ctx context.Context) {
	a.ctx = ctx
	// 接管旧进程: 用户可能之前手动启动过 pi-web / 残留 node 占着 30141。
	// launcher 作为唯一入口,启动时强制清场,确保 UI 状态与实际一致。
	safeGo("takeOver", func() {
		pids := listPIPids()
		freePort(piPort)
		killed := len(pids)
		if killed > 0 && a.ctx != nil {
			wailsruntime.EventsEmit(a.ctx, "pi:takeover:done", killed)
		}
	})
}

// shutdown is called when the app is closing. Ensure pi is killed
// so we never leak a child process.
func (a *App) shutdown(ctx context.Context) {
	a.stopPI()
}

// ---- Types exposed to the frontend ----

// CheckResult is returned by CheckEnv.
type CheckResult struct {
	NodePath    string   `json:"nodePath"`
	NodeVersion string   `json:"nodeVersion"`
	NodeOK      bool     `json:"nodeOK"`
	PiPath      string   `json:"piPath"`
	PiVersion   string   `json:"piVersion"`
	CredFile    string   `json:"credFile"`
	CredExists  bool     `json:"credExists"`
	HomePiDir   string   `json:"homePiDir"`
	PortBusy    bool     `json:"portBusy"`
	PortBusyBy  string   `json:"portBusyBy"`
	Issues      []string `json:"issues"` // 始终非 nil,前端可放心访问
}

// StartResult is returned by Start.
type StartResult struct {
	OK     bool   `json:"ok"`
	URL    string `json:"url"`
	Error  string `json:"error"`
	Output string `json:"output"`
	Hidden bool   `json:"hidden"` // 是否已自动隐藏窗口
}

// StatusResult is returned by GetStatus.
type StatusResult struct {
	Running   bool   `json:"running"`
	URL       string `json:"url"`
	StartedAt string `json:"startedAt"`
	Pid       int    `json:"pid"`
}

// ---- 3 core methods ----

// CheckEnv inspects Node, pi-web, ~/.pi credentials and port 30141.
// 所有外部命令都套超时 + panic recover,任何一个失败不能让整个 app 闪退。
func (a *App) CheckEnv() (res CheckResult) {
	defer func() {
		if r := recover(); r != nil {
			log.Printf("[panic:CheckEnv] %v\n%s", r, debugStack())
			res.Issues = append(res.Issues, fmt.Sprintf("CheckEnv 内部错误: %v", r))
		}
	}()

	home := os.Getenv("HOME")
	if home == "" {
		home = "/tmp"
	}
	res = CheckResult{
		HomePiDir: filepath.Join(home, ".pi"),
		CredFile:  filepath.Join(home, ".pi", ".credentials.yaml"),
		PortBusy:  false,
		Issues:    []string{}, // 确保 JSON 序列化为 [] 而非 null
	}

	// node
	res.NodePath = lookPath("node")
	if res.NodePath != "" {
		if v, err := runQuiet(res.NodePath, "-v"); err == nil {
			res.NodeVersion = strings.TrimSpace(v)
			if nodeMajor(res.NodeVersion) >= 18 {
				res.NodeOK = true
			}
		} else {
			log.Printf("CheckEnv node -v err: %v", err)
		}
	}
	if !res.NodeOK {
		res.Issues = append(res.Issues, "Node >= 18 未安装或不可用")
	}

	// pi-web
	res.PiPath = lookPath("pi-web")
	piPkgDir := "" // 用来读 package.json 拿版本
	if res.PiPath == "" {
		// fallback to npm prefix bin
		if npm, err := runQuiet("npm", "prefix", "-g"); err == nil {
			prefix := strings.TrimSpace(npm)
			candidate := filepath.Join(prefix, "bin", "pi-web")
			if _, statErr := os.Stat(candidate); statErr == nil {
				res.PiPath = candidate
			}
			piPkgDir = filepath.Join(prefix, "lib", "node_modules", "@agegr", "pi-web")
		} else {
			log.Printf("CheckEnv npm prefix err: %v", err)
		}
	} else {
		// 从 symlink 反推 package.json 路径: .../bin/pi-web -> ../lib/node_modules/@agegr/pi-web/bin/pi-web.js
		// 走 npm prefix -g 是稳的
		if npm, err := runQuiet("npm", "prefix", "-g"); err == nil {
			prefix := strings.TrimSpace(npm)
			piPkgDir = filepath.Join(prefix, "lib", "node_modules", "@agegr", "pi-web")
		}
	}
	if res.PiPath != "" {
		// 注意: pi-web --version 实际上会启动 server 然后失败,不安全。
		// 改用读 npm 全局 package.json 拿版本号。
		if data, err := os.ReadFile(filepath.Join(piPkgDir, "package.json")); err == nil {
			var pkg struct {
				Version string `json:"version"`
			}
			if jerr := json.Unmarshal(data, &pkg); jerr == nil && pkg.Version != "" {
				res.PiVersion = pkg.Version
			}
		}
		if res.PiVersion == "" {
			log.Printf("CheckEnv: 找不到 pi-web package.json (尝试: %s)", piPkgDir)
		}
	} else {
		res.Issues = append(res.Issues, "pi-web 命令未找到(请 npm i -g @agegr/pi-web)")
	}

	// port 30141 — lsof 在受限进程下可能挂死,超时保护
	if pids, err := lsofPort(piPort); err == nil && len(pids) > 0 {
		res.PortBusy = true
		res.PortBusyBy = strings.Join(pids, ", ")
	}

	return res
}

// Start launches pi-web, waits for the service port, and opens the browser.
func (a *App) Start() StartResult {
	a.mu.Lock()
	if a.running {
		a.mu.Unlock()
		return StartResult{OK: false, URL: a.piURL, Error: "已在运行中"}
	}
	a.mu.Unlock()

	// 启动前先清理:杀残留 pi 进程,再强杀占 30141 端口的残留 PID(孤儿 node 等)
	killPITree()
	freePort(piPort)

	piBin := lookPath("pi-web")
	if piBin == "" {
		if npm, err := runQuiet("npm", "prefix", "-g"); err == nil {
			candidate := filepath.Join(strings.TrimSpace(npm), "bin", "pi-web")
			if _, statErr := os.Stat(candidate); statErr == nil {
				piBin = candidate
			}
		}
	}
	if piBin == "" {
		return StartResult{OK: false, Error: "找不到 pi-web 可执行文件"}
	}

	// --no-open 让 pi-web 只起服务不自动开浏览器,我们自己开
	cmd := exec.Command(piBin, "--no-open")
	cmd.Env = buildChildEnv()

	stdout, err := cmd.StdoutPipe()
	if err != nil {
		return StartResult{OK: false, Error: "无法创建 stdout 管道: " + err.Error()}
	}
	stderr, err := cmd.StderrPipe()
	if err != nil {
		return StartResult{OK: false, Error: "无法创建 stderr 管道: " + err.Error()}
	}

	if err := cmd.Start(); err != nil {
		return StartResult{OK: false, Error: "启动 pi-web 失败: " + err.Error()}
	}

	a.mu.Lock()
	a.piCmd = cmd
	a.running = true
	a.startedAt = time.Now()
	a.piURL = ""
	a.mu.Unlock()

	// drain 掉 stdout/stderr 避免阻塞
	safeGo("drainStdout", func() { drainLog(stdout, "pi") })
	safeGo("drainStderr", func() { drainLog(stderr, "pi") })

	// 监听子进程退出
	safeGo("piWait", func() {
		_ = cmd.Wait()
		a.mu.Lock()
		a.running = false
		a.mu.Unlock()
	})

	// polling 等端口 30141 LISTEN(替代等 URL 字符串)
	const timeout = 30 * time.Second
	ready := waitForPort(piPort, timeout)
	if !ready {
		_ = cmd.Process.Kill()
		return StartResult{OK: false, Error: fmt.Sprintf("等待端口 %d 监听超时(30s),pi-web 可能没正常启动", piPort)}
	}

	url := fmt.Sprintf("http://localhost:%d/", piPort)
	a.mu.Lock()
	a.piURL = url
	a.mu.Unlock()

	// 用系统 open 唤起浏览器(cookie session 自动登录)
	if openErr := openBrowser(url); openErr != nil {
		return StartResult{OK: true, URL: url, Error: "已启动,但自动开浏览器失败: " + openErr.Error()}
	}

	// 启动成功 + 已打开浏览器 → 最小化到 Dock
	if a.ctx != nil {
		wailsruntime.WindowMinimise(a.ctx)
	}
	return StartResult{OK: true, URL: url, Hidden: true}
}

// waitForPort 轮询检查端口是否处于 LISTEN,timeout 内返回 true。
func waitForPort(port int, timeout time.Duration) bool {
	deadline := time.Now().Add(timeout)
	for {
		if pids, _ := lsofPort(port); len(pids) > 0 {
			return true
		}
		if time.Now().After(deadline) {
			return false
		}
		time.Sleep(300 * time.Millisecond)
	}
}

// freePort 强制释放端口: lsof 拿到 LISTEN 的所有 PID,逐一 kill -9。
// 返回被杀的 PID 数量。
// 适用于:
//   - Start 前:如果旧 pi-web 进程杀完但端口还被占(孤儿 node 进程),再补刀
//   - Stop 后:如果 pi-web 进程杀完但端口还在 TIME_WAIT,精准 kill 残留 PID
//   - OnShutdown:app 退出前保证不残留任何 pi-web 进程 + 端口
func freePort(port int) int {
	pids, _ := lsofPort(port)
	if len(pids) == 0 {
		return 0
	}
	log.Printf("freePort: %d pid(s) holding :%d", len(pids), port)
	for _, pid := range pids {
		if err := exec.Command("kill", "-9", pid).Run(); err != nil {
			log.Printf("freePort: kill -9 %s: %v", pid, err)
		}
	}
	// 等系统释放 socket
	time.Sleep(300 * time.Millisecond)
	return len(pids)
}

// drainLog 读子进程输出并丢弃(不阻塞子进程 stdout 缓冲区)。
func drainLog(r io.Reader, tag string) {
	scanner := bufio.NewScanner(r)
	scanner.Buffer(make([]byte, 64*1024), 1024*1024)
	for scanner.Scan() {
		_ = scanner.Text()
	}
}

// Stop kills the pi-web process and verifies the port is released.
func (a *App) Stop() StartResult {
	a.mu.Lock()
	cmd := a.piCmd
	a.mu.Unlock()

	if cmd != nil && cmd.Process != nil {
		_ = cmd.Process.Kill()
		_, _ = cmd.Process.Wait()
	}

	// 兜底:把 pi-web 整个进程树都杀(pi-web 主进程 + Electron helper 等)
	killPITree()

	// 再精准 kill 占 30141 的残留 PID(孤儿 node、TIME_WAIT 等)
	freePort(piPort)

	time.Sleep(500 * time.Millisecond)

	a.mu.Lock()
	a.piCmd = nil
	a.piURL = ""
	a.running = false
	a.mu.Unlock()

	if pids, err := lsofPort(piPort); err == nil && len(pids) > 0 {
		return StartResult{OK: false, Error: fmt.Sprintf("端口 %d 仍被占用: %s", piPort, strings.Join(pids, ", "))}
	}
	return StartResult{OK: true}
}

// ShowWindow brings the application window to the front.
func (a *App) ShowWindow() {
	if a.ctx != nil {
		wailsruntime.WindowShow(a.ctx)
	}
}

// HideWindow minimises the application window to Dock.
// 用 WindowMinimise 而不是 WindowHide,这样 macOS 上点 Dock 图标系统会
// 自动 unminimise 恢复窗口(WindowHide 之后点 Dock 不会自动恢复)。
func (a *App) HideWindow() {
	if a.ctx != nil {
		wailsruntime.WindowMinimise(a.ctx)
	}
}

// GetStatus returns the current pi state.
func (a *App) GetStatus() StatusResult {
	a.mu.Lock()
	defer a.mu.Unlock()
	res := StatusResult{Running: a.running, URL: a.piURL}
	if a.piCmd != nil && a.piCmd.Process != nil {
		res.Pid = a.piCmd.Process.Pid
	}
	if !a.startedAt.IsZero() {
		res.StartedAt = a.startedAt.Format(time.RFC3339)
	}
	return res
}

// ---- internal helpers ----

func (a *App) stopPI() {
	a.mu.Lock()
	cmd := a.piCmd
	a.running = false
	a.mu.Unlock()
	if cmd != nil && cmd.Process != nil {
		_ = cmd.Process.Kill()
	}
	// 按 X 关 app / Stop 按钮 / OnShutdown 统一都走这个流程:
	// 1) 杀整个 pi-web 进程树
	// 2) 再精准 kill 占 30141 端口的残留 PID
	killPITree()
	freePort(piPort)
}

// buildChildEnv 手动把 homebrew 路径塞进子进程 PATH。
// macOS GUI 启动的进程不读 ~/.zshrc,直接拿环境变量 PATH 经常缺 /opt/homebrew/bin。
// 注意:本函数不能调任何 exec 子命令(包括 npm),否则会触发栈溢出。
// npm 全局 bin 路径由 cachedNpmPrefix() 在 initNpmPrefix() 中预先算好。
func buildChildEnv() []string {
	env := os.Environ()
	home := os.Getenv("HOME")
	extra := []string{
		"/opt/homebrew/bin",
		"/usr/local/bin",
		"/usr/bin",
		"/bin",
		"/usr/sbin",
		"/sbin",
	}
	// 加上缓存好的 npm 全局 bin(如果有)
	if prefix, ok := cachedNpmPrefix(); ok {
		extra = append(extra, filepath.Join(prefix, "bin"))
	}

	hasPath := false
	for i, e := range env {
		if strings.HasPrefix(e, "PATH=") {
			hasPath = true
			cur := strings.TrimPrefix(e, "PATH=")
			merged := mergePath(cur, extra)
			env[i] = "PATH=" + merged
		}
	}
	if !hasPath {
		env = append(env, "PATH="+strings.Join(extra, ":"))
	}
	if home == "" {
		env = append(env, "HOME=/tmp")
	}
	return env
}

// mergePath 拼接 PATH。绝对不能调 runQuiet / 任何 exec 子命令,
// 否则会触发 buildChildEnv → mergePath 的无限递归 → 栈溢出。
// npm 全局 bin 用 sync.Once 懒加载 + 超时兜底,在 initEnvOnce 里完成。
func mergePath(cur string, extra []string) string {
	seen := map[string]bool{}
	out := []string{}
	add := func(p string) {
		if p == "" || seen[p] {
			return
		}
		seen[p] = true
		out = append(out, p)
	}
	for _, p := range strings.Split(cur, ":") {
		add(p)
	}
	for _, p := range extra {
		add(p)
	}
	return strings.Join(out, ":")
}

// npmPrefixCache 用 sync.Once 缓存 `npm prefix -g` 的输出,
// 避免每次 buildChildEnv 都 exec npm。
var (
	npmPrefixOnce  sync.Once
	npmPrefixValue string
	npmPrefixReady bool
)

func cachedNpmPrefix() (string, bool) {
	npmPrefixOnce.Do(func() {
		// 只在确实有 npm 时才跑
		bin := lookPath("npm")
		if bin == "" {
			return
		}
		// 硬超时 2s,失败就算了,不致命。
		// 注意:这里直接 exec 用 os.Environ(),不走 buildChildEnv,
		// 否则初始化期间可能再次触发 buildChildEnv 形成循环。
		cmd := exec.Command(bin, "prefix", "-g")
		cmd.Env = os.Environ()
		var buf bytes.Buffer
		cmd.Stdout = &buf
		cmd.Stderr = &buf
		if err := cmd.Start(); err != nil {
			return
		}
		done := make(chan error, 1)
		go func() { done <- cmd.Wait() }()
		select {
		case <-done:
			npmPrefixValue = strings.TrimSpace(buf.String())
			npmPrefixReady = npmPrefixValue != ""
		case <-time.After(2 * time.Second):
			_ = cmd.Process.Kill()
			<-done
		}
	})
	return npmPrefixValue, npmPrefixReady
}

func openBrowser(url string) error {
	switch runtime.GOOS {
	case "darwin":
		bin := lookPath("open")
		if bin == "" {
			bin = "/usr/bin/open"
		}
		return exec.Command(bin, url).Start()
	case "windows":
		return exec.Command("rundll32", "url.dll,FileProtocolHandler", url).Start()
	default:
		bin := lookPath("xdg-open")
		if bin == "" {
			return fmt.Errorf("xdg-open not found")
		}
		return exec.Command(bin, url).Start()
	}
}

func lookPath(name string) string {
	// 先用 PATH
	if p, err := exec.LookPath(name); err == nil {
		return p
	}
	// macOS GUI 进程常缺 PATH,兜底几个常见位置
	for _, dir := range []string{"/opt/homebrew/bin", "/usr/local/bin", "/usr/bin"} {
		candidate := filepath.Join(dir, name)
		if _, err := os.Stat(candidate); err == nil {
			return candidate
		}
	}
	return ""
}

func runQuiet(name string, args ...string) (string, error) {
	return runQuietTimeout(name, 3*time.Second, args...)
}

// runQuietTimeout runs a command with a hard timeout. If it doesn't finish in time,
// the child is killed and an error is yielded. macOS 上某些 fork-exec 失败场景,
// 没有超时保护会一直 hang,进而拖垮调用方。
func runQuietTimeout(name string, timeout time.Duration, args ...string) (string, error) {
	if name == "" {
		return "", fmt.Errorf("empty command")
	}
	// 用我们自己的 lookPath(GUI 进程 PATH 缺失时也能找到 /opt/homebrew/bin 等),
	// 不能用 exec.LookPath —— 它只读系统 PATH,看不到我们手动塞的路径。
	bin := lookPath(name)
	if bin == "" {
		return "", fmt.Errorf("not found: %s (也没在 /opt/homebrew/bin 找到)", name)
	}
	cmd := exec.Command(bin, args...)
	cmd.Env = buildChildEnv()
	// 输出大小限制,防止 npm 输出爆 buffer 卡死
	var buf bytes.Buffer
	cmd.Stdout = &buf
	cmd.Stderr = &buf

	if err := cmd.Start(); err != nil {
		return "", fmt.Errorf("start %s: %w", bin, err)
	}

	done := make(chan error, 1)
	go func() { done <- cmd.Wait() }()

	select {
	case err := <-done:
		return buf.String(), err
	case <-time.After(timeout):
		_ = cmd.Process.Kill()
		<-done
		return "", fmt.Errorf("timeout after %s: %s %s", timeout, bin, strings.Join(args, " "))
	}
}

func nodeMajor(v string) int {
	v = strings.TrimPrefix(v, "v")
	parts := strings.SplitN(v, ".", 2)
	if len(parts) == 0 {
		return 0
	}
	n := 0
	for _, ch := range parts[0] {
		if ch < '0' || ch > '9' {
			break
		}
		n = n*10 + int(ch-'0')
	}
	return n
}

// lsofPort 返回占用该端口的 PID 列表(macOS)。带超时 + panic recover。
func lsofPort(port int) (res []string, err error) {
	defer func() {
		if r := recover(); r != nil {
			log.Printf("[panic:lsofPort] %v\n%s", r, debugStack())
			err = fmt.Errorf("lsof panic: %v", r)
		}
	}()

	lsofBin := lookPath("lsof")
	if lsofBin == "" {
		return nil, nil // 没 lsof,跳过
	}
	cmd := exec.Command(lsofBin, "-nP", fmt.Sprintf("-iTCP:%d", port), "-sTCP:LISTEN", "-t")
	cmd.Env = buildChildEnv()
	var buf bytes.Buffer
	cmd.Stdout = &buf
	cmd.Stderr = &buf

	if err := cmd.Start(); err != nil {
		return nil, fmt.Errorf("lsof start: %w", err)
	}

	done := make(chan error, 1)
	go func() { done <- cmd.Wait() }()

	select {
	case err := <-done:
		out := buf.Bytes()
		if err != nil && len(out) == 0 {
			// lsof 无命中时退出码非 0 + 空输出 = 端口空闲
			return nil, nil
		}
		for _, l := range strings.Split(strings.TrimSpace(string(out)), "\n") {
			l = strings.TrimSpace(l)
			if l != "" {
				res = append(res, l)
			}
		}
		return res, err
	case <-time.After(3 * time.Second):
		_ = cmd.Process.Kill()
		<-done
		return nil, fmt.Errorf("lsof timeout")
	}
}

// ---- Install / Update ----

const piPkg = "@agegr/pi-web"

// UpdateInfo describes the available update for pi-web.
type UpdateInfo struct {
	Installed string `json:"installed"`
	Latest    string `json:"latest"`
	HasUpdate bool   `json:"hasUpdate"`
	Raw       string `json:"raw"`
}

// InstallResult is returned by InstallPi / UpdatePi.
type InstallResult struct {
	OK     bool   `json:"ok"`
	Error  string `json:"error"`
	Output string `json:"output"`
}

// killPITree kills all processes related to the pi-web service:
//   - the pi-web CLI itself (npm/node pi-web/lib/bin.js)
//   - any Electron helper (main / renderer / gpu / utility / network)
//
// 不只 kill 主进程: Electron helper 还在跑时,EPIPE 会在 pipe 关闭后让它抛
// "Uncaught Exception" 弹窗,污染退出 UX。
func killPITree() {
	pids := listPIPids()
	if len(pids) == 0 {
		return
	}
	log.Printf("killPITree: %d pids to kill", len(pids))
	for _, pid := range pids {
		// kill -9 强杀,避免 Electron helper 还在做 graceful shutdown 又触发 EPIPE
		if err := exec.Command("kill", "-9", pid).Run(); err != nil {
			log.Printf("killPITree: kill %s: %v", pid, err)
		}
	}
}

// listPIPids 列出所有跟 pi-web 相关的进程 PID(去重 + 排除自身)。
// 用 ps + grep 而不是 pgrep,以兼容 macOS 默认 PATH 不带 /usr/bin 的情况。
func listPIPids() []string {
	out, err := runQuiet("ps", "-axo", "pid=,command=")
	if err != nil {
		log.Printf("listPIPids: ps err: %v", err)
		return nil
	}
	seen := map[string]bool{}
	var pids []string
	self := os.Getpid()
	for _, line := range strings.Split(out, "\n") {
		line = strings.TrimSpace(line)
		if line == "" {
			continue
		}
		// 格式: "PID COMMAND..."
		sp := strings.IndexByte(line, ' ')
		if sp <= 0 {
			continue
		}
		pidStr := line[:sp]
		cmd := line[sp+1:]
		// 跳过自身进程,免得自杀
		if pid, _ := strconv.Atoi(pidStr); pid == self {
			continue
		}
		// 匹配规则: pi-web 启动的所有相关进程
		if isPIProcess(cmd) {
			if !seen[pidStr] {
				seen[pidStr] = true
				pids = append(pids, pidStr)
			}
		}
	}
	return pids
}

// isPIProcess 判断一条 ps command 是不是 pi-web 相关的进程。
// pi-web 基于 Next.js,真正 listen 30141 的是 next-server 进程;
// 主进程 / Electron helper 用包名路径也能匹到。
func isPIProcess(cmd string) bool {
	matches := []string{
		"pi-web",                  // pi-web 任意引用(主进程、cli、helper)
		"@agegr/pi-web",           // npm 包路径
		".pi/electron",            // pi-web 内置 Electron runtime
		"next-server",             // Next.js server(实际 listen 端口的进程)
	}
	for _, m := range matches {
		if strings.Contains(cmd, m) {
			return true
		}
	}
	return false
}

func (a *App) CheckUpdate() UpdateInfo {
	installed := ""
	if p := lookPath("pi-web"); p != "" {
		if v, err := runQuietTimeout(p, 5*time.Second, "--version"); err == nil {
			installed = strings.TrimSpace(v)
		} else {
			log.Printf("CheckUpdate pi-web --version err: %v", err)
		}
	}

	latest, raw := latestVersionFromNPM(piPkg)

	info := UpdateInfo{
		Installed: installed,
		Latest:    latest,
		Raw:       raw,
	}
	if installed != "" && latest != "" && installed != latest {
		info.HasUpdate = true
	}
	return info
}

// latestVersionFromNPM 用 `npm view <pkg> version` 取最新版。
// 带 10 秒超时,带 stderr 捕获以便诊断。
func latestVersionFromNPM(pkg string) (string, string) {
	npmBin := lookPath("npm")
	if npmBin == "" {
		return "", "npm not found in PATH"
	}
	cmd := exec.Command(npmBin, "view", pkg, "version", "--registry=https://registry.npmjs.org/")
	cmd.Env = buildChildEnv()
	var stdout, stderr bytes.Buffer
	cmd.Stdout = &stdout
	cmd.Stderr = &stderr

	if err := cmd.Start(); err != nil {
		return "", "start npm: " + err.Error()
	}

	done := make(chan error, 1)
	go func() { done <- cmd.Wait() }()

	select {
	case err := <-done:
		out := strings.TrimSpace(stdout.String())
		errMsg := strings.TrimSpace(stderr.String())
		if err != nil {
			raw := errMsg
			if raw == "" {
				raw = err.Error()
			}
			return "", raw
		}
		// npm 输出可能带换行 / 警告,只取第一行 token
		first := out
		if i := strings.IndexAny(out, "\n\r"); i >= 0 {
			first = strings.TrimSpace(out[:i])
		}
		// 清理 npm 有时会附加的 @ 标签
		first = strings.TrimPrefix(first, "@")
		return first, out
	case <-time.After(15 * time.Second):
		_ = cmd.Process.Kill()
		<-done
		return "", "npm view 超时(15s),请检查网络"
	}
}

// InstallPi runs `npm install -g @agegr/pi-web` and streams output via Wails events.
// Returns InstallResult once the command exits.
func (a *App) InstallPi() InstallResult {
	return a.runNpmEvent("install", []string{"install", "-g", piPkg}, "pi:install:done")
}

// UpdatePi runs `npm install -g @agegr/pi-web@latest` and streams output.
func (a *App) UpdatePi() InstallResult {
	return a.runNpmEvent("update", []string{"install", "-g", piPkg + "@latest"}, "pi:update:done")
}

func (a *App) runNpmEvent(phase string, args []string, doneEvent string) InstallResult {
	npmBin := lookPath("npm")
	if npmBin == "" {
		errMsg := "找不到 npm(系统 PATH 和 /opt/homebrew/bin 都没找到)"
		if a.ctx != nil {
			wailsruntime.EventsEmit(a.ctx, "pi:"+phase+":log", "✗ "+errMsg+"\n")
			wailsruntime.EventsEmit(a.ctx, doneEvent, InstallResult{Error: errMsg})
		}
		return InstallResult{Error: errMsg}
	}
	if a.ctx != nil {
		wailsruntime.EventsEmit(a.ctx, "pi:"+phase+":log", "▶ "+npmBin+" "+strings.Join(args, " ")+"\n")
	}

	cmd := exec.Command(npmBin, args...)
	cmd.Env = buildChildEnv()
	stdout, err := cmd.StdoutPipe()
	if err != nil {
		return InstallResult{Error: err.Error()}
	}
	stderr, err := cmd.StderrPipe()
	if err != nil {
		return InstallResult{Error: err.Error()}
	}
	if err := cmd.Start(); err != nil {
		return InstallResult{Error: "启动 npm 失败: " + err.Error()}
	}

	var buf strings.Builder
	var mu sync.Mutex
	collect := func(line string) {
		mu.Lock()
		buf.WriteString(line)
		buf.WriteString("\n")
		mu.Unlock()
		if a.ctx != nil {
			wailsruntime.EventsEmit(a.ctx, "pi:"+phase+":log", line+"\n")
		}
	}
	safeGo("scanStdout", func() { scanLines(stdout, collect) })
	safeGo("scanStderr", func() { scanLines(stderr, collect) })

	waitErr := cmd.Wait()
	mu.Lock()
	out := buf.String()
	mu.Unlock()

	res := InstallResult{Output: out}
	if waitErr != nil {
		res.Error = waitErr.Error()
	} else {
		res.OK = true
	}
	if a.ctx != nil {
		wailsruntime.EventsEmit(a.ctx, doneEvent, res)
	}
	return res
}

func scanLines(r io.Reader, fn func(string)) {
	scanner := bufio.NewScanner(r)
	scanner.Buffer(make([]byte, 64*1024), 1024*1024)
	for scanner.Scan() {
		fn(scanner.Text())
	}
}