// internal/process/manager.go
// frpc-console 进程管理模块
// 2.6-preview: 状态机驱动 + 冲突检测 + 生命周期管理
// 2.7-preview: 软化版 - 精确控制 + CONFLICT/STOPPING 状态

package process

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

// ================================================================
// 常量定义
// ================================================================

const (
	LockFileName       = ".frpc.lock"
	PortCheckTimeout   = 500 * time.Millisecond
	StopMaxWaitTime    = 5 * time.Second
	LockAcquireTimeout = 30 * time.Second
	LockRetryInterval  = 100 * time.Millisecond
	APITimeout         = 2 * time.Second

	StartupMaxAttempts = 50
	StartupRetryDelay  = 200 * time.Millisecond
	StartupTimeout     = 10 * time.Second

	HealthCheckInterval = 15 * time.Second
)

// ================================================================
// 进程状态定义
// ================================================================

type ProcessPhase string

const (
	PhaseUnknown  ProcessPhase = "UNKNOWN"
	PhaseStarting ProcessPhase = "STARTING"
	PhaseRunning  ProcessPhase = "RUNNING"
	PhaseDegraded ProcessPhase = "DEGRADED"
	PhaseFailed   ProcessPhase = "FAILED"
	PhaseStopped  ProcessPhase = "STOPPED"
	PhaseStopping ProcessPhase = "STOPPING"
	PhaseConflict ProcessPhase = "CONFLICT"
)

// ================================================================
// 数据结构
// ================================================================

type PortCheckResult struct {
	Ready bool
	Err   error
}

type FrpcInstance struct {
	PID       int
	ParentPID int
	ExecPath  string
	CmdLine   string
	Owned     bool
}

type ProcessState struct {
	Phase     ProcessPhase `json:"phase"`
	PID       int          `json:"pid"`
	Port      int          `json:"port"`
	StartedAt time.Time    `json:"started_at"`
	ExitCode  int          `json:"exit_code,omitempty"`

	Alive     bool   `json:"alive"`
	PortReady bool   `json:"port_ready"`
	PortError string `json:"port_error,omitempty"`
	FRPReady  bool   `json:"frp_ready"`
	Version   string `json:"version,omitempty"`

	ExpectedStop bool `json:"expected_stop"`

	LastOutput string `json:"last_output,omitempty"`
	LastError  string `json:"last_error,omitempty"`
	Error      string `json:"error,omitempty"`

	Conflicts []FrpcInstance `json:"conflicts,omitempty"`
}

// PortStatus 兼容旧接口
type PortStatus struct {
	Port       int    `json:"port"`
	Occupied   bool   `json:"occupied"`
	PID        int    `json:"pid"`
	IsFRPC     bool   `json:"is_frpc"`
	ProcessCmd string `json:"process_cmd,omitempty"`
}

// FRPCStatus 来自 frpc admin API 的状态响应
type FRPCStatus struct {
	Version string `json:"version"`
	RunID   string `json:"run_id"`
	Proxies []struct {
		Name      string `json:"name"`
		Type      string `json:"type"`
		Status    string `json:"status"`
		LocalAddr string `json:"local_addr"`
	} `json:"proxies"`
}

// ================================================================
// 全局变量
// ================================================================

var (
	globalManager *ProcessManager
	globalMu      sync.Mutex
)

// ================================================================
// ProcessManager 主结构
// ================================================================

type ProcessManager struct {
	mu          sync.Mutex
	dataDir     string
	configPath  string
	frpcBinPath string
	adminPort   int

	startTime    time.Time
	expectedStop bool
	exitCode     int
	exitMu       sync.Mutex

	lastOutput string
	lastError  string
	outputMu   sync.Mutex

	lockFile *os.File
	locked   bool

	currentPhase ProcessPhase
	statusMu     sync.RWMutex
}

// ================================================================
// 构造函数
// ================================================================

func NewManager(dataDir, configPath, frpcBinPath string) *ProcessManager {
	pm := &ProcessManager{
		dataDir:      dataDir,
		configPath:   configPath,
		frpcBinPath:  frpcBinPath,
		adminPort:    0,
		currentPhase: PhaseUnknown,
	}
	return pm
}

func SetGlobalManager(pm *ProcessManager) {
	globalMu.Lock()
	defer globalMu.Unlock()
	globalManager = pm
}

func GetGlobalManager() *ProcessManager {
	globalMu.Lock()
	defer globalMu.Unlock()
	return globalManager
}

func (pm *ProcessManager) AdminPort() int {
	return pm.adminPort
}

func (pm *ProcessManager) CurrentPhase() ProcessPhase {
	pm.statusMu.RLock()
	defer pm.statusMu.RUnlock()
	return pm.currentPhase
}

func (pm *ProcessManager) setPhase(phase ProcessPhase) {
	pm.statusMu.Lock()
	defer pm.statusMu.Unlock()
	if pm.currentPhase != phase {
		log.Printf("[STATUS] %s → %s", pm.currentPhase, phase)
		pm.currentPhase = phase
	}
}

// ================================================================
// 配置读取
// ================================================================

func (pm *ProcessManager) LoadConfig() error {
	content, err := os.ReadFile(pm.configPath)
	if err != nil {
		return fmt.Errorf("读取配置文件失败: %w", err)
	}

	log.Printf("[DEBUG] LoadConfig 读取到文件，长度: %d 字节", len(content))

	preview := string(content)
	if len(preview) > 600 {
		preview = preview[:600] + "\n... (截断)"
	}
	log.Printf("[DEBUG] 文件内容预览:\n%s", preview)

	if port := extractIntValue(string(content), "admin_port"); port > 0 {
		pm.adminPort = port
		log.Printf("[DEBUG] ✅ 从 admin_port 解析到端口: %d", port)
		return nil
	}
	log.Printf("[DEBUG] ❌ admin_port 未找到")

	if port := extractIntValueFromSection(string(content), "webServer", "port"); port > 0 {
		pm.adminPort = port
		log.Printf("[DEBUG] ✅ 从 webServer.port 解析到端口: %d", port)
		return nil
	}
	log.Printf("[DEBUG] ❌ webServer.port 未找到")

	if port := extractPortFromAddrSection(string(content), "webServer", "addr"); port > 0 {
		pm.adminPort = port
		log.Printf("[DEBUG] ✅ 从 webServer.addr 解析到端口: %d", port)
		return nil
	}
	log.Printf("[DEBUG] ❌ webServer.addr 未找到或解析失败")

	return fmt.Errorf("未找到 admin_port 或 webServer.port/addr 配置")
}

func extractIntValue(content, key string) int {
	lines := strings.Split(content, "\n")
	for _, line := range lines {
		trimmed := strings.TrimSpace(line)
		if strings.HasPrefix(trimmed, key) {
			parts := strings.SplitN(trimmed, "=", 2)
			if len(parts) == 2 {
				val := strings.TrimSpace(parts[1])
				val = strings.Trim(val, `"`)
				if port, err := strconv.Atoi(val); err == nil && port > 0 {
					return port
				}
			}
		}
	}
	return 0
}

func extractIntValueFromSection(content, section, key string) int {
	lines := strings.Split(content, "\n")
	inSection := false
	for _, line := range lines {
		trimmed := strings.TrimSpace(line)
		if strings.HasPrefix(trimmed, "[") && strings.HasSuffix(trimmed, "]") {
			sectionName := strings.TrimSpace(strings.Trim(trimmed, "[]"))
			inSection = strings.EqualFold(sectionName, section)
			continue
		}
		if inSection && strings.HasPrefix(trimmed, key) {
			parts := strings.SplitN(trimmed, "=", 2)
			if len(parts) == 2 {
				val := strings.TrimSpace(parts[1])
				val = strings.Trim(val, `"`)
				if port, err := strconv.Atoi(val); err == nil && port > 0 {
					return port
				}
			}
		}
	}
	return 0
}

func extractPortFromAddrSection(content, section, key string) int {
	lines := strings.Split(content, "\n")
	inSection := false
	for _, line := range lines {
		trimmed := strings.TrimSpace(line)
		if strings.HasPrefix(trimmed, "[") && strings.HasSuffix(trimmed, "]") {
			sectionName := strings.TrimSpace(strings.Trim(trimmed, "[]"))
			inSection = strings.EqualFold(sectionName, section)
			continue
		}
		if inSection && strings.HasPrefix(trimmed, key) {
			parts := strings.SplitN(trimmed, "=", 2)
			if len(parts) == 2 {
				val := strings.TrimSpace(parts[1])
				val = strings.Trim(val, `"`)
				if idx := strings.LastIndex(val, ":"); idx != -1 {
					portStr := val[idx+1:]
					if port, err := strconv.Atoi(portStr); err == nil && port > 0 {
						return port
					}
				}
			}
		}
	}
	return 0
}

// ================================================================
// 端口检测
// ================================================================

func (pm *ProcessManager) CheckPort() PortCheckResult {
	if pm.adminPort <= 0 {
		return PortCheckResult{Ready: false, Err: fmt.Errorf("admin_port 未配置")}
	}

	conn, err := net.DialTimeout("tcp", fmt.Sprintf("127.0.0.1:%d", pm.adminPort), PortCheckTimeout)
	if err != nil {
		return PortCheckResult{Ready: false, Err: err}
	}
	conn.Close()
	return PortCheckResult{Ready: true, Err: nil}
}

func (pm *ProcessManager) GetPortStatus() (*PortStatus, error) {
	status := &PortStatus{Port: pm.adminPort, Occupied: false, PID: 0, IsFRPC: false}
	result := pm.CheckPort()
	if result.Err != nil {
		return status, result.Err
	}
	if !result.Ready {
		return status, nil
	}
	status.Occupied = true

	pid, err := pm.getPIDByPort(pm.adminPort)
	if err != nil {
		if pidFromFile := pm.readPIDFile(); pidFromFile > 0 {
			if pm.isProcessListeningOnPort(pidFromFile, pm.adminPort) {
				status.PID = pidFromFile
			}
		}
	} else {
		status.PID = pid
	}
	if status.PID == 0 {
		return status, nil
	}
	isFRPC, cmd := pm.isFRPCProcess(status.PID)
	status.IsFRPC = isFRPC
	status.ProcessCmd = cmd
	return status, nil
}

func (pm *ProcessManager) getPIDByPort(port int) (int, error) {
	if pid, err := pm.getPIDBySS(port); err == nil && pid > 0 {
		return pid, nil
	}
	if pid, err := pm.getPIDByNetstat(port); err == nil && pid > 0 {
		return pid, nil
	}
	if pid, err := pm.getPIDByLsof(port); err == nil && pid > 0 {
		return pid, nil
	}
	return 0, fmt.Errorf("无法通过端口反查 PID")
}

func (pm *ProcessManager) getPIDBySS(port int) (int, error) {
	cmd := exec.Command("ss", "-lpn", "state", "listening")
	out, err := cmd.Output()
	if err != nil {
		return 0, err
	}
	scanner := bufio.NewScanner(bytes.NewReader(out))
	for scanner.Scan() {
		line := scanner.Text()
		if !strings.Contains(line, fmt.Sprintf(":%d", port)) {
			continue
		}
		if idx := strings.Index(line, "pid="); idx != -1 {
			end := strings.Index(line[idx:], ",")
			if end == -1 {
				end = strings.Index(line[idx:], ")")
			}
			if end == -1 {
				continue
			}
			pidStr := line[idx+4 : idx+end]
			pidStr = strings.TrimSpace(pidStr)
			if pid, err := strconv.Atoi(pidStr); err == nil && pid > 0 {
				return pid, nil
			}
		}
	}
	return 0, fmt.Errorf("未找到监听端口 %d 的进程", port)
}

func (pm *ProcessManager) getPIDByNetstat(port int) (int, error) {
	cmd := exec.Command("netstat", "-tulpn")
	out, err := cmd.Output()
	if err != nil {
		return 0, err
	}
	scanner := bufio.NewScanner(bytes.NewReader(out))
	for scanner.Scan() {
		line := scanner.Text()
		if !strings.Contains(line, fmt.Sprintf(":%d", port)) {
			continue
		}
		parts := strings.Fields(line)
		if len(parts) < 7 {
			continue
		}
		last := parts[len(parts)-1]
		if idx := strings.Index(last, "/"); idx != -1 {
			pidStr := last[:idx]
			if pid, err := strconv.Atoi(pidStr); err == nil && pid > 0 {
				return pid, nil
			}
		}
	}
	return 0, fmt.Errorf("未找到监听端口 %d 的进程", port)
}

func (pm *ProcessManager) getPIDByLsof(port int) (int, error) {
	cmd := exec.Command("lsof", "-i", fmt.Sprintf(":%d", port), "-sTCP:LISTEN")
	out, err := cmd.Output()
	if err != nil {
		return 0, err
	}
	scanner := bufio.NewScanner(bytes.NewReader(out))
	for scanner.Scan() {
		line := scanner.Text()
		if strings.Contains(line, "frpc") {
			parts := strings.Fields(line)
			if len(parts) >= 2 {
				if pid, err := strconv.Atoi(parts[1]); err == nil && pid > 0 {
					return pid, nil
				}
			}
		}
	}
	return 0, fmt.Errorf("未找到监听端口 %d 的 frpc 进程", port)
}

func (pm *ProcessManager) isProcessListeningOnPort(pid, port int) bool {
	cmd := exec.Command("lsof", "-p", strconv.Itoa(pid), "-a", "-i", fmt.Sprintf(":%d", port), "-sTCP:LISTEN")
	out, err := cmd.Output()
	if err != nil {
		return false
	}
	return strings.Contains(string(out), "LISTEN")
}

func (pm *ProcessManager) isFRPCProcess(pid int) (bool, string) {
	cmdlinePath := fmt.Sprintf("/proc/%d/cmdline", pid)
	if data, err := os.ReadFile(cmdlinePath); err == nil {
		cmd := strings.ReplaceAll(string(data), "\x00", " ")
		if strings.Contains(cmd, "frpc") {
			return true, cmd
		}
	}
	cmd := exec.Command("ps", "-p", strconv.Itoa(pid), "-o", "args=")
	out, err := cmd.Output()
	if err == nil {
		args := strings.TrimSpace(string(out))
		if strings.Contains(args, "frpc") {
			return true, args
		}
	}
	return false, ""
}

// ================================================================
// 进程存活检测
// ================================================================

func (pm *ProcessManager) isProcessAlive(pid int) bool {
	if pid <= 0 {
		return false
	}

	if runtime.GOOS == "windows" {
		cmd := exec.Command("tasklist", "/FI", "PID eq", strconv.Itoa(pid))
		output, err := cmd.CombinedOutput()
		if err != nil {
			return false
		}
		return strings.Contains(string(output), strconv.Itoa(pid))
	}

	process, err := os.FindProcess(pid)
	if err != nil {
		return false
	}
	return process.Signal(syscall.Signal(0)) == nil
}

// ================================================================
// 实例检测（精确扫描）
// ================================================================

// DetectFrpcInstances 检测系统中所有 frpc 实例
// 三重确认：PID存在 + 进程存活 + Executable/CmdLine匹配
func (pm *ProcessManager) DetectFrpcInstances() []FrpcInstance {
	var instances []FrpcInstance

	// 获取当前 frpc 可执行文件的绝对路径
	targetExe := pm.frpcBinPath
	if !filepath.IsAbs(targetExe) {
		if abs, err := filepath.Abs(targetExe); err == nil {
			targetExe = abs
		}
	}

	if runtime.GOOS == "windows" {
		// Windows: 使用 tasklist + wmic 获取进程信息
		cmd := exec.Command("tasklist", "/FO", "CSV", "/FI", "IMAGENAME eq frpc.exe")
		out, err := cmd.Output()
		if err != nil {
			log.Printf("[WARN] 检测 frpc 实例失败: %v", err)
			return instances
		}
		lines := strings.Split(string(out), "\n")
		for _, line := range lines {
			if !strings.Contains(line, "frpc.exe") {
				continue
			}
			parts := strings.Split(line, ",")
			if len(parts) < 2 {
				continue
			}
			pidStr := strings.Trim(parts[1], `"`)
			pid, err := strconv.Atoi(pidStr)
			if err != nil || pid <= 0 {
				continue
			}
			if !pm.isProcessAlive(pid) {
				continue
			}
			// 获取 cmdline（Windows 较难获取，先用进程名匹配）
			inst := FrpcInstance{
				PID:      pid,
				ExecPath: "frpc.exe",
				CmdLine:  "frpc.exe",
				Owned:    false,
			}
			// 检查是否 Owned
			ownedPid := pm.readPIDFile()
			if ownedPid == pid {
				inst.Owned = true
			}
			instances = append(instances, inst)
		}
		return instances
	}

	// Linux: 使用 pgrep + /proc 精确匹配
	cmd := exec.Command("pgrep", "-f", "frpc")
	out, err := cmd.Output()
	if err != nil {
		// 没有找到进程，pgrep 返回非0，属于正常情况
		return instances
	}

	pids := strings.Split(strings.TrimSpace(string(out)), "\n")
	for _, pidStr := range pids {
		pidStr = strings.TrimSpace(pidStr)
		if pidStr == "" {
			continue
		}
		pid, err := strconv.Atoi(pidStr)
		if err != nil || pid <= 0 {
			continue
		}

		if !pm.isProcessAlive(pid) {
			continue
		}

		// 获取命令行
		cmdline, _ := os.ReadFile(fmt.Sprintf("/proc/%d/cmdline", pid))
		cmdLineStr := strings.ReplaceAll(string(cmdline), "\x00", " ")

		// 获取可执行文件路径
		exePath, _ := os.Readlink(fmt.Sprintf("/proc/%d/exe", pid))

		// 获取父进程 PID
		stat, _ := os.ReadFile(fmt.Sprintf("/proc/%d/stat", pid))
		var parentPID int
		if len(stat) > 0 {
			// stat 格式: pid (comm) state ppid ...
			parts := strings.Fields(string(stat))
			if len(parts) > 3 {
				parentPID, _ = strconv.Atoi(parts[3])
			}
		}

		inst := FrpcInstance{
			PID:       pid,
			ParentPID: parentPID,
			ExecPath:  exePath,
			CmdLine:   cmdLineStr,
			Owned:     false,
		}

		// 三重确认 Owned
		ownedPid := pm.readPIDFile()
		if ownedPid == pid {
			// 条件1: PID 匹配
			if pm.isProcessAlive(pid) {
				// 条件2: 进程存在
				// 条件3: 执行路径匹配
				if exePath != "" && (strings.Contains(exePath, "frpc") || strings.Contains(cmdLineStr, "frpc")) {
					inst.Owned = true
				}
			}
		}

		instances = append(instances, inst)
	}

	return instances
}

// filterOwned 返回 Owned 实例
func (pm *ProcessManager) filterOwned(instances []FrpcInstance) []FrpcInstance {
	var result []FrpcInstance
	for _, inst := range instances {
		if inst.Owned {
			result = append(result, inst)
		}
	}
	return result
}

// filterUnknown 返回 Unknown 实例
func (pm *ProcessManager) filterUnknown(instances []FrpcInstance) []FrpcInstance {
	var result []FrpcInstance
	for _, inst := range instances {
		if !inst.Owned {
			result = append(result, inst)
		}
	}
	return result
}

// ================================================================
// 冲突检测
// ================================================================

type ConflictInfo struct {
	HasConflict bool
	Count       int
	Owned       []FrpcInstance
	Unknown     []FrpcInstance
}

func (pm *ProcessManager) DetectConflict() ConflictInfo {
	instances := pm.DetectFrpcInstances()
	owned := pm.filterOwned(instances)
	unknown := pm.filterUnknown(instances)

	return ConflictInfo{
		HasConflict: len(unknown) > 0 || len(owned) > 1,
		Count:       len(instances),
		Owned:       owned,
		Unknown:     unknown,
	}
}

// ================================================================
// 实例健康检查
// ================================================================

func (pm *ProcessManager) isInstanceHealthy(inst FrpcInstance) bool {
	// 1. 进程必须存在
	if !pm.isProcessAlive(inst.PID) {
		return false
	}
	// 2. 端口必须可连接
	result := pm.CheckPort()
	if !result.Ready {
		return false
	}
	// 3. FRP 就绪（通过 stdout 或 admin API）
	stdout := pm.getLastOutput()
	if pm.isFRPReady(stdout) {
		return true
	}
	// 4. 尝试 admin API
	if info := pm.getFRPCStatus(inst.PID); info != nil && info.Version != "" {
		return true
	}
	return false
}

// ================================================================
// 进程清理
// ================================================================

func (pm *ProcessManager) killProcess(pid int) error {
	if pid <= 0 {
		return nil
	}

	if runtime.GOOS == "windows" {
		cmd := exec.Command("taskkill", "/F", "/PID", strconv.Itoa(pid))
		return cmd.Run()
	}

	process, err := os.FindProcess(pid)
	if err != nil {
		return err
	}
	return process.Kill()
}

func (pm *ProcessManager) cleanupOrphans() {
	result := pm.CheckPort()
	if !result.Ready {
		return
	}

	pid := pm.readPIDFile()
	if pid > 0 && pm.isProcessAlive(pid) {
		return
	}

	log.Printf("[WARN] 检测到孤儿 frpc 进程 (端口 %d 被占用但无有效 PID)，正在清理...", pm.adminPort)
	if runtime.GOOS == "windows" {
		exec.Command("taskkill", "/F", "/IM", "frpc.exe").Run()
	} else {
		exec.Command("pkill", "-f", "frpc").Run()
	}
	pm.deletePIDFile()
	time.Sleep(1 * time.Second)
}

// ================================================================
// PID 文件操作
// ================================================================

func (pm *ProcessManager) pidFilePath() string {
	return filepath.Join(pm.dataDir, "frpc.pid")
}

func (pm *ProcessManager) readPIDFile() int {
	data, err := os.ReadFile(pm.pidFilePath())
	if err != nil {
		return 0
	}
	pid, err := strconv.Atoi(strings.TrimSpace(string(data)))
	if err != nil || pid <= 0 {
		return 0
	}
	return pid
}

func (pm *ProcessManager) writePIDFile(pid int) error {
	return os.WriteFile(pm.pidFilePath(), []byte(strconv.Itoa(pid)), 0644)
}

func (pm *ProcessManager) deletePIDFile() error {
	err := os.Remove(pm.pidFilePath())
	if os.IsNotExist(err) {
		return nil
	}
	return err
}

// ================================================================
// stdout/stderr 捕获
// ================================================================

func (pm *ProcessManager) captureOutput(reader io.ReadCloser, isError bool) {
	defer reader.Close()
	scanner := bufio.NewScanner(reader)
	buf := make([]byte, 64*1024)
	scanner.Buffer(buf, 256*1024)

	var lines []string
	const maxLines = 20

	for scanner.Scan() {
		line := scanner.Text()
		pm.outputMu.Lock()
		if isError {
			pm.lastError = line
		} else {
			pm.lastOutput = line
		}
		pm.outputMu.Unlock()

		if isError {
			lines = append(lines, line)
			if len(lines) > maxLines {
				lines = lines[1:]
			}
			pm.outputMu.Lock()
			pm.lastError = strings.Join(lines, "\n")
			pm.outputMu.Unlock()
		} else {
			lines = append(lines, line)
			if len(lines) > maxLines {
				lines = lines[1:]
			}
			pm.outputMu.Lock()
			pm.lastOutput = strings.Join(lines, "\n")
			pm.outputMu.Unlock()
		}
	}
}

func (pm *ProcessManager) getLastOutput() string {
	pm.outputMu.Lock()
	defer pm.outputMu.Unlock()
	return pm.lastOutput
}

func (pm *ProcessManager) getLastError() string {
	pm.outputMu.Lock()
	defer pm.outputMu.Unlock()
	return pm.lastError
}

// ================================================================
// FRPReady 检测
// ================================================================

func (pm *ProcessManager) isFRPReady(stdout string) bool {
	if strings.Contains(stdout, "start proxy success") ||
		strings.Contains(stdout, "login to server success") {
		return true
	}
	return false
}

// ================================================================
// 状态计算
// ================================================================

func (pm *ProcessManager) computeState(pid int, result PortCheckResult) ProcessState {
	alive := pm.isProcessAlive(pid)
	portReady := result.Ready
	portErr := result.Err

	stdout := pm.getLastOutput()
	stderr := pm.getLastError()
	frpReady := pm.isFRPReady(stdout)

	pm.exitMu.Lock()
	exitCode := pm.exitCode
	pm.exitMu.Unlock()

	state := ProcessState{
		PID:          pid,
		Port:         pm.adminPort,
		Alive:        alive,
		PortReady:    portReady,
		PortError:    "",
		FRPReady:     frpReady,
		StartedAt:    pm.startTime,
		ExpectedStop: pm.expectedStop,
		LastOutput:   stdout,
		LastError:    stderr,
		ExitCode:     exitCode,
	}

	if portErr != nil {
		state.PortError = portErr.Error()
	}

	// ============================================================
	// 状态判定逻辑
	// ============================================================

	// 1. 如果是主动停止，直接返回 STOPPING
	if pm.expectedStop && alive {
		state.Phase = PhaseStopping
		return state
	}

	// 2. 进程不存在
	if !alive {
		if pm.expectedStop {
			state.Phase = PhaseStopped
			return state
		}

		if exitCode != 0 && exitCode != -1 {
			state.Error = fmt.Sprintf("进程异常退出 (exit code: %d)", exitCode)
			if stderr != "" {
				state.Error += ": " + stderr
			}
		} else {
			state.Error = "进程意外退出"
			if stderr != "" {
				state.Error += ": " + stderr
			}
		}
		state.Phase = PhaseFailed
		return state
	}

	// 3. 进程存在，检查超时
	if time.Since(pm.startTime) > StartupTimeout {
		state.Error = fmt.Sprintf("启动超时 (超过 %v)", StartupTimeout)
		if portErr != nil {
			state.Error += ": " + portErr.Error()
		}
		state.Phase = PhaseFailed
		return state
	}

	// 4. 冲突检测
	conflict := pm.DetectConflict()
	if conflict.HasConflict {
		state.Phase = PhaseConflict
		state.Conflicts = append(conflict.Owned, conflict.Unknown...)
		if len(conflict.Unknown) > 0 {
			state.Error = fmt.Sprintf("检测到 %d 个未知 frpc 实例", len(conflict.Unknown))
		}
		if len(conflict.Owned) > 1 {
			state.Error = fmt.Sprintf("检测到 %d 个 Owned frpc 实例（异常）", len(conflict.Owned))
		}
		return state
	}

	// 5. 正常运行状态
	if portReady && frpReady {
		state.Phase = PhaseRunning
		return state
	}

	// 6. 端口就绪但 FRP 未就绪
	if portReady && !frpReady {
		state.Phase = PhaseDegraded
		state.Error = "端口已监听，但 frpc 未报告就绪"
		return state
	}

	// 7. 端口未就绪
	if !portReady {
		if portErr != nil && strings.Contains(portErr.Error(), "permission denied") {
			state.Phase = PhaseDegraded
			state.Error = "端口检测权限不足: " + portErr.Error()
			return state
		}
		state.Phase = PhaseStarting
		if portErr != nil {
			state.Error = "等待端口就绪: " + portErr.Error()
		}
		return state
	}

	state.Phase = PhaseUnknown
	return state
}

// ================================================================
// 状态查询
// ================================================================

func (pm *ProcessManager) Status() (*ProcessState, error) {
	pid := pm.readPIDFile()
	result := pm.CheckPort()
	state := pm.computeState(pid, result)
	pm.setPhase(state.Phase)
	return &state, nil
}

// ================================================================
// API 回源 (2.7-preview 预留)
// ================================================================

func (pm *ProcessManager) getFRPCStatus(pid int) *FRPCStatus {
	if pid <= 0 || pm.adminPort <= 0 {
		return nil
	}
	url := fmt.Sprintf("http://127.0.0.1:%d/api/status", pm.adminPort)
	ctx, cancel := context.WithTimeout(context.Background(), APITimeout)
	defer cancel()
	req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
	if err != nil {
		return nil
	}
	client := &http.Client{Timeout: APITimeout}
	resp, err := client.Do(req)
	if err != nil {
		return nil
	}
	defer resp.Body.Close()
	if resp.StatusCode != 200 {
		return nil
	}
	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil
	}
	var status FRPCStatus
	if err := json.Unmarshal(body, &status); err != nil {
		return nil
	}
	return &status
}

// ================================================================
// 操作执行
// ================================================================

// Lock 由平台文件 (lock_*.go) 实现

func (pm *ProcessManager) Start(ctx context.Context) error {
	if err := pm.Lock(); err != nil {
		return fmt.Errorf("获取锁失败: %w", err)
	}
	defer pm.Unlock()

	pm.expectedStop = false

	// 1. 检测冲突
	conflict := pm.DetectConflict()
	if conflict.HasConflict {
		log.Printf("[WARN] 检测到 %d 个 frpc 实例 (Owned: %d, Unknown: %d)，进入 CONFLICT 状态",
			conflict.Count, len(conflict.Owned), len(conflict.Unknown))

		// 清理 Unknown 实例
		for _, inst := range conflict.Unknown {
			log.Printf("[INFO] 清理 Unknown frpc 实例 (PID: %d)", inst.PID)
			pm.killProcess(inst.PID)
		}

		// 如果有且仅有一个 Owned 实例，保留它
		if len(conflict.Owned) == 1 {
			pid := conflict.Owned[0].PID
			log.Printf("[INFO] 保留 Owned frpc 实例 (PID: %d)，清理完成", pid)
			pm.writePIDFile(pid)
			pm.setPhase(PhaseRunning)
			return nil
		}

		// 多个 Owned 或没有 Owned：全部清理，重新启动
		if len(conflict.Owned) > 1 {
			log.Printf("[WARN] 多个 Owned 实例冲突，全部清理")
			for _, inst := range conflict.Owned {
				pm.killProcess(inst.PID)
			}
		}
		pm.deletePIDFile()
	}

	// 2. 清理孤儿
	pm.cleanupOrphans()

	// 3. 正常启动
	return pm.startLocked(ctx)
}

func (pm *ProcessManager) startLocked(ctx context.Context) error {
	result := pm.CheckPort()
	if result.Ready {
		pid := pm.readPIDFile()
		if pid > 0 && pm.isProcessAlive(pid) {
			log.Printf("[INFO] frpc 已在运行 (PID: %d)", pid)
			pm.setPhase(PhaseRunning)
			return nil
		}
		pm.cleanupOrphans()
	}

	pm.startTime = time.Now()
	pm.expectedStop = false

	pm.exitMu.Lock()
	pm.exitCode = -1
	pm.exitMu.Unlock()

	cmd := exec.CommandContext(ctx, pm.frpcBinPath, "-c", pm.configPath)
	setProcessAttributes(cmd)

	stdoutPipe, err := cmd.StdoutPipe()
	if err != nil {
		return fmt.Errorf("创建 stdout pipe 失败: %w", err)
	}
	stderrPipe, err := cmd.StderrPipe()
	if err != nil {
		return fmt.Errorf("创建 stderr pipe 失败: %w", err)
	}

	go pm.captureOutput(stdoutPipe, false)
	go pm.captureOutput(stderrPipe, true)

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

	if err := pm.writePIDFile(cmd.Process.Pid); err != nil {
		log.Printf("[WARN] 写入 PID 文件失败: %v", err)
	}
	log.Printf("[DEBUG] frpc 进程已启动，PID: %d", cmd.Process.Pid)

	pm.setPhase(PhaseStarting)

	go func() {
		err := cmd.Wait()
		var code int
		if err != nil {
			if exitErr, ok := err.(*exec.ExitError); ok {
				code = exitErr.ExitCode()
			} else {
				code = -1
			}
		} else {
			code = 0
		}
		pm.exitMu.Lock()
		pm.exitCode = code
		pm.exitMu.Unlock()
		log.Printf("[INFO] frpc 进程 (PID: %d) 已退出，退出码: %d", cmd.Process.Pid, code)

		if !pm.expectedStop && code != 0 {
			log.Printf("[WARN] frpc 进程异常退出 (exit code: %d)", code)
			pm.setPhase(PhaseFailed)
		}
		if !pm.expectedStop {
			pm.deletePIDFile()
		}
	}()

	// 等待端口就绪
	for attempt := 0; attempt < StartupMaxAttempts; attempt++ {
		r := pm.CheckPort()
		if r.Ready {
			stdout := pm.getLastOutput()
			if pm.isFRPReady(stdout) {
				log.Printf("[INFO] frpc 启动成功 (PID: %d, 端口: %d)，耗时 %dms",
					cmd.Process.Pid, pm.adminPort, attempt*int(StartupRetryDelay/time.Millisecond))
				pm.setPhase(PhaseRunning)
				return nil
			}
			log.Printf("[DEBUG] 端口已就绪，等待 frpc 初始化...")
		}
		time.Sleep(StartupRetryDelay)
	}

	// 超时：检查进程状态
	if pm.isProcessAlive(cmd.Process.Pid) {
		stderr := pm.getLastError()
		log.Printf("[WARN] frpc 启动超时 (PID: %d)，当前 stderr: %s", cmd.Process.Pid, stderr)
		if info := pm.getFRPCStatus(cmd.Process.Pid); info != nil && info.Version != "" {
			log.Printf("[INFO] frpc admin API 可访问，版本: %s", info.Version)
			pm.writePIDFile(cmd.Process.Pid)
			pm.setPhase(PhaseRunning)
			return nil
		}
		pm.killProcess(cmd.Process.Pid)
		pm.deletePIDFile()
		pm.setPhase(PhaseFailed)
		return fmt.Errorf("frpc 启动超时: 进程存在但端口未就绪")
	}

	pm.deletePIDFile()
	pm.setPhase(PhaseFailed)
	return fmt.Errorf("frpc 启动失败: 进程已退出")
}

func (pm *ProcessManager) Stop(ctx context.Context) error {
	if err := pm.Lock(); err != nil {
		return fmt.Errorf("获取锁失败: %w", err)
	}
	defer pm.Unlock()

	pm.expectedStop = true
	pm.setPhase(PhaseStopping)
	return pm.stopLocked(ctx)
}

func (pm *ProcessManager) stopLocked(_ context.Context) error {
	pid := pm.readPIDFile()
	if pid <= 0 {
		if runtime.GOOS == "windows" {
			exec.Command("taskkill", "/F", "/IM", "frpc.exe").Run()
		} else {
			exec.Command("pkill", "-f", "frpc").Run()
		}
		pm.deletePIDFile()
		pm.setPhase(PhaseStopped)
		return nil
	}

	if !pm.isProcessAlive(pid) {
		pm.deletePIDFile()
		pm.setPhase(PhaseStopped)
		return nil
	}

	// 发送 SIGTERM
	process, err := os.FindProcess(pid)
	if err != nil {
		pm.deletePIDFile()
		pm.setPhase(PhaseStopped)
		return nil
	}
	if err := process.Signal(syscall.SIGTERM); err != nil {
		pm.deletePIDFile()
		pm.setPhase(PhaseStopped)
		return nil
	}

	// 等待进程退出
	start := time.Now()
	for time.Since(start) < StopMaxWaitTime {
		if !pm.isProcessAlive(pid) {
			pm.deletePIDFile()
			pm.setPhase(PhaseStopped)
			return nil
		}
		time.Sleep(200 * time.Millisecond)
	}

	// 强制 kill
	if runtime.GOOS == "windows" {
		exec.Command("taskkill", "/F", "/PID", strconv.Itoa(pid)).Run()
	} else {
		process.Kill()
	}
	time.Sleep(500 * time.Millisecond)

	if pm.isProcessAlive(pid) {
		pm.setPhase(PhaseFailed)
		return fmt.Errorf("强制停止失败: 进程仍存活 (PID: %d)", pid)
	}

	pm.deletePIDFile()
	pm.setPhase(PhaseStopped)
	return nil
}

func (pm *ProcessManager) Restart(ctx context.Context) error {
	if err := pm.Lock(); err != nil {
		return fmt.Errorf("获取锁失败: %w", err)
	}
	defer pm.Unlock()

	if err := pm.stopLocked(ctx); err != nil {
		return fmt.Errorf("停止失败: %w", err)
	}
	time.Sleep(1 * time.Second)
	if err := pm.startLocked(ctx); err != nil {
		return fmt.Errorf("启动失败: %w", err)
	}
	return nil
}

// ================================================================
// 健康检查看门狗（由 main.go 调用）
// ================================================================

func (pm *ProcessManager) StartHealthMonitor(ctx context.Context) {
	ticker := time.NewTicker(HealthCheckInterval)
	defer ticker.Stop()

	for {
		select {
		case <-ctx.Done():
			return
		case <-ticker.C:
			pm.runHealthCheck()
		}
	}
}

func (pm *ProcessManager) runHealthCheck() {
	state, err := pm.Status()
	if err != nil {
		log.Printf("[WARN] 健康检查失败: %v", err)
		return
	}

	// 根据状态执行自动恢复
	switch state.Phase {
	case PhaseConflict:
		log.Printf("[WARN] 检测到冲突，尝试自动恢复...")
		// 冲突恢复：清理未知实例
		for _, inst := range state.Conflicts {
			if !inst.Owned {
				pm.killProcess(inst.PID)
			}
		}
		pm.setPhase(PhaseStarting)
	case PhaseDegraded:
		log.Printf("[WARN] frpc 处于降级状态，尝试恢复...")
		// 降级恢复：重启
		pm.Restart(context.Background())
	case PhaseFailed:
		if !state.ExpectedStop {
			log.Printf("[WARN] frpc 已失败，自动重启...")
			pm.Start(context.Background())
		}
	}
}

// ================================================================
// 健康检查
// ================================================================

func (pm *ProcessManager) HealthCheck() map[string]interface{} {
	result := make(map[string]interface{})
	result["admin_port"] = pm.adminPort
	result["phase"] = pm.CurrentPhase()

	state, err := pm.Status()
	if err != nil {
		result["error"] = err.Error()
		return result
	}

	result["pid"] = state.PID
	result["port"] = state.Port
	result["alive"] = state.Alive
	result["port_ready"] = state.PortReady
	result["frp_ready"] = state.FRPReady
	if state.PortError != "" {
		result["port_error"] = state.PortError
	}
	if state.Error != "" {
		result["error"] = state.Error
	}
	if state.Version != "" {
		result["version"] = state.Version
	}
	if len(state.Conflicts) > 0 {
		result["conflicts"] = state.Conflicts
	}

	return result
}