package system

import (
	"fmt"
	"os"
	"os/exec"
	"runtime"
	"strconv"
	"strings"

	"github.com/azoic/wormhole-client/pkg/logger"
)

// SystemProxyManager 系统代理管理器
type SystemProxyManager struct {
	originalSettings map[string]string
	isEnabled        bool
}

// NewSystemProxyManager 创建系统代理管理器
func NewSystemProxyManager() *SystemProxyManager {
	return &SystemProxyManager{
		originalSettings: make(map[string]string),
		isEnabled:        false,
	}
}

// SetGlobalProxy 设置全局代理
func (s *SystemProxyManager) SetGlobalProxy(httpProxy, httpsProxy, socksProxy string) error {
	logger.Info("Setting system proxy...")
	logger.Debug("HTTP: %s, HTTPS: %s, SOCKS: %s", httpProxy, httpsProxy, socksProxy)

	var err error
	switch runtime.GOOS {
	case "darwin":
		err = s.setMacOSProxy(httpProxy, httpsProxy, socksProxy)
	case "windows":
		err = s.setWindowsProxy(httpProxy, httpsProxy, socksProxy)
	case "linux":
		err = s.setLinuxProxy(httpProxy, httpsProxy, socksProxy)
	default:
		return fmt.Errorf("unsupported operating system: %s", runtime.GOOS)
	}

	if err == nil {
		s.isEnabled = true
		logger.Info("✅ System proxy configured successfully")
	}

	return err
}

// RestoreProxy 恢复原始代理设置
func (s *SystemProxyManager) RestoreProxy() error {
	if !s.isEnabled {
		logger.Debug("System proxy was not enabled, nothing to restore")
		return nil
	}

	logger.Info("Restoring system proxy...")

	var err error
	switch runtime.GOOS {
	case "darwin":
		err = s.restoreMacOSProxy()
	case "windows":
		err = s.restoreWindowsProxy()
	case "linux":
		err = s.restoreLinuxProxy()
	default:
		return fmt.Errorf("unsupported operating system: %s", runtime.GOOS)
	}

	if err == nil {
		s.isEnabled = false
		logger.Info("✅ System proxy restored successfully")
	}

	return err
}

// IsEnabled 检查代理是否已启用
func (s *SystemProxyManager) IsEnabled() bool {
	return s.isEnabled
}

// GetCurrentProxy 获取当前代理设置
func (s *SystemProxyManager) GetCurrentProxy() (map[string]string, error) {
	switch runtime.GOOS {
	case "darwin":
		return s.getMacOSCurrentProxy()
	case "windows":
		return s.getWindowsCurrentProxy()
	case "linux":
		return s.getLinuxCurrentProxy()
	default:
		return nil, fmt.Errorf("unsupported operating system: %s", runtime.GOOS)
	}
}

// ===================== macOS 实现 =====================

// macOS 代理设置
func (s *SystemProxyManager) setMacOSProxy(httpProxy, httpsProxy, socksProxy string) error {
	// 获取网络服务名称
	networkService, err := s.getMacOSNetworkService()
	if err != nil {
		return fmt.Errorf("failed to get network service: %v", err)
	}

	logger.Debug("Using network service: %s", networkService)

	// 保存原始设置
	if err := s.saveMacOSOriginalSettings(networkService); err != nil {
		logger.Warn("Failed to save original proxy settings: %v", err)
	}

	// 设置HTTP代理
	if httpProxy != "" {
		host, port := s.parseProxyHostPort(httpProxy)
		if err := s.runCommand("networksetup", "-setwebproxy", networkService, host, port); err != nil {
			return fmt.Errorf("failed to set HTTP proxy: %v", err)
		}

		if err := s.runCommand("networksetup", "-setwebproxystate", networkService, "on"); err != nil {
			return fmt.Errorf("failed to enable HTTP proxy: %v", err)
		}
		logger.Debug("HTTP proxy set to %s", httpProxy)
	}

	// 设置HTTPS代理
	if httpsProxy != "" {
		host, port := s.parseProxyHostPort(httpsProxy)
		if err := s.runCommand("networksetup", "-setsecurewebproxy", networkService, host, port); err != nil {
			return fmt.Errorf("failed to set HTTPS proxy: %v", err)
		}

		if err := s.runCommand("networksetup", "-setsecurewebproxystate", networkService, "on"); err != nil {
			return fmt.Errorf("failed to enable HTTPS proxy: %v", err)
		}
		logger.Debug("HTTPS proxy set to %s", httpsProxy)
	}

	// 设置SOCKS代理
	if socksProxy != "" {
		host, port := s.parseProxyHostPort(socksProxy)
		if err := s.runCommand("networksetup", "-setsocksfirewallproxy", networkService, host, port); err != nil {
			return fmt.Errorf("failed to set SOCKS proxy: %v", err)
		}

		if err := s.runCommand("networksetup", "-setsocksfirewallproxystate", networkService, "on"); err != nil {
			return fmt.Errorf("failed to enable SOCKS proxy: %v", err)
		}
		logger.Debug("SOCKS proxy set to %s", socksProxy)
	}

	return nil
}

// 获取macOS网络服务名称
func (s *SystemProxyManager) getMacOSNetworkService() (string, error) {
	output, err := exec.Command("networksetup", "-listallnetworkservices").Output()
	if err != nil {
		return "", fmt.Errorf("failed to list network services: %v", err)
	}

	lines := strings.Split(string(output), "\n")

	// 优先查找Wi-Fi服务
	for _, line := range lines {
		line = strings.TrimSpace(line)
		if line != "" && !strings.HasPrefix(line, "*") && !strings.Contains(line, "An asterisk") {
			lower := strings.ToLower(line)
			if strings.Contains(lower, "wi-fi") || strings.Contains(lower, "wifi") {
				return line, nil
			}
		}
	}

	// 查找以太网服务
	for _, line := range lines {
		line = strings.TrimSpace(line)
		if line != "" && !strings.HasPrefix(line, "*") && !strings.Contains(line, "An asterisk") {
			lower := strings.ToLower(line)
			if strings.Contains(lower, "ethernet") || strings.Contains(lower, "thunderbolt") {
				return line, nil
			}
		}
	}

	// 返回第一个可用的服务
	for _, line := range lines {
		line = strings.TrimSpace(line)
		if line != "" && !strings.HasPrefix(line, "*") && !strings.Contains(line, "An asterisk") {
			return line, nil
		}
	}

	return "", fmt.Errorf("no active network service found")
}

// 保存macOS原始代理设置
func (s *SystemProxyManager) saveMacOSOriginalSettings(networkService string) error {
	commands := map[string][]string{
		"http_proxy":  {"-getwebproxy", networkService},
		"https_proxy": {"-getsecurewebproxy", networkService},
		"socks_proxy": {"-getsocksfirewallproxy", networkService},
	}

	for key, args := range commands {
		if output, err := exec.Command("networksetup", args...).Output(); err == nil {
			s.originalSettings[key] = strings.TrimSpace(string(output))
		}
	}

	s.originalSettings["network_service"] = networkService
	logger.Debug("Saved original proxy settings for %s", networkService)
	return nil
}

// 恢复macOS代理设置
func (s *SystemProxyManager) restoreMacOSProxy() error {
	networkService, exists := s.originalSettings["network_service"]
	if !exists {
		return fmt.Errorf("no network service information saved")
	}

	// 关闭所有代理
	commands := [][]string{
		{"-setwebproxystate", networkService, "off"},
		{"-setsecurewebproxystate", networkService, "off"},
		{"-setsocksfirewallproxystate", networkService, "off"},
	}

	for _, args := range commands {
		if err := s.runCommand("networksetup", args...); err != nil {
			logger.Warn("Failed to restore proxy setting: %v", err)
		}
	}

	return nil
}

// 获取macOS当前代理设置
func (s *SystemProxyManager) getMacOSCurrentProxy() (map[string]string, error) {
	networkService, err := s.getMacOSNetworkService()
	if err != nil {
		return nil, err
	}

	result := make(map[string]string)

	// 获取HTTP代理
	if output, err := exec.Command("networksetup", "-getwebproxy", networkService).Output(); err == nil {
		result["http"] = strings.TrimSpace(string(output))
	}

	// 获取HTTPS代理
	if output, err := exec.Command("networksetup", "-getsecurewebproxy", networkService).Output(); err == nil {
		result["https"] = strings.TrimSpace(string(output))
	}

	// 获取SOCKS代理
	if output, err := exec.Command("networksetup", "-getsocksfirewallproxy", networkService).Output(); err == nil {
		result["socks"] = strings.TrimSpace(string(output))
	}

	return result, nil
}

// ===================== Windows 实现 =====================

// Windows 代理设置
func (s *SystemProxyManager) setWindowsProxy(httpProxy, httpsProxy, socksProxy string) error {
	// 保存当前设置
	if err := s.saveWindowsOriginalSettings(); err != nil {
		logger.Warn("Failed to save Windows proxy settings: %v", err)
	}

	// 设置HTTP/HTTPS代理
	if httpProxy != "" {
		// 使用 netsh 或注册表设置代理
		proxyServer := httpProxy
		if httpsProxy != "" && httpsProxy != httpProxy {
			proxyServer = fmt.Sprintf("http=%s;https=%s", httpProxy, httpsProxy)
		}

		// 使用PowerShell设置代理
		cmd := fmt.Sprintf(`
			$regPath = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Internet Settings"
			Set-ItemProperty -Path $regPath -Name ProxyEnable -Value 1
			Set-ItemProperty -Path $regPath -Name ProxyServer -Value "%s"
		`, proxyServer)

		if err := s.runPowerShell(cmd); err != nil {
			return fmt.Errorf("failed to set Windows proxy: %v", err)
		}

		logger.Debug("Windows HTTP proxy set to %s", proxyServer)
	}

	return nil
}

// 保存Windows原始代理设置
func (s *SystemProxyManager) saveWindowsOriginalSettings() error {
	// 读取当前注册表设置
	cmd := `
		$regPath = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Internet Settings"
		$enable = Get-ItemProperty -Path $regPath -Name ProxyEnable -ErrorAction SilentlyContinue
		$server = Get-ItemProperty -Path $regPath -Name ProxyServer -ErrorAction SilentlyContinue
		Write-Output "ProxyEnable:$($enable.ProxyEnable)"
		Write-Output "ProxyServer:$($server.ProxyServer)"
	`

	output, err := s.runPowerShellWithOutput(cmd)
	if err != nil {
		return err
	}

	lines := strings.Split(output, "\n")
	for _, line := range lines {
		if strings.HasPrefix(line, "ProxyEnable:") {
			s.originalSettings["windows_proxy_enable"] = strings.TrimPrefix(line, "ProxyEnable:")
		} else if strings.HasPrefix(line, "ProxyServer:") {
			s.originalSettings["windows_proxy_server"] = strings.TrimPrefix(line, "ProxyServer:")
		}
	}

	return nil
}

// 恢复Windows代理设置
func (s *SystemProxyManager) restoreWindowsProxy() error {
	enable := s.originalSettings["windows_proxy_enable"]
	server := s.originalSettings["windows_proxy_server"]

	cmd := fmt.Sprintf(`
		$regPath = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Internet Settings"
		Set-ItemProperty -Path $regPath -Name ProxyEnable -Value %s
		Set-ItemProperty -Path $regPath -Name ProxyServer -Value "%s"
	`, strings.TrimSpace(enable), strings.TrimSpace(server))

	return s.runPowerShell(cmd)
}

// 获取Windows当前代理设置
func (s *SystemProxyManager) getWindowsCurrentProxy() (map[string]string, error) {
	cmd := `
		$regPath = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Internet Settings"
		$enable = Get-ItemProperty -Path $regPath -Name ProxyEnable -ErrorAction SilentlyContinue
		$server = Get-ItemProperty -Path $regPath -Name ProxyServer -ErrorAction SilentlyContinue
		Write-Output "ProxyEnable:$($enable.ProxyEnable)"
		Write-Output "ProxyServer:$($server.ProxyServer)"
	`

	output, err := s.runPowerShellWithOutput(cmd)
	if err != nil {
		return nil, err
	}

	result := make(map[string]string)
	lines := strings.Split(output, "\n")
	for _, line := range lines {
		if strings.HasPrefix(line, "ProxyEnable:") {
			result["enabled"] = strings.TrimSpace(strings.TrimPrefix(line, "ProxyEnable:"))
		} else if strings.HasPrefix(line, "ProxyServer:") {
			result["server"] = strings.TrimSpace(strings.TrimPrefix(line, "ProxyServer:"))
		}
	}

	return result, nil
}

// ===================== Linux 实现 =====================

// Linux 代理设置
func (s *SystemProxyManager) setLinuxProxy(httpProxy, httpsProxy, socksProxy string) error {
	// 保存当前环境变量
	s.saveLinuxOriginalSettings()

	envVars := []string{}

	if httpProxy != "" {
		envVars = append(envVars, fmt.Sprintf("export http_proxy=%s", httpProxy))
		envVars = append(envVars, fmt.Sprintf("export HTTP_PROXY=%s", httpProxy))
	}

	if httpsProxy != "" {
		envVars = append(envVars, fmt.Sprintf("export https_proxy=%s", httpsProxy))
		envVars = append(envVars, fmt.Sprintf("export HTTPS_PROXY=%s", httpsProxy))
	}

	if socksProxy != "" {
		envVars = append(envVars, fmt.Sprintf("export socks_proxy=%s", socksProxy))
		envVars = append(envVars, fmt.Sprintf("export SOCKS_PROXY=%s", socksProxy))
	}

	// 写入到 /etc/environment (需要root权限)
	envContent := strings.Join(envVars, "\n") + "\n"

	// 尝试写入系统环境变量文件
	if err := s.writeLinuxSystemProxy(envContent); err != nil {
		logger.Warn("Failed to write system proxy settings: %v", err)
		logger.Info("Please manually add the following to your shell profile:")
		for _, env := range envVars {
			logger.Info("  %s", env)
		}
	}

	// 设置当前会话的环境变量
	for _, env := range envVars {
		parts := strings.SplitN(strings.TrimPrefix(env, "export "), "=", 2)
		if len(parts) == 2 {
			os.Setenv(parts[0], parts[1])
		}
	}

	return nil
}

// 保存Linux原始代理设置
func (s *SystemProxyManager) saveLinuxOriginalSettings() {
	envVars := []string{"http_proxy", "https_proxy", "socks_proxy", "HTTP_PROXY", "HTTPS_PROXY", "SOCKS_PROXY"}

	for _, env := range envVars {
		if value := os.Getenv(env); value != "" {
			s.originalSettings["linux_"+env] = value
		}
	}
}

// 恢复Linux代理设置
func (s *SystemProxyManager) restoreLinuxProxy() error {
	// 清除当前会话的环境变量
	envVars := []string{"http_proxy", "https_proxy", "socks_proxy", "HTTP_PROXY", "HTTPS_PROXY", "SOCKS_PROXY"}

	for _, env := range envVars {
		originalKey := "linux_" + env
		if originalValue, exists := s.originalSettings[originalKey]; exists {
			os.Setenv(env, originalValue)
		} else {
			os.Unsetenv(env)
		}
	}

	logger.Info("Environment variables restored (session only)")
	logger.Info("Note: You may need to manually remove proxy settings from system files")

	return nil
}

// 获取Linux当前代理设置
func (s *SystemProxyManager) getLinuxCurrentProxy() (map[string]string, error) {
	result := make(map[string]string)

	envVars := map[string]string{
		"http":  "http_proxy",
		"https": "https_proxy",
		"socks": "socks_proxy",
	}

	for key, env := range envVars {
		if value := os.Getenv(env); value != "" {
			result[key] = value
		} else if value := os.Getenv(strings.ToUpper(env)); value != "" {
			result[key] = value
		}
	}

	return result, nil
}

// ===================== 辅助函数 =====================

// 运行系统命令
func (s *SystemProxyManager) runCommand(name string, args ...string) error {
	cmd := exec.Command(name, args...)
	output, err := cmd.CombinedOutput()
	if err != nil {
		logger.Error("Command failed: %s %v, output: %s", name, args, string(output))
		return fmt.Errorf("command '%s %s' failed: %v", name, strings.Join(args, " "), err)
	}
	logger.Debug("Command succeeded: %s %v", name, args)
	return nil
}

// 运行PowerShell命令 (Windows)
func (s *SystemProxyManager) runPowerShell(script string) error {
	cmd := exec.Command("powershell", "-NoProfile", "-ExecutionPolicy", "Bypass", "-Command", script)
	output, err := cmd.CombinedOutput()
	if err != nil {
		logger.Error("PowerShell command failed: %s, output: %s", script, string(output))
		return fmt.Errorf("PowerShell command failed: %v", err)
	}
	return nil
}

// 运行PowerShell命令并获取输出 (Windows)
func (s *SystemProxyManager) runPowerShellWithOutput(script string) (string, error) {
	cmd := exec.Command("powershell", "-NoProfile", "-ExecutionPolicy", "Bypass", "-Command", script)
	output, err := cmd.Output()
	if err != nil {
		return "", fmt.Errorf("PowerShell command failed: %v", err)
	}
	return string(output), nil
}

// 写入Linux系统代理设置
func (s *SystemProxyManager) writeLinuxSystemProxy(content string) error {
	// 尝试写入 /etc/environment
	envFile := "/etc/environment"

	// 检查是否有写权限
	if _, err := os.Stat(envFile); os.IsNotExist(err) {
		return fmt.Errorf("file %s does not exist", envFile)
	}

	// 备份原文件
	if err := exec.Command("cp", envFile, envFile+".wormhole.backup").Run(); err != nil {
		logger.Warn("Failed to backup %s: %v", envFile, err)
	}

	// 追加代理设置
	f, err := os.OpenFile(envFile, os.O_APPEND|os.O_WRONLY, 0644)
	if err != nil {
		return err
	}
	defer f.Close()

	_, err = f.WriteString("\n# Wormhole SOCKS5 Client Proxy Settings\n" + content)
	return err
}

// 解析代理地址
func (s *SystemProxyManager) parseProxyHostPort(proxy string) (host, port string) {
	// 移除协议前缀
	proxy = strings.TrimPrefix(proxy, "http://")
	proxy = strings.TrimPrefix(proxy, "https://")
	proxy = strings.TrimPrefix(proxy, "socks5://")

	parts := strings.Split(proxy, ":")
	if len(parts) >= 2 {
		host = parts[0]
		port = parts[1]
	} else {
		host = proxy
		port = "8080" // 默认端口
	}

	// 验证端口
	if _, err := strconv.Atoi(port); err != nil {
		port = "8080"
	}

	return host, port
}