//go:build kanholec_gui

package gui

import (
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
)

type ServiceManager struct {
	binaryPath  string
	serviceName string
}

func NewServiceManager() *ServiceManager {
	exe, _ := os.Executable()
	return &ServiceManager{
		binaryPath:  exe,
		serviceName: "kanholec",
	}
}

func (s *ServiceManager) IsInstalled() bool {
	if runtime.GOOS != "windows" {
		return false
	}
	cmd := exec.Command("sc", "query", s.serviceName)
	err := cmd.Run()
	return err == nil
}

func (s *ServiceManager) Install(configPath string) error {
	if runtime.GOOS != "windows" {
		return fmt.Errorf("service installation is only supported on Windows")
	}

	if s.IsInstalled() {
		return fmt.Errorf("service %q is already installed", s.serviceName)
	}

	args := []string{
		"create", s.serviceName,
		"binPath=", fmt.Sprintf(`"%s" -c "%s"`, s.binaryPath, configPath),
		"DisplayName=", "kanholec - kanhole Client",
		"start=", "auto",
		"obj=", "LocalSystem",
	}

	cmd := exec.Command("sc", args...)
	out, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("failed to install service: %s: %w", string(out), err)
	}

	descArgs := []string{"description", s.serviceName, "kanhole reverse proxy client service"}
	cmd = exec.Command("sc", descArgs...)
	cmd.Run()

	return nil
}

func (s *ServiceManager) Uninstall() error {
	if runtime.GOOS != "windows" {
		return fmt.Errorf("service management is only supported on Windows")
	}

	if !s.IsInstalled() {
		return fmt.Errorf("service %q is not installed", s.serviceName)
	}

	s.Stop()

	cmd := exec.Command("sc", "delete", s.serviceName)
	out, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("failed to uninstall service: %s: %w", string(out), err)
	}
	return nil
}

func (s *ServiceManager) Start() error {
	if runtime.GOOS != "windows" {
		return fmt.Errorf("service management is only supported on Windows")
	}

	cmd := exec.Command("sc", "start", s.serviceName)
	out, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("failed to start service: %s: %w", string(out), err)
	}
	return nil
}

func (s *ServiceManager) Stop() error {
	if runtime.GOOS != "windows" {
		return fmt.Errorf("service management is only supported on Windows")
	}

	cmd := exec.Command("sc", "stop", s.serviceName)
	out, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("failed to stop service: %s: %w", string(out), err)
	}
	return nil
}

func (s *ServiceManager) IsRunning() bool {
	if runtime.GOOS != "windows" {
		return false
	}
	cmd := exec.Command("sc", "query", s.serviceName)
	out, err := cmd.CombinedOutput()
	if err != nil {
		return false
	}
	return contains(string(out), "RUNNING")
}

func (s *ServiceManager) GetConfigPath() string {
	programData := os.Getenv("ProgramData")
	if programData == "" {
		programData = `C:\ProgramData`
	}
	return filepath.Join(programData, "kanholec", "kanholec.toml")
}

func contains(s, substr string) bool {
	return len(s) >= len(substr) && searchString(s, substr)
}

func searchString(s, substr string) bool {
	for i := 0; i <= len(s)-len(substr); i++ {
		if s[i:i+len(substr)] == substr {
			return true
		}
	}
	return false
}