//go:build windows

package installer

import (
	"encoding/json"
	"errors"
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
)

type windowsConfig struct {
	Listen string   `json:"Listen"`
	Allow  []string `json:"Allow"`
}

func Install(opts InstallOptions) error {
	if opts.Listen == "" {
		opts.Listen = "127.0.0.1:8765"
	}

	installDir, err := windowsInstallDir()
	if err != nil {
		return err
	}
	exePath := filepath.Join(installDir, ServiceName+".exe")
	configPath := filepath.Join(installDir, "config.json")

	cfg := windowsConfig{Listen: opts.Listen, Allow: opts.Allow}
	cfgBytes, err := json.MarshalIndent(cfg, "", "  ")
	if err != nil {
		return err
	}

	if opts.DryRun {
		return nil
	}

	if err := os.MkdirAll(installDir, 0o755); err != nil {
		return err
	}
	if err := os.WriteFile(configPath, cfgBytes, 0o644); err != nil {
		return err
	}

	self, err := os.Executable()
	if err != nil {
		return err
	}
	if err := copySelfAtomic(self, exePath, 0o755); err != nil {
		return err
	}

	if err := registerWindowsScheduledTask(exePath, opts.Listen, opts.Allow); err != nil {
		return err
	}
	return nil
}

func Uninstall(opts UninstallOptions) error {
	installDir, err := windowsInstallDir()
	if err != nil {
		return err
	}
	exePath := filepath.Join(installDir, ServiceName+".exe")
	configPath := filepath.Join(installDir, "config.json")

	if opts.DryRun {
		return nil
	}

	_ = unregisterWindowsScheduledTask()

	if opts.KeepConfig {
		_ = os.Remove(exePath)
		// keep directory + config.json
		return nil
	}

	_ = os.Remove(configPath)
	_ = os.Remove(exePath)
	_ = os.RemoveAll(installDir)
	return nil
}

func windowsInstallDir() (string, error) {
	if v := strings.TrimSpace(os.Getenv("LOCALAPPDATA")); v != "" {
		return filepath.Join(v, ServiceName), nil
	}
	home, err := os.UserHomeDir()
	if err != nil {
		return "", err
	}
	// Fallback for older environments.
	return filepath.Join(home, "AppData", "Local", ServiceName), nil
}

func registerWindowsScheduledTask(exePath, listen string, allow []string) error {
	// Use PowerShell scheduled task cmdlets to ensure per-user + interactive logon.
	allowJSON, err := json.Marshal(allow)
	if err != nil {
		return err
	}

	ps := `
param(
	[string]$ExePath,
	[string]$Listen,
	[string]$AllowJson
)
$ErrorActionPreference = 'Stop'
$ServiceName = 'luxtools-client'
$TaskName = $ServiceName

function Quote-Arg([string]$s) {
  if ($null -eq $s) { return '""' }
  if ($s -match '[\s\"]') {
    $escaped = $s -replace '"', '\\"'
    return '"' + $escaped + '"'
  }
  return $s
}

# Stop existing
try { Stop-ScheduledTask -TaskName $TaskName -ErrorAction SilentlyContinue | Out-Null } catch {}
try { schtasks.exe /End /TN $TaskName 2>$null | Out-Null } catch {}

# Build args
$Allow = @()
if ($AllowJson -and $AllowJson.Trim().Length -gt 0) {
  $Allow = (ConvertFrom-Json -InputObject $AllowJson)
}
$argList = @('-listen', $Listen)
foreach ($p in $Allow) {
  if ($p -and $p.ToString().Trim().Length -gt 0) {
    $argList += @('-allow', $p)
  }
}
$argString = ($argList | ForEach-Object { Quote-Arg $_ }) -join ' '

$principalUser = [System.Security.Principal.WindowsIdentity]::GetCurrent().Name
$action = New-ScheduledTaskAction -Execute $ExePath -Argument $argString
$trigger = New-ScheduledTaskTrigger -AtLogOn -User $principalUser
$principal = New-ScheduledTaskPrincipal -UserId $principalUser -LogonType Interactive -RunLevel Limited
$settings = New-ScheduledTaskSettingsSet -RestartCount 3 -RestartInterval (New-TimeSpan -Minutes 1) -AllowStartIfOnBatteries -DontStopIfGoingOnBatteries
$task = New-ScheduledTask -Action $action -Trigger $trigger -Principal $principal -Settings $settings
Register-ScheduledTask -TaskName $TaskName -InputObject $task -Force | Out-Null
try { Start-ScheduledTask -TaskName $TaskName | Out-Null } catch {}
`

	psFile, err := os.CreateTemp("", "luxtools-client-install-*.ps1")
	if err != nil {
		return err
	}
	psPath := psFile.Name()
	if _, err := psFile.WriteString(ps); err != nil {
		_ = psFile.Close()
		_ = os.Remove(psPath)
		return err
	}
	if err := psFile.Close(); err != nil {
		_ = os.Remove(psPath)
		return err
	}
	defer os.Remove(psPath)

	cmd := exec.Command("powershell.exe",
		"-NoProfile",
		"-NonInteractive",
		"-ExecutionPolicy", "Bypass",
		"-File", psPath,
		"-ExePath", exePath,
		"-Listen", listen,
		"-AllowJson", string(allowJSON),
	)
	out, err := cmd.CombinedOutput()
	if err != nil {
		msg := strings.TrimSpace(string(out))
		if msg == "" {
			return err
		}
		return errors.New(msg)
	}
	return nil
}

func unregisterWindowsScheduledTask() error {
	ps := `
$ErrorActionPreference = 'SilentlyContinue'
$TaskName = 'luxtools-client'
try { Stop-ScheduledTask -TaskName $TaskName -ErrorAction SilentlyContinue | Out-Null } catch {}
try { schtasks.exe /End /TN $TaskName 2>$null | Out-Null } catch {}
try { Unregister-ScheduledTask -TaskName $TaskName -Confirm:$false -ErrorAction SilentlyContinue | Out-Null } catch {}
try { schtasks.exe /Delete /TN $TaskName /F 2>$null | Out-Null } catch {}
`
	cmd := exec.Command("powershell.exe", "-NoProfile", "-NonInteractive", "-ExecutionPolicy", "Bypass", "-Command", ps)
	out, err := cmd.CombinedOutput()
	if err != nil {
		msg := strings.TrimSpace(string(out))
		if msg != "" {
			return fmt.Errorf("%s", msg)
		}
		return err
	}
	return nil
}