package main

import (
	"errors"
	"fmt"
	"os"
	"path/filepath"
	"runtime"
	"strings"
)

func (a *App) setOptions(autorun, onBoot bool) error {
	a.mu.Lock()
	defer a.mu.Unlock()
	if onBoot && a.settings.Last == "" {
		return errors.New("connect a profile once before enabling On boot")
	}
	if onBoot != a.settings.OnBoot {
		if err := a.installBoot(onBoot); err != nil {
			return err
		}
	}
	old := a.settings
	a.settings.Autorun = autorun
	a.settings.OnBoot = onBoot
	if err := saveSettings(a.dir, a.settings); err != nil {
		if old.OnBoot != onBoot {
			_ = a.installBoot(old.OnBoot)
		}
		a.settings = old
		return err
	}
	return nil
}
func systemdQuote(s string) string {
	return `"` + strings.NewReplacer(`\`, `\\`, `"`, `\"`, `%`, `%%`, `$`, `$$`, "\n", `\n`, "\r", `\r`).Replace(s) + `"`
}
func (a *App) installBoot(enable bool) error {
	if !admin() {
		return errors.New("On boot requires root / Administrator")
	}
	exe, err := os.Executable()
	if err != nil {
		return err
	}
	exe, err = filepath.EvalSymlinks(exe)
	if err != nil {
		return err
	}
	if runtime.GOOS == "windows" {
		if !enable {
			return command("schtasks", "/Delete", "/TN", "wswg", "/F")
		}
		if strings.ContainsAny(exe+a.dir, "\"\r\n") {
			return errors.New("unsupported path characters")
		}
		return command("schtasks", "/Create", "/TN", "wswg", "/SC", "ONSTART", "/RU", "SYSTEM", "/RL", "HIGHEST", "/TR", fmt.Sprintf(`"%s" --data-dir "%s" -a`, exe, a.dir), "/F")
	}
	if _, err = os.Stat("/run/systemd/system"); err != nil {
		return errors.New("On boot is available only on systems running systemd")
	}
	path := "/etc/systemd/system/wswg.service"
	if !enable {
		if err = command("systemctl", "disable", "wswg.service"); err != nil {
			return err
		}
		if err = os.Remove(path); err != nil && !os.IsNotExist(err) {
			return err
		}
		return command("systemctl", "daemon-reload")
	}
	unit := fmt.Sprintf("[Unit]\nDescription=WireGuard with optional wstunnel\nWants=network-online.target\nAfter=network-online.target\n\n[Service]\nType=simple\nExecStart=%s --data-dir %s -a\nRestart=on-failure\nRestartSec=5\nUMask=0077\n\n[Install]\nWantedBy=multi-user.target\n", systemdQuote(exe), systemdQuote(a.dir))
	if err = os.WriteFile(path, []byte(unit), 0644); err != nil {
		return err
	}
	if err = command("systemctl", "daemon-reload"); err != nil {
		return err
	}
	return command("systemctl", "enable", "wswg.service")
}