2

app.go

@@ -24,6 +24,8 @@ type CommandRunner interface {
 	Run(name string, args ...string) error
 }
 
+type LookPathFunc func(file string) (string, error)
+
 type RealUserManager struct{}
 
 func (RealUserManager) UserExists(name string) bool {
@@ -49,14 +51,18 @@ func (OSCommandRunner) Run(name string, args ...string) error {
 type App struct {
 	configPath string
 	users      UserManager
+	runner     CommandRunner
+	lookPath   LookPathFunc
 	reader     *bufio.Reader
 	writer     *bufio.Writer
 }
 
-func NewApp(configPath string, users UserManager) *App {
+func NewApp(configPath string, users UserManager, runner CommandRunner, lookPath LookPathFunc) *App {
 	return &App{
 		configPath: configPath,
 		users:      users,
+		runner:     runner,
+		lookPath:   lookPath,
 		reader:     bufio.NewReader(os.Stdin),
 		writer:     bufio.NewWriter(os.Stdout),
 	}
@@ -65,9 +71,17 @@ func NewApp(configPath string, users UserManager) *App {
 func (a *App) Run() error {
 	doc, err := ParseConfigFile(a.configPath)
 	if err != nil {
+		if os.IsNotExist(err) {
+			doc, err = a.handleMissingConfig()
+			if err == nil {
+				goto loaded
+			}
+		}
+
 		return fmt.Errorf("read config: %w", err)
 	}
 
+loaded:
 	for {
 		shareSections := doc.ShareSections()
 		a.println("")
@@ -118,6 +132,47 @@ func (a *App) Run() error {
 	}
 }
 
+func (a *App) handleMissingConfig() (*Document, error) {
+	a.println("")
+	a.println("Samba is not set up yet on this computer.")
+	a.printf("I couldn't find the Samba config file at %s.\n", a.configPath)
+
+	plan, ok := DetectSambaInstallPlan(a.lookPath, os.Geteuid() == 0)
+	if !ok {
+		a.println("I also couldn't find a supported package manager automatically.")
+		a.println("Install the Samba server package for your Linux distribution, then run this tool again.")
+		a.flush()
+		return nil, os.ErrNotExist
+	}
+
+	a.println("")
+	a.printf("I found %s and can try to install the Samba server for you.\n", plan.ManagerName)
+	a.printf("This would run: %s\n", plan.DisplayCommand())
+	a.println("You may be asked for your administrator password.")
+	a.flush()
+
+	install, err := a.confirm("Install Samba server now", true)
+	if err != nil {
+		return nil, err
+	}
+	if !install {
+		return nil, os.ErrNotExist
+	}
+
+	if err := a.runner.Run(plan.Command[0], plan.Command[1:]...); err != nil {
+		return nil, fmt.Errorf("install Samba with %s: %w", plan.ManagerName, err)
+	}
+
+	doc, err := ParseConfigFile(a.configPath)
+	if err != nil {
+		return nil, fmt.Errorf("Samba installation finished, but the config file is still missing at %s: %w", a.configPath, err)
+	}
+
+	a.println("Samba was installed and the config file is now available.")
+	a.flush()
+	return doc, nil
+}
+
 func (a *App) addShare(doc *Document) error {
 	cfg, err := a.collectShareConfig(ShareConfig{})
 	if err != nil {