add profile manager with error handling for profile operations

client/internal/profilemanager/error.go

@@ -0,0 +1,8 @@
+package profilemanager
+
+import "errors"
+
+var (
+	ErrProfileNotFound      = errors.New("profile not found")
+	ErrProfileAlreadyExists = errors.New("profile already exists")
+)

client/internal/profilemanager/profilemanager.go

@@ -0,0 +1,69 @@
+package profilemanager
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/netbirdio/netbird/util"
+)
+
+type Profile struct {
+	Name  string
+	Email string
+}
+
+type ProfileManager struct {
+}
+
+func NewProfileManager() *ProfileManager {
+	return &ProfileManager{}
+}
+
+func (pm *ProfileManager) AddProfile(profile Profile) error {
+	configDir, err := getConfigDir()
+	if err != nil {
+		return fmt.Errorf("failed to get config directory: %w", err)
+	}
+
+	profPath := filepath.Join(configDir, profile.Name+".json")
+	if fileExists(profPath) {
+		return ErrProfileAlreadyExists
+	}
+
+}
+
+func getConfigDir() (string, error) {
+	configDir, err := os.UserConfigDir()
+	if err != nil {
+		return "", err
+	}
+
+	configDir = filepath.Join(configDir, "netbird")
+	if _, err := os.Stat(configDir); os.IsNotExist(err) {
+		if err := os.MkdirAll(configDir, 0755); err != nil {
+			return "", err
+		}
+	}
+
+	return configDir, nil
+}
+
+func fileExists(path string) bool {
+	_, err := os.Stat(path)
+	return !os.IsNotExist(err)
+}
+
+// createNewConfig creates a new config generating a new Wireguard key and saving to file
+func createNewConfig(input ConfigInput) (*Config, error) {
+	config := &Config{
+		// defaults to false only for new (post 0.26) configurations
+		ServerSSHAllowed: util.False(),
+	}
+
+	if _, err := config.apply(input); err != nil {
+		return nil, err
+	}
+
+	return config, nil
+}