chore(tui): validate profile name (#97)

## What does this PR do?

Adds profile name validation.

Author: fiffeek

internal/tui/profile_name_picker.go

@@ -3,6 +3,7 @@ package tui
 import (
 	"errors"
 	"fmt"
+	"regexp"
 
 	"github.com/charmbracelet/bubbles/help"
 	"github.com/charmbracelet/bubbles/key"
@@ -65,6 +66,28 @@ func (p *ProfileNamePicker) SetHeight(height int) {
 	p.height = height
 }
 
+// validateProfileName validates the profile name
+func validateProfileName(name string) error {
+	if name == "" {
+		return errors.New("profile name cannot be empty")
+	}
+
+	if len(name) > 50 {
+		return errors.New("profile name must be 50 characters or less")
+	}
+
+	if (name[0] < 'a' || name[0] > 'z') && (name[0] < 'A' || name[0] > 'Z') {
+		return errors.New("profile name must start with a letter")
+	}
+
+	validName := regexp.MustCompile(`^[a-zA-Z][a-zA-Z0-9_-]*$`)
+	if !validName.MatchString(name) {
+		return errors.New("profile name can only contain letters, numbers, hyphens, and underscores")
+	}
+
+	return nil
+}
+
 func (p *ProfileNamePicker) Update(msg tea.Msg) tea.Cmd {
 	cmds := []tea.Cmd{}
 	// nolint:gocritic
@@ -75,10 +98,8 @@ func (p *ProfileNamePicker) Update(msg tea.Msg) tea.Cmd {
 			cmds = append(cmds, profileNameToogled())
 		case key.Matches(msg, p.keyMap.Create):
 			text := p.textInput.Value()
-			// todo validate profile name, no spaces etc, check other profiles here from cfg
-			if text == "" {
-				cmds = append(cmds, OperationStatusCmd(OperationNameCreateProfile,
-					errors.New("cant create empty name profile")))
+			if err := validateProfileName(text); err != nil {
+				cmds = append(cmds, OperationStatusCmd(OperationNameCreateProfile, err))
 			} else {
 				p.textInput.SetValue("")
 				logrus.Debugf("Setting name to: %s", text)

internal/tui/profile_name_picker_test.go

@@ -0,0 +1,123 @@
+package tui
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestValidateProfileName(t *testing.T) {
+	tests := []struct {
+		name        string
+		profileName string
+		wantErr     bool
+		errContains string
+	}{
+		{
+			name:        "valid lowercase",
+			profileName: "home",
+			wantErr:     false,
+		},
+		{
+			name:        "valid with numbers",
+			profileName: "office2",
+			wantErr:     false,
+		},
+		{
+			name:        "valid with hyphens",
+			profileName: "home-office",
+			wantErr:     false,
+		},
+		{
+			name:        "valid with underscores",
+			profileName: "home_office",
+			wantErr:     false,
+		},
+		{
+			name:        "valid complex",
+			profileName: "my-profile_123",
+			wantErr:     false,
+		},
+		{
+			name:        "valid starts with uppercase",
+			profileName: "Home",
+			wantErr:     false,
+		},
+		{
+			name:        "valid all uppercase",
+			profileName: "HOME",
+			wantErr:     false,
+		},
+		{
+			name:        "valid camelCase",
+			profileName: "homeOffice",
+			wantErr:     false,
+		},
+		{
+			name:        "valid PascalCase",
+			profileName: "HomeOffice",
+			wantErr:     false,
+		},
+		{
+			name:        "valid mixed case with numbers",
+			profileName: "MyProfile123",
+			wantErr:     false,
+		},
+		{
+			name:        "empty string",
+			profileName: "",
+			wantErr:     true,
+			errContains: "cannot be empty",
+		},
+		{
+			name:        "starts with number",
+			profileName: "1home",
+			wantErr:     true,
+			errContains: "must start with a letter",
+		},
+		{
+			name:        "contains space",
+			profileName: "home office",
+			wantErr:     true,
+			errContains: "letters, numbers, hyphens, and underscores",
+		},
+		{
+			name:        "contains special characters",
+			profileName: "home@office",
+			wantErr:     true,
+			errContains: "letters, numbers, hyphens, and underscores",
+		},
+		{
+			name:        "too long",
+			profileName: "this_is_a_very_long_profile_name_that_exceeds_the_maximum_allowed_length",
+			wantErr:     true,
+			errContains: "must be 50 characters or less",
+		},
+		{
+			name:        "starts with hyphen",
+			profileName: "-home",
+			wantErr:     true,
+			errContains: "must start with a letter",
+		},
+		{
+			name:        "starts with underscore",
+			profileName: "_home",
+			wantErr:     true,
+			errContains: "must start with a letter",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := validateProfileName(tt.profileName)
+			if tt.wantErr {
+				assert.Error(t, err)
+				if tt.errContains != "" {
+					assert.Contains(t, err.Error(), tt.errContains)
+				}
+			} else {
+				assert.NoError(t, err)
+			}
+		})
+	}
+}