Add password generation UI profile workflow

passwords/generator.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"math/big"
+	"slices"
 	"strings"
 )
 
@@ -16,6 +17,7 @@ const (
 )
 
 var ErrImpossibleProfile = errors.New("impossible password profile")
+var ErrUnknownProfile = errors.New("unknown password profile")
 
 type Profile struct {
 	Name           string
@@ -61,6 +63,31 @@ func DefaultProfiles() map[string]Profile {
 	}
 }
 
+func DefaultProfileNames() []string {
+	return ProfileNames(DefaultProfiles())
+}
+
+func LookupProfile(name string, profiles map[string]Profile) (Profile, error) {
+	profile, ok := profiles[strings.TrimSpace(name)]
+	if !ok {
+		return Profile{}, fmt.Errorf("%w %q", ErrUnknownProfile, strings.TrimSpace(name))
+	}
+	return profile, nil
+}
+
+func LookupDefaultProfile(name string) (Profile, error) {
+	return LookupProfile(name, DefaultProfiles())
+}
+
+func ProfileNames(profiles map[string]Profile) []string {
+	names := make([]string, 0, len(profiles))
+	for name := range profiles {
+		names = append(names, name)
+	}
+	slices.Sort(names)
+	return names
+}
+
 func Generate(profile Profile) (string, error) {
 	if err := validateProfile(profile); err != nil {
 		return "", err

passwords/generator_test.go

@@ -1,6 +1,8 @@
 package passwords
 
 import (
+	"errors"
+	"slices"
 	"strings"
 	"testing"
 )
@@ -9,17 +11,17 @@ func TestGenerateRespectsProfileRequirements(t *testing.T) {
 	t.Parallel()
 
 	profile := Profile{
-		Name:            "strong",
-		Length:          24,
-		Lowercase:       true,
-		Uppercase:       true,
-		Digits:          true,
-		Symbols:         true,
-		MinLowercase:    2,
-		MinUppercase:    2,
-		MinDigits:       2,
-		MinSymbols:      2,
-		ExcludeSimilar:  true,
+		Name:           "strong",
+		Length:         24,
+		Lowercase:      true,
+		Uppercase:      true,
+		Digits:         true,
+		Symbols:        true,
+		MinLowercase:   2,
+		MinUppercase:   2,
+		MinDigits:      2,
+		MinSymbols:     2,
+		ExcludeSimilar: true,
 	}
 
 	password, err := Generate(profile)
@@ -86,6 +88,33 @@ func TestProfileSetReturnsNamedProfiles(t *testing.T) {
 	}
 }
 
+func TestDefaultProfileNamesReturnsSortedNames(t *testing.T) {
+	t.Parallel()
+
+	got := DefaultProfileNames()
+	want := []string{"memorable", "strong"}
+	if !slices.Equal(got, want) {
+		t.Fatalf("DefaultProfileNames() = %v, want %v", got, want)
+	}
+}
+
+func TestLookupDefaultProfileResolvesKnownProfilesAndRejectsUnknownNames(t *testing.T) {
+	t.Parallel()
+
+	profile, err := LookupDefaultProfile(" strong ")
+	if err != nil {
+		t.Fatalf("LookupDefaultProfile(\" strong \") error = %v", err)
+	}
+	if profile.Name != "strong" {
+		t.Fatalf("LookupDefaultProfile(\" strong \").Name = %q, want %q", profile.Name, "strong")
+	}
+
+	_, err = LookupDefaultProfile("invalid")
+	if !errors.Is(err, ErrUnknownProfile) {
+		t.Fatalf("LookupDefaultProfile(\"invalid\") error = %v, want ErrUnknownProfile", err)
+	}
+}
+
 func countFromSet(password, chars string) int {
 	count := 0
 	for _, r := range password {