feat: authsession service

authsession/internal/domain/userresolution/model.go

@@ -0,0 +1,110 @@
+// Package userresolution defines the domain result returned by the user
+// resolution boundary before session creation.
+package userresolution
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"galaxy/authsession/internal/domain/common"
+)
+
+// Kind identifies the coarse user-resolution result for one normalized e-mail.
+type Kind string
+
+const (
+	// KindExisting reports that the e-mail belongs to an existing user.
+	KindExisting Kind = "existing"
+
+	// KindCreatable reports that the e-mail is free and user creation is
+	// allowed.
+	KindCreatable Kind = "creatable"
+
+	// KindBlocked reports that the e-mail or subject is blocked from login or
+	// registration.
+	KindBlocked Kind = "blocked"
+)
+
+// IsKnown reports whether Kind is one of the user-resolution kinds supported
+// by the current domain model.
+func (k Kind) IsKnown() bool {
+	switch k {
+	case KindExisting, KindCreatable, KindBlocked:
+		return true
+	default:
+		return false
+	}
+}
+
+// BlockReasonCode stores one machine-readable user-block reason.
+type BlockReasonCode string
+
+// String returns BlockReasonCode as its stored code value.
+func (code BlockReasonCode) String() string {
+	return string(code)
+}
+
+// IsZero reports whether BlockReasonCode is empty.
+func (code BlockReasonCode) IsZero() bool {
+	return strings.TrimSpace(string(code)) == ""
+}
+
+// Validate reports whether BlockReasonCode is non-empty and normalized for
+// domain use.
+func (code BlockReasonCode) Validate() error {
+	switch {
+	case code.IsZero():
+		return errors.New("block reason code must not be empty")
+	case strings.TrimSpace(string(code)) != string(code):
+		return errors.New("block reason code must not contain surrounding whitespace")
+	default:
+		return nil
+	}
+}
+
+// Result stores the coarse user-resolution outcome consumed by later auth
+// workflow stages.
+type Result struct {
+	// Kind reports the coarse resolution outcome.
+	Kind Kind
+
+	// UserID is set only when Kind is KindExisting.
+	UserID common.UserID
+
+	// BlockReasonCode is set only when Kind is KindBlocked.
+	BlockReasonCode BlockReasonCode
+}
+
+// Validate reports whether Result satisfies the Stage-2 structural invariants.
+func (r Result) Validate() error {
+	if !r.Kind.IsKnown() {
+		return fmt.Errorf("user resolution kind %q is unsupported", r.Kind)
+	}
+
+	switch r.Kind {
+	case KindExisting:
+		if err := r.UserID.Validate(); err != nil {
+			return fmt.Errorf("user resolution user id: %w", err)
+		}
+		if !r.BlockReasonCode.IsZero() {
+			return errors.New("existing user resolution must not contain block reason code")
+		}
+	case KindCreatable:
+		if !r.UserID.IsZero() {
+			return errors.New("creatable user resolution must not contain user id")
+		}
+		if !r.BlockReasonCode.IsZero() {
+			return errors.New("creatable user resolution must not contain block reason code")
+		}
+	case KindBlocked:
+		if !r.UserID.IsZero() {
+			return errors.New("blocked user resolution must not contain user id")
+		}
+		if err := r.BlockReasonCode.Validate(); err != nil {
+			return fmt.Errorf("user resolution block reason code: %w", err)
+		}
+	}
+
+	return nil
+}

authsession/internal/domain/userresolution/model_test.go

@@ -0,0 +1,113 @@
+package userresolution
+
+import (
+	"github.com/stretchr/testify/require"
+	"testing"
+
+	"galaxy/authsession/internal/domain/common"
+)
+
+func TestKindIsKnown(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name  string
+		value Kind
+		want  bool
+	}{
+		{name: "existing", value: KindExisting, want: true},
+		{name: "creatable", value: KindCreatable, want: true},
+		{name: "blocked", value: KindBlocked, want: true},
+		{name: "unknown", value: Kind("unknown"), want: false},
+	}
+
+	for _, tt := range tests {
+		tt := tt
+
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			if got := tt.value.IsKnown(); got != tt.want {
+				require.Failf(t, "test failed", "IsKnown() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestResultValidate(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name    string
+		value   Result
+		wantErr bool
+	}{
+		{
+			name: "existing valid",
+			value: Result{
+				Kind:   KindExisting,
+				UserID: common.UserID("user-123"),
+			},
+		},
+		{
+			name: "creatable valid",
+			value: Result{
+				Kind: KindCreatable,
+			},
+		},
+		{
+			name: "blocked valid",
+			value: Result{
+				Kind:            KindBlocked,
+				BlockReasonCode: BlockReasonCode("policy_blocked"),
+			},
+		},
+		{
+			name: "existing requires user id",
+			value: Result{
+				Kind: KindExisting,
+			},
+			wantErr: true,
+		},
+		{
+			name: "creatable rejects user id",
+			value: Result{
+				Kind:   KindCreatable,
+				UserID: common.UserID("user-123"),
+			},
+			wantErr: true,
+		},
+		{
+			name: "blocked requires reason",
+			value: Result{
+				Kind: KindBlocked,
+			},
+			wantErr: true,
+		},
+		{
+			name: "blocked rejects user id",
+			value: Result{
+				Kind:            KindBlocked,
+				UserID:          common.UserID("user-123"),
+				BlockReasonCode: BlockReasonCode("policy_blocked"),
+			},
+			wantErr: true,
+		},
+	}
+
+	for _, tt := range tests {
+		tt := tt
+
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			err := tt.value.Validate()
+			if tt.wantErr && err == nil {
+				require.FailNow(t, "Validate() returned nil error")
+			}
+			if !tt.wantErr && err != nil {
+				require.Failf(t, "test failed", "Validate() returned error: %v", err)
+			}
+		})
+	}
+}