feat: game lobby service

lobby/internal/domain/common/ids.go

@@ -0,0 +1,123 @@
+package common
+
+import (
+	"fmt"
+	"strings"
+)
+
+// gameIDPrefix is the mandatory opaque-identifier prefix for one Game Lobby
+// game record.
+const gameIDPrefix = "game-"
+
+// applicationIDPrefix is the mandatory opaque-identifier prefix for one
+// Game Lobby application record.
+const applicationIDPrefix = "application-"
+
+// inviteIDPrefix is the mandatory opaque-identifier prefix for one Game
+// Lobby invite record.
+const inviteIDPrefix = "invite-"
+
+// membershipIDPrefix is the mandatory opaque-identifier prefix for one
+// Game Lobby membership record.
+const membershipIDPrefix = "membership-"
+
+// GameID identifies one game record owned by Game Lobby Service. The value
+// is opaque and stable; only its `game-*` prefix is observable to callers.
+type GameID string
+
+// String returns GameID as its stored identifier string.
+func (id GameID) String() string {
+	return string(id)
+}
+
+// IsZero reports whether GameID does not contain a usable value.
+func (id GameID) IsZero() bool {
+	return strings.TrimSpace(string(id)) == ""
+}
+
+// Validate reports whether GameID is non-empty, already trimmed, and carries
+// the frozen `game-*` opaque prefix.
+func (id GameID) Validate() error {
+	return validatePrefixedID("game id", string(id), gameIDPrefix)
+}
+
+// ApplicationID identifies one application record owned by Game Lobby
+// Service. The value is opaque and stable; only its `application-*` prefix
+// is observable to callers.
+type ApplicationID string
+
+// String returns ApplicationID as its stored identifier string.
+func (id ApplicationID) String() string {
+	return string(id)
+}
+
+// IsZero reports whether ApplicationID does not contain a usable value.
+func (id ApplicationID) IsZero() bool {
+	return strings.TrimSpace(string(id)) == ""
+}
+
+// Validate reports whether ApplicationID is non-empty, already trimmed, and
+// carries the frozen `application-*` opaque prefix.
+func (id ApplicationID) Validate() error {
+	return validatePrefixedID("application id", string(id), applicationIDPrefix)
+}
+
+// InviteID identifies one invite record owned by Game Lobby Service. The
+// value is opaque and stable; only its `invite-*` prefix is observable to
+// callers.
+type InviteID string
+
+// String returns InviteID as its stored identifier string.
+func (id InviteID) String() string {
+	return string(id)
+}
+
+// IsZero reports whether InviteID does not contain a usable value.
+func (id InviteID) IsZero() bool {
+	return strings.TrimSpace(string(id)) == ""
+}
+
+// Validate reports whether InviteID is non-empty, already trimmed, and
+// carries the frozen `invite-*` opaque prefix.
+func (id InviteID) Validate() error {
+	return validatePrefixedID("invite id", string(id), inviteIDPrefix)
+}
+
+// MembershipID identifies one membership record owned by Game Lobby
+// Service. The value is opaque and stable; only its `membership-*` prefix
+// is observable to callers.
+type MembershipID string
+
+// String returns MembershipID as its stored identifier string.
+func (id MembershipID) String() string {
+	return string(id)
+}
+
+// IsZero reports whether MembershipID does not contain a usable value.
+func (id MembershipID) IsZero() bool {
+	return strings.TrimSpace(string(id)) == ""
+}
+
+// Validate reports whether MembershipID is non-empty, already trimmed, and
+// carries the frozen `membership-*` opaque prefix.
+func (id MembershipID) Validate() error {
+	return validatePrefixedID("membership id", string(id), membershipIDPrefix)
+}
+
+// validatePrefixedID reports whether raw is a non-empty, trimmed identifier
+// with the given opaque prefix and a non-empty suffix. The label is used to
+// format error messages.
+func validatePrefixedID(label, raw, prefix string) error {
+	switch {
+	case strings.TrimSpace(raw) == "":
+		return fmt.Errorf("%s must not be empty", label)
+	case strings.TrimSpace(raw) != raw:
+		return fmt.Errorf("%s must not contain surrounding whitespace", label)
+	case !strings.HasPrefix(raw, prefix):
+		return fmt.Errorf("%s must start with %q", label, prefix)
+	case len(raw) == len(prefix):
+		return fmt.Errorf("%s must carry a non-empty suffix after %q", label, prefix)
+	default:
+		return nil
+	}
+}

lobby/internal/domain/common/types.go

@@ -0,0 +1,8 @@
+// Package common defines shared value objects used across the Game Lobby
+// Service domain model.
+//
+// The package exposes the opaque identifier types used by the game,
+// application, invite, and membership entities. Each identifier validates
+// its own frozen prefix and rejects surrounding whitespace so higher-level
+// domains can trust the value without re-checking.
+package common