feat: invitation accept screen and api

internal/infrastructure/useCases/GetInvite.go

@@ -0,0 +1,41 @@
+package useCases
+
+import (
+	"RenewCMS/internal/domain/hash"
+	"RenewCMS/internal/domain/invite"
+	"time"
+)
+
+type GetInviteUseCase struct {
+	inviteRepository invite.Repository
+	hasher           hash.Hasher
+}
+
+func NewGetInviteUseCase(inviteRepository invite.Repository, hasher hash.Hasher) *GetInviteUseCase {
+	return &GetInviteUseCase{inviteRepository, hasher}
+}
+
+func (g *GetInviteUseCase) GetInvite(code string) (invite.Invite, error) {
+	return findUsableInvite(g.inviteRepository, g.hasher, code, time.Now())
+}
+
+func findUsableInvite(inviteRepository invite.Repository, hasher hash.Hasher, code string, now time.Time) (invite.Invite, error) {
+	if code == "" {
+		return invite.Invite{}, invite.ErrInviteInvalid
+	}
+
+	for _, candidate := range inviteRepository.GetAll() {
+		if candidate.AcceptedAt != nil {
+			continue
+		}
+		if hasher.Compare(candidate.HashedCode, code) != nil {
+			continue
+		}
+		if candidate.StatusAt(now) == invite.StatusExpired {
+			return invite.Invite{}, invite.ErrInviteExpired
+		}
+		return candidate, nil
+	}
+
+	return invite.Invite{}, invite.ErrInviteInvalid
+}