refactor(service): 重构用户注册逻辑并新增注销校验

src/main/java/com/yolo/keyborad/common/ErrorCode.java

@@ -85,6 +85,7 @@ public enum ErrorCode {
     REPORT_TYPE_INVALID(40020, "举报类型无效"),
     REPORT_COMPANION_ID_EMPTY(40021, "被举报的AI角色ID不能为空"),
     REPORT_TYPE_EMPTY(40022, "举报类型不能为空"),
+    ACCOUNT_RECENTLY_CANCELLED(50038, "账号注销未满7天，暂不允许注册"),
     VERSION_NOT_FOUND(40022, "未找到可用的版本配置");
 
     /**

src/main/java/com/yolo/keyborad/service/impl/UserServiceImpl.java

@@ -27,6 +27,8 @@ import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
 import java.math.BigDecimal;
+import java.time.Instant;
+import java.time.temporal.ChronoUnit;
 import java.util.Date;
 import com.yolo.keyborad.service.impl.user.UserInviteCodeBinder;
 import com.yolo.keyborad.service.impl.user.UserMailVerificationHandler;
@@ -90,8 +92,26 @@ public class UserServiceImpl extends ServiceImpl<KeyboardUserMapper, KeyboardUse
                 .eq(KeyboardUser::getStatus, false));
     }
 
+    private static final int ACCOUNT_REUSE_COOLDOWN_DAYS = 7;
+
+    private void ensureSubjectIdNotRecentlyCancelled(String sub) {
+        Date cooldownStart = Date.from(Instant.now().minus(ACCOUNT_REUSE_COOLDOWN_DAYS, ChronoUnit.DAYS));
+        KeyboardUser recentlyDeleted = keyboardUserMapper.selectOne(
+                new LambdaQueryWrapper<KeyboardUser>()
+                        .eq(KeyboardUser::getSubjectId, sub)
+                        .eq(KeyboardUser::getDeleted, true)
+                        .gt(KeyboardUser::getDeletedAt, cooldownStart)
+                        .last("LIMIT 1")
+        );
+        if (recentlyDeleted != null) {
+            throw new BusinessException(ErrorCode.ACCOUNT_RECENTLY_CANCELLED);
+        }
+    }
+
     @Override
     public KeyboardUser createUserWithSubjectId(String sub) {
+        ensureSubjectIdNotRecentlyCancelled(sub);
+
         KeyboardUser keyboardUser = buildNewUserWithSubjectId(sub);
         keyboardUserMapper.insert(keyboardUser);
         keyboardCharacterService.addDefaultUserCharacter(keyboardUser.getId());

src/main/java/com/yolo/keyborad/service/impl/user/UserRegistrationHandler.java

@@ -18,6 +18,8 @@ import com.yolo.keyborad.service.KeyboardUserQuotaTotalService;
 import com.yolo.keyborad.service.KeyboardUserWalletService;
 import com.yolo.keyborad.utils.RedisUtil;
 import java.math.BigDecimal;
+import java.time.Instant;
+import java.time.temporal.ChronoUnit;
 import java.util.Date;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.security.crypto.password.PasswordEncoder;
@@ -33,6 +35,7 @@ import org.springframework.transaction.annotation.Transactional;
 public class UserRegistrationHandler {
 
     private static final String USER_CODE_PREFIX = "user:";
+    private static final int ACCOUNT_REUSE_COOLDOWN_DAYS = 7;
 
     private final KeyboardUserMapper keyboardUserMapper;
     private final PasswordEncoder passwordEncoder;
@@ -91,6 +94,24 @@ public class UserRegistrationHandler {
         if (userMail != null) {
             throw new BusinessException(ErrorCode.USER_HAS_EXISTED);
         }
+
+        ensureNotRecentlyCancelled(
+                new LambdaQueryWrapper<KeyboardUser>()
+                        .eq(KeyboardUser::getEmail, mailAddress)
+        );
+    }
+
+    private void ensureNotRecentlyCancelled(LambdaQueryWrapper<KeyboardUser> baseQuery) {
+        Date cooldownStart = Date.from(Instant.now().minus(ACCOUNT_REUSE_COOLDOWN_DAYS, ChronoUnit.DAYS));
+        KeyboardUser recentlyDeleted = keyboardUserMapper.selectOne(
+                baseQuery
+                        .eq(KeyboardUser::getDeleted, true)
+                        .gt(KeyboardUser::getDeletedAt, cooldownStart)
+                        .last("LIMIT 1")
+        );
+        if (recentlyDeleted != null) {
+            throw new BusinessException(ErrorCode.ACCOUNT_RECENTLY_CANCELLED);
+        }
     }
 
     private void validatePasswords(UserRegisterDTO userRegisterDTO) {