feat(purchase): 新增主题购买全流程接口

新增主题购买功能，包括余额校验、订单生成、交易记录等完整流程。同时扩展错误码支持余额不足、主题不存在等场景。

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

@@ -46,7 +46,11 @@ public enum ErrorCode {
     REPEATEDLY_ADDING_CHARACTER(50009, "重复添加键盘人设"),
     MAIL_SEND_BUSY(50010,"邮件发送频繁，1分钟后再试" ),
     PASSWORD_CAN_NOT_NULL(50011, "密码不能为空" ),
-    USER_HAS_EXISTED(50012, "用户已存在" );
+    USER_HAS_EXISTED(50012, "用户已存在" ),
+    INSUFFICIENT_BALANCE(50013, "余额不足"),
+    THEME_NOT_FOUND(40410, "主题不存在"),
+    THEME_ALREADY_PURCHASED(50014, "主题已购买"),
+    THEME_NOT_AVAILABLE(50015, "主题不可购买");
     /**
      * 状态码
      */

src/main/java/com/yolo/keyborad/config/SaTokenConfigure.java

@@ -87,7 +87,8 @@ public class SaTokenConfigure implements WebMvcConfigurer {
                 "/chat/talk",
                 "/chat/save_embed",
                 "/themes/listByStyle",
-                "/wallet/balance"
+                "/wallet/balance",
+                "/themes/purchase"
         };
     }
     @Bean

src/main/java/com/yolo/keyborad/controller/ThemesController.java

@@ -1,19 +1,20 @@
 package com.yolo.keyborad.controller;
 
+import cn.dev33.satoken.stp.StpUtil;
 import com.yolo.keyborad.common.BaseResponse;
 import com.yolo.keyborad.common.ResultUtils;
+import com.yolo.keyborad.model.dto.purchase.ThemePurchaseReq;
+import com.yolo.keyborad.model.vo.purchase.ThemePurchaseRespVO;
 import com.yolo.keyborad.model.vo.themes.KeyboardThemeStylesRespVO;
 import com.yolo.keyborad.model.vo.themes.KeyboardThemesRespVO;
+import com.yolo.keyborad.service.KeyboardThemePurchaseService;
 import com.yolo.keyborad.service.KeyboardThemeStylesService;
 import com.yolo.keyborad.service.KeyboardThemesService;
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.tags.Tag;
 import jakarta.annotation.Resource;
 import lombok.extern.slf4j.Slf4j;
-import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.*;
-import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RequestParam;
-import org.springframework.web.bind.annotation.RestController;
 
 import java.util.List;
 
@@ -33,6 +34,9 @@ public class ThemesController {
     @Resource
     private KeyboardThemeStylesService keyboardThemeStylesService;
 
+    @Resource
+    private KeyboardThemePurchaseService themePurchaseService;
+
 
     @GetMapping("/listByStyle")
     @Operation(summary = "按风格查询主题", description = "按主题风格查询主题列表接口")
@@ -46,5 +50,12 @@ public class ThemesController {
         return ResultUtils.success(keyboardThemeStylesService.selectAllThemeStyles());
     }
 
+    @PostMapping("/purchase")
+    @Operation(summary = "购买主题", description = "购买主题接口，扣减用户余额")
+    public BaseResponse<ThemePurchaseRespVO> purchaseTheme(@RequestBody ThemePurchaseReq req) {
+        Long userId = StpUtil.getLoginIdAsLong();
+        ThemePurchaseRespVO result = themePurchaseService.purchaseTheme(userId, req.getThemeId());
+        return ResultUtils.success(result);
+    }
 
 }

src/main/java/com/yolo/keyborad/model/dto/purchase/ThemePurchaseReq.java

@@ -0,0 +1,14 @@
+package com.yolo.keyborad.model.dto.purchase;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+import lombok.Data;
+
+/**
+ * 主题购买请求
+ */
+@Data
+public class ThemePurchaseReq {
+
+    @Schema(description = "主题ID")
+    private Long themeId;
+}

src/main/java/com/yolo/keyborad/model/vo/purchase/ThemePurchaseRespVO.java

@@ -0,0 +1,26 @@
+package com.yolo.keyborad.model.vo.purchase;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+import lombok.Data;
+
+import java.math.BigDecimal;
+
+/**
+ * 主题购买响应
+ */
+@Schema(description = "主题购买响应")
+@Data
+public class ThemePurchaseRespVO {
+
+    @Schema(description = "订单号")
+    private String orderNo;
+
+    @Schema(description = "主题ID")
+    private Long themeId;
+
+    @Schema(description = "支付金额")
+    private BigDecimal paidAmount;
+
+    @Schema(description = "剩余余额")
+    private BigDecimal remainingBalance;
+}

src/main/java/com/yolo/keyborad/service/KeyboardThemePurchaseService.java

@@ -2,6 +2,7 @@ package com.yolo.keyborad.service;
 
 import com.yolo.keyborad.model.entity.KeyboardThemePurchase;
 import com.baomidou.mybatisplus.extension.service.IService;
+import com.yolo.keyborad.model.vo.purchase.ThemePurchaseRespVO;
     /*
 * @author: ziin
 * @date: 2025/12/10 19:17
@@ -9,5 +10,8 @@ import com.baomidou.mybatisplus.extension.service.IService;
 
 public interface KeyboardThemePurchaseService extends IService<KeyboardThemePurchase>{
 
-
+    /**
+     * 购买主题
+     */
+    ThemePurchaseRespVO purchaseTheme(Long userId, Long themeId);
 }

src/main/java/com/yolo/keyborad/service/KeyboardWalletTransactionService.java

@@ -2,6 +2,9 @@ package com.yolo.keyborad.service;
 
 import com.yolo.keyborad.model.entity.KeyboardWalletTransaction;
 import com.baomidou.mybatisplus.extension.service.IService;
+
+import java.math.BigDecimal;
+
     /*
 * @author: ziin
 * @date: 2025/12/10 18:54
@@ -9,5 +12,10 @@ import com.baomidou.mybatisplus.extension.service.IService;
 
 public interface KeyboardWalletTransactionService extends IService<KeyboardWalletTransaction>{
 
-
+    /**
+     * 创建钱包交易记录
+     */
+    KeyboardWalletTransaction createTransaction(Long userId, Long orderId, BigDecimal amount,
+                                                Short type, BigDecimal beforeBalance,
+                                                BigDecimal afterBalance, String description);
 }

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

@@ -1,8 +1,22 @@
 package com.yolo.keyborad.service.impl;
 
+import com.yolo.keyborad.common.ErrorCode;
+import com.yolo.keyborad.exception.BusinessException;
+import com.yolo.keyborad.model.entity.KeyboardThemes;
+import com.yolo.keyborad.model.entity.KeyboardUserWallet;
+import com.yolo.keyborad.model.entity.KeyboardWalletTransaction;
+import com.yolo.keyborad.model.vo.purchase.ThemePurchaseRespVO;
+import com.yolo.keyborad.service.KeyboardThemesService;
+import com.yolo.keyborad.service.KeyboardUserWalletService;
+import com.yolo.keyborad.service.KeyboardWalletTransactionService;
 import org.springframework.stereotype.Service;
 import org.springframework.beans.factory.annotation.Autowired;
-import java.util.List;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.math.BigDecimal;
+import java.util.Date;
+import java.util.UUID;
+
 import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
 import com.yolo.keyborad.model.entity.KeyboardThemePurchase;
 import com.yolo.keyborad.mapper.KeyboardThemePurchaseMapper;
@@ -15,4 +29,116 @@ import com.yolo.keyborad.service.KeyboardThemePurchaseService;
 @Service
 public class KeyboardThemePurchaseServiceImpl extends ServiceImpl<KeyboardThemePurchaseMapper, KeyboardThemePurchase> implements KeyboardThemePurchaseService{
 
+    @Autowired
+    private KeyboardThemesService themesService;
+
+    @Autowired
+    private KeyboardUserWalletService walletService;
+
+    @Autowired
+    private KeyboardWalletTransactionService transactionService;
+
+    @Override
+    @Transactional(rollbackFor = Exception.class)
+    public ThemePurchaseRespVO purchaseTheme(Long userId, Long themeId) {
+        // 1. 验证主题是否存在且可购买
+        // 从数据库获取主题信息
+        KeyboardThemes theme = themesService.getById(themeId);
+        // 检查主题是否存在或已被删除
+        if (theme == null || theme.getDeleted()) {
+            throw new BusinessException(ErrorCode.THEME_NOT_FOUND);
+        }
+        // 检查主题状态是否可用（上架状态）
+        if (!theme.getThemeStatus()) {
+            throw new BusinessException(ErrorCode.THEME_NOT_AVAILABLE);
+        }
+
+        // 2. 检查是否已购买
+        // 查询用户是否已经购买过该主题（支付状态为1表示已支付）
+        Long purchaseCount = this.lambdaQuery()
+                .eq(KeyboardThemePurchase::getUserId, userId)
+                .eq(KeyboardThemePurchase::getThemeId, themeId)
+                .eq(KeyboardThemePurchase::getPayStatus, (short) 1)
+                .count();
+        // 如果已购买，抛出异常
+        if (purchaseCount > 0) {
+            throw new BusinessException(ErrorCode.THEME_ALREADY_PURCHASED);
+        }
+
+        // 3. 获取用户钱包
+        // 查询用户钱包信息
+        KeyboardUserWallet wallet = walletService.lambdaQuery()
+                .eq(KeyboardUserWallet::getUserId, userId)
+                .one();
+        // 如果钱包不存在，抛出余额不足异常
+        if (wallet == null) {
+            throw new BusinessException(ErrorCode.INSUFFICIENT_BALANCE);
+        }
+
+        // 4. 检查余额是否充足
+        // 获取主题价格
+        BigDecimal themePrice = theme.getThemePrice();
+        // 比较钱包余额和主题价格，余额不足则抛出异常
+        if (wallet.getBalance().compareTo(themePrice) < 0) {
+            throw new BusinessException(ErrorCode.INSUFFICIENT_BALANCE);
+        }
+
+        // 5. 扣减余额（使用乐观锁）
+        // 记录扣款前余额
+        BigDecimal beforeBalance = wallet.getBalance();
+        // 计算扣款后余额
+        BigDecimal afterBalance = beforeBalance.subtract(themePrice);
+        // 更新钱包余额
+        wallet.setBalance(afterBalance);
+        wallet.setUpdatedAt(new Date());
+        // 执行更新操作，乐观锁机制确保并发安全
+        boolean updateSuccess = walletService.updateById(wallet);
+        if (!updateSuccess) {
+            throw new BusinessException(ErrorCode.OPERATION_ERROR);
+        }
+
+        // 6. 创建购买记录
+        // 生成唯一订单号：ORDER_时间戳_8位UUID
+        String orderNo = "ORDER_" + System.currentTimeMillis() + "_" + UUID.randomUUID().toString().substring(0, 8);
+        // 构建购买记录对象
+        KeyboardThemePurchase purchase = new KeyboardThemePurchase();
+        purchase.setOrderNo(orderNo);                           // 订单号
+        purchase.setUserId(userId);                             // 用户ID
+        purchase.setThemeId(themeId);                           // 主题ID
+        purchase.setCostPoints(themePrice.intValue());          // 消费积分
+        purchase.setPaidPoints(themePrice.intValue());          // 实付积分
+        purchase.setPayStatus((short) 1);                       // 支付状态：1-已支付
+        purchase.setCreatedAt(new Date());                      // 创建时间
+        purchase.setPaidAt(new Date());                         // 支付时间
+        purchase.setUpdatedAt(new Date());                      // 更新时间
+        // 保存购买记录到数据库
+        this.save(purchase);
+
+        // 7. 创建钱包交易记录
+        // 调用交易服务创建一条钱包交易记录
+        KeyboardWalletTransaction transaction = transactionService.createTransaction(
+                userId,                                          // 用户ID
+                purchase.getId(),                                // 关联的购买记录ID
+                themePrice.negate(),                            // 交易金额（负数表示支出）
+                (short) 1,                                      // 交易类型：1-购买主题
+                beforeBalance,                                   // 交易前余额
+                afterBalance,                                    // 交易后余额
+                "购买主题: " + theme.getThemeName()             // 交易备注
+        );
+
+        // 8. 更新购买记录的交易ID
+        // 将交易记录ID关联到购买记录中
+        purchase.setWalletTxId(transaction.getId());
+        this.updateById(purchase);
+
+        // 9. 构造返回结果
+        // 创建响应对象，封装购买结果信息
+        ThemePurchaseRespVO respVO = new ThemePurchaseRespVO();
+        respVO.setOrderNo(orderNo);                             // 订单号
+        respVO.setThemeId(themeId);                             // 主题ID
+        respVO.setPaidAmount(themePrice);                       // 支付金额
+        respVO.setRemainingBalance(afterBalance);               // 剩余余额
+
+        return respVO;
+    }
 }

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

@@ -2,6 +2,8 @@ package com.yolo.keyborad.service.impl;
 
 import org.springframework.stereotype.Service;
 import org.springframework.beans.factory.annotation.Autowired;
+import java.math.BigDecimal;
+import java.util.Date;
 import java.util.List;
 import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
 import com.yolo.keyborad.mapper.KeyboardWalletTransactionMapper;
@@ -15,4 +17,20 @@ import com.yolo.keyborad.service.KeyboardWalletTransactionService;
 @Service
 public class KeyboardWalletTransactionServiceImpl extends ServiceImpl<KeyboardWalletTransactionMapper, KeyboardWalletTransaction> implements KeyboardWalletTransactionService{
 
+    @Override
+    public KeyboardWalletTransaction createTransaction(Long userId, Long orderId, BigDecimal amount,
+                                                       Short type, BigDecimal beforeBalance,
+                                                       BigDecimal afterBalance, String description) {
+        KeyboardWalletTransaction transaction = new KeyboardWalletTransaction();
+        transaction.setUserId(userId);
+        transaction.setOrderId(orderId);
+        transaction.setAmount(amount);
+        transaction.setType(type);
+        transaction.setBeforeBalance(beforeBalance);
+        transaction.setAfterBalance(afterBalance);
+        transaction.setDescription(description);
+        transaction.setCreatedAt(new Date());
+        this.save(transaction);
+        return transaction;
+    }
 }