feat(subscription): 新增订阅订单价格计算接口

- 添加 SubscriptionOrderController 控制器，提供 /calculate-price 接口
- 实现订阅价格试算逻辑，支持续费、升级及支付方式系数计算
- 新增 SubscriptionOrderParam 入参类，定义请求参数结构
- 新增 SubscriptionPriceResult 返回结果类，封装价格计算结果
- 支持从配置中读取套餐价格、折扣因子及支付方式调整系数
- 添加多配置键兼容机制，增强系统健壮性
- 提供详细的价格计算说明与异常提示信息

src/main/java/com/gxwebsoft/common/system/controller/SubscriptionOrderController.java

@@ -0,0 +1,195 @@
+package com.gxwebsoft.common.system.controller;
+
+import com.alibaba.fastjson.JSONArray;
+import com.alibaba.fastjson.JSONObject;
+import com.gxwebsoft.common.core.web.ApiResult;
+import com.gxwebsoft.common.core.web.BaseController;
+import com.gxwebsoft.common.system.entity.User;
+import com.gxwebsoft.common.system.param.SubscriptionOrderParam;
+import com.gxwebsoft.common.system.result.SubscriptionPriceResult;
+import com.gxwebsoft.common.system.service.SettingService;
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import javax.annotation.Resource;
+import java.math.BigDecimal;
+import java.math.RoundingMode;
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * 订阅订单接口
+ */
+@Tag(name = "订阅订单")
+@RestController
+@RequestMapping("/api/system/subscription-order")
+public class SubscriptionOrderController extends BaseController {
+
+  @Resource
+  private SettingService settingService;
+
+  @Operation(summary = "计算订阅订单价格")
+  @PostMapping("/calculate-price")
+  public ApiResult<SubscriptionPriceResult> calculatePrice(@RequestBody SubscriptionOrderParam param) {
+    final User loginUser = getLoginUser();
+    if (loginUser == null) {
+      return fail("请先登录", null);
+    }
+    if (param.getPackageId() == null) {
+      return fail("套餐ID不能为空", null);
+    }
+
+    JSONObject config = loadSubscriptionConfig();
+    final SubscriptionPriceResult result = buildPriceResult(param, config);
+    return success(result);
+  }
+
+  /**
+   * 从配置表读取订阅套餐配置（尝试多种key以兼容历史数据）
+   */
+  private JSONObject loadSubscriptionConfig() {
+    final List<String> keys = Arrays.asList("subscription", "subscription-package", "subscriptionOrder");
+    for (String key : keys) {
+      try {
+        JSONObject cfg = settingService.getBySettingKey(key);
+        if (cfg != null) {
+          return cfg;
+        }
+      } catch (Exception ignored) {
+      }
+    }
+    return new JSONObject();
+  }
+
+  /**
+   * 计算价格结果
+   */
+  private SubscriptionPriceResult buildPriceResult(SubscriptionOrderParam param, JSONObject config) {
+    BigDecimal originalPrice = resolveBasePrice(param.getPackageId(), config);
+    BigDecimal factor = BigDecimal.ONE;
+    StringBuilder remark = new StringBuilder();
+
+    if (config == null || config.isEmpty()) {
+      remark.append("未查询到订阅价格配置，已按0元试算；");
+    }
+    if (originalPrice.compareTo(BigDecimal.ZERO) == 0 && config != null && !config.isEmpty()) {
+      remark.append("未找到套餐价格，已按0元试算；");
+    }
+
+    if (isTrue(param.getIsRenewal())) {
+      BigDecimal renewalFactor = resolveFactor(config, "renewalDiscount");
+      factor = factor.multiply(renewalFactor);
+      remark.append("续费系数:").append(renewalFactor).append(";");
+    }
+
+    if (isTrue(param.getIsUpgrade())) {
+      BigDecimal upgradeFactor = resolveFactor(config, "upgradeDiscount");
+      factor = factor.multiply(upgradeFactor);
+      remark.append("升级系数:").append(upgradeFactor).append(";");
+    }
+
+    BigDecimal payTypeFactor = resolvePayTypeFactor(config, param.getPayType());
+    factor = factor.multiply(payTypeFactor);
+    if (param.getPayType() != null) {
+      remark.append("支付系数:").append(payTypeFactor).append(";");
+    }
+
+    BigDecimal payPrice = originalPrice.multiply(factor).setScale(2, RoundingMode.HALF_UP);
+    BigDecimal discount = originalPrice.subtract(payPrice);
+    if (discount.compareTo(BigDecimal.ZERO) < 0) {
+      discount = BigDecimal.ZERO;
+    }
+
+    SubscriptionPriceResult result = new SubscriptionPriceResult();
+    result.setPackageId(param.getPackageId());
+    result.setIsRenewal(param.getIsRenewal());
+    result.setIsUpgrade(param.getIsUpgrade());
+    result.setPayType(param.getPayType());
+    result.setOriginalPrice(originalPrice.setScale(2, RoundingMode.HALF_UP));
+    result.setTotalPrice(originalPrice.setScale(2, RoundingMode.HALF_UP));
+    result.setPayPrice(payPrice);
+    result.setDiscountAmount(discount.setScale(2, RoundingMode.HALF_UP));
+    result.setRemark(remark.toString());
+    return result;
+  }
+
+  private boolean isTrue(Integer value) {
+    return value != null && value.equals(1);
+  }
+
+  /**
+   * 解析套餐价格，支持 packages 数组、priceMap 或单价配置
+   */
+  private BigDecimal resolveBasePrice(Integer packageId, JSONObject config) {
+    if (config != null) {
+      JSONArray packages = config.getJSONArray("packages");
+      if (packages != null) {
+        for (Object item : packages) {
+          if (item instanceof JSONObject) {
+            JSONObject pkg = (JSONObject) item;
+            Integer id = pkg.getInteger("id");
+            if (id == null) {
+              id = pkg.getInteger("packageId");
+            }
+            if (packageId.equals(id)) {
+              BigDecimal price = pkg.getBigDecimal("price");
+              if (price != null) {
+                return price;
+              }
+            }
+          }
+        }
+      }
+
+      JSONObject priceMap = config.getJSONObject("priceMap");
+      if (priceMap != null) {
+        BigDecimal price = priceMap.getBigDecimal(packageId.toString());
+        if (price != null) {
+          return price;
+        }
+      }
+
+      BigDecimal fallbackPrice = config.getBigDecimal("price");
+      if (fallbackPrice != null) {
+        return fallbackPrice;
+      }
+    }
+    return BigDecimal.ZERO;
+  }
+
+  /**
+   * 获取折扣系数，默认 1
+   */
+  private BigDecimal resolveFactor(JSONObject config, String key) {
+    if (config != null) {
+      BigDecimal factor = config.getBigDecimal(key);
+      if (factor != null) {
+        return factor;
+      }
+    }
+    return BigDecimal.ONE;
+  }
+
+  /**
+   * 支付方式系数，可在配置中通过 payTypeDiscount 或 payTypeAdjustments 定义
+   */
+  private BigDecimal resolvePayTypeFactor(JSONObject config, Integer payType) {
+    if (config != null && payType != null) {
+      JSONObject payTypeDiscount = config.getJSONObject("payTypeDiscount");
+      if (payTypeDiscount == null) {
+        payTypeDiscount = config.getJSONObject("payTypeAdjustments");
+      }
+      if (payTypeDiscount != null) {
+        BigDecimal factor = payTypeDiscount.getBigDecimal(payType.toString());
+        if (factor != null) {
+          return factor;
+        }
+      }
+    }
+    return BigDecimal.ONE;
+  }
+}

src/main/java/com/gxwebsoft/common/system/param/SubscriptionOrderParam.java

@@ -0,0 +1,24 @@
+package com.gxwebsoft.common.system.param;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+import lombok.Data;
+
+/**
+ * 订阅订单价格试算入参
+ */
+@Data
+@Schema(description = "订阅订单价格试算参数")
+public class SubscriptionOrderParam {
+
+  @Schema(description = "是否续费，1=续费 0=新购")
+  private Integer isRenewal;
+
+  @Schema(description = "是否升级，1=升级 0=非升级")
+  private Integer isUpgrade;
+
+  @Schema(description = "套餐ID")
+  private Integer packageId;
+
+  @Schema(description = "支付方式")
+  private Integer payType;
+}

src/main/java/com/gxwebsoft/common/system/result/SubscriptionPriceResult.java

@@ -0,0 +1,41 @@
+package com.gxwebsoft.common.system.result;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+import lombok.Data;
+
+import java.math.BigDecimal;
+
+/**
+ * 订阅订单价格试算结果
+ */
+@Data
+@Schema(description = "订阅订单价格试算结果")
+public class SubscriptionPriceResult {
+
+  @Schema(description = "套餐ID")
+  private Integer packageId;
+
+  @Schema(description = "是否续费，1=续费 0=新购")
+  private Integer isRenewal;
+
+  @Schema(description = "是否升级，1=升级 0=非升级")
+  private Integer isUpgrade;
+
+  @Schema(description = "支付方式")
+  private Integer payType;
+
+  @Schema(description = "原价")
+  private BigDecimal originalPrice;
+
+  @Schema(description = "优惠金额")
+  private BigDecimal discountAmount;
+
+  @Schema(description = "应付金额")
+  private BigDecimal payPrice;
+
+  @Schema(description = "总价(同原价，用于兼容前端字段)")
+  private BigDecimal totalPrice;
+
+  @Schema(description = "价格说明")
+  private String remark;
+}