feat: 新增租户余额内部查询与扣减接口

internal/app/system/controller/tenant_balance.go

@@ -0,0 +1,58 @@
+package controller
+
+import (
+	"context"
+
+	"github.com/gogf/gf/v2/errors/gerror"
+	"github.com/gogf/gf/v2/frame/g"
+	"github.com/gogf/gf/v2/util/gconv"
+	"github.com/tiger1103/gfast/v3/api/v1/system"
+	"github.com/tiger1103/gfast/v3/internal/app/system/service"
+)
+
+var (
+	TenantBalance = tenantBalanceController{}
+)
+
+type tenantBalanceController struct{}
+
+// callerUser 归属校验只取租户字段（调用方经 X-User-Info 头携带用户信息）
+type callerUser struct {
+	TenantId uint64 `json:"tenantId"`
+}
+
+// callerTenantId 从 X-User-Info 头解析调用方租户 id；头缺失/解析失败返回 0
+func (c *tenantBalanceController) callerTenantId(ctx context.Context) uint64 {
+	r := g.RequestFromCtx(ctx)
+	if r == nil {
+		return 0
+	}
+	userInfoHeader := r.Header.Get("X-User-Info")
+	if userInfoHeader == "" {
+		return 0
+	}
+	var caller callerUser
+	if err := gconv.Struct(userInfoHeader, &caller); err != nil {
+		return 0
+	}
+	return caller.TenantId
+}
+
+// Balance 查询租户余额（内部接口，供 model-gateway 调用；调用方只能查询自己所属租户）
+func (c *tenantBalanceController) Balance(ctx context.Context, req *system.TenantBalanceReq) (res *system.TenantBalanceRes, err error) {
+	if caller := c.callerTenantId(ctx); caller == 0 || caller != req.TenantId {
+		return nil, gerror.New("无权查询该租户余额")
+	}
+	res = new(system.TenantBalanceRes)
+	res.Tenant, err = service.Tenant().GetTenantDetails(ctx, req.TenantId)
+	return
+}
+
+// Deduct 扣减租户余额（内部接口；surplus 传负值走 Edit 的 Counter 增量即扣减；调用方只能扣减自己所属租户）
+func (c *tenantBalanceController) Deduct(ctx context.Context, req *system.TenantDeductReq) (res *system.TenantDeductRes, err error) {
+	if caller := c.callerTenantId(ctx); caller == 0 || caller != uint64(req.Id) {
+		return nil, gerror.New("无权扣减该租户余额")
+	}
+	err = service.Tenant().Edit(ctx, &system.TenantEditReq{Id: req.Id, Surplus: req.Surplus})
+	return
+}