重构交易处理逻辑，合并充值与购买流程，优化交易状态管理；更新相关数据结构和接口

web/domains/bill/bill.go

@@ -0,0 +1,34 @@
+package bill
+
+import (
+	"github.com/shopspring/decimal"
+	m "platform/web/models"
+)
+
+func NewForRecharge(uid int32, billNo string, info string, amount decimal.Decimal, trade *m.Trade) *m.Bill {
+	return &m.Bill{
+		UserID:  uid,
+		BillNo:  billNo,
+		TradeID: &trade.ID,
+		Type:    int32(TypeRecharge),
+		Info:    &info,
+		Amount:  amount,
+	}
+}
+
+func NewForConsume(uid int32, billNo string, info string, amount decimal.Decimal, resource *m.Resource, trade ...*m.Trade) *m.Bill {
+	var bill = &m.Bill{
+		UserID:     uid,
+		BillNo:     billNo,
+		ResourceID: &resource.ID,
+		Type:       int32(TypeConsume),
+		Info:       &info,
+		Amount:     amount,
+	}
+
+	if len(trade) > 0 {
+		bill.TradeID = &trade[0].ID
+	}
+
+	return bill
+}