优化优惠积分使用逻辑

src/components/payCard/payCard.vue

@@ -206,7 +206,7 @@
                 <el-form-item label="积分抵扣">
                     <div class="flex">
                         <el-input v-model="couponForm.pointsNum"
-                            :disabled="!couponFormUser.id || !pointOptions.usable || goodsStore.cartInfo.costSummary.finalPayAmount < pointOptions.minPaymentAmount || (couponFormUser.accountPoints || 0) < (pointOptions.minPoints || 0)"
+                            :disabled="!couponFormUser.id || !pointOptions.usable || goodsStore.cartInfo.costSummary.finalPayAmount < pointOptions.minPaymentAmount"
                             :placeholder="pointOptions.usable ? '请输入需要抵扣的积分' : pointOptions.unusableReason"
                             v-loading="pointOptions.loading" @input="pointInput">
                             <template #prepend>现有积分：{{ couponFormUser.accountPoints || 0 }}</template>
@@ -214,10 +214,11 @@
                         </el-input>
                         <el-button type="danger" @click="clearPoint">清除</el-button>
                     </div>
-                    <div class="point_tips err"
-                        v-if="couponFormUser.id && goodsStore.cartInfo.costSummary.finalPayAmount < pointOptions.minPaymentAmount">
-                        注意：订单金额不足￥{{
-                            formatDecimal(+pointOptions.minPaymentAmount) }}，无法使用积分抵扣
+                    <div class="point_tips err" v-if="couponFormUser.id && !pointOptions.usable">
+                        注意：{{ pointOptions.unusableReason || (`订单金额不足￥${formatDecimal(+pointOptions.minPaymentAmount)}，无法使用积分抵扣`) }}
+                    </div>
+                    <div class="point_tips" v-if="couponFormUser.id && pointOptions.usable">
+                        说明：订单已满足使用门槛，当前积分可抵扣最多￥{{ pointOptions.potentialAmount }}（当前积分 {{ couponFormUser.accountPoints || 0 }}）
                     </div>
                 </el-form-item>
             </el-form>
@@ -666,6 +667,7 @@ const pointOptions = ref({
     usable: true,
     unusableReason: '',
     amount: 0, // 抵扣金额（元）
+    potentialAmount: 0, // 用户当前积分可抵扣的最大金额（元，供展示）
     loading: false
 })
 
@@ -775,7 +777,8 @@ const pointInput = _.debounce(function (e) {
 
     // 未登录用户或无可用积分时直接归0并返回
     const userAvailablePoints = Number(couponFormUser.value && couponFormUser.value.accountPoints ? couponFormUser.value.accountPoints : 0)
-    if (!couponFormUser.value || !couponFormUser.value.id || userAvailablePoints <= 0) {
+    // 如果未登录、无可用积分或积分抵扣不可用（不满足门槛或商家未开启），直接归0并返回
+    if (!couponFormUser.value || !couponFormUser.value.id || userAvailablePoints <= 0 || !pointOptions.value.usable) {
         couponForm.value.pointsNum = 0
         pointOptions.value.amount = 0
         updateCartCalc()
@@ -788,12 +791,11 @@ const pointInput = _.debounce(function (e) {
     }
 
     // 边界限制：不得超过最大/小于最小
-    if (couponForm.value.pointsNum > pointOptions.value.maxPoints) {
+    if (pointOptions.value.maxPoints && couponForm.value.pointsNum > pointOptions.value.maxPoints) {
         couponForm.value.pointsNum = pointOptions.value.maxPoints
     }
-    if (couponForm.value.pointsNum < pointOptions.value.minPoints) {
-        couponForm.value.pointsNum = pointOptions.value.minPoints
-    }
+    // 允许输入少于 minPoints 的积分（前端做友好展示），实际抵扣金额由 calcPointMoney 和后端规则决定
+    // 如果希望严格按照 minPoints 阈值生效，可在此恢复置0逻辑
 
     if (!e) {
         couponForm.value.pointsNum = 0
@@ -806,7 +808,7 @@ const pointInput = _.debounce(function (e) {
 
 
     // 满足条件式开始计算抵扣金额，由后端返回
-    if (couponForm.value.pointsNum >= pointOptions.value.minPoints && couponForm.value.pointsNum <= pointOptions.value.maxPoints) {
+    if (couponForm.value.pointsNum > 0 && (!pointOptions.value.maxPoints || couponForm.value.pointsNum <= pointOptions.value.maxPoints)) {
         pointOptions.value.loading = true
         calcPointMoney()
     }
@@ -822,25 +824,30 @@ const calcPointMoney = async () => {
         const points = Number(couponForm.value.pointsNum || 0)
         const orderAmount = Number(goodsStore.cartInfo.costSummary.finalPayAmount || 0)
 
-        if (!pointsPerYuan || points <= 0) {
+        // 若不满足计算条件，则直接退出并复位
+        if (!pointOptions.value.usable || !pointsPerYuan || points <= 0) {
             pointOptions.value.amount = 0
-            // 若未初始化 couponForm.value.amount，则用订单原价
             couponForm.value.amount = couponForm.value.amount || originOrderAmount.value || orderAmount
             updateCartCalc()
+            pointOptions.value.loading = false
             return
         }
 
         // 积分可抵扣的金额（元） => 积分 / (积分数/元)
-        let deductionFromPoints = points / pointsPerYuan
+        const deductionFromPoints = points / pointsPerYuan
 
-        // 最大可抵扣金额基于订单金额和最大抵扣比例
+        // 最大可抵扣金额基于订单金额和最大抵扣比例（后端规则）
         const maxDeductionAmount = orderAmount * (pointOptions.value.maxDeductionRatio || 0)
 
-        // 最终抵扣为积分抵扣金额与最大比例的较小者，且不超过订单可支付金额
-        const baseAmount = Number(couponForm.value.amount || originOrderAmount.value || orderAmount)
+        // 基数为当前可用于抵扣的订单金额（可能已经包含其他优惠），不能小于0
+        const baseAmount = Math.max(0, Number(couponForm.value.amount || originOrderAmount.value || orderAmount))
+
+        // 最终抵扣为：积分折算金额、最大可抵扣金额、当前可抵扣金额三者的最小值
         let deduction = Math.min(deductionFromPoints, maxDeductionAmount, baseAmount)
 
-        pointOptions.value.amount = formatDecimal(deduction)
+        deduction = Number(formatDecimal(deduction))
+
+        pointOptions.value.amount = deduction
         couponForm.value.amount = formatDecimal(baseAmount - deduction)
 
         updateCartCalc()
@@ -977,19 +984,46 @@ async function pointOptionsAjax() {
         // 后端的 equivalentPoints 表示 积分数/元（例如 20 表示 20 积分 = 1 元）
         pointOptions.value.pointsPerYuan = pointOptions.value.equivalentPoints
 
+        // 规范化 maxDeductionRatio：后端可能以百分比(如50)返回，若大于1则认为是百分比并除以100
+        if (pointOptions.value.maxDeductionRatio > 1) {
+            pointOptions.value.maxDeductionRatio = pointOptions.value.maxDeductionRatio / 100
+        }
+
         // 计算页面需要的最小/最大可用积分（按接口返回的金额阈值与比例换算为积分）
         const pointsPerYuan = pointOptions.value.pointsPerYuan || 0
         const orderAmount = Number(goodsStore.cartInfo.costSummary.finalPayAmount || 0)
 
         // 最少使用积分：基于最小抵扣金额换算（若无则为0），minPaymentAmount 单位为元
-        pointOptions.value.minPoints = pointOptions.value.minPaymentAmount && pointsPerYuan ? Math.ceil(pointOptions.value.minPaymentAmount * pointsPerYuan) : 0
+        pointOptions.value.minPoints = (pointOptions.value.minPaymentAmount && pointsPerYuan) ? Math.ceil(pointOptions.value.minPaymentAmount * pointsPerYuan) : 0
 
-        // 最大可用积分：基于订单金额与最大抵扣比例换算
-        pointOptions.value.maxPoints = (pointOptions.value.maxDeductionRatio && pointsPerYuan) ? Math.floor(orderAmount * pointOptions.value.maxDeductionRatio * pointsPerYuan) : 0
+        // 最大可用积分：基于订单金额与最大抵扣比例换算。后端返回的 maxDeductionRatio 表示可抵扣的最大金额占比，需换算为积分
+        const maxDeductionAmount = orderAmount * (pointOptions.value.maxDeductionRatio || 0)
+        pointOptions.value.maxPoints = (pointOptions.value.maxDeductionRatio && pointsPerYuan) ? Math.floor(maxDeductionAmount * pointsPerYuan) : 0
 
-        // 可用性
-        pointOptions.value.usable = pointOptions.value.enableRewards === 1 && pointOptions.value.maxPoints > 0
-        pointOptions.value.unusableReason = pointOptions.value.usable ? '' : (pointOptions.value.enableRewards !== 1 ? '商家未开启积分抵扣' : '订单不可抵扣积分')
+        // 可用性：必须开启、订单满足最小支付金额门槛且最大可用积分>0
+        pointOptions.value.usable = (pointOptions.value.enableRewards === 1) && (orderAmount >= (pointOptions.value.minPaymentAmount || 0)) && pointOptions.value.maxPoints > 0
+
+        if (!pointOptions.value.usable) {
+            if (pointOptions.value.enableRewards !== 1) {
+                pointOptions.value.unusableReason = '商家未开启积分抵扣'
+            } else if (orderAmount < (pointOptions.value.minPaymentAmount || 0)) {
+                pointOptions.value.unusableReason = `订单金额不足￥${formatDecimal(+pointOptions.value.minPaymentAmount)}，无法使用积分抵扣`
+            } else {
+                pointOptions.value.unusableReason = '订单不可抵扣积分'
+            }
+        } else {
+            pointOptions.value.unusableReason = ''
+        }
+
+        // 计算当前用户积分在当前订单下的潜在最大抵扣金额（仅供展示）
+        let potential = 0
+        const userPoints = Number(couponFormUser.value && couponFormUser.value.accountPoints ? couponFormUser.value.accountPoints : 0)
+        if (pointsPerYuan && userPoints > 0) {
+            potential = Math.min(userPoints / pointsPerYuan, maxDeductionAmount, orderAmount)
+        }
+        pointOptions.value.potentialAmount = formatDecimal(potential)
+
+        console.log('pointOptions after calc:', JSON.parse(JSON.stringify(pointOptions.value)), 'couponFormUser:', JSON.parse(JSON.stringify(couponFormUser.value)), 'orderAmount:', orderAmount)
     } catch (error) {
         console.log(error);
     }