fix bug 3

src/models/products.ts

@@ -25,6 +25,7 @@ export interface  Product {
     max_order_cash?: number | null
     direct_price: number | undefined
     price_offset_percent?: number | null
+    use_last_price_if_zero?: boolean
     reading_method: any
     created_at: any
     updated_at: any

src/utils/productPrice.ts

@@ -2,6 +2,10 @@ import type { Product } from '@/models/products'
 import { getTradeBuyPrice, getTradeSellPrice, lastPrice } from '@/utils/price'
 import { isMetalCommodityGroup, isMeltedProductUsingAppPrice, isMeltedTradeGroup } from '@/utils/productCategories'
 
+function productUsesLastPriceIfZero(product: Product): boolean {
+  return Boolean(product.use_last_price_if_zero)
+}
+
 function applyPriceOffsetPercent(basePrice: number, offsetPercent?: number | null) {
   const offset = Number(offsetPercent ?? 0)
   if (!offset) {
@@ -14,12 +18,27 @@ function applyPriceOffsetPercent(basePrice: number, offsetPercent?: number | nul
 /** قیمت پایه بدون کارمزد — اگر صفر باشد نباید فقط cash_fee به‌عنوان قیمت نمایش داده شود */
 export function getProductBaseBuyPrice(product: Product): number {
   if (isMeltedProductUsingAppPrice(product)) {
-    const tradeBuy = getTradeBuyPrice(lastPrice.value)
-    if (tradeBuy > 0) {
-      return applyPriceOffsetPercent(tradeBuy, product.price_offset_percent)
+    const apiPrice = Number(product.price ?? 0)
+    const useLast = productUsesLastPriceIfZero(product)
+
+    if (!useLast) {
+      const liveBuy = getTradeBuyPrice(lastPrice.value)
+      if (liveBuy > 0) {
+        return applyPriceOffsetPercent(liveBuy, product.price_offset_percent)
+      }
+      return 0
     }
-    // provider صفر — آخرین قیمت ذخیره‌شده از API (وقتی use_last_price_if_zero فعال است)
-    return Number(product.price ?? 0)
+
+    if (apiPrice > 0) {
+      return apiPrice
+    }
+
+    const liveBuy = getTradeBuyPrice(lastPrice.value)
+    if (liveBuy > 0) {
+      return applyPriceOffsetPercent(liveBuy, product.price_offset_percent)
+    }
+
+    return 0
   }
 
   if (isMeltedTradeGroup(product.group_type)) {
@@ -58,12 +77,27 @@ export function getProductBuyPrice(product: Product): number {
 
 function getProductBaseSellPrice(product: Product): number {
   if (isMeltedProductUsingAppPrice(product)) {
-    const tradeSell = getTradeSellPrice(lastPrice.value)
-    if (tradeSell > 0) {
-      return applyPriceOffsetPercent(tradeSell, product.price_offset_percent)
+    const apiPrice = Number(product.price ?? 0)
+    const useLast = productUsesLastPriceIfZero(product)
+
+    if (!useLast) {
+      const liveSell = getTradeSellPrice(lastPrice.value)
+      if (liveSell > 0) {
+        return applyPriceOffsetPercent(liveSell, product.price_offset_percent)
+      }
+      return 0
     }
-    // provider صفر — همان آخرین قیمت ذخیره‌شده (فروش از همان مبنا)
-    return Number(product.price ?? 0)
+
+    if (apiPrice > 0) {
+      return apiPrice
+    }
+
+    const liveSell = getTradeSellPrice(lastPrice.value)
+    if (liveSell > 0) {
+      return applyPriceOffsetPercent(liveSell, product.price_offset_percent)
+    }
+
+    return 0
   }
 
   if (isMeltedTradeGroup(product.group_type)) {