progress on vendor database

merchant.lua

@@ -1,18 +1,27 @@
 local private, public = {}, {}
 Aux.merchant = public
 
-local sell_data = {}
-local buy_data = {}
+aux_merchant_buy, aux_merchant_sell = {}, {}
 
 function public.on_load()
     Aux.control.event_listener('MERCHANT_SHOW', private.scan_merchant).start()
 end
 
+function public.info(item_id)
+    local unit_price, unlimited
+    if aux_merchant_buy[item_id] then
+        local buy_fields = Aux.util.split(aux_merchant_buy[item_id], '#')
+        unit_price, unlimited = tonumber(buy_fields[1]), not not tonumber(buy_fields[2])
+    end
+
+    return aux_merchant_sell[item_id], unit_price, unlimited
+end
+
 function private.scan_merchant()
     Aux.util.loop_inventory(function(bag, slot)
         local item_info = Aux.info.container_item(bag, slot)
         if item_info then
-            sell_data[item_info.item_id] = item_info.tooltip.money / item_info.aux_quantity
+            aux_merchant_sell[item_info.item_id] = item_info.tooltip.money / item_info.aux_quantity
         end
     end)
 
@@ -21,6 +30,29 @@ function private.scan_merchant()
     for i=1,merchant_item_count do
         local item_id = Aux.info.parse_hyperlink(GetMerchantItemLink(i))
         local _, _, price, count, stock = GetMerchantItemInfo(i)
-        buy_data[item_id] = Aux.util.join({price / count, stock}, '#')
+        local new_unit_price, new_unlimited = price / count, Aux.persistence.blizzard_boolean(stock == -1)
+        if aux_merchant_buy[item_id] then
+            local fields = Aux.util.split(aux_merchant_buy[item_id], '#')
+            local old_unit_price, old_unlimited = tonumber(fields[1]), tonumber(fields[2])
+
+            local unit_price
+            if old_unlimited and not new_unlimited then
+                unit_price = old_unit_price
+            elseif new_unlimited and not old_unlimited then
+                unit_price = new_unit_price
+            else
+                unit_price = min(old_unit_price, new_unit_price)
+            end
+
+            aux_merchant_buy[item_id] = Aux.util.join({
+                unit_price,
+                old_unlimited or new_unlimited,
+            }, '#')
+        else
+            aux_merchant_buy[item_id] = Aux.util.join({
+                new_unit_price,
+                new_unlimited,
+            }, '#')
+        end
     end
 end