Trade: A list of buyable items is now calculated with the maximum amount buyable (given the currency), the minimum buyable amount and the minimum price.

Port casual trading to use this system.
Refactor the offer function to also support dedicated trading.

trade/prices.lua

@@ -87,7 +87,7 @@ function npc.trade.prices.get_items_for_currency_count(tier, count, price_factor
     if price.tier == tier and price.count <= count then
       result[item_name] = {price = price}
 
-      minetest.log("Item name: "..dump(item_name)..", Price: "..dump(price))
+      --minetest.log("Item name: "..dump(item_name)..", Price: "..dump(price))
 
       local min_buying_item_count = 1
       -- Calculate price NPC is going to buy for
@@ -111,11 +111,11 @@ function npc.trade.prices.get_items_for_currency_count(tier, count, price_factor
       --minetest.log("Maximum item buy quantity: "..dump(max_buying_item_count))
 
       result[item_name].min_buyable_item_count = min_buying_item_count
-      result[item_name].min_buyable_item_price = min_buying_item_count * buying_price_count
+      result[item_name].min_buyable_item_price = buying_price_count
       result[item_name].max_buyable_item_count = max_buying_item_count
     end
   end
-  --minetest.log("Final result: "..dump(result))
+  minetest.log("Final result: "..dump(result))
   return result
 end
 

trade/trade.lua

@@ -147,7 +147,8 @@ function npc.trade.get_casual_trade_offer(self, offer_type)
     -- so that the price count is always an integer number
     local amount_to_buy = math.random(buyable_items[item].min_buyable_item_count, buyable_items[item].max_buyable_item_count)
     -- Create trade offer
-    result = npc.trade.create_offer(npc.trade.OFFER_BUY, item, price, amount_to_buy)
+    minetest.log("Buyable item: "..dump(buyable_items[item]))
+    result = npc.trade.create_offer(npc.trade.OFFER_BUY, item, buyable_items[item].price, buyable_items[item].min_buyable_item_price, amount_to_buy)
   else
     -- Make sell offer, NPC will sell items to player at regular price
     -- NPC will also offer items from their inventory
@@ -164,59 +165,33 @@ function npc.trade.get_casual_trade_offer(self, offer_type)
     -- Choose how many of this item will be sold to player
     local count = math.random(npc.get_item_count(item))
     -- Create trade offer
-    result = npc.trade.create_offer(npc.trade.OFFER_SELL, npc.get_item_name(item), nil, count)
+    result = npc.trade.create_offer(npc.trade.OFFER_SELL, npc.get_item_name(item), nil, nil, count)
   end
 
   return result
 end
 
 -- Creates a trade offer based on the offer type, given item and count. If
--- the offer is a "buy" offer, it is required to provide currency items for
+-- the offer is a "buy" offer, it is required to provide the price item and
--- payment. The currencies should come from either the NPC's inventory or a
+-- the minimum price item count.
--- chest belonging to it.
+function npc.trade.create_offer(offer_type, item, price, min_price_item_count, count)
-function npc.trade.create_offer(offer_type, item, price_item_count, count)
-
-  minetest.log("Item:"..dump(item))
   local result = {}
   -- Check offer type
   if offer_type == npc.trade.OFFER_BUY then
     -- Get price for the given item
-    local item_price = npc.trade.prices.table[item]
+    -- Create price itemstring
-    minetest.log("Item price: "..dump(item_price))
+    local price_string = price.tier.." "
-    -- Choose buying quantity. Since this is a buy offer, NPC will buy items 
+      ..tostring( min_price_item_count * count )
-    -- at half the price. Therefore, NPC will always ask for even quantities
-    -- so that the price count is always an integer number
-    minetest.log("Count: "..dump(count)..", price item count: "..dump(item_price.count))
-    local price_item_count = item_price.count * ((count) / 2)
-    minetest.log("Price item: "..dump(price_item_count))
-    -- Increase the amount to buy if the result of the price is a decimal number
-    while price_item_count % 1 ~= 0 do
-      minetest.log("Count: "..dump(count))
-      count = count + 1
-      price_item_count = item_price.count * ((count) / 2)
-      minetest.log("Price item: "..dump(price_item_count))
-    end
-    -- Check if the currency items can pay for the selected amount to buy
-    for i = 1, #currency_items do
-      minetest.log("Currency item: "..dump(currency_items[i]))
-      minetest.log("Name: "..dump(item_price.tier)..", Count: "..dump(price_item_count))
-      if currency_items[i].name == item_price.tier and currency_items[i].count >= item_price.count then
-        -- Create price itemstring
-        local price_string = item_price.tier.." "
-          ..tostring( item_price.count * (count / 2) )
 
-        -- Build the return object
+    -- Build the return object
-        result = {
+    result = {
-          offer_type = offer_type,
+      offer_type = offer_type,
-          item = item.." "..count,
+      item = item.." "..count,
-          price = price_string
+      price = price_string
-        }
+    }
-      end
-    end
   else
     -- Make sell offer, NPC will sell items to player at regular price
     -- Get and calculate price for this object
-    minetest.log("Item: "..dump(item)..", name: "..dump(npc.get_item_name(item)))
     local price_object = npc.trade.prices.table[item]
     -- Check price object, if price < 1 then offer to sell for 1
     if price_object.count < 1 then