Added a market retailer to manage the markets

features/retailer.lua

@@ -0,0 +1,106 @@
+local Debug = require 'map_gen.Diggy.Debug'
+local Global = require 'utils.global'
+local format = string.format
+local insert = table.insert
+
+local Retailer = {}
+
+---Global storage
+---Markets are indexed by the group_name and is a sequential list of LuaEntities
+---Items are indexed by the group name and is a list indexed by the item name and contains the prices per item
+local memory = {
+    markets = {},
+    items = {},
+}
+
+Global.register({
+    memory = memory,
+}, function (tbl)
+    memory = tbl.memory
+end)
+
+---Add a market to the group_name retailer.
+---@param group_name string
+---@param market_entity LuaEntity
+function Retailer.add_market(group_name, market_entity)
+    if not memory.markets[group_name] then
+        memory.markets[group_name] = {market_entity}
+        return
+    end
+
+    insert(memory.markets[group_name], market_entity)
+end
+
+---Sets an item for all the group_name markets.
+---@param group_name string
+---@param item_name string
+---@param prices table associative table where the key is the currency item and the value the amount of it
+function Retailer.set_item(group_name, item_name, prices)
+    if not memory.items[group_name] then
+        memory.items[group_name] = {}
+    end
+
+    local market_format_prices = {}
+    for currency, amount in pairs(prices) do
+        insert(market_format_prices, {currency, amount})
+    end
+
+    memory.items[group_name][item_name] = market_format_prices
+end
+
+---Returns all item for the group_name retailer.
+---@param group_name string
+function Retailer.get_items(group_name)
+    return memory.items[group_name] or {}
+end
+
+---Removes an item from the markets for the group_name retailer.
+---@param group_name string
+---@param item_name string
+function Retailer.remove_item(group_name, item_name)
+    if not memory.items[group_name] then
+        return
+    end
+
+    memory.items[group_name][item_name] = nil
+end
+
+---Ships the current list of items with their prices to all markets for the group_name retailer.
+---@param group_name string
+function Retailer.ship_items(group_name)
+    local markets = memory.markets[group_name]
+    if not markets then
+        return
+    end
+
+    local market_items = memory.items[group_name]
+    if not market_items then
+        -- items have not been added yet
+        return
+    end
+
+    for _, market in ipairs(markets) do
+        if market.valid then
+            -- clean the current inventory
+            local remove_market_item = market.remove_market_item
+            -- remove re-indexes the offers, to prevent shifting, go backwards
+            local current_market_items = market.get_market_items()
+            if current_market_items then
+                for current_index = #current_market_items, 1, -1 do
+                    remove_market_item(current_index)
+                end
+            end
+
+            -- re-add the whole list
+            local add_market_item = market.add_market_item
+            for item_name, prices in pairs(market_items) do
+                add_market_item({
+                    price = prices,
+                    offer = {type = 'give-item', item = item_name, count = 1}
+                })
+            end
+        end
+    end
+end
+
+return Retailer