Started Inventory class; added item sorting

jturtle/inventory.lua

@@ -0,0 +1,150 @@
+-- Created by Jef Roosens
+
+-- Manages the inventory
+local Inventory = {
+    selected = nil,  -- Currently selected slot
+    slots    = nil,  -- table containing contents of all slots
+    items    = nil,  -- table containing items and their slots (fast lookup)
+    free     = nil,  -- table containing free slots
+}
+
+
+function Inventory:new(o)
+    o = o or {}
+    setmetatable(o, self)
+    self.__index = self
+
+    o.selected = selected or turtle.getSelectedSlot()
+
+    -- Update inventory if no data is provided
+    -- Empty tables are also truethy
+    if o.slots == nil or o.items == nil then o:update() end
+
+    return o
+end
+
+
+-- Select the given slot if valid
+--
+-- @param slot slot to select
+function Inventory:select(slot)
+    -- Exit if needed
+    if self.selected == slot or slot < 1 or slot > 16 then return end
+
+    turtle.select(slot)
+    self.selected = slot
+end
+
+
+-- Transfer items between slots.
+--
+-- @param from slot to transfer from
+-- @param to slot to transfer to
+-- @param count amount of items to transfer. If count is not specified or count
+-- is greater than the possible transfer, the maximum transfer will be done.
+-- @return wether all items were transferred
+function Inventory:transfer(from, to, count)
+    -- Exit if from is empty
+    if not self.slots[from] then return true end
+
+    count = count or self.slots[from].count
+    local return_value = true
+
+    -- If to isn't empty, check if we can fit it all and if they're the same
+    -- item type
+    if self.slots[to] then
+        -- Exit if it's a differen item type or if there's no space left
+        if self.slots[to].name ~= self.slots[from].name or
+            self.slots[to].count == 64 then return false end
+
+        count = math.min(count, 64 - self.slots[to].count)
+        return_value = count == self.slots[from].count
+    end
+
+    -- Transfer the items
+    self:select(from)
+    turtle.transferTo(to, count)
+
+    self:update()
+
+    return return_value
+end
+
+
+-- Scan inventory and store updates
+function Inventory:update()
+    local slots, items = {}, {}
+
+    for i = 1, 16 do
+        local data = turtle.getItemDetail(i)
+
+        if data then
+            slots[i] = data
+
+            if items[data.name] then
+                table.insert(items[data.name], i)
+
+            else
+                items[data.name] = {i}
+            end
+        end
+    end
+
+    self.slots = slots
+    self.items = items
+end
+
+
+-- Returns wether or not the inventory contains the given item
+--
+-- @param item_name item name to look for
+-- @return bool wether or not the item is in the inventory
+function Inventory:has(item_name)
+    return self.items[item_name] ~= nil
+end
+
+
+-- Returns wether the requested slot is free
+--
+-- @param slot slot to check
+function Inventory:is_free(slot)
+    return self.slots[slot] == nil
+end
+
+
+-- Compact an item in the inventory; this means moving as much of the items to
+-- as little of the used slots as possible
+--
+-- @param item_name item to compact
+function Inventory:sort_item(item_name)
+    -- atm we assume the item is in the inventory
+    local slots = self.items[item_name]
+
+    local i, j = 1, 2
+
+    while j <= #slots do
+        if self:transfer(slots[j], slots[i]) then
+            j = j + 1
+
+        else
+            i = i + 1
+            j = i + 1
+        end
+    end
+end
+
+
+-- Compact the inventory; this means moving all items to the lowest possible
+-- slots
+function Inventory:sort()
+    -- Sort all items
+    for item, _ in pairs(self.items) do
+        self:sort_item(item)
+    end
+
+    -- Move them all to lowest slots
+    -- TODO implement this
+end
+
+
+return {Inventory=Inventory}