local inventory = require("component").inventory_controller
local side = require("sides").front

local fuel_names = { ["minecraft:coal"] = true, ["minecraft:planks"] = true, ["minecraft:log"] = true, ["minecraft:blaze_rod"] = true, ["minecraft:lava_bucket"] = true}

local function getCoal(stack_info)
    if computer.energy() <= 200 then
        robot.select(5); robot.drop(); robot.select(16); robot.drop()
        robot.select(14); robot.place(); robot.select(15)
        return fuel_names[stack_info]
    end

    for slot=1,27 do
        local item = inventory.getStackInSlot(side, slot)
        if item and fuel_names[item.id] then
            inventory.suckFromSlot(sides.front, slot)
            break
        end
    end
    robot.select(16); inventory.dropIntoSlot(side, 1); robot.select(5); robot.swing(); robot.transferTo(14)
end

getCoal("minecraft:planks")