Wither Boss Builder Computercraft

-- Minecraft Wither Boss Builder (left to right).
-- Requires:
-- 5x5x5 area
-- chest (Place the chest next(Left side) the turtle)
-- Slot 1, Soul Sand
-- Slot 2, Wither Skeleton Skull (if you wanna test it first ,use a regular Skeleton Skull instead )
-- Slot 3, Coal




local td ={ name = {"minecraft:soul_sand","minecraft:skull","minecraft:coal"}, min = {5,3,1} }
local chestSide =0


function NeedFuel()
    if turtle.getFuelLevel() ~= "unlimited" and turtle.getFuelLevel() < 1  then

    turtle.select(3)
            if turtle.refuel() then
                print("Fuel level is: ", ( turtle.getFuelLevel() / turtle.getFuelLimit() ) * 100, "%")
            else
                print("Can't refuel ,Place some Coal in the 1st Slot")
            end
    else print("Fuel level is: ", ( turtle.getFuelLevel() / turtle.getFuelLimit() ) * 100, "%","We can still move", turtle.getFuelLevel(), "blocks")
end
end


function findchest()
local ChestEx
local EnderChestEx

    for i=1 , 4 do
        local success, data = turtle.inspect()
            if success then
                    ChestEx= string.find(data.name, "chest")
                    EnderChestEx= string.find(data.name, "Chest")

                    if ChestEx or EnderChestEx then
                        for i=1 , 3 do
                        turtle.select(i)
                        turtle.drop()
                        end
                        chestSide=i
                        getItems()
                        return true
                    else
                        turtle.turnRight()
                    end
            else
                turtle.turnRight()
            end
    end
        --shell.run("clear")
        print("Place the chest next(L) the turtle then add at last soul sand(5),skulls(3),coal(1) into it")
    return false
end


function SortItem(s)
    ItemDatastack=turtle.getItemDetail(s)

    if ItemDatastack then

                turtle.select(s)
        if (ItemDatastack.name==td.name[1] )  then
                turtle.transferTo(1)
            elseif  (ItemDatastack.name==td.name[2]) then
                turtle.transferTo(2)
            elseif  (ItemDatastack.name==td.name[3]) then
                turtle.transferTo(3)
            else
                turtle.drop()
        end
    end
end


function getItems()
turtle.select(4)
    while true do
        local Item = turtle.suck()
        if not Item then
            for i=1 , 16 do
                SortItem(i)
            end
            return false
        end
        -- for i=4 , 16 do
        -- turtle.select(i)
        -- turtle.drop()
        -- end
    end
end


function CountItem()
local count =true
local ItemDatastack={}
for i=1 , 2 do
turtle.select(i)
ItemDatastack=turtle.getItemDetail(i)
    if  ItemDatastack then
        if (ItemDatastack.count<td.min[i]) then
        print("---------------------------------------")
        print("add more: ",string.sub(ItemDatastack.name, 11))
        print("---------------------------------------")
        count=false
        end
        else
        print("---------------------------------------")
        print("add : ",string.sub(td.name[i], 11)," to chest")
        print("---------------------------------------")
        count=false
    end
end
if not count then
return false
else
return true
end
turtle.select(1)
end


function PreBuild()
for i=4 , 16 do
turtle.select(i)
turtle.drop()
end
for i=1, chestSide+1 do
turtle.turnRight()
end
end


function BuildWither()
turtle.forward()
turtle.up()
turtle.select(1)
turtle.place()
PlaceWitherHead()
MoveToNext()
PlaceWitherHead()
turtle.down()
turtle.place()
turtle.up()
MoveToNext()
PlaceWitherHead()
end


function MoveToNext()
turtle.turnRight()
turtle.forward()
turtle.turnLeft()
turtle.place()
end


function PlaceWitherHead()
turtle.select(2)
turtle.up()
turtle.place()
turtle.down()
turtle.select(1)
end


function BackToFirst()
turtle.turnLeft()
turtle.forward()
turtle.forward()
turtle.turnRight()
turtle.down()
turtle.back()
end


if findchest()   then
PreBuild()
while CountItem() do
NeedFuel()
BuildWither()
BackToFirst()
sleep(15)
end
end