SpawnerVerticalBuilder

-- ItemSupply:
-- rows, starting with 1
stoneBlock = 1
dirtBlock = 2
redstoneBlock = 3
fanBlock = 4

spawnerHeight = 1

-- moves row to the first slow of the row
-- at least keep Target supply in slot
function moveSupplyRow(row, target)
    if not target then target = 16 end

    local start = (row-1)*4+2
    for i = start, (row)*4 do
        -- exit if enough items
        if turtle.getItemCount(start-1) >= target then break end

        turtle.select(i)
        turtle.transferTo(start-1)
    end
end

function row2slot(row)
    return (row-1)*4+1
end

function buildLevel()
    -- place dirt
    if dirtEnabled then
        moveSupplyRow(dirtBlock)
        turtle.select(row2slot(dirtBlock))
        turtle.place()
    end
    -- move up
    turtle.up()
    --place stone brick below
    moveSupplyRow(stoneBlock)
    turtle.select(row2slot(stoneBlock))
    turtle.placeDown()
    -- place fan
    if fanEnabled then
        turtle.forward(); turtle.forward(); turtle.turnLeft(); turtle.turnLeft()
        moveSupplyRow(fanBlock)
        turtle.select(row2slot(fanBlock))
        turtle.place()
        --move up and back to wall position
        turtle.up()
        turtle.turnLeft(); turtle.turnLeft(); turtle.back(); turtle.back()
    else
        turtle.up()
    end

    -- place redstone block below?
    if redstoneEnabled then
        moveSupplyRow(redstoneBlock)
        turtle.select(row2slot(redstoneBlock))
        turtle.placeDown()
    end

    turtle.select(row2slot(stoneBlock))
    -- Which height?
    -- i = 1 -> 2 blocks height
    -- i = 2 -> 3 blocks height
    -- ...
    for i = 1, spawnerHeight do
        -- place stone brick
        turtle.up()
        turtle.placeDown()
    end

    -- place floor of the next level
    turtle.place()

    turtle.up()
    turtle.placeDown()
end

buildLevels = 1
fanEnabled = false
redstoneEnabled = false
stoneEnabled = true
dirtEnabled = true

print("How many levels to build? Default: 1")
buildLevels = tonumber(io.read()) or 1
print("--> ".. tostring(buildLevels) .. " levels")

print("Build redstone? Y/n")
redstoneEnabled = false
if string.lower(io.read()) == "n" then
    redstoneEnabled = false
else
    redstoneEnabled = true
end

print("--> Build redstone: ".. tostring(redstoneEnabled))

print("Build fans? y/N")
fanEnabled = string.lower(io.read()) == "y" and true or false
print("--> Build fans: ".. tostring(fanEnabled))

for n = 1, buildLevels do
    buildLevel()
end