pathBuilder

-- pastebin run FuQ3WvPs NJWn1GC5 pathBuilder
-- config
print ("Enter path width (must be odd): ")
local pathWidth = tonumber(read())
print ("\nEnter path length: ")
local pathLength = tonumber(read())
print ("\nPress Enter to start!")
local start = read("")
--local pathWidth = 3 -- has to be odd, but can be changed
local placeTorchAt = 8
--local pathLength = 32

-- DONT CHANGE (JUST YET)
local ceiling = true -- unused right now
local wallHeight = 2 -- not variable yet
local errorLv = 0
local torches = turtle.getItemCount(1)
local fuel = turtle.getItemCount(2)
local maxFuel = fuel
local torchType = turtle.getItemDetail(1).name
local fuelType = turtle.getItemDetail(2).name
local buildingBlockType = turtle.getItemDetail(3).name
local distance = 0
local buildSlot = 3

function selectBuildingBlockSlot ()
    buildingMaterial = 0
    local maxMaterial = -1
    local maxSlot = 3
    for i = 3, 16, 1 do
        local det = turtle.getItemDetail(i)
        if det and det.name == buildingBlockType then
            if det.count > maxMaterial then maxSlot = i end
            buildingMaterial = buildingMaterial + det.count
        end
    end
    buildSlot = maxSlot

    if buildingMaterial <= ((pathWidth * 2) + (wallHeight * 2)) then
        print ("Not enough building material!\n")
        errorLv = 1
    end

    return buildSlot
end

function placeBlock (direction)
    if direction == "down" then
        local _, data = turtle.inspectDown()
        if data.name == buildingBlockType then return end
        while turtle.detectDown() do turtle.digDown() end
        checkSlot()
        if not turtle.placeDown() then
            turtle.select(selectBuildingBlockSlot())
            turtle.placeDown()
        end
    elseif direction == "up" then
        local _, data = turtle.inspectUp()
        if data.name == buildingBlockType then return end
        while turtle.detectUp() do turtle.digUp() end
        checkSlot()
        if not turtle.placeUp() then
            turtle.select(selectBuildingBlockSlot())
            turtle.placeUp()
        end
    else
        local _, data = turtle.inspect()
        if data.name == buildingBlockType then return end
        while turtle.detect() do turtle.dig() end
        checkSlot()
        if not turtle.place() then
            turtle.select(selectBuildingBlockSlot())
            turtle.place()
        end
    end
end

function checkInventory ()
    print ("Checking inventory...\n")
    torches = turtle.getItemCount(1)
    fuel = turtle.getItemCount(2)

    selectBuildingBlockSlot()

    print ("Torches: " .. tostring(torches) .. "\nFuel: " .. tostring(fuel) .. "\nBuilding Material: " .. tostring(buildingMaterial) .. "\n")

    if pathWidth > 1 and torches <= 1 or turtle.getItemDetail(1).name ~= torchType then
        print ("Not enough torches!\n")
        errorLv = 1
    end
    if turtle.getFuelLevel() <= distance and turtle.getItemDetail(2).name ~= fuelType  then
        print ("Not enough fuel!\n")
        errorLv = 1
    end

    print ("Error Level: " .. tostring(errorLv) .. "\n")
end

function home ()
    turtle.turnLeft()
    turtle.turnLeft()

    for i = 1, distance, 1 do
        turtle.forward()
    end
end

function checkSlot ()
    if turtle.getItemCount(turtle.getSelectedSlot()) == 0 or turtle.getItemCount(turtle.getSelectedSlot()) > 0 and turtle.getItemDetail(turtle.getSelectedSlot()) ~= buildingBlockType then
        turtle.select(selectBuildingBlockSlot())
    end
end

function run ()
    print ("Starting Program...\n")
    while (true) do
        checkInventory ()
        if errorLv ~= 0 or distance >=  pathLength then
            home()
            return
        end

        -- Refuel
        if turtle.getFuelLevel() == 0 then
            turtle.select(2)
            turtle.refuel()
        end

        -- Dig width
        --print ("dig width\n")
        turtle.select(selectBuildingBlockSlot())
        while turtle.detectUp() do
            turtle.digUp()
        end

        placeBlock("down")

        -- right side
        --print ("right side\n")
        turtle.turnRight()
        for i = 1, (pathWidth - 1) / 2, 1 do
            while not turtle.forward() do
                turtle.dig()
            end

            placeBlock("down")
        end

        placeBlock()

        while not turtle.up() do
            turtle.digUp()
        end

        placeBlock("up")

        placeBlock()

        -- check if torch should be placed
        if pathWidth > 1 and distance % placeTorchAt == 0 then
            turtle.select(1)
            turtle.placeDown()
            turtle.select(selectBuildingBlockSlot())
        end

        -- go back
        --print ("go back\n")
        turtle.turnLeft()
        turtle.turnLeft()
        for i = 1, (pathWidth - 1) / 2, 1 do
            while not turtle.forward() do
                turtle.dig()
            end

            placeBlock ("up")
        end

        -- left side
        --print ("left side\n")
        for i = 1, (pathWidth - 1) / 2, 1 do
            while not turtle.forward() do
                turtle.dig()
            end

            placeBlock("up")
        end

        placeBlock()

        while not turtle.down() do
            turtle.digDown()
        end

        placeBlock("down")

        placeBlock()

        -- go back
        --print ("go back 2\n")
        turtle.turnLeft()
        turtle.turnLeft()
        for i = 1, (pathWidth - 1) / 2, 1 do
            while not turtle.forward() do
                turtle.dig()
            end
            if i < ((pathWidth - 1) / 2) then
                placeBlock("down")
            end
        end

        --print ("Turn left\n")
        turtle.turnLeft()

        -- Move forward
        --print ("move forward\n")
        while not turtle.forward() do
            turtle.dig()
        end
        distance = distance + 1
        print ("Current distance: " .. tostring(distance) .. " / " .. tostring(pathLength) .. "\n")
    end
end

run()