Computercraft Turtle place Windmill

local forwardStep = 0
local continue = true
local goHome = false
local goBack = false
local atHome = true


--functions for Preparing Work--
function refuel()
    turtle.select(16)
    turtle.refuel()
    turtle.select(1)
end

function getWindmills()
    for i=1,14 do
        turtle.select(i)
        if turtle.getItemCount() == 0 then
            turtle.suck(1)
        end
    end
    turtle.select(15)
end

function getCablesAndBlocks()
    turtle.turnRight()
    turtle.select(15)
    if turtle.getItemCount() >= 1 then
        if turtle.getItemDetail().name == "mekanism:transmitter" then
            turtle.suck(turtle.getItemSpace())
        else
            os.exit()
        end
    else turtle.suck(turtle.getItemSpace())
    end
    turtle.turnLeft()
    turtle.turnLeft()
    turtle.select(16)
    if turtle.getItemCount() >= 1 then
        if turtle.getItemDetail().name == "minecraft:quartz_block" then
            turtle.suck(turtle.getItemSpace())
        else
            os.exit()
        end
    else turtle.suck(turtle.getItemSpace())
    end
    turtle.turnRight()
end

--Functions for Work

function goToStart()
    turtle.down()
    turtle.down()
    turtle.down()
    while not turtle.detect() do
        turtle.forward()
    end
    while not turtle.detectDown() do
        turtle.down()
    end
    turtle.forward()
    turtle.forward()
    turtle.forward()
    turtle.select(16)
    if not turtle.detectUp() then
        turtle.placeUp()
    end
end

function goBackInLine()
    turtle.turnLeft()
    turtle.turnLeft()
    while not turtle.detectUp() do
        turtle.forward()
    end
end

function returnToHome()
    goBackInLine()
    if turtle.detect() then
        local atReturnPoint = false
        turtle.turnLeft()

        while not atReturnPoint do
            turtle.forward()
            if not turtle.detectUp() then
                turtle.forward()
            else
                turtle.turnRight()
                if turtle.detect() then
                    atReturnPoint = false
                    turtle.turnLeft()
                else
                    atReturnPoint = true
                end

            end
        end
        turtle.forward()
        turtle.forward()
        turtle.forward()
        while not turtle.detectUp() do turtle.up() end
        while not turtle.detect() do turtle.forward() end
        turtle.up()
        turtle.up()
        turtle.up()
        turtle.turnLeft()
        turtle.turnLeft()
    end
    goHome = false
end



local function getCurrentTurbineSlot()
    for i=1,14 do
        turtle.select(i)
        if turtle.getItemCount() >= 1 then
            return i
        end
    end
    return 16
end

local function checkIfSufficientLeft()
    if getCurrentTurbineSlot() >= 15 then
        write("Not enough Wind generators. \nGoing to return Home\n")
        goHome = true
        return false
    else
        write("Enough Wind generators available.\n")
        goHome = false
        return true
    end
end

function placeTurbines()
    turtle.down()
    turtle.down()
    turtle.turnRight()
    turtle.select(16)
    turtle.place()
    turtle.turnLeft()
    turtle.turnLeft()
    turtle.place()
    turtle.up()
    turtle.select(getCurrentTurbineSlot())
    turtle.place()
    turtle.turnRight()
    turtle.turnRight()
    turtle.select(getCurrentTurbineSlot())
    turtle.place()
    turtle.turnLeft()
    turtle.up()
    turtle.select(15)
    turtle.placeDown()
end


function toNextStop()
    for i=1,4 do
        if not turtle.detectDown() then
            turtle.select(15)
            turtle.placeDown()
        end
        turtle.forward()
    end
end

function doLine()
    toNextStop()
    forwardStep = 1
    while forwardStep <=21 and not goHome do
        if not turtle.detectDown() then
            placeTurbines()
        end
        checkIfSufficientLeft()
        if not goHome then
            toNextStop()
        end
        forwardStep = forwardStep + 1
    end
    if forwardStep > 21 then
        goBack = true
    end

end

function operateNormal()
    write("Starting Operation\n")
    checkIfSufficientLeft() --sets goHome to true if not enough Windmills left
    if not goHome and not goBack then
        write("sufficient Windmills left\n")
        -- Checking if active Line is to be used (defined by block)
        if not turtle.detect() and not turtle.detectUp() then --if block is detected means line is closed
            write("line is not yet started\n")
            --Placing block left and right
            turtle.turnLeft()
            turtle.select(16)
            turtle.place()
            turtle.turnRight()
            turtle.turnRight()
            turtle.place()
            turtle.turnLeft()

            doLine()

        elseif not turtle.detect() and turtle.detectUp() then
            write("this line is already active. continuing\n")
            doLine()

        else
            write("this line is done. looking for other line\n")
            --Turtle goes to furthest Station Left until hitting Block
            turtle.turnLeft()
            while not turtle.detect() do
                toNextStop()
            end
            write("Found End. Checking if Active line\n")
            turtle.turnRight()
            if turtle.detect() then
                write("Line not active. Starting new Line. \n Building new Station\n")
                turtle.turnLeft()
                --Turtle makes new Station (Station = point from which line goes)
                turtle.dig()
                toNextStop()
                turtle.select(16)
                turtle.placeUp()
                turtle.place()
                turtle.turnLeft()
                turtle.place()
                turtle.turnRight()
                turtle.turnRight()
                --Turtle does new line
                doLine()
            else
                write("Active Line detected. Continuing\n")
                doLine()
            end
        end
    elseif goBack then
        write("going back to start of Lane,\n")
        goBackInLine()
        turtle.turnRight()
        turtle.turnRight()
        turtle.select(16)
        turtle.place()
        goBack = false
    elseif goHome then
        write("going Home.\n")
        returnToHome()
        getCablesAndBlocks()
        getWindmills()
        atHome = true
        continue = not redstone.getInput("back")
        if continue then
            goToStart()
            atHome = false
        end

    end
end

--Calls for preparing work--

--Optional:
--refuel()



--Calls for Starting to Work

while true do
    if atHome then
        continue = not redstone.getInput("back")
        if continue then
            getCablesAndBlocks()
            getWindmills()
            goToStart()
        end
    else
        continue = true
    end
    while continue do
        operateNormal()
    end
end