init = false
finished = false

function flip()
    turtle.turnLeft()
    turtle.turnLeft()
end

while true do
    if(turtle.getFuelLevel() < 1000) then
        turtle.refuel()
    end

    while not init do
        if(rs.getInput("top")) then
            switch = true
            init = true
        end
    end

    startingPosition = false
    while switch do
        --set turtle to correct position
        turtle.forward()
        turtle.turnLeft()
        while not startingPosition do
            local succes, data = turtle.inspect()
            if succes then
                if not data.name == "minecraft:piston" then
                    turtle.forward()
                else
                    turtle.turnRight()
                    turtle.turnRight()
                    startingPosition = true
                end
            end
        end

        --place ender pearl on empty spot (best on endstone)
        while startingPosition do
            local succes, data = turtle.inspect()

            if not succes then -- if "air" then
            turtle.forward()
            else if succes and data.name == "ExtraUtilities:etherealglass" then
                turtle.turnLeft()
                if not turtle.detect() then
                    turtle.forward()
                    turtle.turnLeft()
                else
                    switch = false
                    finished = true
                    startingPosition = true
                end
            else if succes and data.name == "minecraft:piston" then
                turtle.turnRight()
                if not turtle.detect() then
                    turtle.forward()
                    turtle.turnRight()
                else
                    switch = false
                    finished = true
                    startingPosition = false
                end
            end
        end

        --go back to docking station
        while finished do
            flip()
            local movingBackToStartLocation = true
            while movingBackToStartLocation do
                turtle.forward()
                succes, data = turtle.inspectDown()
                if succes then
                    if data.name == "minecraft:chest" then
                        movingBackToStartLocation = false;
                    else if not data.name == "minecraft:chest" then
                        turtle.turnLeft()
                        if turtle.detect() then
                            flip()
                            while not data.name == "minecraft:chest" do
                                turtle.forward()
                            end
                        end
                    end
                end
            end
        end
    end
end