Cow Farmer

local HOME = vector.new(7,69,124)
local STARTROW1 = vector.new(6, 71, 122)
local ENDROW1 = vector.new(-14, 71, 122)
local STARTROW2 = vector.new(-14, 71, 121)
local ENDROW2 = vector.new(6, 71, 121)

local pos, dir

function init()
    main()
end

function getOrientation()
    print("getting Orientation")
    loc1 = vector.new(gps.locate(2, false))
    if not turtle.forward() then
        for j=1,6 do
                if not turtle.forward() then
                        turtle.turnRight()
             else break end
        end
    end
    loc2 = vector.new(gps.locate(2, false))
    heading = loc2 - loc1
    return ((heading.x + math.abs(heading.x) * 2) + (heading.z + math.abs(heading.z) * 3))
end

function forward()
    while not turtle.forward() do end
    local heading = vector.new(0,0,0)
    if dir == 1 then
        heading = vector.new(-1,0,0)
    elseif dir == 2 then
        heading = vector.new(0,0,-1)
    elseif dir == 3 then
        heading = vector.new(1,0,0)
    elseif dir == 4 then
        heading = vector.new(0,0,1)
    end
    pos = pos + heading
end

function back()
    while not turtle.back() do end
    if dir == 1 then
        heading = vector.new(-1,0,0)
    elseif dir == 2 then
        heading = vector.new(0,0,-1)
    elseif dir == 3 then
        heading = vector.new(1,0,0)
    elseif dir == 4 then
        heading = vector.new(0,0,1)
    end
    pos = pos - heading
end

function up()
    while not turtle.up() do end
    pos = pos + vector.new(0,1,0)
end

function down()
    while not turtle.down() do end
    pos = pos - vector.new(0,1,0)
end

function left()
    turtle.turnLeft()
    dir = dir - 1
    if dir < 1 then dir = dir + 4 end
end

function right()
    turtle.turnRight()
    dir = dir + 1
    if dir > 4 then dir = dir - 4 end
end

function setDir(destDir)
    while dir ~= destDir do
        right()
    end
end

function goto(vec, finalDir)
    if pos.x < vec.x then
        setDir(3)
    elseif pos.x > vec.x then
        setDir(1)
    end

    while pos.x ~= vec.x do
        forward()
    end

    if pos.z > vec.z then
        setDir(2)
    elseif pos.z < vec.z then
        setDir(4)
    end

    while pos.z ~= vec.z do
        forward()
    end

    while pos.y > vec.y do
        down()
    end

    while pos.y < vec.y do
        up()
    end

    setDir(finalDir)
end

function goHome()
    goto(HOME, 4)
end

function makeARound()
    goto(STARTROW1, 1)
    while pos ~= ENDROW1 do
        while turtle.attackDown() do end
        forward()
    end
    goto(STARTROW2, 3)
    while pos ~= ENDROW2 do
        while turtle.attackDown() do end
        forward()
    end
    goHome()
end

function main()
    while true do
        makeARound()
        sleep(120)
    end
end

dir = getOrientation()
pos = vector.new(gps.locate())

print(dir)
print(pos)
init()