GPS api v1

BetterGPS = {
    pos = vector.new(0, 0, 0),
    dir = "N"
}

function BetterGPS:new(pos, dir)
    local pos = pos or vector.new(0, 0, 0)
    local dir = dir or "e"
    if type(pos) ~= "table" then
        error("new pos expects to be a vector, currently is " .. type(pos), 2)
    elseif type(dir) ~= "string" then
        error("new dir expects to be a string, currently is " .. type(dir), 2)
    elseif dir:lower() ~= "n" and dir:lower() ~= "s" and dir:lower() ~= "w" and dir:lower() ~= "e" then
        error("new dir expects to be n, s, w or e, currently is " .. dir:lower(), 2)
    end
    setmetatable({}, BetterGPS)
    self.pos = pos
    self.dir = dir
    return self
end

function BetterGPS:forward()
    if turtle.forward() then
        if self.dir == "n" then
            self.pos.y = self.pos.y - 1
        elseif self.dir == "s" then
            self.pos.y = self.pos.y + 1
        elseif self.dir == "e" then
            self.pos.x = self.pos.x + 1
        elseif self.dir == "w" then
            self.pos.x = self.pos.x - 1
        end
        return true
    end
    return false
end
function BetterGPS:back()
    if turtle.back() then
        if self.dir == "n" then
            self.pos.y = self.pos.y + 1
        elseif self.dir == "s" then
            self.pos.y = self.pos.y - 1
        elseif self.dir == "e" then
            self.pos.x = self.pos.x - 1
        elseif self.dir == "w" then
            self.pos.x = self.pos.x + 1
        end
        return true
    end
    return false
end
function BetterGPS:left()
    if turtle.turnLeft() then
        if self.dir == "n" then
            self.dir = "w"
        elseif self.dir == "w" then
            self.dir = "s"
        elseif self.dir == "s" then
            self.dir = "e"
        elseif self.dir == "e" then
            self.dir = "n"
        end
    end
end
function BetterGPS:right()
    if turtle.turnRight() then
        if self.dir == "n" then
            self.dir = "e"
        elseif self.dir == "e" then
            self.dir = "s"
        elseif self.dir == "s" then
            self.dir = "w"
        elseif self.dir == "w" then
            self.dir = "n"
        end
    end
end

function BetterGPS:hasModem()
    if peripheral.getType("right") == "modem" or peripheral.getType("left") == "modem" then
        return true
    else
        return false
    end
end
function BetterGPS:scan(scans)
    local scans = scans or 5
    local side, position = nil, nil
    if type(scans) ~= "number" then
        error("GPS scan expects to get a number, currently is " .. type(scans), 2)
    end
    if rednet.isOpen("left") then
        side = "left"
        rednet.close("left")
    elseif rednet.isOpen("right") then
        side = "right"
        rednet.close("right")
    elseif rednet.isOpen("front") then
        side = "front"
        rednet.close("front")
    elseif rednet.isOpen("back") then
        side = "back"
        rednet.close("back")
    elseif rednet.isOpen("top") then
        side = "top"
        rednet.close("top")
    elseif rednet.isOpen("bottom") then
        side = "bottom"
        rednet.close("bottom")
    end

    position = vector.new(gps.locate(scans))
    if not position.x then
        return false
    end
    self.pos = position:round()
    if side ~= nil then
        rednet.open(side)
    end
    return self.pos
end
function BetterGPS:locate(scans)
    local scans = scans or 5
    local this_new_position
    if type(scans) ~= "number" then
        error("GPS locate expects to get a number, currently is " .. type(scans), 2)
    end
    local slot
    local equip = "left"
    if peripheral.getType("left") == "chunkLoader" then
        equip = "right"
    end
    if not self:hasModem() then
        for i = 1, 16 do
            slot = turtle.getItemDetail(i)
            if slot and slot.name == "ComputerCraft:CC-Peripheral" then
                turtle.select(i)
                if equip == "left" then
                    turtle.equipLeft()
                else
                    turtle.equipRight()
                end
                if peripheral.getType(equip) == "modem" then
                    return self:scan(scans)
                end
                if equip == "left" then
                    turtle.equipLeft()
                else
                    turtle.equipRight()
                end
            end
        end
        error("BetterGPS Couldn't find a modem", 2)
    else
        return self:scan(scans)
    end
end
function BetterGPS:getDir(scans)
    local scans = scans or 5
    local turns = 0
    local yLocations = {}
    local xLocations = {}
    local location = nil
    location = self:locate(scans)
    if location then
        table.insert(xLocations, tonumber(location.x))
        table.insert(yLocations, tonumber(location.y))
    else
        error("getDir No location found", 2)
    end
    location = nil

    while not self:forward() do
        self:left()
        turns = turns + 1
        if turns == 4 then
            while turtle.detect() do
                turtle.dig()
                turtle.attack()
            end
            turns = 0
        end
    end

    location = self:locate(scans)
    if location then
        table.insert(xLocations, tonumber(location.x))
        table.insert(yLocations, tonumber(location.y))
    else
        error("getDir No location found", 2)
    end
    while not self:back() do
        sleep(1)
    end

    if yLocations[1] ~= yLocations[2] then
        if yLocations[1] + 1 == yLocations[2] then
            self.dir = "s"
        else
            self.dir = "n"
        end
    elseif xLocations[1] ~= xLocations[2] then
        if xLocations[1] + 1 == xLocations[2] then
            self.dir = "e"
        else
            self.dir = "w"
        end
    end
    for i = 1, turns do
        self:right()
    end
    return self.dir
end