Traffic Lights v2

if turtle then
    turtle.equipLeft()
    turtle.equipLeft()
    turtle.equipRight()
    turtle.equipRight()
end

local function fetch(u)
    local h = http.get(u)
    local c = h.readAll()
    h.close()
    return c
end

local function update()
    local data = fetch "https://pastebin.com/raw/ZfhJz6n4"
    if data then
        local f = fs.open("startup", "w")
        f.write(data)
        f.close()
    end
end

if process then process.signal("signd", process.signals.KILL) end

local ni = peripheral.find "neuralInterface"
local sign = peripheral.find "minecraft:sign"
local sensor, laser
if not ni then
    sensor = peripheral.find "plethora:sensor"
    laser = peripheral.find "plethora:laser"
else
    sensor = ni
    laser = ni
end
local speaker = peripheral.find "speaker"

local function get_direction(entity)
    local x, y, z = entity.x, entity.y, entity.z
    local pitch = -math.atan2(y, math.sqrt(x * x + z * z))
    local yaw = math.atan2(-x, z)

    print(yaw, pitch)

    return math.deg(yaw), math.deg(pitch)
end

local function shoot(entity)
    local dn = entity.displayName
    if dn:find "gollark" or dn:find "laser" or dn:find "Arrow" then return end
    local y, p = get_direction(entity)
    if speaker then speaker.playSound "entity.lightning.impact" end
    laser.fire(y, p, 5)
end

local banned = {
}

local function update_banned()
    while true do
        local l = textutils.unserialise(fetch(settings.get "traffic.ban_list" or "https://pastebin.com/raw/phbWuSXd"))
        if type(l) == "table" then
            banned = {}
            for _, v in pairs(l) do
                print("Banned:", v)
                banned[v] = true
            end
        else
            printError "Invalid Banned List."
        end
        sleep(15)
    end
end

local function main()
    local incidents = 0
    while true do
        local entities = sensor.sense()
        for _, entity in pairs(entities) do
            --if entity.displayName:find "item." then shoot(entity) end
            local velocity = vector.new(entity.motionX, entity.motionY + 0.0784, entity.motionZ) -- compensate for gravity
            local position = vector.new(entity.x, entity.y, entity.z)
            local distance = position:length()
            local speed = velocity:length()
            if (speed > 0.8) and not settings.get "traffic.ignore_speed" then
                incidents = incidents + 1
                shoot(entity)
            end
            if (distance < 1.5) and not settings.get "traffic.ignore_near" then
                shoot(entity)
            end
            if speed > 1e-5 then
                print(entity.displayName, "V", speed, "D", distance)
            end
            if banned[entity.displayName] then shoot(entity) end
        end
        if sign then sign.setSignText("Speed Limit", "Violations:", tostring(incidents)) end
        sleep(1)
    end
end

parallel.waitForAll(update, main, update_banned, function()
    while true do local _, k = os.pullEvent "key" if k == keys.u then break end end
    update()
    os.reboot()
end)