ARR Switch

local monitor = peripheral.find "monitor"

local function set_color(c)
    monitor.setBackgroundColor(c)
    monitor.clear()
end

set_color(colors.lime)
local sensor = peripheral.find "plethora:sensor"
local label = os.getComputerLabel()
local switch_config = dofile "config.lua"

local function spudnet()
    if not http or not http.websocket then return "Websockets do not actually exist on this platform" end

    local ws

    local function send_packet(msg)
        local ok, err = pcall(ws.send, textutils.serialiseJSON(msg))
        if not ok then printError(err) try_connect_loop() end
    end

    local function send(data)
        send_packet { type = "send", channel = "comm:arr", data = data }
    end

    local function connect()
        if ws then ws.close() end
        ws, err = http.websocket "wss://spudnet.osmarks.net/v4?enc=json"
        if not ws then print("websocket failure %s", err) return false end
        ws.url = "wss://spudnet.osmarks.net/v4?enc=json"

        send_packet { type = "identify", implementation = "ARR switching unit", key = settings.get "spudnet_key" }
        send_packet { type = "set_channels", channels = { "comm:arr" } }

        print("websocket connected")

        return true
    end

    local function try_connect_loop()
        while not connect() do
            sleep(0.5)
        end
    end

    try_connect_loop()

    local function recv()
        while true do
            local e, u, x = os.pullEvent "websocket_message"
            if u == ws.url then return textutils.unserialiseJSON(x) end
        end
    end

    local ping_timeout_timer = nil

    local function ping_timer()
        while true do
            local _, t = os.pullEvent "timer"
            if t == ping_timeout_timer and ping_timeout_timer then
                -- 15 seconds since last ping, we probably got disconnected
                print "SPUDNET timed out, attempting reconnect"
                try_connect_loop()
            end
        end
    end

    local function main()
        while true do
            local packet = recv()
            if packet.type == "ping" then
                send_packet { type = "pong", seq = packet.seq }
                if ping_timeout_timer then os.cancelTimer(ping_timeout_timer) end
                ping_timeout_timer = os.startTimer(15)
            elseif packet.type == "error" then
                print("SPUDNET error", packet["for"], packet.error, packet.detail, textutils.serialise(packet))
            elseif packet.type == "message" then
                os.queueEvent("spudnet_message", packet.data)
            end
        end
    end

    return send, function() parallel.waitForAll(ping_timer, main) end
end

local spudnet_send, spudnet_handler = spudnet()

local directions = {
    ["+ "] = "east",
    [" +"] = "south",
    ["- "] = "west",
    [" -"] = "north"
}

local function direction_name(vec)
    local function symbol(v)
        if math.abs(v) < 0.1 then return " "
        elseif v < 0 then return "-"
        else return "+" end
    end
    return directions[symbol(vec.x) .. symbol(vec.z)]
end

local function main()
    while true do
        local entities = sensor.sense()
        for _, entity in pairs(entities) do
            entity.position = vector.new(entity.x, entity.y, entity.z) + switch_config.offset
            entity.velocity = vector.new(entity.motionX, entity.motionY, entity.motionZ)
        end
        table.sort(entities, function(a, b) return a.position:length() < b.position:length() end)
        local carts = {}
        for _, entity in pairs(entities) do
            if entity.displayName == "entity.MinecartRideable.name" then
                entity.riders = {}
                table.insert(carts, entity)
                break
            end
        end
        local new_carts = {}
        local relevant_carts = 0
        for _, cart in pairs(carts) do
            local new = {
                pos = direction_name(cart.position), dir = direction_name(cart.velocity),
                distance = cart.position:length(),
                riders = {},
                id = cart.id
            }
            for _, entity in pairs(entities) do
                if entity.displayName ~= "entity.MinecartRideable.name" and entity ~= cart and (cart.position - entity.position):length() < 1 then
                        table.insert(new.riders, entity.displayName)
                    break
                end
            end
            if new.dir and #new.riders > 0 then
                relevant_carts = relevant_carts + 1
            end
            table.insert(new_carts, new)
        end
        spudnet_send { id = label, type = "sw_ping", carts = new_carts }
        if relevant_carts == 0 then sleep(0.5) elseif relevant_carts == 1 then sleep(0.25) else sleep(0.1) end
    end
end

local function spudnet_listen()
    while true do
        local _, data = os.pullEvent "spudnet_message"
        if type(data) == "table" and data.type == "sw_cmd" and (data.id == label or data.id == nil) then
            --print(data.type, data.cmd)
            if data.cmd == "set" then
                print("set", data.switch)
                if data.lamp then set_color(colors[data.lamp]) end
                if data.switch ~= nil then rs.setOutput(switch_config.side, data.switch) end
                spudnet_send { type = "sw_ack", cid = data.cid }
            elseif data.cmd == "update" then
                local h, e = http.get "https://pastebin.com/raw/g9gfxwsb"
                if not h then printError(e)
                else
                    set_color(colors.purple)
                    local t = h.readAll()
                    h.close()
                    local f, e = load(t)
                    if f then
                        local f = fs.open("startup", "w")
                        f.write(t)
                        f.close()
                        print "reboot"
                        sleep(1)
                        os.reboot()
                    else printError(e) end

                end
            end
        end
    end
end

parallel.waitForAll(spudnet_handler, main, spudnet_listen)