startup.lua

local ws;

local function init(url)
    if ws then
        ws.close();
        ws = nil;
    end

    local connection = http.websocket(url);

    if connection then
        ws = connection;
        print("Connection opened!");
    else
        print("Failed to connect to: " .. url);
    end
end

local function cleanup()
    print("Exiting...");
    ws.close();
    ws = nil;
    shell.exit()
end

local function executeInstruction(s)
    if s == "::close" then
        print("Connection closed.");
        cleanup();
        return 0;
    elseif s == "::forward" then
        forward();
        return 0;
    elseif s == "::back" then
        back();
        return 0;
    elseif s == "::left" then
        left();
        return 0;
    elseif s == "::right" then
        right();
        return 0;
    elseif s == "::up" then
        up();
        return 0;
    elseif s == "::down" then
        down();
        return 0;
    end
    return -1;
end

init("ws://localhost:8080");

while true do
    local event = os.pullEventRaw(); if event == "terminate" then print("Program terminated"); cleanup(); break; end;

    local message = ws.receive();
    if message then
        if executeInstruction(message) == -1 then
            print(message);
        end
    else
        print("Connection closed.");
        cleanup();
        break;
    end
end