-module(rtp_app).
-behaviour(application).

-export([start/2, stop/1, print_banner/0]).

start(_StartType, _StartArgs) ->
    print_banner(),

    % Configure N2O programmatically to work with both rebar3 and mix
    application:set_env(n2o, port, 8001),
    application:set_env(n2o, protocols, [nitro_n2o, n2o_heart]),
    application:set_env(n2o, routes, routes),
    application:set_env(n2o, mq, rtp_syn),

    % 1. Initialize KVS schema bindings
    kvs:join(),

    % Initialize session tokens ETS table
    session_token:init_table(),

    % 2. Initialize Syn registry rooms scope
    ok = syn:add_node_to_scopes([rooms, n2o_mq]),

    % 3. WebSocket listener on Port 8001 (N2O WS + signaling)
    {ok, _} = 'Elixir.Bandit':start_link([{plug, 'Elixir.Rtp.WS'}, {port, 8001}]),

    % 4. Static file server on Port 8081
    {ok, _} = 'Elixir.Bandit':start_link([{plug, 'Elixir.Rtp.Static'}, {port, 8081}]),

    rtp_sup:start_link().

stop(_State) ->
    ok.

print_banner() ->
    Cores = erlang:system_info(logical_processors_online),
    MemStr = string:trim(os:cmd("sysctl -n hw.memsize 2>/dev/null || awk '/MemTotal/ {print $2 * 1024}' /proc/meminfo 2>/dev/null || echo 0")),
    MemBytes = try list_to_integer(MemStr) catch _:_ -> 0 end,
    MemGB = if MemBytes > 0 -> MemBytes div (1024*1024*1024); true -> unknown end,

    % Example WebRTC capacity heuristics based on hardware
    MaxRooms = Cores * 10,
    RoomCapacity = 50,
    MaxParticipants = MaxRooms * RoomCapacity,
    Logo = "\e[93;44mERP\e[97;45m/1\e[0m",

    io:format("~n"),
    io:format("╔════════════════════════════════════════════════════════╗~n"),
    io:format("║  ~s: RTP Server / Signaling & Telemetry             ║~n", [Logo]),
    io:format("║  WS  : ws://localhost:8001/ws/app/<page>.htm           ║~n"),
    io:format("║  HTTP: http://localhost:8081/app/login.htm             ║~n"),
    io:format("╚════════════════════════════════════════════════════════╝~n"),
    io:format("  Hardware   : ~p Cores, ~p GB RAM~n", [Cores, MemGB]),
    io:format("  Max Rooms  : ~p (heuristic based on cores)~n", [MaxRooms]),
    io:format("  Capacity   : ~p max participants (~p per room)~n", [MaxParticipants, RoomCapacity]),
    io:format("  RTP Codecs : Opus (Audio), VP8, VP9, H.264 (Video)~n"),
    io:format("~n").