// Client pipeline data flow
// Sender machine (Wayland, VAAPI GPU)
digraph client_pipeline {
    graph [fontname="monospace" bgcolor="#1e1e2e" rankdir=TB pad="0.6" splines=polyline]
    node  [fontname="monospace" fontcolor="#cdd6f4" style=filled shape=box
           fillcolor="#313244" color="#585b70" margin="0.25,0.12"]
    edge  [color="#585b70" fontname="monospace" fontcolor="#a6adc8" labelfontname="monospace"]

    // Hardware
    drm   [label="/dev/dri/card0\n(KMS scanout)" shape=cylinder fillcolor="#1e3a2f" color="#a6e3a1"]
    vaapi [label="/dev/dri/renderD128\n(VAAPI)" shape=cylinder fillcolor="#1e3a2f" color="#a6e3a1"]
    pulse [label="PulseAudio\n─────────────\nmonitor: default_sink.monitor\nmic: default-source" shape=cylinder fillcolor="#1e3a2f" color="#a6e3a1"]
    net   [label="TCP :4447\nmcrndeb" shape=parallelogram fillcolor="#1e2a3e" color="#89b4fa"]

    subgraph cluster_main {
        label="main thread (tokio async)" fontcolor="#a6adc8" color="#45475a" fontname="monospace"

        wait_server   [label="wait_for_server\n─────────────\nretry connect / 2s\nCtrl-C to cancel" fillcolor="#2d2038" color="#cba6f7"]
        session_start [label="session_start\n─────────────\nid: YYYYMMDD_HHMMSS\nvideo + audio params" fillcolor="#2d2038" color="#cba6f7"]
        mux           [label="select!\npkt_rx | keepalive | ctrl-c" fillcolor="#2d2038" color="#cba6f7"]
        write         [label="BufWriter\nwrite_packet()" fillcolor="#1e2d3e" color="#89b4fa"]
        shutdown      [label="Shutdown\n─────────────\npipeline.stop() (5s timeout)\nSessionStop (2s timeout)\nsingle Ctrl-C" fillcolor="#2d2038" color="#cba6f7"]
    }

    subgraph cluster_subprocess {
        label="Subprocess backend (default)" fontcolor="#a6adc8" color="#45475a" fontname="monospace"

        ffmpeg_cli [label="ffmpeg subprocess\n─────────────\nkmsgrab → VAAPI h264\n+ PulseAudio inputs:\n  amix(monitor, mic)\noutput: NUT pipe" fillcolor="#1e2d3e" color="#89b4fa"]

        demux [label="NUT Demuxer\n─────────────\nffmpeg-next in-process\nfinds video + audio streams\nsends EncodedPacket\n  { data, pts, media_type }" fillcolor="#1e2d3e" color="#89b4fa"]

        chan [label="mpsc::channel(64)\nEncodedPacket" shape=parallelogram fillcolor="#2d2038" color="#cba6f7"]
    }

    subgraph cluster_direct {
        label="VaapiDirect backend (experimental)" fontcolor="#6c7086" color="#45475a" fontname="monospace" style=dashed

        capture [label="KmsCapture\n─────────────\nDRM_PRIME frames" fillcolor="#2d1e1e" color="#f38ba8"]
        encoder [label="VaapiEncoder\n─────────────\nhwmap → scale_vaapi\nh264_vaapi QP=20" fillcolor="#2d1e1e" color="#f38ba8"]
    }

    // Flow — subprocess
    drm   -> ffmpeg_cli [label="kmsgrab"]
    vaapi -> ffmpeg_cli [label="h264_vaapi"]
    pulse -> ffmpeg_cli [label="-f pulse\nmonitor + mic"]
    ffmpeg_cli -> demux [label="NUT pipe\n(stdout)"]
    demux -> chan [label="EncodedPacket\n(Video or Audio)"]

    // Flow — direct (dashed, experimental)
    drm -> capture [style=dashed]
    vaapi -> encoder [style=dashed]
    capture -> encoder [style=dashed label="DRM_PRIME"]
    encoder -> chan [style=dashed]

    // Flow — main
    chan -> mux
    wait_server -> session_start
    session_start -> write
    mux -> write [label="WirePacket\nVideo | Audio"]
    write -> net
    mux -> shutdown [label="Ctrl-C or\nchannel closed"]

    // Types note
    types [label="WirePacket types\n─────────────\nVideo:   H.264 NALUs + keyframe flag\nAudio:   AAC frames\nControl: SessionStart/Stop/Keepalive"
           shape=note fillcolor="#2a2a3e" color="#585b70"]
}