// Server pipeline — current implementation
// Receiver machine (mcrndeb: X11, RTX 3080, NVDEC)
digraph server_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"]

    net    [label="TCP :4447\n(WirePacket)" shape=parallelogram fillcolor="#1e2a3e" color="#89b4fa"]
    python [label="Python GUI\n(cht app)" shape=parallelogram fillcolor="#2a2a3e" color="#cba6f7"]

    subgraph cluster_rust {
        label="cht-server (Rust)" fontcolor="#a6e3a1" color="#a6e3a1" fontname="monospace"

        listener [label="Listener\n─────────────\nTCP accept\nreads WirePacket\nroutes by type:\n  Video → ffmpeg + scene relay\n  Audio → ADTS file\n  Control → session lifecycle"
                  fillcolor="#1e2d3e" color="#89b4fa"]

        ffmpeg_rec [label="ffmpeg subprocess\n─────────────\nH.264 pipe:0 → 2 outputs:\n  1. fMP4 (frag_keyframe)\n  2. UDP :4445 (mpegts)"
                    fillcolor="#1e2d3e" color="#89b4fa"]

        scene_relay [label="Scene Relay\n─────────────\nUnix socket (scene.sock)\nbuffers latest keyframe\nbest-effort: drops if slow\n100ms write timeout"
                     fillcolor="#1e2d3e" color="#89b4fa"]

        audio_writer [label="Audio Writer\n─────────────\nADTS header + raw AAC\n→ stream/audio.aac"
                      fillcolor="#1e2d3e" color="#89b4fa"]

        active_session [label="active-session\n─────────────\nfile at data/active-session\nPython polls to discover\nsession dir" shape=note
                        fillcolor="#2a2a3e" color="#585b70"]
    }

    subgraph cluster_python {
        label="Python (cht app)" fontcolor="#cba6f7" color="#cba6f7" fontname="monospace"

        scene_ffmpeg [label="Scene Detector\n─────────────\nconnects to scene.sock\npipes H.264 → ffmpeg:\n  CUDA decode\n  select=gt(scene,thresh)\n  showinfo → timestamps\n  MJPEG → JPEG frames"
                      fillcolor="#2d2038" color="#cba6f7"]

        audio_extract [label="Audio Extractor\n─────────────\nreads audio.aac\nffmpeg → 16kHz mono WAV\nchunks + transcript WAVs"
                       fillcolor="#2d2038" color="#cba6f7"]

        transcriber [label="Transcriber\n─────────────\nfaster-whisper (CUDA)\nsegment grouping\nslider: chunk size + lines/group"
                     fillcolor="#2d2038" color="#cba6f7"]
    }

    // Flow — Rust server
    net -> listener [label="WirePacket"]
    listener -> ffmpeg_rec [label="H.264 video"]
    listener -> scene_relay [label="H.264 copy\n+ keyframe flag"]
    listener -> audio_writer [label="AAC audio"]
    listener -> active_session [style=dashed label="on SessionStart"]

    // Flow — Python scene detection
    scene_relay -> scene_ffmpeg [label="raw H.264\n(Unix socket)" color="#a6e3a1"]

    // Outputs
    fmp4     [label="stream/\nrecording_000.mp4\n(fragmented MP4)" shape=folder fillcolor="#2a2a3e" color="#585b70"]
    udp_live [label="UDP :4445\n(mpegts → mpv)" shape=parallelogram fillcolor="#2a2a3e" color="#585b70"]
    aac_file [label="stream/\naudio.aac\n(ADTS-wrapped)" shape=folder fillcolor="#2a2a3e" color="#585b70"]
    frames   [label="frames/\nindex.json + *.jpg" shape=folder fillcolor="#2a2a3e" color="#585b70"]
    audio_dir [label="audio/\nchunk_*.wav\ntranscript_*.wav" shape=folder fillcolor="#2a2a3e" color="#585b70"]

    ffmpeg_rec -> fmp4 [label="copy"]
    ffmpeg_rec -> udp_live [label="copy"]
    audio_writer -> aac_file
    scene_ffmpeg -> frames [label="JPEG on\nscene change"]
    audio_extract -> audio_dir
    audio_dir -> transcriber [label="WAV chunks"]

    // Python reads files
    aac_file -> audio_extract [label="reads" style=dashed]
    active_session -> python [label="discovers\nsession dir" style=dashed]
}