# `nix run .#hyperhive-the-movie` — gource visualisation of the git
# history of the repo it is run from. `-- --record` renders
# gource-hyperhive.webm in the cwd instead of opening a window: AV1 in WebM,
# which plays in current Firefox and Chrome and compresses this flat,
# dark picture far better than H.264. Milestones show as captions, from the git
# tags of the repo and from `hyperhive-the-movie-milestones.txt`.
{
  lib,
  writeShellApplication,
  gource,
  ffmpeg,
  xvfb-run,
  librsvg,
  curl,
  git,
  coreutils,
  gnugrep,
  logo,
}:
writeShellApplication {
  name = "hyperhive-the-movie";
  runtimeInputs = [
    gource
    ffmpeg
    xvfb-run
    librsvg
    curl
    git
    coreutils
    gnugrep
  ];
  text = ''
    usage() {
      cat <<'USAGE'
    hyperhive-the-movie - gource visualisation of this repo's git history

    Usage: nix run .#hyperhive-the-movie -- [--record | --help]

      (no flag)   open a gource window and play the history
      --record    render gource-hyperhive.webm in the current directory
                  instead (1280x720, 30 fps, AV1 in WebM; plays in recent
                  Firefox and Chrome). Needs no display.
      -h, --help  show this text

    Run it from inside the repo. Captions come from two places: the git tags
    (shown at the tagged commit's date) and the milestones file,
    nix/packages/hyperhive-the-movie-milestones.txt, one "YYYY-MM-DD|caption"
    per line. Edit that file, or tag a commit with `git tag NAME COMMIT`.
    USAGE
    }

    record=false
    case "''${1:-}" in
      "") ;;
      --record) record=true ;;
      -h | --help)
        usage
        exit 0
        ;;
      *)
        echo "hyperhive-the-movie: unknown argument '$1'" >&2
        usage >&2
        exit 2
        ;;
    esac

    cd "$(git rev-parse --show-toplevel)"

    # Per-agent avatars from the local forge (same icons the dashboard
    # uses), rasterised because --user-image-dir needs png. Cached.
    # müde is the human operator: no forge icon.
    avatar_dir="''${XDG_CACHE_HOME:-$HOME/.cache}/hyperhive-the-movie/avatars"
    mkdir -p "$avatar_dir"
    while IFS= read -r author; do
      [[ "$author" == "müde" || -f "$avatar_dir/$author.png" ]] && continue
      svg="$avatar_dir/$author.svg"
      curl -sSf "http://localhost/agent/$author/icon" -o "$svg" 2>/dev/null || rm -f "$svg"
      # unknown agents get a 200 html fallback page, not a 404
      if [[ -f "$svg" ]]; then
        if head -c 200 "$svg" | grep -qi '<svg'; then
          rsvg-convert -w 256 -h 256 "$svg" -o "$avatar_dir/$author.png"
        fi
        rm -f "$svg"
      fi
    done < <(git log --format='%an' | sort -u)

    # Milestone captions, `unix time|text`, sorted by time: the tracked
    # milestones file (`YYYY-MM-DD|text`) and the repo's git tags.
    captions="$(mktemp)"
    trap 'rm -f "$captions"' EXIT
    {
      while IFS='|' read -r day text; do
        [[ -z "$day" || "$day" == \#* ]] && continue
        echo "$(date -d "$day" +%s)|$text"
      done < ${./hyperhive-the-movie-milestones.txt}
      git for-each-ref --format='%(creatordate:unix)|%(refname:short)' refs/tags
    } | sort -n > "$captions"

    # Catppuccin Mocha, as in frontend/packages/shared/src/colors.css.
    args=(
      -s 1 -1280x720 --auto-skip-seconds 1 --multi-sampling --stop-at-end
      --date-format "%Y-%m-%d"
      --caption-file "$captions" --caption-size 28 --caption-duration 4
      --caption-colour f9e2af
      --background-colour 1e1e2e --font-colour cdd6f4
      --highlight-colour f9e2af --highlight-users --highlight-dirs
      --filename-colour 585b70 --dir-colour 89b4fa
      --bloom-multiplier 1.5 --bloom-intensity 0.75 --elasticity 0.1
      --title hyperhive
      --logo ${logo} --logo-offset 20x20
      --user-image-dir "$avatar_dir"
      --key
    )

    if $record; then
      xvfb-run -a --server-args="-screen 0 1280x720x24" \
        gource "''${args[@]}" --output-ppm-stream - --output-framerate 30 \
        | ffmpeg -y -r 30 -f image2pipe -vcodec ppm -i - \
          -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" \
          -c:v libsvtav1 -preset 6 -crf 34 -g 300 -pix_fmt yuv420p \
          gource-hyperhive.webm
    else
      gource "''${args[@]}"
    fi
  '';
  meta = {
    description = "gource movie of the hyperhive git history";
    mainProgram = "hyperhive-the-movie";
    platforms = lib.platforms.linux;
  };
}