#!/bin/bash
# knelpdf-mermaid: render a mermaid diagram to PNG without Node.js.
# Uses bundled mermaid.min.js + headless chromium.
# usage: knelpdf-mermaid input.mmd output.png [theme] [width] [height]
set -euo pipefail
IN="${1:?usage: knelpdf-mermaid input.mmd output.png [theme] [width] [height]}"
OUT="${2:?usage: knelpdf-mermaid input.mmd output.png [theme] [width] [height]}"
THEME="${3:-default}"
W="${4:-1600}"; H="${5:-1200}"
case "$IN" in *.svg|*.png) echo "output-only extension in OUT, not IN" >&2; exit 2;; esac
WORK="$(mktemp -d)"
trap 'rm -rf "$WORK"' EXIT
{
echo ''
echo ''
echo ''
cat "$IN"
echo '
'
echo ''
echo ""
echo ''
} > "$WORK/render.html"
chromium --headless=new --no-sandbox --disable-gpu \
--allow-file-access-from-files --hide-scrollbars \
--screenshot="$OUT" --window-size="${W},${H}" \
--virtual-time-budget=10000 "file://$WORK/render.html" 2>/dev/null
test -s "$OUT" && echo "wrote $OUT"