#!/usr/bin/env bash

set -euo pipefail

SCRIPT_DIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
DEFAULT_INPUT="$SCRIPT_DIR/酷哇商城网页登录接入SSO方案文档.md"

usage() {
  cat <<'EOF'
Usage:
  ./export-sso-pdf.sh [input.md] [output.pdf]

Examples:
  ./export-sso-pdf.sh
  ./export-sso-pdf.sh notes.md notes.pdf

The script renders Mermaid diagrams and prints the Markdown document as A4 PDF.
EOF
}

if [[ ${1:-} == "-h" || ${1:-} == "--help" ]]; then
  usage
  exit 0
fi

INPUT=${1:-$DEFAULT_INPUT}
OUTPUT=${2:-"${INPUT%.md}.pdf"}

if [[ ! -f "$INPUT" ]]; then
  echo "Markdown file not found: $INPUT" >&2
  exit 1
fi

if [[ ${INPUT##*.} != "md" ]]; then
  echo "Input must be a .md file: $INPUT" >&2
  exit 1
fi

if ! command -v node >/dev/null 2>&1; then
  echo "Node.js is required. Install Node.js 18 or newer and retry." >&2
  exit 1
fi

for candidate in google-chrome chromium chromium-browser; do
  if command -v "$candidate" >/dev/null 2>&1; then
    CHROME=$(command -v "$candidate")
    break
  fi
done

if [[ -z ${CHROME:-} ]]; then
  echo "Chrome or Chromium is required to create PDF." >&2
  exit 1
fi

INPUT_DIR=$(cd "$(dirname "$INPUT")" && pwd)
INPUT="$INPUT_DIR/$(basename "$INPUT")"
OUTPUT_DIR=$(cd "$(dirname "$OUTPUT")" && pwd)
OUTPUT="$OUTPUT_DIR/$(basename "$OUTPUT")"
WORK_DIR=$(mktemp -d "${TMPDIR:-/tmp}/markdown-pdf.XXXXXX")

cleanup() {
  rm -rf "$WORK_DIR"
}
trap cleanup EXIT

render_mermaid() {
  if command -v mmdc >/dev/null 2>&1; then
    PUPPETEER_EXECUTABLE_PATH="$CHROME" mmdc "$@"
    return
  fi

  PUPPETEER_EXECUTABLE_PATH="$CHROME" npm exec --yes \
    --package=@mermaid-js/mermaid-cli -- mmdc "$@"
}

node "$SCRIPT_DIR/scripts/render-markdown-pdf.mjs" prepare "$INPUT" "$WORK_DIR"

shopt -s nullglob
for diagram in "$WORK_DIR"/diagram-*.mmd; do
  render_mermaid -i "$diagram" -o "${diagram%.mmd}.svg"
done
shopt -u nullglob

HTML="$WORK_DIR/document.html"
node "$SCRIPT_DIR/scripts/render-markdown-pdf.mjs" render "$INPUT" "$WORK_DIR" "$HTML"

"$CHROME" --headless=new --no-sandbox --disable-gpu --no-pdf-header-footer \
  --print-to-pdf="$OUTPUT" "file://$HTML" >/dev/null 2>&1

echo "PDF created: $OUTPUT"