#!/usr/bin/env bash
# Generate the documentation export(s) from README.adoc.
#
#   docs/generate-readme-pdf.sh           # README.html + README.pdf
#   docs/generate-readme-pdf.sh --html    # README.html only
#   docs/generate-readme-pdf.sh --pdf     # README.pdf only
#
# Both outputs land in the project root and are Git-ignored.
#
# Requirements:
#   - asciidoctor            (e.g. gem install asciidoctor)
#   - chromium               (headless PDF rendering)
#   - fonts-noto-color-emoji (color emoji in the PDF)
#
# Why Chromium instead of asciidoctor-pdf (used by the VSCodium extension)?
# Its Prawn engine cannot embed color-emoji fonts (CBDT/COLR), so emoji
# disappear. Chromium handles them fine as long as "Noto Color Emoji"
# is installed. The docs/docinfo.html stylesheet (emoji fallback + print
# rules) is injected only for this build, via Asciidoctor's docinfo
# mechanism, and adapts the layout for print (TOC in flow, table/page
# breaks, wrapped code listings).

set -euo pipefail

cd "$(dirname "$0")/.."

MODE="${1:---all}"
HTML_OUT="README.html"
PDF_OUT="README.pdf"

build_html() {
    asciidoctor -b html5 -a docinfodir=docs -a docinfo=shared README.adoc -o "$1"
    echo "HTML generated: $1"
}

build_pdf() {
    # Resolve to an absolute path for the file:// URL
    local html_path="$1"
    [[ "$html_path" != /* ]] && html_path="$PWD/$html_path"
    chromium --headless --disable-gpu --no-sandbox \
        --no-pdf-header-footer \
        --print-to-pdf="$PDF_OUT" \
        "file://$html_path"
    echo "PDF generated: $PDF_OUT"
}

case "$MODE" in
    --html)
        build_html "$HTML_OUT"
        ;;
    --pdf)
        TMP_HTML="$(mktemp --suffix=.html)"
        trap 'rm -f "$TMP_HTML"' EXIT
        build_html "$TMP_HTML" >/dev/null
        build_pdf "$TMP_HTML"
        ;;
    --all)
        build_html "$HTML_OUT"
        build_pdf "$HTML_OUT"
        ;;
    -h|--help)
        sed -n '2,10p' "$0"
        exit 0
        ;;
    *)
        echo "Usage: $0 [--html|--pdf|--all]" >&2
        exit 1
        ;;
esac