#!/bin/sh
# Build the site into public/: each posts/*.org becomes public/posts/<name>.html
# (via pandoc and template.html), and the newest-first post list replaces the
# <!-- POSTS --> markers in index.html. Posts need #+TITLE and #+DATE: YYYY-MM-DD.
# Builds into public.tmp/ and swaps it in at the end, so a failed build keeps the old site.
set -eu
cd "$(dirname "$0")"

out=public.tmp
rm -rf "$out"
mkdir -p "$out/posts"
cp style.css "$out/"

list=$(mktemp) sorted=$(mktemp)
trap 'rm -f "$list" "$sorted"' EXIT

for f in posts/*.org; do
	[ -e "$f" ] || continue
	name=$(basename "$f" .org)
	title=$(sed -n 's/^#+title:[[:space:]]*//Ip' "$f" | head -n 1)
	[ -n "$title" ] || title=$name
	date=$(sed -n 's/^#+date:[[:space:]]*//Ip' "$f" | grep -o '[0-9]\{4\}-[0-9][0-9]-[0-9][0-9]' | head -n 1)
	pandoc -f org -t html5 --template template.html --syntax-highlighting=none \
		-M title="$title" -M date="$date" -o "$out/posts/$name.html" "$f"
	html_title=$(printf '%s' "$title" | sed 's/&/\&amp;/g; s/</\&lt;/g; s/>/\&gt;/g')
	printf '%s\t<a href="posts/%s.html" class="post-entry"><h2>%s</h2><small>%s</small></a>\n' \
		"$date" "$name" "$html_title" "$date" >>"$list"
done

if [ -s "$list" ]; then
	sort -r "$list" | cut -f 2- >"$sorted"
else
	echo 'No stories to tell...' >"$sorted"
fi

awk -v list="$sorted" '
	/<!-- POSTS -->/ { while ((getline line < list) > 0) print line; close(list); next }
	{ print }
' index.html >"$out/index.html"

rm -rf public
mv "$out" public