#!/bin/sh
set -eu
MARKDOWN=pandoc
IFS='	'

# Create tab separated file with filename, title, creation date, last update
index_tsv() {
	for f in "$1"/*.md
	do	
		created=$(git log --pretty='format:%aI' "$f" 2> /dev/null | tail -1)
		updated=$(git log --pretty='format:%aI' "$f" 2> /dev/null | head -1)
		title=$(sed -n '/^# /{s/# //p; q;}' "$f")
		printf '%s\t%s\t%s\t%s\n' "$f" "${title:="No Title"}" "${created}" "${updated}"
	done
}

index_html() {
	# Print header
	title=$(sed -n '/^# /{s/# //p; q;}' index.md)
	sed -e 's/{{TITLE}}//g' header.html

	# Intro text
	$MARKDOWN index.md

	# Posts
	while read -r f title created updated; do
		link=$(echo "$f" | sed -E 's|.*/(.*).md|\1.html|')
		created=$(echo "$created" | sed -E 's/T.*//')
		# Reverse date from YYYY-MM-DD to DD-MM-YY
		created=$(echo "$created" | awk -F'-' '{printf("%02d-%02d-%02d\n",$3,$2,$1)}')
	 	echo "$created &mdash; <a href=\"$link\">$title</a><br>"
	done < "$1"

	# Print footer after post list
	year=$(date +"%Y")
	sed "s/{{YEAR}}/$year/" footer.html
}

atom_xml() {
	uri=$(sed -rn '/atom.xml/ s/.*href="([^"]*)".*/\1/ p' header.html)
	host=$(echo "$uri" | sed -r 's|.*//([^/]+).*|\1|')
	first_commit_date=$(git log --pretty='format:%ai' . | cut -d ' ' -f1 | tail -1)

	cat <<EOF
<?xml version="1.0" encoding="utf-8"?>
<feed xmlns="http://www.w3.org/2005/Atom">
	<icon>https://justine.smithies.me.uk/public/favicon-32x32.png</icon>
	<title>$(grep -o '<title>.*</title>' header.html | sed 's/\(<title>\|{{TITLE}}<\/title>\)//g')</title>
	<link href="$uri" rel="self" />
	<updated>$(date -Iseconds)</updated>
	<author>
		<name>$(git config user.name)</name>
	</author>
	<id>tag:$host,$first_commit_date:default-atom-feed</id>
EOF

	while read -r f title created updated; do
		day=$(echo "$created" | sed 's/T.*//')
		content=$($MARKDOWN "$f" | sed 's/&/\&amp;/g; s/</\&lt;/g; s/>/\&gt;/g; s/"/\&quot;/g; s/'"'"'/\&#39;/g')

		cat <<EOF
	<entry>
		<title>$title</title>
		<content type="html">$content</content>
		<link href="$(echo "$f" | sed -E 's|posts/(.*).md|\1.html|')"/>
		<id>tag:$host,$day:$f</id>
		<published>$created</published>
		<updated>$updated</updated>
	</entry>
EOF
	done < "$1"

	echo '</feed>'
}

write_page() {
	filename=$1
	target=$(echo "$filename" | sed -r 's|\w+/(.*).md|build/\1.html|')
	# year=$(date +"%Y")
	created=$(echo "$3" | sed 's/T.*//')
	# Reverse date from YYYY-MM-DD to DD-MM-YY
	created=$(echo "$created" | awk -F'-' '{printf("%02d-%02d-%02d\n",$3,$2,$1)}')
	updated=$(echo "$4" | sed 's/T.*//')
	# Reverse date from YYYY-MM-DD to DD-MM-YY
	updated=$(echo "$updated" | awk -F'-' '{printf("%02d-%02d-%02d\n",$3,$2,$1)}')
	dates_text="Published on ${created}"
	if [[ "$created" == "00-00-00" ]]; then
		dates_text=""
	elif [ "$created" != "$updated" ]; then
		dates_text="$dates_text ( Updated ${updated} )"
	fi
	title=$2

	$MARKDOWN "$filename" | \
		sed -e '1,/h1>/{/h1>/a\
			 <small><b>'$dates_text'</b></small>' -e '}' | \
		cat header.html - | \
		sed "s/{{TITLE}}/ - $title/" \
		> "$target" && sed "s/{{YEAR}}/$year/" footer.html >> "$target"

}

rm -fr build && mkdir build

# Blog posts
index_tsv posts | sort -rt "	" -k 3 > build/posts.tsv
index_html build/posts.tsv > build/index.html
atom_xml build/posts.tsv > build/atom.xml
while read -r f title created updated; do
	write_page "$f" "$title" "$created" "$updated"
done < build/posts.tsv

# Pages
index_tsv pages > build/pages.tsv
while read -r f title created updated; do
	write_page "$f" "$title" "$created" "$updated"
done < build/pages.tsv

# Create public directory if it doesn't exist and sync with build/public
mkdir -p public/
rsync -r public/ build/public