#!/usr/bin/env bash

getBlogSlug(){
	echo "$1" | sed 's/^content\//\//' | sed 's/.md$/.html/' | sed -E 's/[0-9]+-//'
}

blog(){
	echo "Generating Blog pages"
	[ ! -f "tmp/templates/tagList.html" ] && echo "No taglist file" | tee "tmp/templates/tagList.html" > /dev/stderr
	local newer=""
	[ -f tmp/lastBlogUpdate ] && newer="-newer tmp/lastBlogUpdate"
	find content/ -type f -name '*.md' $newer | while read file; do
		newFileName=$(getBlogSlug "$file")
		mkdir -p "public_html/${newFileName%/*}"
		pandoc --template=templates/blog.html -f markdown -t html5 "$file" > "public_html/$newFileName"
	done
	touch tmp/lastBlogUpdate
}

makeIntro(){
	local file="$1"
	local output="tmp/intros/$file"
	local rssoutput="tmp/rss/$file"
	# We delete tmp each time the build script runs, so if the file exists, we have already generated one this time
	[ -f "$output" ] && return 1
	mkdir -p "${output%/*}"
	mkdir -p "${rssoutput%/*}"
	local info="$(sed -n '/---/,/---/p' "$file" | sed '/^$/,$d' | sed -n '1,/---/p' | sed '/^---$/d')"
	local slug=$(getBlogSlug "$file")
	local date="$(echo "$info" | yq -r .date)"
	local rfc822="$(date --utc -d "$date" "+%a, %d %b %Y %H:%M:%S") UT"
	local tags="$(echo "$info" | yq -r 'if ( .tags | type ) == "array" then .tags else [ .tags ] end | join("\n")' | awk '{print "<li>" $0 "</li>"}' )"
	local title="$(echo "$info" | yq -r .title)"
	local description="$(echo "$info" | yq -r .description)"
	echo "<article>
		<h2><a href='$slug'>$title</a></h2>
		<div class="article-details">
			<div class="date">
				$date
			</div>
		</div>
		<p>$description</p>
		<p><a href='$slug'>Read More</a></p>
	</article>" > "$output"
	echo "<item>
		<title>
		<![CDATA[$title]]></title>
		<link>https://jonathanh.co.uk/$slug</link>
		<guid isPermaLink=\"true\">https://jonathanh.co.uk/$slug</guid>
		<pubDate>$rfc822</pubDate>
		<description><![CDATA[$description]]></description>
	</item>" > "$rssoutput"
}

getIntro(){
	local file="$1"
	local output="tmp/intros/$file"

	if [ "$2" = "rss" ]; then
		local output="tmp/rss/$file"
	fi
	makeIntro "$file"
	cat "$output"
}

index(){
	echo "Generating Home Page"
	[ ! -f "tmp/templates/tagList.html" ] && echo "No taglist file" | tee "tmp/templates/tagList.html" > /dev/stderr
	local template="$(echo "" | pandoc --template=templates/blog.html -f markdown -t html5 -M frontpage 2> /dev/null )"

	# First loop makes all the intros needed and stores them in tmp/intros
	find content/blog/ -type f -name '*.md' | grep -v 'xxx' | sort -r | head -n 20 | while read file; do
		makeIntro "$file" &
	done
	wait

	# Once they are created, we will put them in, in order
	(
		echo "$template" | sed -n '1,/#CONTENT#/p' | head -n -1
		find content/blog/ -type f -name '*.md' | grep -v 'xxx' | sort -r | head -n 20 | while read file; do
			grep -Eq '^draft: true' "$file" || getIntro "$file"
		done
		echo "$template" | sed -n '/#CONTENT#/,$p' | sed '1d'
	) > public_html/index.html
}

tagIndex(){
	local tag="$1"
	local title="$(basename "$tag")"

	[ ! -f "tmp/templates/tagList.html" ] && echo "No taglist file" | tee "tmp/templates/tagList.html" > /dev/stderr
	local template="$(echo "" | pandoc --template=templates/blog.html -f markdown -t html5 -M archive -M title:"$title Archive" 2> /dev/null )"

	cat "$1" | grep -v 'xxx' | sort -r | while read file; do
		makeIntro "$file" &
	done
	wait

	echo "$template" | sed -n '1,/#CONTENT#/p' | head -n -1
	cat "$1" | sort -r | while read file; do
		getIntro "$file"
	done
	echo "$template" | sed -n '/#CONTENT#/,$p' | sed '1d'
}


html_tag_list(){
	if [ -d "tmp/tag" ]; then
		echo "<ul class='taglist'>"
			wc -l tmp/tag/* | head -n -1 | sort -nr | while read line; do
				local link=$(echo "$line" | awk '{print $2 ".html"}' | sed 's/^tmp//' | tr '[A-Z]' '[a-z]' | tr ' ' '-')
				local name=$(echo "$line" | sed 's/tmp\/tag\///' | awk '{print $2 " (" $1 ")"}' | tr '_' ' ')
				echo "<li><a href='$link'>$name</a></li>"
			done
		echo "</ul>"
	else
		echo "Need to generate the taglist" > /dev/stderr
	fi
}

tags(){

	echo "Generating Tags"

	# Loops through each blog and puts it in tag lists, although only blogs that have changed
	local newer=""
	[ -f tmp/lastTagUpdate ] && newer="-newer tmp/lastTagUpdate"
	find content/blog/ -type f -name '*.md' -not -name 'xxx-*' $newer | while read file; do
		sed -n '/---/,/---/p' "$file" | sed -n '1,/---/p' | sed '/^---$/d' | sed '/^$/,$d' | yq -r 'if ( .tags | type ) == "array" then .tags else [ .tags ] end | join("\n")' | while read tag; do
			tag=$(echo "$tag" | tr ' ' '_')
			# Adds the file to the tags list if it's not already in there
			grep -q "$file" tmp/tag/"$tag" 2> /dev/null || echo "$file" >> tmp/tag/"$tag"
		done
	done

	echo "Generating Taglist HTML"
	html_tag_list > tmp/templates/tagList.html

	# We should now have a folder with a text file for each tag containing each blog
	echo "Generating Tag Index Pages"

	find tmp/tag/ -type f $newer | while read tag; do
		filename="$(echo $tag | sed 's/^tmp//' | tr '[A-Z]' '[a-z]').html"
		tagIndex "$tag" > "public_html/$filename"
	done

	touch tmp/lastTagUpdate
}

card(){
	echo "Generating Card"
	content/card.curl > public_html/card
}

rss(){
	echo "Generating RSS Feed"
	lastUpdate="$(date --utc "+%a, %d %b %Y %H:%M:%S") UT"

	# First loop makes all the intros needed and stores them in tmp/intros
	find content/blog/ -type f -name '*.md' | grep -v 'xxx' | sort -r | head -n 20 | while read file; do
		makeIntro "$file" &
	done
	wait

	(
	echo "<?xml version='1.0' encoding='UTF-8' ?>
	<rss xmlns:dc=\"http://purl.org/dc/elements/1.1/\" xmlns:content=\"http://purl.org/rss/1.0/modules/content/\" xmlns:atom=\"http://www.w3.org/2005/Atom\" version=\"2.0\">
	<channel>
		<title><![CDATA[Jonathan Hodgson]]></title>
		<description><![CDATA[Jonathan Hodgson's Blog]]></description>
		<link>https://jonathanh.co.uk</link>
		<lastBuildDate>$lastUpdate</lastBuildDate>"
		find content/blog/ -type f -name '*.md' | grep -v 'xxx' | sort -r | head -n 20 | while read file; do
			grep -Eq '^draft: true' "$file" || getIntro "$file" rss
		done
	echo "</channel></rss>";
	) > public_html/feed.rss
}


clean(){
	rm -rf tmp > /dev/null 2> /dev/null
	# Don't remove the public_html folder or docker won't re-attach it
	rm -rf public_html/*
}


# Make sure the folders we will need exist
mkdir -p public_html/{blog,tag}
mkdir -p tmp/{tag,templates,intros}


case "$1" in
	clean) clean ;;
	index) index ;;
	blog) blog ;;
	tags) tags ;;
	card) card ;;
	rss) rss ;;
	all) tags && blog && index && rss && card ;;
esac