#!/bin/bash

DIRECTORY="pages/blog"

FILES=`ls $DIRECTORY/*.md -1 | sort`

RETURNDATE=""

function printcut {
# argument 1: filename

	CUT=`grep -m 1 -n '<!--[[:space:]]*cut[[:space:]]*-->[[:space:]]*' $1`
	if [ -n "$CUT" ]; then
		CUTLINE=`echo "$CUT" | cut -d ':' -f 1`
		head -n $(($CUTLINE - 1)) $1 | grep -v '^%'
	else
		return 1
	fi
}

# date is read from the 3rd %ed line of the document or from the git commit date
function getdate {

	FILEDATE=`grep "^%" $1 | sed '3q;d' | cut -d ' ' -f 2-`
	
	if [ $? -eq 0 ]; then
	FTIME=`date -u --date="$FILEDATE" "+%s"`
	else
		RETURNDATE=0
		return 1
	fi

	if [ $? -eq 0 ]; then
		RETURNDATE=$FTIME
		return 0
	else
		RETURNDATE=0
		return 0
	fi
}

echo -n > blogdates.txt
for f in $FILES; do
	getdate $f
	printf "%d\t%s\n" $RETURNDATE $f >> blogdates.txt
done

# resort by resulting times
FILES=`cat blogdates.txt | sort -nr | cut -f 2-`

cat << RSSHEADER
<?xml version="1.0" encoding="UTF-8" ?>
<rss version="2.0">
<channel>
<title>rnd's blog</title>
<link>https://rnd.neocities.org/blog</link>
<description>The RSS feed of articles published on the blog thingy</description>
RSSHEADER

for f in $FILES; do

	getdate $f
	MTIME=$RETURNDATE

	TITLE=`head -n 1 $f`
	TITLE=${TITLE#"% "}

	OUTPAGE=${f%.md}.html
	OUTPAGE=${OUTPAGE#pages/blog/}

	echo "<item>"
	echo "<title>$TITLE</title>"
	echo "<link>https://rnd.neocities.org/blog/$OUTPAGE</link>"

	if [ $MTIME -gt 0 ]; then
		RDATE=`date -R -u -d @$MTIME`
		if [[ "$RDATE" == *UTC ]]; then
			RDATE="${RDATE%UTC}+0000"
		fi
		echo "<pubdate>$RDATE</pubdate>"
	fi
	DESCRIPTION="`printcut $f`"
	if [ $? -eq 0 ]; then
		DESC_HTML=`echo "$DESCRIPTION" | markdown`
		echo "<description>$DESC_HTML</description>"
	fi
	echo "</item>"

done

cat << RSSFOOTER
</channel>
</rss>
RSSFOOTER