#!/bin/sh
# irl -- irc-rss-listener
set -e

die() {
	echo "$*" 1>&2
	exit 1
}

usage() {
	die 'Usage: irl.sh -c CHANNEL [-h HOST] [-p PORT]'
}

port=6667
host=localhost

args=$(getopt c:h:p: $*)
if [ $? -ne 0 ]; then
	usage
fi

set -- $args
while [ $# -ne 0 ]; do
	case "$1"
	in
		-c)
			channel="$2"; shift; shift;;
		-h)
			host="$2"; shift; shift;;
		-p)
			port="$2"; shift; shift;;
		--)
			shift; break;;
	esac
done

[ -z "$channel" ] && usage


notify() {
	nc $host $port <<EOM >/dev/null
NICK rssbot
USER rssbot rssbot $host :rssbot
PRIVMSG #$channel :New post '$1' here: $2
QUIT
EOM
}

feeds=/etc/irl/$host.$channel
known_ids=/tmp/irl-known.$host.$channel.ids
all_ids=/tmp/irl-all.$host.$channel.ids
new_ids=/tmp/irl-new.$host.$channel.ids

[ ! -e $feeds ] && die "Create $feeds to begin!"
command -v sfeed >/dev/null || die "sfeed not installed"

# Truncate last pull
>"$all_ids"

for feed in $(cat "$feeds"); do
	curl -sS "$feed" | sfeed | \
		awk -F'	' "{ print \$3, \$2 }" >>"$all_ids"
done

if [ -e "$known_ids" ]; then
	diff "$known_ids" "$all_ids" | grep '^>' | sed 's/^..//' > "$new_ids"
	while read url subj; do
		notify "$subj" "$url"
	done < "$new_ids"
fi

# Update
cp -f "$all_ids" "$known_ids"