#!/bin/sh
#Auteur :      thuban <thuban@yeuxdelibad.net>  
#licence :     GNU General Public Licence v3

#Description : simple feed reader
#Depends : wget, xmlstarlet

# Thanks to Patric Haller : http://lists.suckless.org/dev/1110/9813.html
# Thanks to Hiltjo Posthuma <hiltjo@codemadness.org> for sfeed 
#    http://www.codemadness.nl/sfeed-simple-feed-parser.html

if [ -n "$1" ]; then
    SRSSDIR=$1
else
    SRSSDIR=~/.srss
fi
FEEDS=$SRSSDIR/feeds
FEEDLIST=$SRSSDIR/feedlist # one feed url per line
TMP=$(mktemp)
SEP="---.---"

dl() {
        wget --timeout=60 -q -O $TMP 2>/dev/null "$1"
        return $? 
}

check() {
    # initial checks
    mkdir -p $SRSSDIR
    mkdir -p $FEEDS
    if [ ! -e $FEEDLIST ]; then
        echo "Add feed url in $FEEDLIST. One url per line"
    fi
}

get_rss(){
    echo "> Downloading feeds"
    TOTAL=$(wc -l < "${FEEDLIST}")
    i=1
    while read url; do
        echo "* [$i/$TOTAL] : $url"
        dl $url
        if [ $? -eq 0 ]; then
            TITLE=$(xmlstarlet sel -t -m "/rss/channel" -v "title" < $TMP)
            if [ $? -ne 0 ]; then
                TITLE=$(echo $url |cut -d'/' -f3) #ugly
            fi
            xmlstarlet sel -t -m "/rss/channel/item" \
            -v "title" -n \
            -v "link" -n \
            -v "description" -n\
            -o $SEP -n\ < $TMP \
            | xmlstarlet unesc > "${FEEDS}/${TITLE}.new"
        fi
        i=$(($i+1))
    done < $FEEDLIST
}

keepnew(){
    echo "> Merging feeds"
    for i in "${FEEDS}"/*.new; do
        BN="${i%.new}.feed"
        NEW="$i"
        OLD="${i%.new}.old"
        rm "${BN}" && touch "${BN}" # empty feed
        if [ ! -e "${OLD}" ]; then # first check
            touch "${OLD}"
            cp "${NEW}" "${BN}"
        else
            # last line is first of old feed
            STOP="$(sed -n 1p "${OLD}")"
            while read line; do
                if [ "$line" != "$STOP" ]; then
                    echo "$line" >> "${BN}"
                else
                    break
                fi
            done < "${NEW}"

            #grep -v -F -x -f "${OLD}" "${NEW}" > $BN
            #diff "${OLD}" "${NEW}" --unchanged-group-format='' > $BN
            #cat "${OLD}" "${NEW}" | sort | uniq -u
        fi
        mv "${NEW}" "${OLD}"
    done

}

check
get_rss
keepnew

exit 0