#!/bin/sh -e
trap _restore_all 1 2 3 6

# list of filenames can can be fetched from $_url
_list=/etc/unwind/blocklistproject.txt
_url=https://blocklistproject.github.io/Lists/alt-version

# download blocklists here
_dir=/etc/unwind/lists

# combined, sorted and filtered list of all lists configured in $_list
# configure in /etc/unwind.conf:
# block list "/etc/unwind/_assembled.txt" log
_unwind_blocklist="/etc/unwind/_assembled.txt"

if [ ! -f $_list ]
then
    echo "Creating new adlist /etc/unwind/blocklistproject.txt:"
    doas mkdir -p $_dir
    doas tee $_list <<EOF
	## from https://github.com/blocklistproject/Lists
	## ## => comment
	## #  => disabled list (will be deleted if present)
	abuse-nl.txt
	adobe-nl.txt
	ads-nl.txt
	basic-nl.txt
	crypto-nl.txt
	drugs-nl.txt
	#everything-nl.txt
	facebook-nl.txt
	fortnite-nl.txt
	fraud-nl.txt
	gambling-nl.txt
	malware-nl.txt
	phishing-nl.txt
	piracy-nl.txt
	porn-nl.txt
	ransomware-nl.txt
	redirect-nl.txt
	scam-nl.txt
	smart-tv-nl.txt
	tiktok-nl.txt
	torrent-nl.txt
	tracking-nl.txt
	twitter-nl.txt
	vaping-nl.txt
	whatsapp-nl.txt
	youtube-nl.txt
EOF
fi

_restore_all() {
    echo "Signal received, aborting..."
    for _f in $_dir/*.old
    do
        echo "Restore: $(basename $_f)"
        doas mv -f "$_f" "${_f%%.old}"
    done
    _assemble
    _restart_unwind
    exit 1
}

_backup() {
    _f=$(basename "$1")
    if [ -f "$_dir/$_f" ]
    then
        echo "Backup: $_f -> $_f.old"
        doas mv -f "$_dir/$_f" "$_dir/$_f.old"
    fi
}

_restore() {
    _f=$(basename "$1")
    if [ -f "$_dir/$_f.old" ]
    then
        echo "Restore: $_f.old -> $_f"
        doas mv -f "$_dir/$_f" "$_dir/$_f.old"
    fi
}

_download() {
    echo "Download: $_file"
    doas ftp -V -o "$_dir/$_file" "$_url/$_file" > /dev/null \
        && doas rm -f "$_dir/$_file.old"
}

_disabled() {
    if echo "$1" | grep -q "^#"
    then
        _f=$(basename "$1" | tr -d '# ')
        echo "Skip (disabled): $_f"
        doas rm -f $_dir/$_f
        return 0
    fi
    return 1
}

_domainfilter() {
    # chain grep commands used in assemble pipe
    grep -Ev "torrent|instagram\.com|tattoo|whatsapp\.com"
}

_assemble() {
    echo "Assemble blocklist: $_unwind_blocklist"
    cat $_dir/*.txt \
        | tr -d " " \
        | grep -v '^#' \
        | grep -v '^-' \
        | grep -v '^$' \
        | cut -d "#" -f1 \
        | sed 's/\.$//g' \
        | _domainfilter \
        | doas sort -uo $_unwind_blocklist
}

_restart_unwind() {
    doas rcctl restart unwind
}


for _file in $(grep -v "^##" $_list \
                    | cut -d "#" -f1 \
                    | xargs)
do 
    if ! _disabled $_file
    then
        _backup $_file
        _download || _restore
    fi
done
_assemble
_restart_unwind