#!/bin/sh

# START
set -e

PROGNAME=$(basename $0)
CONFIG=($HOME/.maza/)
LIST="list"
START_TAG="## MAZA - List ad blocking"
END_TAG="## END MAZA"

# FUNCTIONS

## HELP
usage() {
    if [ "$*" != "" ] ; then
        echo "Error: $*"
    fi

    cat << EOF
Usage: $PROGNAME [OPTION]
Simple and efficient local ad blocking throughout the network.

Options:
update       Update the list of DNS to be blocked
start        Activate blocking DNS.
stop         Stop blocking DNS.
--help       Display this usage message and exit
EOF

    exit 1
}


## UPDATE
update() {
    # Make conf folder
    rm -f $CONFIG/$LIST
    mkdir -p $CONFIG
    # Download DNS list
    curl -L -s "https://pgl.yoyo.org/adservers/serverlist.php?showintro=0;hostformat=hosts" -o "$CONFIG/$LIST"
    # Clear list
    ## Get PRE tag
    sed -i .bak -n "/<pre>/,/<\/pre>/p" "$CONFIG/$LIST"
    ## Remove first line
    sed -i .bak '1d' "$CONFIG/$LIST"
    ## Remove last line
    sed -i .bak '$ d' "$CONFIG/$LIST"
    ## Add start tag DNS list in first line
    sed -i .bak "1i\\
        $START_TAG
        " "$CONFIG/$LIST"
    ## Add end tag DNS list in first line
    echo $END_TAG >> "$CONFIG/$LIST"
    # Notify user
    echo "Done!"
}

# CONTROLE ARGUMENTS
isArg=""

while [ $# -gt 0 ] ; do
    case "$1" in
    --help)
        usage
        ;;
    update)
        isArg="1"
        update
        ;;
    start)
        echo "Start"
        isArg="1"
        ;;
    stop)
        echo "Stop"
        isArg="1"
        ;;
    *)
    esac
    shift
done

if [ -z $isArg ] ; then
    usage "Not enough arguments"
fi