#! /bin/bash
# vim: set fileencoding=utf-8 ts=4 sts=4 sw=4 tw=80 expandtab :

# Copyright (C) 2012 Florian Bruhin <me@the-compiler.org>

# tagswitch is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# 
# tagswitch is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with tagswitch  If not, see <http://www.gnu.org/licenses/>.

# Changes herbstluftwm tags

checkuse() {
    if [[ "${tags[$1]}" != [.!]* ]]; then # tag is not unused
        herbstclient use "${tags[$1]:1}" # cutting off first char (.#:!)
        exit 0
    fi
}

tags=( $(herbstclient tag_status) )

# Find the currently active tag
for ((i=0; i<="${#tags[@]}"; i++)); do
    [[ "${tags[i]}" == "#"* ]] && activetag="$i"
done

if [[ "$1" == next ]]; then # next active tag
    for ((i="$((activetag+1))"; i<"${#tags[@]}"; i++)); do
        checkuse "$i"
    done
    # at the end of the taglist, wrap around
    for ((i=0; i<"$activetag"; i++)); do
        checkuse "$i"
    done
elif [[ "$1" == prev ]]; then # previous active tag
    for ((i="$((activetag-1))"; i>=0; i--)) do
        checkuse "$i"
    done
    # at the beginning of the taglist, wrap around
    for ((i=${#tags[@]}-1; i>$((activetag-1)); i--)) do
        checkuse "$i"
    done
else
    echo "Usage: $0 [next|prev]"
    exit 1
fi