#!/bin/bash
# tmux-session.  Starts a consistently-named tmux session; if there is already
# an existing session, use that instead.

###############################################################################
### Configuration #############################################################
###############################################################################

CONFIG_DIR=~/.config/config.d/tmux
BASENAME=`basename $0`

## Name of the tmux session
NAME=${1:-UNSET}

## Count of the tmux session - that is, connect multiple times?
COUNT=${2:-UNSET}

###############################################################################
### Functions #################################################################
###############################################################################

# sets tmux_nb to the number of tmux entries matching the name
tmux_count() {
    tmux_nb=$(echo `tmux ls 2> /dev/null | egrep "^${1}:" | wc -l`)
}

###############################################################################
### main () ###################################################################
###############################################################################

if [ "$1" == "UNSET" ]; then
    echo "Usage: $BASENAME SESSION [COUNT]"
    exit 1
fi

tmux_count $NAME

if [[ "$tmux_nb" == "0" ]]; then
    if [ -f "${CONFIG_DIR}/${NAME}" ]; then
        . ${CONFIG_DIR}/${NAME}
    else
        tmux new-session -d -s ${NAME} -n ${NAME}
    fi
    tmux select-window -t ${NAME}:0
    exec tmux attach-session -t ${NAME}

elif [[ "$COUNT" != "UNSET" ]]; then
    new="${NAME}-${COUNT}"
    tmux_count $new
    if [[ "$tmux_nb" == "0" ]]; then
        tmux new-session -d -t $NAME -s $new
        exec tmux attach-session -t $new \; set-option destroy-unattached
    else
        exec tmux attach-session -t ${NAME}-${1}
    fi

else
    exec tmux attach-session -t ${NAME}
fi

exit 0

###############################################################################
### Documentation #############################################################
###############################################################################

# Documentation.  Use a hack to hide this from the shell.  Because of the
# above exit line, this should never be executed.
DOCS=<<__END_OF_DOCS__

=head1 NAME

tmux-session - manage named tmux sessions

=head1 SYNOPSIS

B<tmux-session> I<name>

B<tmux-session> I<name> I<count>

=head1 DESCRIPTION

tmux-session manages arbitrary tmux sessions with consistent names, so that we
can connect to them multiple times.  

=head1 USAGE

=over 4

=item I<name>

Name of the session to connect to, as well as the configuration file to load 
in F<~/config/config.d/tmux/*>.  Use something memorable.

=item (I<count>)

If set, connect to another instance of the same session.  This emulates the old
screen behaviour, where you can have multiple sessions looking at different
windows.  Once this session closes, the extra sessions disappear.

=back

=head1 FILES

=over 4

=item B<~/.config/config.d/tmux/*>

If a file in this directory matches I<name>, it will be loaded to create
a custom tmux session, rather than just building something empty.
These files must at least include 'tmux new-session'.  

A sample configuration:

    tmux new-session -d -s locust -n 'daishi' 'ssh-krb5 daishi.fnal.gov'
    tmux new-window -t locust:1   -n 'kf1'
    tmux new-window -t locust:2   -n 'kf2'
    tmux new-window -t locust:3   -n 'log'    'log-weekly'
    tmux new-window -t locust:4   -n 'flea'   'ssh flea.killfile.org'
    tmux new-window -t locust:5   -n 'kodiak' 'ssh kodiak.killfile.org'

=item B<~/.tmux.conf>

Shared tmux configuration.

=back

=head1 SEE ALSO

tmux(1)

=head1 AUTHOR

Tim Skirvin <tskirvin@killfile.org>

=cut

__END_OF_DOCS__