#!/usr/bin/env bash


VERSION='202001'


# DESCRIPTION
#    This script provides terminal emulator multiplexing
#    through an xfce4-terminal replacement in ~/bin/.


# USAGE
#    $ xfce4-terminal [optional arguments]
#
#
#    Preferred Applications
#    ~~~~~~~~~~~~~~~~~~~~~~
#    In Settings → Preferred Applications → Utilities → Terminal Emulator, put:
#
#        xfce4-terminal --command="%s" --title="%s"
#
#
#    Launcher
#    ~~~~~~~~
#    In a Terminal Emulator launcher, just put:
#
#        xfce4-terminal
#
#    (Default is: exo-open --launch TerminalEmulator.)
#
#
#    vim
#    ~~~
#    In .vimrc, put:
#
#        command! Terminal :call system("xfce4-terminal --working-directory='".expand("%:p:h")."' &")
#        noremap  <silent> <F4> :Terminal<CR>
#        vnoremap <silent> <F4> <ESC>:Terminal<CR>
#        inoremap <silent> <F4> <ESC>:Terminal<CR>
#
#
#    SpaceFM
#    ~~~~~~~
#    In SpaceFM → View → Preferences → Advanced → Terminal, put:
#
#        xfce4-terminal --title="%D"


# REQUIRES
#    awk, pidof, wmctrl, xfce4-terminal


# COPYRIGHT
#    Copyright (C) 2015-2020  Serge Y. Stroobandt
#
#    This program 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.
#
#    This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.


# CONTACT
#    xdg-open mailto:$(echo c2VyZ2VAc3Ryb29iYW5kdC5jb20K |base64 -d)


# TODO
#    Some console programs should run in their own window:
#    YFKTEST=$(wmctrl -lp |awk '{print$5}' |grep 'YFKtest')


if [[ $DISPLAY ]]; then
    TERMINAL='/usr/bin/xfce4-terminal'


    # Store the arguments for later use.
    # Spaces in the arguments are to be expected.
    # Hence, the internal field separator (IFS) is set to tab.
    # https://stackoverflow.com/a/30439949/2192488
    OLD_IFS="$IFS"
    IFS=$'\t'
    ARGUMENTS="$*"


    # Check whether an xfce4-terminal instance is already running.
    TERM_PID=$(pidof $TERMINAL)    # Beware, pidof is not available in all GNU/Linux distributions!
    echo $TERM_PID


    # Determine the terminal instance title
    # by processing the command line options
    TITLE=''
    WORKING_DIR=''

    while [[ -n $1 ]]; do
        case $1 in
            --working-directory=*)
                WORKING_DIR=`echo $1 |sed -e 's/^[^=]*=//g'`
                ;;
            --title=*)
                TITLE=`echo $1 |sed -e 's/^[^=]*=//g'`
                ;;
            -T)
                shift
                TITLE=$1
                ;;
            *)
                ;;
        esac
        shift
    done


    if [[ -z $TITLE ]]; then
        TITLE=$WORKING_DIR
    fi


    if [[ -z $TITLE ]]; then
        TITLE='~'
    fi


    # If another terminal instance is running, use --tab as the first option.
    # Otherwise, open a new xfce4-terminal window, which will be maximised if the file ~/.maximize exists.
    # Note that repeating the same argument twice does not entail any negative consequences.
    if [[ -n $TERM_PID ]]; then
        $TERMINAL --tab --title=$TITLE $ARGUMENTS
    elif [[ -f $HOME/.maximize ]]; then
        $TERMINAL --maximize --title=$TITLE $ARGUMENTS
    else
        $TERMINAL --title=$TITLE $ARGUMENTS
    fi


    IFS="$OLD_IFS"


    # Focus the last opened xfce4-terminal window
    TERM_PID=$(pidof $TERMINAL)
    TERM_WIN=$(wmctrl -lp |grep -E "^.+\b.+\b$TERM_PID\b" |tail -n1)    # window number

    wmctrl -ia $TERM_WIN
else
    echo 'On this system, xfce4-terminal is not available.'
fi