#!/bin/sh

# Copyright (C) 2022  Sean Whitton
#
# 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/>.



# emacsclient(1) wrapper to handle updating the environment of existing
# daemons and choosing between installed and in-tree builds of Emacs.

for arg do
    shift
    case "$arg" in
	'--spw/installed') mode=--spw/installed ;;
	'--spw/update-environment') update=true ;;
	*) set -- "$@" "$arg" ;;
    esac
done

processes=$(ps -o exe -u "$LOGNAME" -U "$LOGNAME")
echo "$processes" | grep -q "$HOME/src/emacs/src/emacs" && devel_running=true
echo "$processes" | grep -q $(command -v emacs) && installed_running=true

if [ "$devel_running" = true -a "$mode" = --spw/installed ]; then
    pgrep --full "$HOME/src/emacs/src/emacs" | while read pid; do
	kill $pid
    done
    socket="/run/user/$(id -u)/emacs/server"
    [ -e $socket ] && inotifywait -qqt 2 -e delete $socket
    devel_running=false
fi

# We check whether there is something which looks like the installed Emacs
# running because we do not want the in-tree emacsclient to try to connect to
# that, and we check whether there is a build in progress and no running
# daemon, as we don't want to start a new daemon until the build is finished.
# The idea is that I can always hit C-i e without worrying about builds.
if [ "$mode" != --spw/installed -a "$installed_running" != true \
	     -a -e "$HOME/src/emacs/admin/flagfile.melete" \
	     -a -x "$HOME/src/emacs/lib-src/emacsclient" \
	     -a -d "/usr/share/emacs-snapshot/site-lisp/elpa" ] \
       && ! ( [ "$devel_running" != true ] && ps h -o pid -C make \
		      | xargs pwdx | grep -q "$HOME/src/emacs" ); then
    emacs="$HOME/src/emacs/src/emacs"
    emacsclient="$HOME/src/emacs/lib-src/emacsclient"
else
    emacs=$(command -v emacs)
    emacsclient=$(PATH=$(echo "$PATH" | sed -e "s#$HOME/src/dotfiles/bin:##") \
		      command -v emacsclient)
fi

# Update Emacs daemon environment vars for a new interactive session.  This
# allows us to have the Emacs daemon survive restarts of the graphical desktop
# environment, and to update Emacs on a remote host when there is a new
# forwarded SSH agent socket.  See 'upenv' in .bash_defns.
if [ "$update" = true \
	       -a \( "$devel_running" = true \
	             -o "$installed_running" = true \) ]; then
    for var in DISPLAY WAYLAND_DISPLAY \
		       XAUTHORITY WINDOWID \
		       XDG_SESSION_TYPE XDG_CURRENT_DESKTOP \
		       SWAYSOCK I3SOCK \
		       SSH_ASKPASS SSH_CONNECTION \
		       SSH_AUTH_SOCK SSH_AGENT_PID; do
	eval isset=\${$var+x}
	if [ "$isset" = "x" ]; then
	    eval val=\$$var
	    args="$args"' (setenv "'$var'" "'$val'")'
	fi
    done
    "$emacsclient" --eval "(progn$args (spw/propagate-new-environment))"
fi

# emacsclient(1) requires an argument.  As a special case, if there are no
# arguments and no daemon is running, just start one.  And if there were no
# arguments but we were requested just to update env vars, exit peacefully.
if [ "$#" -eq 0 \
	  -a "$devel_running" != true -a "$installed_running" != true ]; then
    exec "$emacs" --daemon
elif ! [ "$#" -eq 0 -a "$update" = true ]; then
    exec "$emacsclient" -a "" "$@"
fi