#!/bin/sh

# ----------------------------------------------------------------------
# reference
# ----------------------------------------------------------------------

# compose key in this setup is shift+ralt, release, then hit dead key and live key
# e.g. shift+ralt, ', e = é

# both shifts simultaneously switches between first and second group (en and gr)

# /etc/udev/rules.d/00-keyboard.rules
# ACTION=="add", SUBSYSTEM=="input", ENV{DISPLAY}=":0", ENV{XAUTHORITY}="/home/ethan/.Xauthority", RUN+="/home/ethan/bin/wm/init-keyboard"

# $HOME/.config/systemd/user/xcape.service
# [Unit]
# Description=Xcape Daemon
# After=graphical.target
#
# [Service]
# Type=forking
# Environment=DISPLAY=:0
# ExecStart=/usr/bin/xcape -e "Hyper_L=Tab;Hyper_R=backslash"
# Restart=always
# RestartSec=1
#
# [Install]
# WantedBy=default.target

# ----------------------------------------------------------------------
# Standard Boilerplate
# ----------------------------------------------------------------------
# I use this standard boilerplate in multiple scripts where I might
# need to re-run as the X user. Some items are not necessary in all
# scripts but I'd rather keep it consistent. In general, the *ctl
# scripts (audioctl, displayctl) require this as they may be called
# by udev or acpi and thus by root.

# script values and config file if we need it
SCRIPTNAME=$(basename $0)
SCRIPTPATH=$(readlink -f $0)
SCRIPTDIR=$(dirname $SCRIPTPATH)
SCRIPTOWNER=$(stat -c '%U' $SCRIPTPATH)

# rerun as X user if running as root
# ------------------------------------------------------------------------
# attempt to grab xuser assuming it has been run "normally" via a
# display manager or startx
XUSER=$(ps -C Xorg -C X -ouser=)
# if we are running via xlogin@ systemd service, it will be running
# as root, so attempt to match based on the script owner
#[ "$XUSER" = root ] && systemctl is-active xlogin@$SCRIPTOWNER && XUSER=$SCRIPTOWNER
[ "$XUSER" = root ] && XUSER=$SCRIPTOWNER
# if at this point our XUSER is not root, restart as the XUSER
[ "$(id -un)" = root ] && [ "$XUSER" != root ] && exec su -c "$0 $*" "$XUSER"

# grab X user id if necessary
XUSERID=$(id -u $XUSER)

# key environment variables
export DISPLAY=":0"
export XAUTHORITY=$HOME/.Xauthority
export DBUS_SESSION_BUS_ADDRESS="unix:path=/run/user/$XUSERID/bus"
export PULSE_RUNTIME_PATH="/run/user/${XUSERID}/pulse/"

CONFIG=/home/$XUSER/.config/$SCRIPTNAME

# ----------------------------------------------------------------------
# Lock
# ----------------------------------------------------------------------

# locking not working properly... udev triggers this but locking is
# present it fails... possibly it it running before udev has populated
# all attached usb devices?

# going to try adding a sleep here to give it time to get its act together

#LOCKFILE=/tmp/${SCRIPTNAME}.lock
#exec 200>$LOCKFILE
#flock -n 200 || exit 0
#sleep 1 # give udev time to finish

# ----------------------------------------------------------------------
# dump config to file
# ----------------------------------------------------------------------

# rather than dump these to a file, I could keep them in static files
# in, say, .config/xkb or .xkb, but I prefer this method as it centralizes
# the configuration data to just this file

XKBDIR=/tmp/xkb
[ -d ${XKBDIR}/symbols ] || mkdir -p ${XKBDIR}/{keymap,symbols}

# the following is generated first from a setxkbmap command similar to:
#     setxkbmap -layout "us,gr(polytonic)" -option "ctrl:nocaps,grp:shifts_toggle,misc:typo,shift:break_caps,lv3:alt_switch"
# and then:
#     setxkbmap -print
# the final tweak being the addition of the "+custom(hypers)" to use my local customizations

# lv3:ralt_switch_multikey
# level3(alt_switch)
# level3(ralt_switch_multikey)

cat > $XKBDIR/keymap/custom.xkb << EOF
xkb_keymap {
    xkb_keycodes  { include "evdev+aliases(qwerty)"	};
    xkb_types     { include "complete"	};
    xkb_compat    { include "complete"	};
    xkb_symbols   { include "pc+us+gr(polytonic):2+inet(evdev)+group(shifts_toggle)+level3(ralt_switch_multikey)+ctrl(nocaps)+typo(base):1+typo(base):2+custom(hypers)" };
    xkb_geometry  { include "pc(pc104)"	};
};
EOF

cat > $XKBDIR/symbols/custom << EOF
default partial
xkb_symbols "hypers" {
    key  <TAB> { [ Hyper_L, Hyper_L ] };
    key <BKSL> { [ Hyper_R, Hyper_R ] };
    key <I252> { [ Tab,	ISO_Left_Tab ] };
    key <I253> { [ backslash, bar ] };
    modifier_map Mod4 { Super_L, Super_R, Hyper_L, Hyper_R };
};
EOF

# ----------------------------------------------------------------------
# reinitialize keyboard
# ----------------------------------------------------------------------

export DBUS_SESSION_BUS_ADDRESS="unix:path=/run/user/$XUSERID/bus"
notify-send -u low "Keyboard initialized"
xkbcomp -synch -w3 -I$XKBDIR $XKBDIR/keymap/custom.xkb $DISPLAY &>/dev/null
#(exec killall -q xcape) & # gets restarted by the xcape systemd user service
# if no service running, just start xcape here
# if more than one xcape, just kill them all and let service respawn
if (( $(pgrep -c xcape) > 0 )) && systemctl --user status xcape &>/dev/null
then
	for PID in $(pgrep xcape)
	do
		kill -9 $PID
	done
elif systemctl --user status xcape &>/dev/null
then
	# try starting service or just run xcape if that fails
	systemctl --user start xcape || /usr/bin/xcape -e "Hyper_L=Tab;Hyper_R=backslash"
fi