#!/bin/bash
#
#   CDM: The Console Display Manager
#
#   Copyright (C) 2009-2011, Daniel J Griffiths <ghost1227@archlinux.us>
#   Thanks to:
#
#       Andrwe          beta-testing and submitting the fix for the all
#                       important X incrementation function
#       brisbin33       code cleanup
#       tigrmesh        finding a critical issue with the gnome-session handler
#       Profjim         several incredibly useful patches
#       lambchops468    consolekit and hibernation patches
#
#   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 2 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, write to the Free Software
#   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
#   MA 02110-1301, USA.

name="Console Display Manager"
ver="0.5.3"
info="\e[1;34m==>\e[1;37m"
error="\e[1;31m==>\e[1;37m"
success="\e[1;32m==>\e[1;37m"
reset="\e[0m"
# Ignore SIGINT (^C) and SIGTSTP (^Z)
trap "" 2 20
userclientrc=$HOME/.xinitrc
sysclientrc=/etc/X11/xinit/xinitrc
# userserverrc=$HOME/.xserverrc
# sysserverrc=/etc/X11/xinit/xserverrc

# Source cdm configuration
if [[ -f /etc/X11/cdm/cdmrc ]]; then
	source /etc/X11/cdm/cdmrc
	count=0
	while [[ ${count} -lt ${#userconfig[@]} ]]; do
		if [[ "$USER" == "${userconfig[${count}]}" ]]; then
			${userconfig[${count}]}
		fi
		let count=count+1
	done
	countfrom=${countfrom:-0}
	consolekittime=${consolekittime:-30}
else
	echo -e "${error} ERROR: A valid cdm configuration was not found!${reset}"
	echo -e "${info} Logging out.${reset}"
	sleep 3
	exit 1
fi

# Offer all available sessions in /etc/X11/Sessions
# if wmbinlist if not explicitly set in cdmrc

if [[ "${#wmbinlist[@]}" -eq 0 ]]; then
    wmbinlist=($(ls /etc/X11/Sessions))
    wmdisplist=($(echo ${wmbinlist[@]^}))
fi

unset DIALOGRC
# Source theme file
if [[ ! -z ${theme} ]]; then
	if [[ -f /usr/share/cdm/themes/${theme} ]]; then
		DIALOGRC=/usr/share/cdm/themes/${theme}
	else
		echo -e "${info} Theme file ${theme} is invalid, reverting to default theme.${reset}"
	fi
fi
if [[ -z $DIALOGRC ]]; then
	if [[ -f /usr/share/cdm/themes/default ]]; then
		DIALOGRC=/usr/share/cdm/themes/default
	else
		echo -e "${info} A valid theme file was not found, using system defaults.${reset}"
	fi
fi

# Based on FreeBSD's /etc/rc.subr
#
# checkyesno var
#    Test $1 variable, and warn if not set to YES or NO.
#    Return 0 if it's "yes" (et al), nonzero otherwise.
#    to make default yes, do "checkyesno var yes"

checkyesno() {
	local value=${!1}
	# debug "checkyesno: $1 is set to $value."
	if [[ -n $2 ]]; then
		value=${value:-$2}
	else
		value=${value:-no}
	fi
	case $value in
	#    "yes", "true", "on", or "1"
	[Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|[Oo][Nn]|1)
	return 0
	;;
	#    "no", "false", "off", or "0"
	[Nn][Oo]|[Ff][Aa][Ll][Ss][Ee]|[Oo][Ff][Ff]|0)
	return 1
	;;
	*)
	echo "\$${1} is not set properly." >&2
	exit 1
	;;
	esac
}

# If X is already running and locktty=yes, activate it,
# otherwise, increment.
if $(checkyesno locktty); then
	# Verify display exists
	if [[ -n "${display//[0-9]/}" ]]; then
		display=0
	fi
	# Activate existing X session
	if xdpyinfo -display :${display}.0 &> /dev/null; then
		let tty=display+xtty
		chvt ${tty}
		exit 0
	fi
else
	# Get the first empty display
	display=0
	while [[ ${display} -lt 7 ]]; do
		if dpyinfo=$(xdpyinfo -display :${display}.0 2>&1 1>/dev/null); then
			let display=display+1
		elif [[ $dpyinfo = No\ protocol\ specified* ]]; then
			# Display is in use by another user
			let display=display+1
		else
			break
		fi
	done
fi

mainmenu() {
	# Generate main menu
	count=0
	menu=$(
		while [[ ${count} -lt ${#wmdisplist[@]} ]]; do
			echo -ne "$((count+countfrom)) ${wmdisplist[${count}]} "
			let count=count+1
		done
	)

	# Check if console access is allowed
	if $(checkyesno allowconsole); then
		if ! $(checkyesno allowshutdown); then
			let halt=99
		fi
		let console=${#wmdisplist[@]}+countfrom
		menu="${menu} ${console} Console "
	fi

	# Check if shutdown access is allowed
	if $(checkyesno allowshutdown); then
		if ! $(checkyesno allowconsole); then
			let halt=${#wmdisplist[@]}
		else
			let halt=${#wmdisplist[@]}+1
		fi
		let halt=halt+countfrom
		menu="${menu} ${halt} Shutdown "
	fi
	
	# Override dialog display if only one option is available
	if ! $(checkyesno allowconsole) && ! $(checkyesno allowshutdown) && [[ ${#wmdisplist[@]} == 1 ]]; then
		wm=$countfrom
	else
		# Display selection dialog
		wm=$(
			DIALOGRC="$DIALOGRC" dialog --colors \
			--backtitle "${name} v${ver}" --stdout \
			--ok-label " Select " --cancel-label " Logout " \
			--menu "Select Window Manager" 0 0 0 ${menu}
		)
		if [[ $? != 0 ]]; then
			clear
			exit 0
		fi
	fi

	# Set wm_bin
	clear
	if [[ ${wm} -eq ${console} ]]; then
		exit 2 #2 signals to the profile file to not exit.
	elif [[ ${wm} -eq ${halt} ]]; then
		shutdownmenu
	else
		let wm=wm-countfrom
		wm_bin="${wmbinlist[${wm}]}"
		xstart
	fi
}

shutdownmenu() {
	count=$countfrom
	haltmenu=$(
		for opt in Shutdown Reboot Suspend Hibernate; do
			# Check if suspend/hibernate is enabled
			if ([[ $opt != Suspend ]] && [[ $opt != Hibernate ]]) ||
				([[ $opt == Suspend ]] && $(checkyesno allowsuspend)) ||
				([[ $opt == Hibernate ]] && $(checkyesno allowhibernate)); then
				echo -ne "$count $opt "
				let count=count+1
			fi
		done
	)

	# Display shutdown dialog
	haltopt=$(
		DIALOGRC="$DIALOGRC" dialog --colors \
		--backtitle "${name} v${ver}" --stdout \
		--ok-label " Select " --cancel-label " Cancel " \
		--menu "Shutdown" 0 0 0 ${haltmenu}
	)
	
	if [[ $? == 0 ]]; then
		clear
		if [[ ${haltopt} -eq $countfrom ]]; then
			${shutdowncommand}
		elif [[ ${haltopt} -eq $((countfrom+1)) ]]; then
			${rebootcommand}
		elif [[ ${haltopt} -eq $((countfrom+2)) ]] && $(checkyesno allowsuspend); then
			${suspendcommand}
		else
			${hibernatecommand}
		fi
	else
		mainmenu
	fi
}

xstart() {
	# Start X
	if $(checkyesno usexinit); then
		if [[ -f $userclientrc ]]; then
			wm_bin="$userclientrc $wm_bin"
		elif [[ -f $sysclientrc ]]; then
			wm_bin="$sysclientrc $wm_bin"
		fi
	else
		wm_bin="/etc/X11/cdm/xinitrc $wm_bin"
	fi

	serverargs=":${display} ${serverargs} vt$((xtty+display))"

	if $(checkyesno consolekit); then #do first to avoid race conditions
		echo -ne "${info} Waiting for ConsoleKit to register X session (timeout ${consolekittime}s)..."

		sleep $consolekittime &
		clockpid=$!
	
		trap "echo -e \"Registered! ${reset}\"" USR1
	
		#have to store pid of dbus-monitor this way since dbus-monitor will run until killed.
		fifo=$(mktemp --dry-run)
		mkfifo --mode=700 $fifo
		(dbus-monitor --system type=signal,interface=org.freedesktop.ConsoleKit.Seat,member=SessionAdded & echo $! > $fifo ) | \
		 sed -un 's|[[:space:]]*object path \"\(/[a-zA-Z0-9/]*\)\"|\1|p' | while read object; do
			if dbus-send --system --print-reply  --dest=org.freedesktop.ConsoleKit "$object" org.freedesktop.ConsoleKit.Session.GetX11Display | \
		       	  grep -qF "$display"; then
				kill -USR1 $$
				break
			fi
		 done &

		 read dbuspid < $fifo
		 rm -f $fifo
	fi

	if $(checkyesno loginshell); then
		nohup bash --login -c "startx $wm_bin -- ${serverargs}" &> /dev/null &
	else
		nohup startx $wm_bin -- ${serverargs} &> /dev/null &
	fi

	if [[ -n $clockpid ]]; then
		#if wait returns with a value >128, it was interrupted by the trap, so registration was sucessful.
		if wait $clockpid; then
			echo -e "Timed out, giving up.\nCheck to see if you are wrapping your session with ck-launch-session or increase the timeout. ${reset}"
			kill $dbuspid
			exit 1
		else
			kill $dbuspid $clockpid
			exit 0
		fi
	fi

	exit 0
}
mainmenu