#!/bin/sh
#
# Automatically select a display configuration based on connected devices
#
# Stefan Tomanek <stefan.tomanek@wertarbyte.de>
#
# How to use:
#
# Save your current display configuration and setup with:
#  $ autorandr --save mobile
#
# Connect an additional display, configure your setup and save it:
#  $ autorandr --save docked
#
# Now autorandr can detect which hardware setup is active:
#  $ autorandr
#    mobile
#    docked (detected)
#
# To automatically reload your setup, just append --change to the command line
#
# To manually load a profile, you can use the --load <profile> option.
#
# autorandr tries to avoid reloading an identical configuration. To force the
# (re)configuration, apply --force.
#
# To prevent a profile from being loaded, place a script call "block" in its
# directory. The script is evaluated before the screen setup is inspected, and
# in case of it returning a value of 0 the profile is skipped. This can be used
# to query the status of a docking station you are about to leave.
#
# If no suitable profile can be identified, the current configuration is kept.
# To change this behaviour and switch to a fallback configuration, specify
# --default <profile>
#
# Another script called "postswitch "can be placed in the directory
# ~/.autorandr as well as in all profile directories: The scripts are executed
# after a mode switch has taken place and can notify window managers or other
# applications about it.
#
#
# While the script uses xrandr by default, calling it by the name "autodisper"
# or "auto-disper" forces it to use the "disper" utility, which is useful for
# controlling nvidia chipsets. The formats for fingerprinting the current setup
# and saving/loading the current configuration are adjusted accordingly.

XRANDR=/usr/bin/xrandr
DISPER=/usr/bin/disper
XDPYINFO=/usr/bin/xdpyinfo
PROFILES=~/.autorandr
CONFIG=~/.autorandr.conf
RESERVED_PROFILE_NAMES=`cat <<EOF
 common     Clone all connected outputs at the largest common resolution
 horizontal Stack all connected outputs horizontally at their largest resolution
 vertical   Stack all connected outputs vertically at their largest resolution
EOF`

CHANGE_PROFILE=0
FORCE_LOAD=0
DEFAULT_PROFILE=""
SAVE_PROFILE=""

FP_METHODS="setup_fp_sysfs_edid setup_fp_xrandr_edid"
CURRENT_CFG_METHOD="current_cfg_xrandr"
LOAD_METHOD="load_cfg_xrandr"

SCRIPTNAME="$(basename $0)"
# when called as autodisper/auto-disper, we assume different defaults
if [ "$SCRIPTNAME" = "auto-disper" ] || [ "$SCRIPTNAME" = "autodisper" ]; then
	echo "Assuming disper defaults..." >&2
	FP_METHODS="setup_fp_disper"
	CURRENT_CFG_METHOD="current_cfg_disper"
	LOAD_METHOD="load_cfg_disper"
fi

if [ -f $CONFIG ]; then
	echo "Loading configuration from '$CONFIG'" >&2
	. $CONFIG
fi

setup_fp_xrandr_edid() {
	$XRANDR -q --verbose | awk '
	/^[^ ]+ (dis)?connected / { DEV=$1; }
	$1 ~ /^[a-f0-9]+$/ { ID[DEV] = ID[DEV] $1 }
	END { for (X in ID) { print X " " ID[X]; } }'
}

setup_fp_sysfs_edid() {
	# xrandr triggers the reloading of EDID data
	$XRANDR -q > /dev/null
	# hash the EDIDs of all _connected_ devices
	for P in /sys/class/drm/card*-*/; do
		# nothing found
		[ ! -d "$P" ] && continue
		if grep -q "^connected$" < "${P}status"; then
			echo -n "$(basename "$P") "
			md5sum ${P}edid | awk '{print $1}'
		fi
	done
}

setup_fp_disper() {
	$DISPER -l | grep '^display '
}

setup_fp() {
	local FP="";
	for M in $FP_METHODS; do
		FP="$($M)"
		if [ -n "$FP" ]; then
			break
		fi
	done
	if [ -z "$FP" ]; then
		echo "Unable to fingerprint display configuration" >&2
		return
	fi
	echo "$FP"
}

current_cfg_xrandr() {
	local PRIMARY_SETUP="";
	if [ -x "$XDPYINFO" ]; then
		PRIMARY_SETUP="$($XDPYINFO -ext XINERAMA | awk '/^  head #0:/ {printf $3 $5}')"
	fi
	$XRANDR -q | awk -v primary_setup="${PRIMARY_SETUP}" '
	# display is connected and has a mode
	/^[^ ]+ connected [^(]/ {
		print "output "$1;
		if ($3 == "primary") {
			print $3
			split($4, A, "+")
			$4=$5
		}
		else {
			split($3, A, "+");
			if (A[1] A[2] "," A[3] == primary_setup)
				print "primary";
		}
		if (($4 == "left") || ($4 == "right")) {
			split(A[1], B, "x");
			A[1] = B[2]"x"B[1];
		}
		print "mode "A[1];
		print "pos "A[2]"x"A[3];
		if ($4 !~ /^\(/) {
			print "rotate "$4;
		}
		else {
			print "rotate normal";
		}
		next;
	}
	# disconnected or disabled displays
	/^[^ ]+ (dis)?connected / ||
	/^[^ ]+ unknown connection / {
		print "output "$1;
		print "off";
		next;
	}'
}

current_cfg_disper() {
	$DISPER -p
}

common_cfg_xrandr() {
	$XRANDR -q | awk '
	# variables:
	#   output: current output
	#   outputlist: space sep list of all outputs
	#   outputarr: array of all connected outputs
	#   outputarrsize: number of connected outputs
	#   modelist[800x600]: space sep list of outputs supporting mode
	# display is connected
	/^[^ ]+ connected / {
	    output=$1;
	    outputlist=outputlist " " output
	    outputarr[outputarrsize++]=output
	}
	# disconnected or disabled displays
	/^[^ ]+ disconnected / ||
	/^[^ ]+ unknown connection / {
	    print "output " $1;
	    print "off";
	}
	# modes available on a screen
	/^   [0-9]+x[0-9]+/ {
	    modelist[$1]=modelist[$1] " " output
	}
	END {
	    # find common mode with largest screen area
	    for (m in modelist) {
		if (modelist[m] == outputlist) {
		    # calculate area of resolution
		    split(m, wh, "x");
		    if (wh[1]*wh[2] >= maxdim) {
			maxdim=wh[1]*wh[2]
			maxmode=m
		    }
		}
	    }
	    if (maxmode) {
		for (i in outputarr) {
		    print "output " outputarr[i];
		    print "mode " maxmode;
		    print "pos 0x0";
		    if (i > 0) {
		        print "same-as " outputarr[0]
		    }
		}
	    }
	}' \
		| load_cfg_xrandr -
}

stack_cfg_xrandr() {
	$XRANDR -q | awk -v stack="${STACK}" '
	# variables:
	#   stack: "horizontal" (anything except vertical) or "vertical"
	#   output: current output
	#   firstmode: pick first mode after output
	#   posX,posY: position of the next output
	BEGIN {
	    posX=posY=0
	}
	# display is connected
	/^[^ ]+ connected / {
	    output=$1;
	    print "output " $1;
	    firstmode=1
	}
	# disconnected or disabled displays
	/^[^ ]+ disconnected / ||
	/^[^ ]+ unknown connection / {
	    print "output " $1;
	    print "off";
	}
	# modes available on a screen, but pick only the first
	/^   [0-9]+x[0-9]+/ {
	    if (!firstmode) next;
	    firstmode=0
	    # output mode at current virtual desktop pos
	    print "mode " $1;
	    print "pos " posX "x" posY;
	    # calculate position of next output
	    split($1, wh, "x");
	    if (stack == "vertical")
		posY += wh[2];
	    else
		posX += wh[1];
	}' \
		| load_cfg_xrandr -
}

current_cfg() {
	$CURRENT_CFG_METHOD;
}

blocked() {
	local PROFILE="$1"
	[ ! -x "$PROFILES/$PROFILE/block" ] && return 1

	"$PROFILES/$PROFILE/block" "$PROFILE"
}

config_equal() {
	local PROFILE="$1"
	if [ "$(cat "$PROFILES/$PROFILE/config")" = "$(current_cfg)" ]; then
		echo "Config already loaded"
		return 0
	else
		return 1
	fi
}

load_cfg_xrandr() {
	# sed 1: Prefix arguments with "--"
	# sed 2: Merge arguments into one line per output
	# sed 3: Merge into two lines, all --off outputs in the first one
	sed 's/^/--/' "$1" | sed -e '
		:START
		/\n--output/{P;D}
		s/\n/ /
		N;bSTART' | sed -e '
			### First line
			/ --off/{
				G
				# Merge if next line contains --off
				s/\n\([^\n]* --off\)/ \1/
				h
				$!d;b
			}
			### Last line
			H;x
			# Merge if previous line contains --mode
			s/\(--mode [^\n]*\)\n/\1 /
			h
			$!d' | xargs -L 1 $XRANDR
}

load_cfg_disper() {
	$DISPER -i < "$1"
}

load() {
	local PROFILE="$1"
	local CONF="$PROFILES/$PROFILE/config"
	local IS_VIRTUAL_PROFILE=`echo "$RESERVED_PROFILE_NAMES" | grep -c "^ $PROFILE "`

	if [ ! -f "$CONF" -a $IS_VIRTUAL_PROFILE -eq 0 ]; then
		echo " -> Error: Profile '$PROFILE' does not exist." >&2
		return
	fi

	if [ -x "$PROFILES/preswitch" ]; then
		"$PROFILES/preswitch" "$PROFILE"
	fi
	if [ -x "$PROFILES/$PROFILE/preswitch" ]; then
		"$PROFILES/$PROFILE/preswitch" "$PROFILE"
	fi

	if [ -f "$CONF" ]; then
		echo " -> loading profile $PROFILE"
		if [ $IS_VIRTUAL_PROFILE -ne 0 ]; then
			echo " -> Warning: Existing profile overrides virtual profile with same name" >&2
		fi
		$LOAD_METHOD "$CONF"
	else
		# Virtual profiles
		if [ $PROFILE = "common" ]; then
			echo " -> setting largest common mode in cloned mode"
			common_cfg_xrandr
	        elif [ $PROFILE = "horizontal" ]; then
			echo " -> stacking all outputs horizontally at their largest modes"
			STACK="horizontal" stack_cfg_xrandr
	        elif [ $PROFILE = "vertical" ]; then
			echo " -> stacking all outputs vertically at their largest modes"
			STACK="vertical" stack_cfg_xrandr
		fi
	fi

	if [ -x "$PROFILES/$PROFILE/postswitch" ]; then
		"$PROFILES/$PROFILE/postswitch" "$PROFILE"
	fi
	if [ -x "$PROFILES/postswitch" ]; then
		"$PROFILES/postswitch" "$PROFILE"
	fi
}

help() {
	cat <<EOH
Usage: $SCRIPTNAME [options]

-h, --help 		get this small help
-c, --change 		reload current setup
-s, --save <profile>	save your current setup to profile <profile>
-l, --load <profile> 	load profile <profile>
-d, --default <profile> make profile <profile> the default profile
--force			force (re)loading of a profile
--fingerprint		fingerprint your current hardware setup
--config		dump your current xrandr setup

 To prevent a profile from being loaded, place a script call "block" in its
 directory. The script is evaluated before the screen setup is inspected, and
 in case of it returning a value of 0 the profile is skipped. This can be used
 to query the status of a docking station you are about to leave.

 If no suitable profile can be identified, the current configuration is kept.
 To change this behaviour and switch to a fallback configuration, specify
 --default <profile>.

 Another script called "postswitch "can be placed in the directory
 ~/.autorandr as well as in any profile directories: The scripts are executed
 after a mode switch has taken place and can notify window managers.

 When called by the name "autodisper" or "auto-disper", the script uses "disper"
 instead of "xrandr" to detect, configure and save the display configuration.

 If xrandr is used, the following virtual configurations are available:
${RESERVED_PROFILE_NAMES}

EOH
	exit
}
# process parameters
OPTS=$(getopt -n autorandr -o s:l:d:cfh --long change,default:,save:,load:,force,fingerprint,config,help -- "$@")
if [ $? != 0 ] ; then echo "Terminating..." >&2 ; exit 1 ; fi
eval set -- "$OPTS"

while true; do
	case "$1" in
		-c|--change) CHANGE_PROFILE=1; shift ;;
		-d|--default) DEFAULT_PROFILE="$2"; shift 2 ;;
		-s|--save) SAVE_PROFILE="$2"; shift 2 ;;
		-l|--load) LOAD_PROFILE="$2"; shift 2 ;;
	 	-h|--help) help ;;
		--force) FORCE_LOAD=1; shift ;;
		--fingerprint) setup_fp; exit 0;;
		--config) current_cfg; exit 0;;
		--) shift; break ;;
		*) echo "Error: $1"; exit 1;;
	esac
done

CURRENT_SETUP="$(setup_fp)"

if [ -n "$SAVE_PROFILE" ]; then
	if echo "$RESERVED_PROFILE_NAMES" | grep -q "^ $SAVE_PROFILE "; then
		echo "Cannot save current configuration as profile '${SAVE_PROFILE}': This configuration name is a reserved virtual configuration."
		exit 1
	fi
	echo "Saving current configuration as profile '${SAVE_PROFILE}'"
	mkdir -p "$PROFILES/$SAVE_PROFILE"
	echo "$CURRENT_SETUP" > "$PROFILES/$SAVE_PROFILE/setup"
	$CURRENT_CFG_METHOD > "$PROFILES/$SAVE_PROFILE/config"
	exit 0
fi

if [ -n "$LOAD_PROFILE" ]; then
	CHANGE_PROFILE=1 FORCE_LOAD=1 load "$LOAD_PROFILE"
	exit $?
fi

for SETUP_FILE in $PROFILES/*/setup; do
	if ! [ -e $SETUP_FILE ]; then
		break
	fi
	PROFILE="$(basename $(dirname "$SETUP_FILE"))"
	echo -n "$PROFILE"

	if blocked "$PROFILE"; then
		echo " (blocked)"
		continue
	fi

	FILE_SETUP="$(cat "$PROFILES/$PROFILE/setup")"
	if [ "$CURRENT_SETUP" = "$FILE_SETUP" ]; then
		echo " (detected)"
		if [ "$CHANGE_PROFILE" -eq 1 ]; then
			if [ "$FORCE_LOAD" -eq 1 ] || ! config_equal "$PROFILE"; then
				load "$PROFILE"
			fi
		fi
		# found the profile, exit with success
		exit 0
	else
		echo ""
	fi
done

# we did not find the profile, load default
if [ -n "$DEFAULT_PROFILE" ]; then
	echo "No suitable profile detected, falling back to $DEFAULT_PROFILE"
	load "$DEFAULT_PROFILE"
fi
exit 1

# Local Variables:
# tab-width: 8
# sh-basic-offset: 8
# sh-indentation: 8
# indent-tabs-mode: t
# End: