#!/bin/bash

print_help() {
	echo "
	Used for hiding/unhiding programs to acheive quake-dropdown-like-functionality. Can create a dropdown window if one does not already exist and provides options to control the intial size and position, e.g. to leave panels visible. When used with a terminal, provides the option to specify the name of a tmuxinator or tmux session to automatically start or attach to.

	Also supports the ability to auto-hide and auto-show. For example, this can be used to automatically hide a window when opening something, e.g. image viewer, video player, etc. from it, and then re-show the window whenever the image view, video player, etc. is closed.

	Takes a window as an argument or one of auto_show, auto_hide, or toggle_auto_hide. 'toggle_auto_hide' toggles whether calling 'auto_hide' or 'auto_show' will have any effect. 'current' will turn the current window into a dropdown.

usage: tdrop [options] <program or 'current'> or one of <auto_show/auto_hide/toggle_auto_hide>
options:
	-h height    specify a height for a newly created term (default: 100%)
	-w width     specify a width for a newly created term (default: 45%)
	-x pos       specify x offset for a newly created term (default: 0)
	-y pos       specify y offset for a newly created term (default: 1, see BUGS in man)
	-s name      name for tmux or tmuxinator session (if not given, will not use tmux)
	-n num       num or extra text; only needed if want multiple dropdowns of same program (default: "")
	-p cmd       provide a pre-map command to float the window if necessary
	-P cmd       provide a post-map command to float the window if necessary
	-M cmd       provide a post-unmap command; can be used for example with a window manager that doesn't support floating to turn fullscreen on when mapping a terminal then off when unmapping it
	-O cmd       provide a one time command only for when a dropdown is created/initiated (useful for 'tdrop current')
	-d XxY       give decoration/border size to accurately save position; only applicable with auto_show; on applicable with a few window managers (e.g. blackbox)
	-z           use a different sleep time to wait for terminal to be created (advanced; see man page)
	-Z           use a different sleep time for -W program to be created (advanced; see man page)
	-a           automatically detect window manager and if settings exist for it, automatically set -p, -P, and -d values as necessary; this can have affect when used with a terminal or with auto_show or auto_hide (default: false)
	-m           for use with multiple monitors and only with dropdowns (not for auto_show or auto_hide); convert percentages used for width or height to values relative to the size of the current monitor and force reszing of the dropdown when the monitor changes (default: false)
	-W           the given program is not a terminal (or lacks an -e flag) (default: assume it IS a terminal)
	--clear      clear saved window id; useful accidentally make a window a dropdown (e.g. '$ tdrop --clear current')
	--no-cancel  don't cancel auto-showing
	             (default is to prevent this when manually toggling a term after it is auto-hidden)
	--help       print help

See man page for more details.
"
	if [[ $1 == illegal_opt ]]; then
		exit 1
	else
		exit 0
	fi
}

#
# Default Options
#

# xdotool can take percentages; cannot take decimal percentages though
width="100%"
height="45%"
xoff=0
yoff=2
session_name=""
num=""
map_pre=""
map_post=""
unmap_post=""
oneshot_post=""
dec_fix=""
sleep_term_time=0.01
sleep_term_user_set=false
sleep_win_time=0.5
sleep_win_user_set=false
normal_window=false
clearwid=false
cancel_auto_show=true
term=${*:0-1}
auto_detect_wm=false
multiple_monitors=false
while getopts :h:w:x:y:s:n:p:P:M:O:d:z:Z:-:Wam opt
do
	case $opt in
	h) height=$OPTARG;;
	w) width=$OPTARG;;
	x) xoff=$OPTARG;;
	y) yoff=$OPTARG;;
	s) session_name=$OPTARG;;
	n) num=$OPTARG;;
	p) map_pre=$OPTARG;;
	P) map_post=$OPTARG;;
	M) unmap_post=$OPTARG;;
	O) oneshot_post=$OPTARG;;
	d) dec_fix=$OPTARG;;
	z) sleep_term_time=$OPTARG
		sleep_term_user_set=true;;
	Z) sleep_win_time=$OPTARG
		sleep_win_user_set=true;;
	W) normal_window=true;;
	a) auto_detect_wm=true;;
	m) multiple_monitors=true;;
	-)
		OPTION=$(echo "$OPTARG" | awk -F '=' '{print $1}')
		OPTARG=$(echo "$OPTARG" | awk -F '=' '{print $2}')
		case $OPTION in
		height) height=$OPTARG;;
		width) width=$OPTARG;;
		x-offset) xoff=$OPTARG;;
		y-offset) yoff=$OPTARG;;
		session) session_name=$OPTARG;;
		number) num=$OPTARG;;
		pre-command) map_pre=$OPTARG;;
		post-command) map_post=$OPTARG;;
		post-unmap) unmap_post=$OPTARG;;
		oneshot-post) oneshot_post=$OPTARG;;
		decoration-fix) dec_fix=$OPTARG;;
		sleep-terminal) sleep_term_time=$OPTARG
			sleep_term_user_set=true;;
		sleep-window) sleep_win_time=$OPTARG
			sleep_win_user_set=true;;
		normal-window) normal_window=true;;
		auto-detect-wm) auto_detect_wm=true;;
		multiple-monitors) multiple_monitors=true;;
		clear) clearwid=true;;
		no-cancel) cancel_auto_show=false;;
		help) print_help;;
		esac;;
	*) print_help illegal_opt;;
    esac
done
# non-user-settable global vars

# necessary to account for differences in geometry/positioning output from xwininfo
# for different WMs (matters when a window is in a corner or on the side)
subtract_when_same=true
# will be set to true to eliminate or reduce flicker for WMs that alter window
# position when remapping; when true, windowmap and windowmove are combined, so that
# the window is correctly positioned earlier
combine_map_post=false
# set to true if the -m option is being used and the monitor has changed
# in order to force resize the dropdown to the given width/height percentages
# for the current monitor
monitor_changed=false

#
# Multiple Monitor Automatic Re-Sizing
#

update_geometry_settings_for_monitor() {
	# 1. Correctly interpret width/height percentages when there exist multiple
	#    monitors so an initially created dropdown is the correct size (xdotool
	#    would create a dropdown the width of all screens for 100% width)
	# 2. Force resize the dropdown to the correct percentage of the current
	#    monitor IF the monitor has changed since the last time the dropdown
	#    was used

	# determine curent monitor
	wininfo=$(xwininfo -id "$(xdotool getactivewindow)")
	window_x=$(echo "$wininfo" | awk '/Absolute.*X/ {print $4}')
	window_y=$(echo "$wininfo" | awk '/Absolute.*Y/ {print $4}')
	monitors_info=$(xrandr --query | awk '/ connected/ {gsub("primary ",""); print}')
	while read -r monitor; do
		monitor_geo=$(echo "$monitor" | awk '{print $3}')
		x_begin=$(echo "$monitor_geo" | awk -F '+' '{print $2}')
		y_begin=$(echo "$monitor_geo" | awk -F '+' '{print $3}')
		x_width=$(echo "$monitor_geo" | awk -F 'x' '{print $1}')
		y_height=$(echo "$monitor_geo" | awk -F 'x|+' '{print $2}')
		x_end=$((x_begin+x_width))
		y_end=$((y_begin+y_height))
		if [[ $window_x -ge $x_begin ]] && [[ $window_x -lt $x_end ]] && \
			[[ $window_y -ge $y_begin ]] && [[ $window_y -lt $y_end ]]; then
			current_monitor=$(echo "$monitor" | awk '{print $1}')
			break
		fi
	done <<< "$monitors_info"

	# update x and y offsets, so that will appear on correct screen
	# (required for some WMs apparently, but not for others)
	((xoff+=x_begin))
	((yoff+=y_begin))

	# convert w/h percentages to pixels based on size of current screen
	if [[ $height =~ %$ ]]; then
		height=$(awk "BEGIN {printf(\"%.0f\", 0.01*${height%\%}*$y_height)}")
	elif [[ $height =~ ^- ]]; then
		minus_height=${height#-}
		height=$((y_height-minus_height))
	fi
	if [[ $width =~ %$ ]]; then
		width=$(awk "BEGIN {printf(\"%.0f\", 0.01*${width%\%}*$x_width)}")
	elif [[ $width =~ ^- ]]; then
		minus_width=${width#-}
		width=$((x_width-minus_width))
	fi

	# determine if monitor has changed and save current monitor
	last_monitor=$(< /tmp/tdrop/last_monitor)
	echo "$current_monitor" > /tmp/tdrop/last_monitor
	if [[ $current_monitor != $last_monitor ]]; then
		monitor_changed=true
	fi
}

set_geometry_for_monitor() {
	xdotool windowmove "$1" "$xoff" "$yoff" windowsize "$1" "$width" "$height"
}

#
# WM Detection and Settings
#

get_window_manager() {
	# xfwm4 and fvwm at least will give two names (hence piping into head)
	xprop -notype -id "$(xprop -root -notype | awk '$1=="_NET_SUPPORTING_WM_CHECK:"{print $5}')" -f _NET_WM_NAME 8u | awk -F "\"" '/WM_NAME/ {print $2}' | head -n 1
}

# settings that apply for both tdrop <term> and tdrop auto_(hide|show)
# e.g. tilers w/ floating support: settings for floating a window when mapping it
# can set up a rule for always floating a window or term type/class
# alternatively, can use these settings to float just the dropdown
wm_autoset_for_all() {
	wm=$(get_window_manager)
	# bspwm will use previous size when floating already
	if [[ $wm == bspwm ]]; then
		map_pre() {
			bspc rule -a "$1" -o floating=on
		}
	elif [[ $wm == awesome ]]; then
		# awesome remembers size, but need to float and then set size first
		map_post_oneshot() {
			# need sleep time to wait for window be created or will float wrong one.. not sure if way to float by window id
			if ! $sleep_win_user_set; then
				# what I've had best results with
				sleep_win_time=0.1
			fi
			sleep $sleep_win_time && echo 'local awful = require("awful") ; awful.client.floating.set(c, true)' | awesome-client && \
			xdotool windowmove "$1" "$xoff" "$yoff" windowsize "$1" "$width" "$height"
		}
		map_post() {
			echo 'local awful = require("awful") ; awful.client.floating.set(c, true)' | awesome-client
		}
	
	# tilers that won't remember sizing
	elif [[ $wm == i3 ]]; then
		# need to sleep first time to wait for window to be created
		map_post_oneshot() {
			if ! $sleep_win_user_set; then
				# what I've had best results with
				sleep_win_time=0.1
			fi
			sleep $sleep_win_time && \
			i3-msg "[id=$1] floating enable" > /dev/null && \
			xdotool windowmove "$1" "$xoff" "$yoff" windowsize "$1" "$width" "$height"
		}
		map_post() {
			i3-msg "[id=$1] floating enable" > /dev/null && \
			xdotool windowmove "$1" "$xoff" "$yoff"
		}

	# floating WMs that need extra sleep time to wait for dropdown to spawn initially
	elif [[ $wm =~ ^(Fluxbox|Mutter|GNOME Shell|Mutter \(Muffin\)|KWin)$ ]]; then
		if ! $sleep_term_user_set; then
			sleep_term_time=0.05
		fi
	fi
}

# settings for maintining previous size/placement of windows when unhiding them
wm_autoset_for_hide_show() {
	# tilers: is_floating function so that hidden tiling windows don't become floating
	if [[ $wm == bspwm ]]; then
		subtract_when_same=false
		is_floating() {
			# checking if the window id (converted from decimal to hex) is floating; empty if not floating
			bspc query -T | grep -i "$(printf 0x%x "$1").*f-"
		}
	elif [[ $wm == i3 ]]; then
		subtract_when_same=false
		is_floating() {
			# do you even sed?
			i3-msg -t get_tree | awk 'gsub(/{"id"/, "\n{\"id\"")' | awk '/focused":true.*floating":"user_on/ {print $1}'
		}

	# settings for stacking/floating wms where can't get right position easily from xwininfo
	# take borders into account
	elif [[ $wm == Blackbox ]]; then
		dec_fix_auto="1x22"
	elif [[ $wm =~ ^(Mutter|GNOME Shell)$ ]]; then
		dec_fix_auto="-10x-8"
		subtract_when_same=false
	elif [[ $wm =~ ^(Mutter \(Muffin\))$ ]]; then
		dec_fix_auto="-9x-8"
	
	# NOTE:
	# pekwm, xfwm4, sawfish, openbox need subtract_when_same to be true (default)
	# for fluxbox, blackbox, fvwm, and metacity, the value does not matter
	elif [[ $wm == GoomwW ]]; then
		subtract_when_same=false
	fi

	if [[ $wm =~ ^(pekwm|Fluxbox|Blackbox|xfwm4|Metacity|FVWM|Sawfish|GoomwW|Mutter|GNOME Shell|Mutter \(Muffin\)|KWin|Metacity \(Marco\))$ ]]; then
		combine_map_post=true
		map_post() {
			xdotool windowmap "$1" windowmove "$1" "$2" "$3"
		}
	fi
}

wm_autoset_for_dropdown() {
	wm=$(get_window_manager)

	# tilers without floating support: can toggle fullscreen instead for the dropdown
	if [[ $wm == herbstluftwm ]]; then
		map_post() {
			herbstclient fullscreen on
		}
		unmap_post() {
			herbstclient fullscreen off
		}

	# floating window managers that may both move and resize a window after unmapping then mapping it
	elif [[ $wm == Openbox ]]; then
		# openbox will resize window to be slightly less than the width of the screen when mapping
		# this is necessary when want width to be 100%
		combine_map_post=true
		map_post() {
			xdotool windowmap "$1" windowmove "$1" "$xoff" "$yoff" \
				windowsize "$1" "$width" "$height"
		}
	# floating window managers that may move a window after unmapping then mapping it
elif [[ $wm =~ ^(pekwm|Fluxbox|Blackbox|xfwm4|Metacity|FVWM|Sawfish|GoomwW|Mutter|GNOME Shell|Mutter \(Muffin\)|KWin|Metacity \(Marco\))$ ]]; then
		# most will center
		# mutter/gnome shell will move to top centerish (just below panel on gnome shell)
		# xfwm4 will normally move to top left; metacity will move close to top left
		# sawfish just moves all over the place
		combine_map_post=true
		map_post() {
			xdotool windowmap "$1" windowmove "$1" "$xoff" "$yoff"
		}
	fi
}

#
# Helper Functions for Specific Dropdowns and Auto Hide/Show
#

get_class_name() {
	xprop -id "$1" WM_CLASS | awk '{gsub(/"/, ""); print $4}'
}

get_visibility() {
	xwininfo -id "$1" | awk '/Map State/ {print $3}'
}

map_pre_command() {
	# a user set option has higher priority
	if [[ -n $map_pre ]]; then
		eval "$map_pre"
	# use automatically set function if exists
	elif [[ -n $(type map_pre 2> /dev/null) ]]; then
		# needed when creating oneshot rules for programs where cmd differs from actual class name
		if [[ $1 == "gnome-terminal" ]]; then
			map_pre "Gnome-terminal"
		else
			map_pre "$1"
		fi
	fi
}

map_post_command() {
	if [[ -n $oneshot_post ]] && [[ $1 == oneshot ]]; then
		eval "$oneshot_post"
	elif [[ -n $(type map_post_oneshot 2> /dev/null) ]] && [[ $1 == oneshot ]]; then
		map_post_oneshot "$2"
	elif [[ -n $map_post ]]; then
		eval "$map_post"
	elif [[ -n $(type map_post 2> /dev/null) ]]; then
		map_post "$@"
	fi
}

unmap_post_command() {
	if [[ -n $unmap_post ]]; then
		eval "$unmap_post"
	elif [[ -n $(type unmap_post 2> /dev/null) ]]; then
		unmap_post
	fi
}

maybe_cancel_auto_show() {
	if $cancel_auto_show && [[ $1 == "$(cat /tmp/tdrop/auto_hidden/wid 2> /dev/null)" ]]; then
		> /tmp/tdrop/auto_hidden/wid
	fi
}

#
# Dropdown Initialization
#

term_create() {
	if [[ -n $session_name ]]; then
		# ugly workarounds due to how different terms different -e flags work
		if [[ $term == urxvt ]]; then
			$term -e bash -c "sleep $sleep_term_time && xdotool getactivewindow > /tmp/tdrop/$term$num && xdotool getactivewindow windowmove $xoff $yoff windowsize $width $height && tmux attach-session -dt $session_name || tmuxinator start $session_name || tmux new-session -s $session_name" &
		else
			# starting with '/bin/bash -c' because required by termite
			$term -e "/bin/bash -c 'sleep $sleep_term_time && xdotool getactivewindow > /tmp/tdrop/$term$num && xdotool getactivewindow windowmove $xoff $yoff windowsize $width $height && tmux attach-session -dt $session_name || tmuxinator start $session_name || tmux new-session -s $session_name'" &
		fi
	else
		# not using hold, because flag is different for different terminals
		if [[ $term == urxvt ]]; then
			$term -e bash -c "sleep $sleep_term_time && xdotool getactivewindow > /tmp/tdrop/$term$num && xdotool getactivewindow windowmove $xoff $yoff windowsize $width $height && $SHELL" &
		else
			# not using hold, because flag is different for different terminals
			$term -e "/bin/bash -c 'sleep $sleep_term_time && xdotool getactivewindow > /tmp/tdrop/$term$num && xdotool getactivewindow windowmove $xoff $yoff windowsize $width $height && $SHELL'" &
		fi
	fi
}

win_create() {
	$term &
	# need to wait for window to be created
	sleep $sleep_win_time
	# often pids have two wids
	wids=$(xdotool search --pid $!)
	wid1=$(echo "$wids" | head -n 1)
	wid2=$(echo "$wids" | tail -n 1)
	if [[ -n $wid2 ]]; then
		if [[ $(get_visibility "$wid2") == IsUnMapped ]]; then
			wid=$wid1
		else
			wid=$wid2
		fi
	else
		wid=$wid1
	fi
	# only works with pre-command
	xdotool windowmove "$wid" "$xoff" "$yoff" windowsize "$wid" "$width" "$height"
	echo "$wid" > /tmp/tdrop/"$term$num"
}

current_create() {
	# turns active window into a dropdown
	wid=$(xdotool getactivewindow)
	echo "$wid" > /tmp/tdrop/current"$num"
	get_class_name "$wid" > /tmp/tdrop/current"$num"_type
	echo "$wid"
}

wid_toggle() {
	mkdir -p /tmp/tdrop
	# get saved window id if already created
	wid=$(< /tmp/tdrop/"$term$num")
	exists=true
	if [[ -n $wid ]]; then
		visibility=$(get_visibility "$wid")
		# sometimes xwininfo will still report a window as existing hence xprop check
		if [[ -z $visibility ]] || [[ -z $(xprop -id "$wid") ]]; then
			# window no longer exists
			exists=false
		fi
	else
		exists=false
	fi
	if $exists; then
		if [[ $visibility == IsUnMapped ]]; then
			if [[ $term == current ]]; then
				map_pre_command "$(< /tmp/tdrop/current"$num"_type)"
			else
				map_pre_command "$term"
			fi
			if ! $combine_map_post; then
				xdotool windowmap "$wid"
				map_post_command "$wid"
			else
				# combine mapping with resizing/moving when possible to reduce flicker
				map_post_command "$wid"
			fi
			maybe_cancel_auto_show "$wid"
			# would be much too messy to integrate a resize into existing map_post commands
			# or add for those WMs that don't even need an xdotool command
			# cleaner to do after any map_post command with the downside of potential
			# for minimal flicker or redundancy
			if $monitor_changed; then
				set_geometry_for_monitor "$wid"
			fi
		else
			xdotool windowunmap "$wid"
		fi
	else
		# make it
		map_pre_command "$term"
		if [[ $term == current ]]; then
			wid=$(current_create)
			xdotool windowunmap "$wid"
		else
			if $normal_window; then
				win_create
			else
				term_create
			fi
			# get saved wid of newly created dropdown
			wid=""
			count=0
			while [[ -z $wid ]] && [[ $count -lt 100 ]]; do
				wid=$(< /tmp/tdrop/"$term$num")
				sleep 0.01
				((count++))
			done
			map_post_command oneshot "$wid"
		fi
	fi
}

#
# Helper Functions for Auto Hiding/Showing
#

get_geometry() {
	# so that won't float a tiled window later when showing
	if [[ -n $(type is_floating 2> /dev/null) ]] && [[ -z $(is_floating "$1") ]]; then
		# window is not floating; don't bother saving geometry
		echo "false"
	else
		wininfo=$(xwininfo -id "$1")
		x=$(echo "$wininfo" | awk '/Absolute.*X/ {print $4}')
		y=$(echo "$wininfo" | awk '/Absolute.*Y/ {print $4}')
		rel_x=$(echo "$wininfo" | awk '/Relative.*X/ {print $4}')
		rel_y=$(echo "$wininfo" | awk '/Relative.*Y/ {print $4}')
		if $subtract_when_same; then
			# behaviour works for most WMs (at least floating ones)
			x=$((x-rel_x))
			y=$((y-rel_y))
		else
			# don't subtract when abs and rel values are the same
			# necessary for WMs like bspwm and i3
			if [[ $x -ne $rel_x ]]; then
				x=$((x-rel_x))
			fi
			if [[ $y -ne $rel_y ]]; then
				y=$((y-rel_y))
			fi
		fi
		echo -e "X=$x\nY=$y"
	fi
}

give_geometry() {
	eval "$(< /tmp/tdrop/auto_hidden/geometry)"
	if [[ -n $dec_fix ]]; then
		x_fix=$(echo "$dec_fix" | awk -F "x" '{print $1}')
		y_fix=$(echo "$dec_fix" | awk -F "x" '{print $2}')
		X=$((X-x_fix))
		Y=$((Y-y_fix))
	elif [[ -n $dec_fix_auto ]]; then
		x_fix=$(echo "$dec_fix_auto" | awk -F "x" '{print $1}')
		y_fix=$(echo "$dec_fix_auto" | awk -F "x" '{print $2}')
		X=$((X-x_fix))
		Y=$((Y-y_fix))
	fi
	echo "$X $Y"
}

set_geometry() {
	xdotool windowmove "$1" "$(give_geometry)"
}

toggle_auto_hide() {
	no_hide=$(< /tmp/tdrop/auto_hidden/no_hide)
	mkdir -p /tmp/tdrop/auto_hidden
	if [[ -z $no_hide ]]; then
		echo "true" > /tmp/tdrop/auto_hidden/no_hide
	else
		> /tmp/tdrop/auto_hidden/no_hide
	fi
}

#
# Auto Hiding/Showing
#

auto_hide() {
	no_hide=$(< /tmp/tdrop/auto_hidden/no_hide)
	if [[ -z $no_hide ]]; then
		wid=$(xdotool getactivewindow)
		mkdir -p /tmp/tdrop/auto_hidden
		echo "$wid" > /tmp/tdrop/auto_hidden/wid
		get_class_name "$wid" > /tmp/tdrop/auto_hidden/class
		get_geometry "$wid" > /tmp/tdrop/auto_hidden/geometry
		xdotool windowunmap "$wid"
	fi
}

auto_show() {
	no_hide=$(< /tmp/tdrop/auto_hidden/no_hide)
	if [[ -z $no_hide ]]; then
		wid=$(< /tmp/tdrop/auto_hidden/wid)
		class=$(< /tmp/tdrop/auto_hidden/class)
		was_floating=$(< /tmp/tdrop/auto_hidden/geometry)
		if [[ $was_floating != false ]]; then
			map_pre_command "$class"
		fi
		if ! $combine_map_post; then
			xdotool windowmap "$wid"
		fi
		if [[ $was_floating != false ]]; then
			if $combine_map_post; then
				XY=$(give_geometry "$wid")
				X=$(echo "$XY" | awk '{print $1}')
				Y=$(echo "$XY" | awk '{print $2}')
				map_post_command "$wid" "$X" "$Y"
			else
				map_post_command "$wid"
				set_geometry "$wid"
			fi
		else
			xdotool windowmap "$wid"
		fi
	fi
}

#
# Main
#

if $multiple_monitors; then
	update_geometry_settings_for_monitor
fi

if $auto_detect_wm; then
	wm_autoset_for_all
	if [[ $term == auto_show ]] || [[ $term == auto_hide ]]; then
		wm_autoset_for_hide_show
	else
		wm_autoset_for_dropdown
	fi
fi

if [[ -n $1 ]]; then
	if $clearwid; then
		> /tmp/tdrop/"$term$num"
	elif [[ $term == toggle_auto_hide ]]; then
		toggle_auto_hide
	elif [[ $term == auto_hide ]]; then
		auto_hide
	elif [[ $term == auto_show ]]; then
		auto_show
	else
		wid_toggle
	fi
else
	print_help illegal_opt
fi
# vim is dumb
# vim: set ft=sh: