#!/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 command to float the window if necessary
	-P cmd       provide a post command to float the window if necessary
	-O cmd       provide a one time command only for when a dropdown is created/initiated (useful for 'tdrop -c')
	-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)
	-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)
	-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=1
float_pre=""
float_post=""
oneshot_post=""
session_name=""
num=""
normal_window=false
clearwid=false
cancel_auto_show=true
term=${*:0-1}
auto_detect_wm=false
while getopts :h:w:x:y:s:n:p:P:O:d:-:Wa opt
do
	case $opt in
	h) height=$OPTARG;;
	w) width=$OPTARG;;
	x) xoff=$OPTARG;;
	y) yoff=$OPTARG;;
	s) session_name=$OPTARG;;
	n) num=$OPTARG;;
	p) float_pre=$OPTARG;;
	P) float_post=$OPTARG;;
	O) oneshot_post=$OPTARG;;
	d) dec_fix=$OPTARG;;
	W) normal_window=true;;
	a) auto_detect_wm=true;;
	-)
		OPTION=$(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=$OPTARG;;
		pre-command) float_pre=$OPTARG;;
		post-command) float_post=$OPTARG;;
		oneshot-post) oneshot_post=$OPTARG;;
		decoration-fix) dec_fix=$OPTARG;;
		normal-window) normal_window=true;;
		auto-detect-wm) auto_detect_wm=true;;
		clear) clearwid=true;;
		no-cancel) cancel_auto_show=false;;
		help) print_help;;
		esac;;
	*) print_help illegal_opt;;
    esac
done

#
# WM Detection
#

wm_autodetect_settings() {
	wm=$(xprop -notype -id "$(xprop -root -notype | awk '$1=="_NET_SUPPORTING_WM_CHECK:"{print $5}')" -f _NET_WM_NAME 8u | awk -F "\"" '/WM_NAME/ {print $2}')

	# floating or position saving setup
	if [[ $wm == bspwm ]]; then
		float_pre() {
			bspc rule -a "$1" -o floating=on
		}
	# 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%
		float_post() {
			xdotool windowmove "$1" "$xoff" "$yoff" windowsize "$1" "$width" "$height"
		}
	# floating window managers that may both move a window after unmapping then mapping it
	elif [[ $wm == pekwm ]] || [[ $wm == fluxbox ]] || [[ $wm == Blackbox ]]; then
		float_post() {
			xdotool windowmove "$1" "$xoff" "$yoff"
		}
	elif [[ $wm == i3 ]]; then
		float_post() {
			i3-msg floating enable && \
			xdotool windowmove "$1" "$xoff" "$yoff" windowsize "$1" "$width" "$height"
		}
		# function to check if floating when auto-hiding so restores properly (prevent floating a previously tiled window)
		is_floating() {
			# do you even sed?
			i3-msg -t get_tree | awk 'gsub(/{"id"/, "\n{\"id\"")' | awk '/focused":true.*floating":"user_on/ {print $1}'
		}
	fi

	# for auto_show proper positioning
	if [[ $wm == Blackbox ]]; then
		dec_fix_auto="1x22"
	fi
}

if $auto_detect_wm; then
	wm_autodetect_settings
fi

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

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

float_pre_command() {
	# a user set option has higher priority
	if [[ -n $float_pre ]]; then
		eval "$float_pre"
	# use automatically set function if exists
	elif [[ -n $(type float_pre) ]]; then
		float_pre "$1"
	fi
}

float_post_command() {
	if [[ -n $oneshot_post ]] && [[ $1 == oneshot ]]; then
		eval "$oneshot_post"
	elif [[ -n $float_post ]]; then
		eval "$float_post"
	elif [[ -n $(type float_post) ]]; then
		float_post "$1"
	fi
}

maybe_cancel_auto_show() {
	if $cancel_auto_show && [[ $1 == "$(< /tmp/tdrop/auto_hidden/wid)" ]]; 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
			$term -e bash -c "sleep 0.01 && xdotool getactivewindow > /tmp/tdrop/$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
			$term -e "/bin/bash -c 'sleep 0.01 && xdotool getactivewindow > /tmp/tdrop/$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
			$term -e bash -c "sleep 0.01 && xdotool getactivewindow > /tmp/tdrop/$term$num && xdotool getactivewindow windowmove $xoff $yoff windowsize $width $height && $SHELL" &
		else
			# not using hold, because flag is different for different terminals
			$term -e "/bin/bash -c 'sleep 0.01 && xdotool getactivewindow > /tmp/tdrop/$term$num && xdotool getactivewindow windowmove $xoff $yoff windowsize $width $height && $SHELL'" &
		fi
	fi
}

win_create() {
	$term &
	# need to wait for window to be created
	sleep 0.5
	# often pids have two wids; first one has always been the right one for what I've tested
	wid=$(xdotool search --pid $! | head -n 1)
	echo "$wid" > /tmp/tdrop/"$term$num"
	xdotool windowmove "$wid" "$xoff" "$yoff" windowsize "$wid" "$width" "$height"
}

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
}

wid_toggle() {
	mkdir -p /tmp/tdrop
	# get saved window id if already created
	wid=$(< /tmp/tdrop/"$term$num")
	exists=true
	if [[ -n $wid ]]; then
		visibility=$(xwininfo -id "$wid" | awk '/Map State/ {print $3}')
		if [[ -z $visibility ]]; then
			# window no longer exists
			exists=false
		fi
	else
		exists=false
	fi
	if $exists && [[ $visibility != IsUnviewable ]]; then
		if [[ $visibility == IsUnMapped ]]; then
			if [[ $term == current ]]; then
				float_pre_command "$(< /tmp/tdrop/current"$num"_type)"
			else
				float_pre_command "$term"
			fi
			xdotool windowmap "$wid"
			float_post_command "$wid"
			maybe_cancel_auto_show "$wid"
		else
			xdotool windowunmap "$wid"
		fi
	else
		# make it
		float_pre_command "$term"
		if [[ $term == current ]]; then
			current_create
		elif $normal_window; then
			win_create
		else
			term_create
		fi
		float_post_command oneshot
	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) ]] && [[ -z $(is_floating) ]]; then
		# window is not floating; don't bother saving geometry
		# this is going to be eval'd in set_geometry.. maybe not best/ most explicit way to do this but funny to me
		echo "false"
	else
		wininfo=$(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 [[ $x -ne $rel_x ]]; then
			x=$((x-rel_x))
		fi
		if [[ $y -ne $rel_y ]]; then
			y=$((y-rel_y))
		fi
		echo -e "X=$x\nY=$y"
	fi
}

set_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
	xdotool windowmove "$1" "$X" "$Y"
}

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 [[ $was_floating != false ]]; then
			float_pre_command "$class"
		fi
		xdotool windowmap "$wid"
		if [[ $was_floating != false ]]; then
			float_post_command "$wid"
			set_geometry "$wid"
		fi
	fi
}

#
# Main
#

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: