#!/bin/sh

# record - record an area of the screen

lock="/tmp/record.lock"

# dependencies: ffmpeg, hacksaw (part), xwininfo & lsw (window), xdotool (active) 
# optional:
# 	- hacksaw: part
# 	- xwininfo, lsw, commander: window
# 	- xdotool: active
# 	- xdg-user-dir

audio=

# $1: width
# $2: height
# $3: x
# $4: y
# $5: output dir
# $6: output name
record_cmd()
{
	if [ -f "$lock" ] 
	then
		>&2 printf 'already recording, please stop recording first\n'
		exit 1
	else
		touch "$lock"
	fi

	herbe "started recording." &
	w=$(($3 + $3 % 2))
	h=$(($4 + $4 % 2))
	ffmpeg $audio        \
	    -v 16            \
	    -r 30            \
	    -f x11grab       \
	    -s "${w}x${h}"   \
	    -i ":0.0+$1,$2"  \
	    -preset slow     \
	    -c:v h264        \
	    -pix_fmt yuv420p \
	    -crf 20          \
	    "$5/$6.mp4"
	printf '%s\n' "$5/$6.mp4"
	rm -f "$lock"
	herbe "stopped recording." & 
}

if [ -d "$1" ]
then
	dir="$1" 
	shift
else 
	dir="$(which xdg-user-dir > /dev/null 2>&1 && xdg-user-dir VIDEOS)"
	[ "$dir" ] && dir="$dir/records" || dir="$HOME/vids/records"
fi
mkdir -p "$dir"

if [ "$1" = "-a" ]
then
	audio="-f pulse -ac 2 -i default"
	shift
fi

if [ "$1" = "-l" ]
then
	find vids/records/ -type f | sort | tail -n 1
	exit
fi

current=$(date +%F_%H-%M-%S)

[ "$1" ] && option="$1" || option="$(printf 'active\nwindow\npart\nstop\nfull\naudio' | commander -c)"
case "$option" in
    active)
        record_cmd $(xwininfo -id "$(xdotool getactivewindow)" |
            sed -e '/Absolute\|Width:\|Height:/!d;s/.*:\s*//' | tr '\n' ' ') $dir $current
        ;;

    window)
    	winid="$(lsw | commander -cxl | cut -d' ' -f1)"
    	[ "$winid" ] || exit 1
    	values="$(xwininfo -id "$winid" | sed -e '/Absolute\|Width:\|Height:/!d;s/.*:\s*//' | tr '\n' ' ')"
	[ "$values" ] || exit 1
        record_cmd $values $dir $current
        ;;
        
    part) 
        hacksaw | {
            IFS=+x read -r w h x y
            record_cmd $w $h $x $y $dir $current
        }
        ;;
    stop) kill "$(pgrep ffmpeg | xargs ps | grep 'x11grab' | awk '{print $1}')"; rm -f "$lock" ;;
    full) record_cmd 0 0 1920 1080 $dir $current ;;
    audio) $0 -a; exit ;;
    help|*) >&2 printf 'record [dir] (active|window|part|stop|full)\n' ;;
esac