#!/bin/bash

# Usage info
show_help() {
cat << EOF
temptoanim converts temp.mkv to anim.gif

Usage: temptoanim [-h -s# -r# -k -g -e -o type -d working_dir]

    -h          display this help and exit

    -s #        i.e. Silentcast # - the number of instances of Silentcast
                that are running

	# must be 0, 1, or 2 (default is 0 meaning temptoanim was started
	outside of the Silentcast application)

	0: tries to convert ./temp.mkv (if working_dir is also 
	   specified, it will be ignored)
	1: tries to convert working_dir/silentcast/temp.mkv
	2: tries to convert working_dir/silentcast/silentcast/temp.mkv

    -r #        i.e. rate # or fps (default is 8)
	        # is a natural number (2 to 120) that should match the 
		frames per second of temp.mkv for making or using png
		images. A rate does not need to be specified if not using
		png images at all, and will be ignored if specified. When
		making anim.gif, png images are always necessary so that
		if a rate is not specified, 8 will be used.

		temptoanim doesn't verify the actual fps in temp.mkv. 

    -k          keep all the png images that are created. Default is to
                delete them unless '-o png' is used, in which case -k isn't
		needed.

    -g          generate png images and use them to create the webm or mp4
                video. No need to specifiy -g for a gif because png images
		are required in that cast, but for webm or mp4, the default
	       	is to use temp.mkv directly so that png images are not 
		generated or used.

    -e		existing png images will be used, so don't generate them. If
                -g and -e are both used, exising images will be used unless 
		there are none, then they will be generated. The default for
		making anim.gif is to delete any existing png images and
		generate new ones from temp.mkv. For webm and mp4, the
		default is to use temp.mkv directly so if you want to
		edit frame by frame, you have to specify -g or -e for
		frame png images to be used in creating the video.

    -o type	final desired output. Default is anim.gif. The recognized types are

                png		generates a series of png images: ew-???.png
		                ew-001.png ew-002.png .... ew-999.png
				If more than 999 pngs, the first ones will
				be overwritten

		gif		generates an animated gif named anim.gif.
		                ew-???.png images used will be deleted
				unless -k is used.

		webm		generates a compressed video named anim.webm
		                from the uncompressed video temp.mkv unless
				-e or -g is used, then it will create anim.webm
				from png images. Those png images will be
				deleted unless -k is used.

		mp4		same as webm except it will be anim.mp4 that
		                is created. 

		All of these outputs are many times smaller than temp.mkv,
		which is uncompressed, and sometimes hundreds of times smaller.

    -d working_dir  
                defaults to the current directory and is where temptoanim 
                will expect to find the silentcast or silentcast/silentcast 
		directory

There are some dialogues that come up, and it's important to read
and understand them. View /usr/share/doc/silentcast/README.md with
a markdown viewer and get an animated gif demo made with silentcast,
as well as a step by step guide and a list of tips.
EOF
}

#defaults

castnum=""
anims_from="temp.mkv"
otype="gif"       # default to making anim.gif if no -o type is specified
rm_png=true       # this is whether or not to remove pngs after output is generated
use_pngs=false    # default to making webm/mp4 from temp.mkv but if true, make from existing pngs instead
gen_pngs=false    # generate pngs and make webm/mp4 from those if true
fps=8
cut=0
total_cut=0
group=0
count=0

check_for_temp() {
	if ! [ -f temp.mkv ]
	then
		echo "temp.mkv not found, so can't generate anything from it" \
		| yad --text-info --wrap --on-top --center --window-icon="$doc_dir/record$castnum".svg --title="Error" \
		--text="<b>SILENTCAST $castnum </b>"
		exit -1
	fi
}

check_for_pngs() {
	if ! [ -f ew-[0-9][0-9][0-9].png ] 
	then
		echo "ew-???.png not found, so can't convert them to webm or mp4, use -g to generate pngs" \
		| yad --text-info --wrap --on-top --center --window-icon="$doc_dir/record$castnum".svg \
		--title="Error" --text="<b>SILENTCAST $castnum </b>"
		exit -1
	fi
}

mem_error() {
	echo "Too many images for the available memory. Try closing other applications, creating a swap file, or removing unecessary images." |\
		yad --text-info --wrap --on-top --center --window-icon="$doc_dir/record$castnum".svg --title="Error" \
		--text="<b>SILENTCAST $castnum </b>"
	(($? != 0)) && exit 1 #Cancel was clicked
}

check_for_anim() {
	if ! [ -f anim.gif ]
	then 
		mem_error
	else
		[ "$rm_png" = true ] && rm ew-[0-9][0-9][0-9].png
	fi

	xdotool key 'F5' # in testing, Dolphin used by KDE needs this sometimes
}

generate_pngs() {
	find -maxdepth 1 -regex '\.\/ew-[0-9][0-9][0-9]\.png' -delete
	check_for_temp
	ffmpeg -i temp.mkv -r $fps ew-%03d.png \
		| yad --progress --on-top --center --window-icon="$doc_dir/record$castnum".svg --text="<b>SILENTCAST $castnum </b> \n\
	Creating images from temp.mkv" --pulsate --auto-close

	xdotool key 'F5' # in testing, Dolphin used by KDE needs this sometimes
}

edit_pngs() {
        cut=`yad --entry --on-top --center --window-icon="$doc_dir/record$castnum".svg \
		--title="Prepare images before converting to animated gif or video" \
		--text="<b>SILENTCAST $castnum </b> \n\
	Manually delete or otherwise manipulate the images and click OK,\n\
	Or \n\
	Enter any positive integer less than the total number of images. It works like this:\n\
	0 do nothing\n\
	1 delete every other\n\
	2 delete 2 out of every 3\n\
	3 delete 3 out of every 4 ..."\
		--entry-text="0"`
   	(($? != 0)) && exit 1 #Cancel was clicked

	let group=$cut+1
	let total_cut=$total_cut+$cut
	if (($group > 1))
	then
	count=0
	for f in ew-[0-9][0-9][0-9].png
	do
		    let count++
		    if (($count % $group != 1))
		    then
			    rm $f
		    fi
	done
	fi
}

make_webm_from_pngs() {
	ffmpeg -r $fps -i $silentcast_dir/ew-[0-9][0-9][0-9].png -c:v libvpx -qmin 0 -qmax 50 -crf 5 -b:v 749k \
		$silentcast_dir/anim.webm \
		| yad --progress --on-top --center --window-icon="$doc_dir/record$castnum".svg \
		--text="<b>SILENTCAST $castnum </b> \nCreating anim.webm from ew-???.png" --pulsate --auto-close
}

make_mp4_from_pngs() {
	ffmpeg -r $fps -i $silentcast_dir/ew-[0-9][0-9][0-9].png -pix_fmt yuv420p -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" \
		$silentcast_dir/anim.mp4 \
		| yad --progress --on-top --center --window-icon="$doc_dir/record$castnum".svg \
		--text="<b>SILENTCAST $castnum </b> \nCreating anim.mp4 from ew-???.png" --pulsate --auto-close
}

make_webm_from_temp() {
	ffmpeg -i $silentcast_dir/temp.mkv -c:v libvpx -qmin 0 -qmax 50 -crf 5 -b:v 749k $silentcast_dir/anim.webm \
		| yad --progress --on-top --center --window-icon="$doc_dir/record$castnum".svg \
		--text="<b>SILENTCAST $castnum </b> \nCreating anim.webm from temp.mkv" --pulsate --auto-close
}

make_mp4_from_temp() {
	# -pix_fmt yuv420p was suggested by ffmpeg itself for max compatibility and -vf ... is because dim have to be even
	ffmpeg -i $silentcast_dir/temp.mkv -pix_fmt yuv420p -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" $silentcast_dir/anim.mp4 \
		| yad --progress --on-top --center --window-icon="$doc_dir/record$castnum".svg \
		--text="<b>SILENTCAST $castnum </b> \nCreating anim.mp4 from temp.mkv" --pulsate --auto-close
}

generate_anim() {
	vidtype=$1
	[ "$use_pngs" = false ] && check_for_temp
	[ "$gen_pngs" = true ] && generate_pngs
	find -maxdepth 1 -name 'anim.$vidtype' -delete

	if [ "$use_pngs" = true ] || [ "$gen_pngs" = true ]
	then
		check_for_pngs
		if [ "$vidtype" = webm ]
		then
			make_webm_from_pngs
		elif [ "$vidtype" = mp4 ]
		then
			make_mp4_from_pngs
		fi
		[ "$rm_pngs" = true ] && rm ew-[0-9][0-9][0-9].png
		xdotool key 'F5' # in testing, Dolphin used by KDE needs this sometimes
	else
		check_for_temp
		if [ "$vidtype" = webm ]
		then
			make_webm_from_temp
		elif [ "$vidtype" = mp4 ]
		then
			make_mp4_from_temp
		fi
	fi
}

OPTIND=1
while getopts ":hs:r:kgeo:d:" opt
do 
	echo $OPTARG # I don't know why I have to echo $OPTARG to get it assigned, but I do
	case $opt in
		h)
			show_help
			exit 0
			;;
		s)
			case $OPTARG in
				1)
					castnum=1
					;;
				2)
					castnum=2
					;;
				[!012])
					echo "Invalid Silentcast#: -s $OPTARG  ('temptoanim -h' for help)" >&2
					exit 1
					;;
			esac
			;;
		r)
			fps=$OPTARG 
			if ! [[ "$fps" =~ ^[0-9]+$ ]] && (($fps<2 || $fps>120)) 
			then
				show_help
				exit 0
			fi
			;;
		k)
			rm_png=false
			;;
		g)
			gen_png=true
			;;
		e)
			use_png=true # if both gen_png and use_png are true, existing pngs will be used if there are any
			;;
		o)
			if [ "$OPTARG" = png ] || [ "$OPTARG" = gif ] || [ "$OPTARG" = webm ] || [ "$OPTARG" = mp4 ]
			then
				otype=$OPTARG
			else
				echo "Invalid output type: -o $OPTARG ('temptoanim -h' for help)" >&2
				exit 1
			fi
			;;
		d)
			working_dir="$OPTARG"
			;;
		\?) 
			echo "Invalid option: -$OPTARG ('genffcom -h' for help)" >&2
			exit 1
			;;
	       	:)
		       	echo "Option -$OPTARG requires an argument. ('genffcom -h' for help)" >&2
		       	exit 1
		       	;;
       	esac
done
shift "$((OPTIND-1))" # get rid of everything just processed leaving anything left as $1
if [ "$1" != "" ] 
then 
	show_help # shouldn't be anything else so show help if there is
	exit 1
fi

if ! [ -d $working_dir/ ]
then
	echo "$working_dir is not an existing directory, so the silentcast directory can't be there" \
	| yad --text-info --wrap --on-top --center --window-icon="$doc_dir/record.svg" --title="Error" --text="<b>SILENTCAST ? </b>"
	exit -1
fi

[ $castnum = 1 ] && cd $working_dir/silentcast
[ $castnum = 2 ] && cd $working_dir/silentcast/silentcast

[ "$use_png" = false ] && find -maxdepth 1 -regex '\.\/ew-[0-9][0-9][0-9]\.png' -delete

if [ "$XDG_CURRENT_DESKTOP" = "GNOME"  ] 
then
	nautilus ./ & file_browserPID=$! # for some reason xdg-open doesn't work inside this script in Gnome
else
	xdg-open ./ 
fi

case $otype in
	png)
		generate_pngs
		;;
	gif)
		[ "$use_png" = false ] || ! [ -f ew-[0-9][0-9][0-9].png ] && generate_pngs
		find -maxdepth 1 -name 'anim.gif' -delete

		while ! [ -f anim.gif ]
		do
			edit_pngs

			# try to make anim.gif from pngs
			convert -adjoin -delay "$((total_cut + 1))"x"$fps" -layers optimize ew-[0-9][0-9][0-9].png anim.gif | \
				yad --progress --on-top --center --title="convert" --window-icon="$doc_dir/record$castnum".svg \
				--text="<b>SILENTCAST $castnum </b> \n\
				Replacing images with anim.gif... (clicking Close below doesn't stop convert, \
				so don't)" --pulsate --auto-close

			check_for_anim
		done
		;;
	*)
		generate_anim $otype
		;;
esac

! [ "$file_browserPID" = "" ] && kill $file_browserPID
cd -

# End of file: temptoanim