update chbg

- better tmp file generation and autoclean.
- further param validation before real work.

bin/chbg

@@ -1,24 +1,33 @@
 #!/bin/bash
 # to change wallpapers both niri workspace and niri tab view
-[ -z "$1" ] && { echo "Usage: $0 <image-file>"; exit 1; }
-
-WP_DIR="${XDG_DATA_HOME:-$HOME/.local/share}"
-TMP_DIR="${XDG_CACHE_HOME:-$HOME/.cache}"
-finput=$1
-
-read -r fw fh < <(magick identify -format "%w %h" -- "$1")
-(( fw > 3840 && fh > 2160 )) && {
-	mkdir -p $TMP_DIR
-	finput="$TMP_DIR/${finput##*/}"
-	echo "WARNING: image too large, resizing ..."
-	magick $1 -resize "3840x2160^" $finput
+[ -z "$1" ] && {
+	echo "Usage: ${0##*/} <image-file>"
+	exit 1
+}
+fsize=$(magick identify -format "%w %h" -- "$1" 2>/dev/null) || {
+	echo "ERROR: unable to identify. is it an EXISTING ACCESSIBLE IMAGE file?"
+	exit 1
 }
 
-echo -n "making blurred version of $finput ... "
+WP_DIR="${XDG_DATA_HOME:-$HOME/.local/share}"
+finput=$1
+
+read -r fw fh <<< "$fsize"
+(( fw > 3840 && fh > 2160 )) && {
+	finput="$(mktemp --dry-run).webp"
+	trap 'rm -f "$finput"' EXIT
+	echo "WARNING: image too large, resizing ..."
+	# echo "DEBUG: resized image at $finput"
+	magick "$1" -resize "3840x2160^" \
+		-quality 90 \
+		-define webp:method=6 \
+		-define webp:alpha-quality=100 "$finput"
+}
+
+echo -n "making blurred version of ${1##*/} ... "
 mkdir -p $WP_DIR
 cp $finput $WP_DIR/.wallpaper
 magick $WP_DIR/.wallpaper -filter Gaussian -blur 0x30 $WP_DIR/.wallpaper_blur
-[[ $finput == $TMP_DIR* ]] && rm -f $finput
 echo "Done."
 
 swww img $WP_DIR/.wallpaper