easyscan: migrate to by-name

nix/packages/by-name/easyscan/package.nix

@@ -0,0 +1,70 @@
+{
+  writeShellApplication,
+  sane-backends,
+  poppler_utils,
+  fzf,
+  ghostscript,
+}:
+writeShellApplication {
+  name = "easyscan";
+
+  runtimeInputs = [
+    sane-backends
+    poppler_utils
+    fzf
+    ghostscript
+  ];
+
+  text = ''
+    if [ $# -eq 0 ]; then
+        OUTPUT_FILE=./scan_"$(date)".pdf
+    else
+        OUTPUT_FILE="''${1%.*}.pdf"
+    fi
+
+    tempdir="$(mktemp -d)"
+
+    device=$(scanimage --formatted-device-list="%d (%v %m)" --list-devices |
+        fzf --header "Pick a device:" |
+        cut -d ' ' -f 1)
+
+    do_scan() {
+    	filename="$tempdir/$(date).pdf"
+    	while ! scanimage --format=pdf --device="$device" --resolution 300 >"$filename"; do
+    		:
+    	done
+    	echo "$filename"
+    }
+
+    do_fix() {
+    	read -r filename
+    	fixed_name="''${filename%.pdf}_fixed.pdf"
+    	gs -o "$fixed_name" -sDEVICE=pdfwrite -dPDFSETTINGS=/prepress "$filename"
+    	rm "$filename"
+    	mv "$fixed_name" "$filename"
+    	echo "$filename"
+    }
+
+    while : ; do
+        do_scan | do_fix
+
+        IFS= read -r -p "Continue scanning ? [Y/n] " cont
+    	case "$cont" in
+    	[nN])
+    		echo "Exiting..."
+    		break
+    		;;
+    	[yY] | *)
+    		;;
+    	esac
+    done
+
+    # Multiple files are scanned, join them
+    merged_filename="$tempdir/$(date)_final.pdf"
+    pdfunite "$tempdir"/*.pdf "$merged_filename"
+    echo "$merged_filename" | do_fix
+
+    # Copy scan to current directory
+    cp "$merged_filename" "$OUTPUT_FILE"
+  '';
+}