Convert screenshot.sh to nix's writeShellApplication

hosts/totsugeki/desktop/scripts/screenshot.nix

@@ -0,0 +1,36 @@
+{ pkgs }:
+
+pkgs.writeShellApplication {
+  name = "screenshot";
+  runtimeInputs = with pkgs; [
+    dunst
+    grim
+    libjxl
+    slurp
+    wl-clipboard
+    xdg-user-dirs
+  ];
+  text = ''
+    usage() {
+      echo "Usage: screenshot { full | section }"
+      exit 1
+    }
+
+    test -n 1 || usage
+
+    FILE_NAME=$(date +'Screenshot_%Y%m%d_%H%M%S')
+    TEMPORARY_PATH="/tmp/$FILE_NAME.png"
+    SCREENSHOT_PATH="$(xdg-user-dir PICTURES)/$FILE_NAME.jxl"
+    if [ "$1" == "full" ]; then
+      grim "$TEMPORARY_PATH"
+    elif [ "$1" == "section" ]; then
+      grim -g "$(slurp -b '#000000aa' -w 0)" "$TEMPORARY_PATH"
+    else
+      usage
+    fi
+    wl-copy < "$TEMPORARY_PATH"
+    cjxl "$TEMPORARY_PATH" "$SCREENSHOT_PATH"
+    dunstify --raw_icon="$TEMPORARY_PATH" "Captura de pantalla realizada" "Guardada como $FILE_NAME.jxl"
+    rm "$TEMPORARY_PATH"
+  '';
+}