feat: redesign the project structure

home/linux/common/xdg.nix

@@ -0,0 +1,54 @@
+# XDG stands for "Cross-Desktop Group", with X used to mean "cross". 
+# It's a bunch of specifications from freedesktop.org intended to standardize desktops and 
+# other GUI applications on various systems (primarily Unix-like) to be interoperable: 
+#   https://www.freedesktop.org/wiki/Specifications/
+{config, pkgs, ...}: let
+  browser = ["firefox.desktop"];
+
+  # XDG MIME types
+  associations = {
+    "application/x-extension-htm" = browser;
+    "application/x-extension-html" = browser;
+    "application/x-extension-shtml" = browser;
+    "application/x-extension-xht" = browser;
+    "application/x-extension-xhtml" = browser;
+    "application/xhtml+xml" = browser;
+    "text/html" = browser;
+    "x-scheme-handler/about" = browser;
+    "x-scheme-handler/ftp" = browser;
+    "x-scheme-handler/http" = browser;
+    "x-scheme-handler/https" = browser;
+    "x-scheme-handler/unknown" = browser;
+
+    "audio/*" = ["mpv.desktop"];
+    "video/*" = ["mpv.dekstop"];
+    "image/*" = ["imv.desktop"];
+    "application/json" = browser;
+    "application/pdf" = browser;  # TODO: pdf viewer
+    "x-scheme-handler/discord" = ["discord.desktop"];
+    "x-scheme-handler/tg" = ["telegramdesktop.desktop"];
+  };
+in {
+  home.packages = with pkgs; [
+    xdg-utils
+    xdg-user-dirs
+  ];
+
+  xdg = {
+    enable = true;
+    cacheHome = config.home.homeDirectory + "/.local/cache";
+
+    mimeApps = {
+      enable = true;
+      defaultApplications = associations;
+    };
+
+    userDirs = {
+      enable = true;
+      createDirectories = true;
+      extraConfig = {
+        XDG_SCREENSHOTS_DIR = "${config.xdg.userDirs.pictures}/Screenshots";
+      };
+    };
+  };
+}