Move Flatpak management to system configuration

Flatpak management has been refactored from Home Manager and nix-flatpak to a new system/flatpak.nix module, now imported in system/common.nix. This centralizes Flatpak enablement and declarative app management at the system level, simplifying configuration and maintenance.

flake.nix

@@ -10,9 +10,6 @@
       inputs.nixpkgs.follows = "nixpkgs";
     };
     
-    # Declarative Flatpak management
-    nix-flatpak.url = "github:gmodena/nix-flatpak";
-    
     # Optional: Hyprland (if you want a tiling Wayland compositor)
     # hyprland.url = "github:hyprwm/Hyprland";
     
@@ -20,7 +17,7 @@
     # nixpkgs-unstable.url = "github:NixOS/nixpkgs/nixos-unstable";
   };
 
-  outputs = { self, nixpkgs, home-manager, nix-flatpak, ... }@inputs: {
+  outputs = { self, nixpkgs, home-manager, ... }@inputs: {
     # NixOS configuration for your hostname(s)
     nixosConfigurations = {
       # Desktop PC configuration
@@ -47,9 +44,6 @@
             
             # User configuration
             home-manager.users.zeph = import ./home/home.nix;
-            
-            # Declarative Flatpak
-            home-manager.sharedModules = [ nix-flatpak.homeManagerModules.nix-flatpak ];
           }
         ];
       };
@@ -78,9 +72,6 @@
             
             # User configuration
             home-manager.users.zeph = import ./home/home.nix;
-            
-            # Declarative Flatpak
-            home-manager.sharedModules = [ nix-flatpak.homeManagerModules.nix-flatpak ];
           }
         ];
       };

home/home.nix

@@ -155,17 +155,7 @@
   #   platformTheme.name = "gtk";
   # };
 
-  # Declarative Flatpak packages
+  # Flatpaks are managed in system/flatpak.nix
-  services.flatpak = {
-    packages = [
-      "io.github.zen_browser.zen"
-      # Add more Flatpak apps here
-    ];
-    update.auto = {
-      enable = true;
-      onCalendar = "weekly";
-    };
-  };
 
   # Let Home Manager manage itself
   programs.home-manager.enable = true;

system/common.nix

@@ -1,6 +1,10 @@
 { config, pkgs, ... }:
 
 {
+  imports = [
+    ./flatpak.nix
+  ];
+
   # Common system configuration shared across all machines
   
   # Bootloader
@@ -10,9 +14,6 @@
   # Networking
   networking.networkmanager.enable = true;
 
-  # Enable Flatpak
-  services.flatpak.enable = true;
-
   # Timezone and locale
   time.timeZone = "Europe/London";
   i18n.defaultLocale = "en_US.UTF-8";

system/flatpak.nix

@@ -0,0 +1,47 @@
+{ config, pkgs, ... }:
+
+let
+  grep = pkgs.gnugrep;
+  
+  # Declare the Flatpaks you want on your system
+  desiredFlatpaks = [
+    "io.github.zen_browser.zen"
+    # Add more Flatpak apps here
+    # "com.spotify.Client"
+    # "com.discordapp.Discord"
+  ];
+in {
+  # Enable Flatpak
+  services.flatpak.enable = true;
+  
+  system.userActivationScripts.flatpakManagement = {
+    text = ''
+      # Ensure the Flathub repo is added
+      ${pkgs.flatpak}/bin/flatpak remote-add --if-not-exists flathub \
+        https://flathub.org/repo/flathub.flatpakrepo
+
+      # Get currently installed Flatpaks
+      installedFlatpaks=$(${pkgs.flatpak}/bin/flatpak list --app --columns=application)
+
+      # Remove any Flatpaks that are NOT in the desired list
+      for installed in $installedFlatpaks; do
+        if ! echo ${toString desiredFlatpaks} | ${grep}/bin/grep -q $installed; then
+          echo "Removing $installed because it's not in the desiredFlatpaks list."
+          ${pkgs.flatpak}/bin/flatpak uninstall -y --noninteractive $installed
+        fi
+      done
+
+      # Install or re-install the Flatpaks you DO want
+      for app in ${toString desiredFlatpaks}; do
+        echo "Ensuring $app is installed."
+        ${pkgs.flatpak}/bin/flatpak install -y flathub $app
+      done
+
+      # Remove unused Flatpaks
+      ${pkgs.flatpak}/bin/flatpak uninstall --unused -y
+
+      # Update all installed Flatpaks
+      ${pkgs.flatpak}/bin/flatpak update -y
+    '';
+  };
+}