add firefox module

hm/default.nix

@@ -1 +1,10 @@
-{}
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}: {
+  imports = [
+    ./programs
+  ];
+}

hm/programs/default.nix

@@ -0,0 +1,10 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}: {
+  imports = [
+    ./firefox
+  ];
+}

hm/programs/firefox/default.nix

@@ -0,0 +1,57 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+with lib; let
+  cfg = config.options.trivium.programs.firefox;
+in {
+  options.options.trivium.programs.firefox = {
+    enable = mkEnableOption "firefox settings";
+
+    workspace = mkOption {
+      type = types.nullOr types.str;
+      default = null;
+      description = ''
+        i3 Workspace in which Firefox should open. If not set, Firefox will not open at startup
+      '';
+    };
+
+    makeDefaultBrowser = mkOption {
+      type = types.bool;
+      default = true;
+      description = ''
+        Take a guess
+      '';
+    };
+  };
+
+  config = mkIf cfg.enable (mkMerge [
+    {
+      programs.firefox.enable = true;
+
+      xsession.windowManager.i3.config.startup = optional (cfg.workspace != null) {
+        command = "${lib.getExe pkgs.i3-gaps} 'workspace ${cfg.workspace}; exec ${lib.getExe pkgs.firefox}'";
+      };
+    }
+
+    (mkIf cfg.makeDefaultBrowser {
+      xdg = {
+        mimeApps = {
+          enable = true;
+          defaultApplications = {
+            "text/html" = ["firefox"];
+            "text/uri-list" = ["firefox"];
+            "x-scheme-handler/http" = ["firefox"];
+            "x-scheme-handler/https" = ["firefox"];
+            "x-scheme-handler/about" = ["firefox"];
+            "x-scheme-handler/unknown" = ["firefox"];
+          };
+        };
+      };
+
+      home.sessionVariables.DEFAULT_BROWSER = "${lib.getExe pkgs.firefox}";
+    })
+  ]);
+}