Fix home-manager impurity and add brew configuration

modules/darwin/brew.nix

@@ -0,0 +1,43 @@
+{ config, lib, pkgs, ... }:
+
+let
+  checkBrew = "command -v brew > /dev/null";
+in
+{
+  environment = {
+    extraInit = ''
+      ${checkBrew} || >&2 echo "brew is not installed (install it via https://brew.sh)"
+    '';
+  };
+
+  homebrew = {
+    enable = true;
+    autoUpdate = true;
+    global = {
+      brewfile = true;
+      noLock = true;
+    };
+
+    brews = [
+      "aws-sam-cli"
+      "fabianishere/personal/pam_reattach"
+      "netdata"
+    ];
+
+    casks = [
+      "1password"
+      "visual-studio-code"
+    ];
+
+    taps = [
+      "aws/tap"
+      "homebrew/bundle"
+      "homebrew/cask"
+      "homebrew/cask-fonts"
+      "homebrew/cask-versions"
+      "homebrew/core"
+      "homebrew/services"
+    ];
+
+  };
+}

modules/darwin/default.nix

@@ -0,0 +1,6 @@
+{ pkgs, ... }: {
+  imports = [
+    ./brew.nix
+    ./preferences.nix
+  ];
+}

modules/darwin/preferences.nix

@@ -0,0 +1,57 @@
+{ config, pkgs, ... }: {
+
+  system.defaults = {
+    loginwindow = {
+      GuestEnabled = false;
+      SHOWFULLNAME = false;
+    };
+
+    finder = {
+      AppleShowAllExtensions = true;
+      FXEnableExtensionChangeWarning = true;
+      _FXShowPosixPathInTitle = true;
+    };
+
+    trackpad = {
+      ActuationStrength = 0;
+      Clicking = true;
+      FirstClickThreshold = 1;
+      SecondClickThreshold = 1;
+      TrackpadRightClick = false;
+    };
+
+    # firewall
+    alf = {
+      # 0 = disabled 1 = enabled 2 = blocks all connections except for essential services
+      globalstate = 1;
+      loggingenabled = 0;
+      stealthenabled = 1;
+    };
+
+    dock = {
+      autohide = true;
+      autohide-delay = "0.0";
+      autohide-time-modifier = "1.0";
+      tilesize = 50;
+      static-only = false;
+      showhidden = false;
+      show-recents = false;
+      show-process-indicators = true;
+      orientation = "bottom";
+      mru-spaces = false;
+    };
+
+    NSGlobalDomain = {
+      "com.apple.sound.beep.feedback" = 0;
+      "com.apple.sound.beep.volume" = "0.000";
+      ApplePressAndHoldEnabled = false;
+      # delay before repeating keystrokes
+      InitialKeyRepeat = 10;
+      # delay between repeated keystrokes upon holding a key
+      KeyRepeat = 1;
+      AppleShowAllExtensions = true;
+      AppleShowScrollBars = "Automatic";
+    };
+  };
+
+}