{ config, pkgs, ... }:

{

  nixpkgs.config.allowUnfree = true;
  # List packages installed in system profile. To search by name, run:
  # $ nix-env -qaP | grep wget
  environment.systemPackages =
    [
      pkgs.git-lfs
      pkgs.vim
      pkgs.iterm2
      pkgs.obsidian
      pkgs.syncthing
      pkgs.slack
      pkgs._1password
      pkgs.tailscale
      # wishlist
      # LICEcap
      # keycastr
      # todo (unsupported on aarch64-darwin):
      # pkgs.spotify
      # pkgs.firefox
      # pkgs.google-chrome
    ];

  services.tailscale.enable = true;

  # Use a custom configuration.nix location.
  # $ darwin-rebuild switch -I darwin-config=$HOME/.config/nixpkgs/darwin/configuration.nix
  # environment.darwinConfig = "$HOME/.config/nixpkgs/darwin/configuration.nix";

  # Auto upgrade nix package and the daemon service.
  services.nix-daemon.enable = true;
  # nix.package = pkgs.nix;

  # Create /etc/bashrc that loads the nix-darwin environment.
  programs.zsh.enable = true; # default shell on catalina
  # programs.fish.enable = true;

  # We need this snippet to allow spotlight to find the applications installed
  # by nix-darwin
  system.activationScripts.applications.text = pkgs.lib.mkForce (
    ''
      rm -rf ~/Applications/Nix\ Apps
      mkdir -p ~/Applications/Nix\ Apps
      for app in $(find ${config.system.build.applications}/Applications -maxdepth 1 -type l); do
        src="$(/usr/bin/stat -f%Y "$app")"
        cp -r "$src" ~/Applications/Nix\ Apps
      done
    ''
  );

  services.yabai = {
    enable = true;
    package = pkgs.yabai;
    config = {
      # layout
      layout = "bsp";
      auto_balance = "off";
      split_ratio = "0.50";
      window_placement = "second_child";
      # Gaps
      window_gap = 5;
      top_padding = 5;
      bottom_padding = 5;
      left_padding = 5;
      right_padding = 5;
      # appearance, shadows, and borders
      window_shadow = "float";
      active_window_opacity = "1.0";
      normal_window_opacity = "0.90";
      active_window_border_color = "0xE0808080";
      normal_window_border_color = "0x00010101";
      window_border = "on";
      window_border_width = "2";
      # mouse
      mouse_follows_focus = "off";
      focus_follows_mouse = "off";
      mouse_modifier = "fn";
      mouse_action1 = "move";
      mouse_action2 = "resize";
      mouse_drop_action = "swap";
    };

    extraConfig = ''
      # Unload the macOS WindowManager process
      launchctl unload -F /System/Library/LaunchAgents/com.apple.WindowManager.plist > /dev/null 2>&1 &

      # Don't bother tiling certain low-info app windows
      yabai -m rule --add label="Finder" app="^Finder$" title="(Co(py|nnect)|Move|Info|Pref)" manage=off
      yabai -m rule --add label="System Preferences" app="^System Preferences$" title=".*" manage=off
      yabai -m rule --add label="System Settings" app="^System Settings$" title=".*" manage=off
      yabai -m rule --add label="App Store" app="^App Store$" manage=off
      yabai -m rule --add label="Activity Monitor" app="^Activity Monitor$" manage=off
      yabai -m rule --add label="Software Update" title="Software Update" manage=off
      yabai -m rule --add label="About This Mac" app="System Information" title="About This Mac" manage=off
      yabai -m rule --add label="Slack" app="^Slack$" title=".*" manage=off
    '';
  };

  services.skhd = {
    enable = true;
    package = pkgs.skhd;
    skhdConfig = ''
      # Float / Unfloat window
      lalt - space : yabai -m window --toggle float

      # Make window zoom to fullscreen
      shift + lalt - f : yabai -m window --toggle zoom-fullscreen

      # Window Navigation (through display borders)
      lalt - h : yabai -m window --focus west  || yabai -m display --focus west
      lalt - j : yabai -m window --focus south || yabai -m display --focus south
      lalt - k : yabai -m window --focus north || yabai -m display --focus north
      lalt - l : yabai -m window --focus east  || yabai -m display --focus east

      # Moving windows between spaces: (Assumes 3 Spaces Max per Display)
      shift + lalt - 1 : DISPLAY="$(yabai -m query --displays --display | jq '.index')";\
                        yabai -m window --space $((1+4*($DISPLAY - 1)))
      shift + lalt - 2 : DISPLAY="$(yabai -m query --displays --display | jq '.index')";\
                        yabai -m window --space $((2+4*($DISPLAY - 1)))
      shift + lalt - 3 : DISPLAY="$(yabai -m query --displays --display | jq '.index')";\
                        yabai -m window --space $((3+4*($DISPLAY - 1)))

      ## Stacks
      # Add the active window to the window or stack to the {direction}
      shift + ctrl - h    : yabai -m window  west --stack $(yabai -m query --windows --window | jq -r '.id')
      shift + ctrl - j    : yabai -m window south --stack $(yabai -m query --windows --window | jq -r '.id')
      shift + ctrl - k    : yabai -m window north --stack $(yabai -m query --windows --window | jq -r '.id')
      shift + ctrl - l    : yabai -m window  east --stack $(yabai -m query --windows --window | jq -r '.id')

      # Stack Navigation: shift + ctrl - {n, p}
      shift + ctrl - n : yabai -m window --focus stack.next
      shift + ctrl - p : yabai -m window --focus stack.prev

      ## Misc
      # Equalize size of windows
      ctrl + lalt - e : yabai -m space --balance
    '';
  };

  launchd.user.agents.syncthing = {
    path = [ pkgs.syncthing ];
    command = "syncthing serve";
    serviceConfig = {
      ProcessType = "Background";
      KeepAlive = true;
    };
  };

  system.keyboard = {
    enableKeyMapping = true;
    remapCapsLockToEscape = true;
  };

  system.defaults = {
    finder.AppleShowAllExtensions = true;

    dock = {
      autohide = true;
      mru-spaces = false;
      showhidden = true;
    };
  };

  # Used for backwards compatibility, please read the changelog before changing.
  # $ darwin-rebuild changelog
  system.stateVersion = 4;
}