{ config
, lib
, pkgs
, ...
}:
let
  cfg = config.services.kanata;
  driverPkg = pkgs.fetchurl {
    url = "https://github.com/pqrs-org/Karabiner-DriverKit-VirtualHIDDevice/releases/download/v6.0.0/Karabiner-DriverKit-VirtualHIDDevice-6.0.0.pkg";
    sha256 = "sha256-S14c06v/L/PraLekzIroG6FQnV5dpx0cyJNb9ylB458=";
  };

  configFile = lib.mkIf (cfg.config != "")
    "${pkgs.writeScript "kanata.kbd" ("\n" + cfg.config + "\n")}";
in
{
  options.services.kanata = {
    enable = lib.mkEnableOption "kanata, a tool to improve keyboard comfort and usability with advanced customization";

    package = lib.mkPackageOption pkgs "kanata" {
      example = [ "kanata-with-cmd" ];
      extraDescription = ''
        ::: {.note}
        If {option}`danger-enable-cmd` is enabled in any of the keyboards, the
        `kanata-with-cmd` package should be used.
        :::
      '';
    };

    errorLogFile = lib.mkOption {
      type = lib.types.path;
      default = "/Library/Logs/Kanata/kanata.err.log";
      example = "/Users/jsmith/Library/Logs/kanata.err.log";
      description = "Path to the Kanata error log file";
    };

    outLogFile = lib.mkOption {
      type = lib.types.path;
      default = "/Library/Logs/Kanata/kanata.out.log";
      example = "/Users/jsmith/Library/Logs/kanata.out.log";
      description = "Path to the Kanata stdout log file";
    };

    config = lib.mkOption {
      type = lib.types.str;
      default = "";
      description = "";
    };
  };

  config = lib.mkIf cfg.enable {
    environment.systemPackages = [ cfg.package ];

    # Install the driver during activation
    system.activationScripts.preActivation.text = ''
      echo "Installing Karabiner DriverKit VirtualHIDDevice..." >&2

      # Check if already installed by looking for the system extension
      if ! systemextensionsctl list 2>/dev/null | grep -q "org.pqrs.Karabiner-DriverKit-VirtualHIDDevice"; then
        echo "Installing driver package..." >&2
        installer -pkg ${driverPkg} -target /

        # Give it a moment to install
        sleep 2

        # Try to activate the system extension
        if [ -f "/Applications/.Karabiner-VirtualHIDDevice-Manager.app/Contents/MacOS/Karabiner-VirtualHIDDevice-Manager" ]; then
          echo "Activating system extension..." >&2
          /Applications/.Karabiner-VirtualHIDDevice-Manager.app/Contents/MacOS/Karabiner-VirtualHIDDevice-Manager activate || {
            echo "System extension activation requires user approval in System Settings > Privacy & Security" >&2
          }
        fi
      else
        echo "Karabiner DriverKit already installed" >&2
      fi
    '';

    # Cleanup when disabled
    system.activationScripts.postActivation.text = lib.mkIf (!cfg.enable) ''
      echo "Cleaning up Karabiner DriverKit..." >&2

      # Stop and remove launchd services
      for service in org.nixos.karabiner-vhiddaemon org.nixos.karabiner-vhidmanager; do
        launchctl unload "/Library/LaunchDaemons/$service.plist" 2>/dev/null || true
        rm -f "/Library/LaunchDaemons/$service.plist" 2>/dev/null || true
      done

      # Remove the manager app copy
      rm -rf /Applications/.Nix-Karabiner-DriverKit/ 2>/dev/null || true

      # Note: We don't uninstall the system extension as that requires manual user action
      # and the extension can be shared with other apps
      echo "Note: Karabiner system extension remains installed (can be removed manually in System Settings)" >&2
    '';

    launchd.daemons.karabiner-vhiddaemon.serviceConfig = {
      Label = "org.nixos.karabiner-vhiddaemon";
      ProgramArguments = [
        "/Library/Application Support/org.pqrs/Karabiner-DriverKit-VirtualHIDDevice/Applications/Karabiner-VirtualHIDDevice-Daemon.app/Contents/MacOS/Karabiner-VirtualHIDDevice-Daemon"
      ];
      RunAtLoad = true;
      KeepAlive = true;
    };

    launchd.daemons.karabiner-vhidmanager.serviceConfig = {
      Label = "org.nixos.karabiner-vhidmanager";
      ProgramArguments = [
        "/Applications/.Karabiner-VirtualHIDDevice-Manager.app/Contents/MacOS/Karabiner-VirtualHIDDevice-Manager"
        "activate"
      ];
      RunAtLoad = true;
    };

    launchd.daemons.kanata.serviceConfig = {
      Label = "org.nixos.kanata";
      ProgramArguments = [
        "${lib.getExe cfg.package}"
        "--port"
        "10000"
        # "--debug"
      ] ++ lib.optionals (cfg.config != "") [ "-c" configFile ];

      RunAtLoad = true;
      KeepAlive = true;
      StandardOutPath = cfg.outLogFile;
      StandardErrorPath = cfg.errorLogFile;
    };
  };

  meta.maintainers = [ ];
}