{
  config,
  lib,
  ...
}:
let
  cfg = config.os.core.bootloader;
in
{
  options.os.core.bootloader = {
    type = lib.mkOption {
      type = lib.types.enum [
        "systemd-boot"
        "grub"
        "none"
      ];
      default = "systemd-boot";
      description = "Which bootloader to use";
    };

    efi = lib.mkOption {
      type = lib.types.bool;
      default = if cfg.grub.device == "nodev" then true else false;
      description = "Whether the system uses UEFI or Legacy BIOS";
    };

    timeout = lib.mkOption {
      type = lib.types.int;
      default = 3;
      description = "Boot menu timeout in seconds";
    };

    grub = {
      device = lib.mkOption {
        type = lib.types.str;
        default = "nodev";
        description = "Device to install GRUB to (e.g. /dev/nvme0n1). Use 'nodev' for UEFI.";
      };
      useOSProber = lib.mkOption {
        type = lib.types.bool;
        default = false;
        description = "Scan for other operating systems";
      };
      defaultEntry = lib.mkOption {
        type = lib.types.int;
        default = 0;
        description = "Index of the default boot entry";
      };
    };

    luks.enable = lib.mkEnableOption "LUKS encryption support";
  };

  config = lib.mkMerge [
    # 1. Common Kernel & Initrd Settings
    {
      boot = {
        loader = {
          timeout = cfg.timeout;
          efi.canTouchEfiVariables = lib.mkDefault cfg.efi;
        };
        supportedFilesystems = [
          "ntfs"
          "btrfs"
        ];
        kernelParams = [
          "quiet"
          "splash"
        ];
        consoleLogLevel = 0;
        initrd.availableKernelModules = [
          "aesni_intel"
          "cryptd"
        ];
      };
      systemd.settings.Manager.DefaultTimeoutStopSec = "5s";
    }

    # 2. Systemd-boot Implementation
    (lib.mkIf (cfg.type == "systemd-boot") {
      boot.loader.systemd-boot = {
        enable = true;
        editor = false;
        consoleMode = "max";
      };
    })

    # 3. GRUB Implementation
    (lib.mkIf (cfg.type == "grub") {
      boot.loader.grub = {
        enable = true;
        efiSupport = cfg.efi;
        useOSProber = cfg.grub.useOSProber;
        default = cfg.grub.defaultEntry;
        enableCryptodisk = cfg.luks.enable;
        copyKernels = true;
      };
    })
  ];
}