# Do not modify this file!  It was generated by ‘nixos-generate-config’
# and may be overwritten by future invocations.  Please make changes
# to /etc/nixos/configuration.nix instead.
{
  config,
  lib,
  pkgs,
  modulesPath,
  ...
}:
{
  imports = [
    (modulesPath + "/installer/scan/not-detected.nix")
  ];

  # Use the EFI boot loader.
  boot.loader.efi.canTouchEfiVariables = true;
  # depending on how you configured your disk mounts, change this to /boot or /boot/efi.
  boot.loader.efi.efiSysMountPoint = "/boot";
  boot.loader.systemd-boot.enable = true;

  # https://github.com/NixOS/nixpkgs/blob/nixos-unstable/pkgs/top-level/linux-kernels.nix
  boot.kernelPackages = pkgs.linuxPackages_latest;
  # boot.kernelPackages = pkgs.linuxPackages_xanmod_latest;

  boot.initrd.availableKernelModules = [
    "xhci_pci"
    "ahci"
    "nvme"
    "usbhid"
    "usb_storage"
    "sd_mod"
  ];
  boot.initrd.kernelModules = [ ];
  boot.kernelModules = [ "kvm-intel" ]; # kvm virtualization support
  boot.extraModprobeConfig = "options kvm_intel nested=1"; # for intel cpu
  boot.extraModulePackages = [ ];
  # clear /tmp on boot to get a stateless /tmp directory.
  boot.tmp.cleanOnBoot = true;

  # Enable binfmt emulation of aarch64-linux, this is required for cross compilation.
  boot.binfmt.emulatedSystems = [
    "aarch64-linux"
    "riscv64-linux"
  ];
  # This enables the kernel to preload the emulator binaries when the binfmt registrations are added,
  # obviating the need to make the emulator binaries available inside chroots and chroot-like sandboxes.
  boot.binfmt.preferStaticEmulators = true; # required to work with podman

  # supported file systems, so we can mount any removable disks with these filesystems
  boot.supportedFilesystems = [
    "ext4"
    "btrfs"
    "xfs"
    "ntfs"
    "fat"
    "vfat"
    "exfat"
  ];

  boot.initrd = {
    # unlocked luks devices via a keyfile or prompt a passphrase.
    luks.devices."crypted-nixos" = {
      # NOTE: DO NOT use device name here(like /dev/sda, /dev/nvme0n1p2, etc), use UUID instead.
      # https://github.com/ryan4yin/nix-config/issues/43
      device = "/dev/disk/by-uuid/a21ca82a-9ee6-4e5c-9d3f-a93e84e4e0f4";
      # the keyfile(or device partition) that should be used as the decryption key for the encrypted device.
      # if not specified, you will be prompted for a passphrase instead.
      #keyFile = "/root-part.key";

      # whether to allow TRIM requests to the underlying device.
      # it's less secure, but faster.
      allowDiscards = true;
      # Whether to bypass dm-crypt’s internal read and write workqueues.
      # Enabling this should improve performance on SSDs;
      # https://wiki.archlinux.org/index.php/Dm-crypt/Specialties#Disable_workqueue_for_increased_solid_state_drive_(SSD)_performance
      bypassWorkqueues = true;
    };
  };

  fileSystems."/btr_pool" = {
    device = "/dev/disk/by-uuid/1167076c-dee1-486c-83c1-4b1af37555cd";
    fsType = "btrfs";
    # btrfs's top-level subvolume, internally has an id 5
    # we can access all other subvolumes from this subvolume.
    options = [ "subvolid=5" ];
  };

  # equal to `mount -t tmpfs tmpfs /`
  fileSystems."/" = {
    device = "tmpfs";
    fsType = "tmpfs";
    # set mode to 755, otherwise systemd will set it to 777, which cause problems.
    # relatime: Update inode access times relative to modify or change time.
    options = [
      "relatime"
      "mode=755"
    ];
  };

  fileSystems."/nix" = {
    device = "/dev/disk/by-uuid/1167076c-dee1-486c-83c1-4b1af37555cd";
    fsType = "btrfs";
    options = [
      "subvol=@nix"
      "noatime"
      "compress-force=zstd:1"
    ];
  };

  # for guix store, which use `/gnu/store` as its store directory.
  fileSystems."/gnu" = {
    device = "/dev/disk/by-uuid/1167076c-dee1-486c-83c1-4b1af37555cd";
    fsType = "btrfs";
    options = [
      "subvol=@guix"
      "noatime"
      "compress-force=zstd:1"
    ];
  };

  fileSystems."/persistent" = {
    device = "/dev/disk/by-uuid/1167076c-dee1-486c-83c1-4b1af37555cd";
    fsType = "btrfs";
    options = [
      "subvol=@persistent"
      "compress-force=zstd:1"
    ];
    # preservation's data is required for booting.
    neededForBoot = true;
  };

  fileSystems."/snapshots" = {
    device = "/dev/disk/by-uuid/1167076c-dee1-486c-83c1-4b1af37555cd";
    fsType = "btrfs";
    options = [
      "subvol=@snapshots"
      "compress-force=zstd:1"
    ];
  };

  fileSystems."/tmp" = {
    device = "/dev/disk/by-uuid/1167076c-dee1-486c-83c1-4b1af37555cd";
    fsType = "btrfs";
    options = [
      "subvol=@tmp"
      "compress-force=zstd:1"
    ];
  };

  # mount swap subvolume in readonly mode.
  fileSystems."/swap" = {
    device = "/dev/disk/by-uuid/1167076c-dee1-486c-83c1-4b1af37555cd";
    fsType = "btrfs";
    options = [
      "subvol=@swap"
      "ro"
    ];
  };

  # remount swapfile in read-write mode
  fileSystems."/swap/swapfile" = {
    # the swapfile is located in /swap subvolume, so we need to mount /swap first.
    depends = [ "/swap" ];

    device = "/swap/swapfile";
    fsType = "none";
    options = [
      "bind"
      "rw"
    ];
  };

  fileSystems."/boot" = {
    device = "/dev/disk/by-uuid/90FB-9F88";
    fsType = "vfat";
  };

  swapDevices = [
    { device = "/swap/swapfile"; }
  ];

  # Enables DHCP on each ethernet and wireless interface. In case of scripted networking
  # (the default) this is the recommended approach. When using systemd-networkd it's
  # still possible to use this option, but it's recommended to use it in conjunction
  # with explicit per-interface declarations with `networking.interfaces.<interface>.useDHCP`.
  networking.useDHCP = lib.mkDefault true;
  # networking.interfaces.enp5s0.useDHCP = lib.mkDefault true;
  # networking.interfaces.wlo1.useDHCP = lib.mkDefault true;

  nixpkgs.hostPlatform = lib.mkDefault "x86_64-linux";
  powerManagement.cpuFreqGovernor = lib.mkDefault "powersave";
  hardware.cpu.intel.updateMicrocode = lib.mkDefault config.hardware.enableRedistributableFirmware;
}