{ modulesPath, config, lib, pkgs, inputs, ... }:

let
  # Find all mount points that start with "/mnt/data-"
  dataDiskMounts = lib.attrsets.attrNames (
    lib.attrsets.filterAttrs (name: value: lib.strings.hasPrefix "/mnt/data-" name) config.fileSystems
  );

  # Find all mount points that start with "/mnt/parity-"
  parityDiskMounts = lib.attrsets.attrNames (
    lib.attrsets.filterAttrs (name: value: lib.strings.hasPrefix "/mnt/parity-" name) config.fileSystems
  );

  # Create an attribute set for snapraid data disks, e.g. { d1 = "/mnt/data-1"; d2 = "/mnt/data-2"; }
  snapraidDataDisks = lib.lists.foldl'
    (acc: path: acc // { "d${toString (acc.i + 1)}" = path; i = acc.i + 1; })
    { i = 0; }
    dataDiskMounts;
in

{
  imports = [
    (modulesPath + "/installer/scan/not-detected.nix")
    (modulesPath + "/profiles/qemu-guest.nix")
    inputs.sops-nix.nixosModules.sops
    ./disk-config.nix
  ];

  # Hardware settings
  hardware.enableRedistributableFirmware = true;
  hardware.cpu.intel.updateMicrocode = true;
  hardware.cpu.amd.updateMicrocode = true;

  # Secrets management
  sops.defaultSopsFile = ./secrets/secrets.yaml;
  sops.age.sshKeyPaths = [ "/home/numbus-admin/.ssh/id_ed25519" ];
  sops.age.keyFile = "/var/lib/sops-nix/key.txt";
  sops.age.generateKey = true;
  sops.secrets."ssh-public-keys" = { owner = "numbus-admin"; path = "/etc/ssh/authorized_keys.d/numbus-admin"; };
  sops.secrets."docker/frigate" = { owner = "numbus-admin"; path = "/etc/docker-compose/frigate/.env"; };
  sops.secrets."docker/traefik" = { owner = "numbus-admin"; path = "/etc/docker-compose/traefik/.env"; };
  sops.secrets."docker/nextcloud" = { owner = "numbus-admin"; path = "/etc/docker-compose/nextcloud/.env"; };
  sops.secrets."docker/passbolt" = { owner = "numbus-admin"; path = "/etc/docker-compose/passbolt/.env"; };
  sops.secrets."docker/hass" = { owner = "numbus-admin"; path = "/etc/docker-compose/hass/.env"; };
  sops.secrets."docker/pihole" = { owner = "numbus-admin"; path = "/etc/docker-compose/pihole/.env"; };
  sops.secrets."disks/data-disk-1" = { owner = "root"; };
  sops.secrets."disks/data-disk-2" = { owner = "root"; };
  sops.secrets."disks/data-disk-3" = { owner = "root"; };
  sops.secrets."disks/data-disk-4" = { owner = "root"; };
  sops.secrets."disks/data-disk-5" = { owner = "root"; };
  sops.secrets."disks/data-disk-6" = { owner = "root"; };
  sops.secrets."disks/parity-disk-1" = { owner = "root"; };
  sops.secrets."disks/parity-disk-2" = { owner = "root"; };
  sops.secrets."disks/parity-disk-3" = { owner = "root"; };

  # Bootloader options
  boot.initrd.systemd.enable = true;
  boot.loader.systemd-boot.enable = true;
  boot.loader.efi.canTouchEfiVariables = true;

  # Timezone
  time.timeZone = "Europe/Paris";

  # Internationalisation properties.
  i18n.defaultLocale = "fr_FR.UTF-8";
  i18n.extraLocaleSettings = {
    LC_ADDRESS = "fr_FR.UTF-8";
    LC_IDENTIFICATION = "fr_FR.UTF-8";
    LC_MEASUREMENT = "fr_FR.UTF-8";
    LC_MONETARY = "fr_FR.UTF-8";
    LC_NAME = "fr_FR.UTF-8";
    LC_NUMERIC = "fr_FR.UTF-8";
    LC_PAPER = "fr_FR.UTF-8";
    LC_TELEPHONE = "fr_FR.UTF-8";
    LC_TIME = "fr_FR.UTF-8";
  };

  # Keyboard mapping
  console.keyMap = "fr";
  services.xserver.xkb = {
    layout = "fr";
    variant = "";
  };

  # Enable SSH
  services.openssh = {
    enable = true;
  };

  # Allow unfree packages
  nixpkgs.config.allowUnfree = true;

  # Install packages
  environment.systemPackages = with pkgs; [
    ncdu
    fastfetch
    tpm2-tss
    sops
    age
    powertop
    pciutils
    hdparm
    hd-idle
    hddtemp
    smartmontools
    cpufrequtils
    intel-gpu-tools
  ];

  # Power savings
  services.autoaspm.enable = true;
  powerManagement.powertop.enable = true;
  boot.kernelParams = [
    "pcie_aspm=force"
    "consoleblank=60"
  ];

  # Enable cron service
  services.cron = {
    enable = true;
    systemCronJobs = [
    ];
  };

  # Enable docker
  virtualisation.docker.enable = true;
  virtualisation.docker.daemon.settings = {
    data-root = "/mnt/config-storage/docker-data/docker-volumes/";
  };

  # Enable networking and firewall
  networking.interfaces.eth0.ipv4.addresses = [
    {
      address = "HOME_SERVER_IP";
      prefixLength = 24;
    }
  ];
  networking.defaultGateway = "HOME_ROUTER_IP";
  networking.nameservers = [ "HOME_SERVER_IP" "9.9.9.9" ];
  networking.networkmanager.enable = true;
  networking.firewall.enable = true;

  # Open ports in the firewall
  networking.firewall.allowPing = false;
  networking.firewall.allowedTCPPorts = [ 53 80 443 ];
  networking.firewall.allowedUDPPorts = [ 53 ];

  # Hostname
  networking.hostName = "numbus-server";

  # User account
  users.users.numbus-admin = {
    isNormalUser = true;
    description = "Numbus Admin";
    extraGroups = [ "networkmanager" "wheel" "docker" ];
    uid = 1000;
    initialPassword = "nixos-at-numbus";
  };

  # Login message
  environment.loginShellInit = ''
    if [ "$(id -u)" -eq 1000 ]; then
      if [ -n "$SSH_TTY" ]; then
        fastfetch
	      echo -e "\n\nWelcome to numbus.eu server !\n\n- This system is managed by NixOS\n- All changes are futile\n- Please consider buying support if you can't get your server running\n- Have a nice day and enjoy !"
      fi
    fi
  '';

  # Enable auto updates
  system.autoUpgrade = {
    enable = true;
    allowReboot = true;
    flake = inputs.self.outPath;
    flags = [ "--print-build-logs" ];
    dates = "02:00";
    randomizedDelaySec = "45min";
  };

  # Enable NixOS flakes
  nix.settings.experimental-features = [ "nix-command" "flakes" ];

  # --- Storage Configuration (MergerFS & SnapRAID) ---

  # Create the mount point for the MergerFS pool
  fileSystems."/mnt/data-storage" = {
    device = "mergerfs";
    fsType = "fuse";
    options = [
      "defaults"
      "allow_other"
      "use_ino"
      "cache.files=off"
      "moveonenospc=true"
      "category.create=mfs"
      "srcmounts=${lib.strings.concatStringsSep ":" dataDiskMounts}"
    ];
  };

  # SnapRAID for data redundancy
  services.snapraid = {
    enable = true;
    contentFiles = map (disk: "${disk}/snapraid.content") dataDiskMounts;
    parityFiles = map (disk: "${disk}/snapraid.parity") parityDiskMounts;
    dataDisks = builtins.removeAttrs snapraidDataDisks [ "i" ]; # This correctly creates the required attribute set.
    # Using default sync and scrub schedules:
    # Sync runs daily at 01:00.
    # Scrub runs weekly on Monday at 02:00.
  };

  system.stateVersion = "25.05";
}