{ hostName, flake, config, pkgs, lib, ... }:
{
  imports = with flake.nixosModules.systemProfiles; [
    ./zfs.nix ./dsl.nix
    initrd-all-crypto-modules default-locale openssh rebuild-machines
    build-server
    initrd-ssh
  ];

  config = {
    nixpkgs = {
      system = "x86_64-linux";
    };

    networking.hostId = "1e7ddd78";
    environment.etc."machine-id".text = "1e7ddd784c525bba2a03d7c160c5da4e";

    boot = {
      loader.grub = {
        enable = true;
        version = 2;
        device = "/dev/disk/by-id/ata-SuperMicro_SSD_SMC0515D95019BDF4083";
      };

      kernelPackages = pkgs.linuxPackages_latest;
      kernelModules = [ "kvm-intel" ];

      kernelParams = [
        "ip=10.141.0.1:::255.255.255.0::eno1:static"
      ];

      tmpOnTmpfs = true;

      initrd = {
        supportedFilesystems = [ "zfs" ];
        availableKernelModules = [ "ehci_pci" "ahci" "nvme" "isci" "xhci_pci" "usb_storage" "usbhid" "sd_mod" "sr_mod" "drbg" "rtsx_pci_sdmmc" "libsas" "scsi_transport_sas" "e1000e" ];
        kernelModules = [ "dm-raid" "dm-integrity" "dm-snapshot" "dm-thin-pool" ];

        luks.devices = {
          nvm0.device = "/dev/disk/by-label/${hostName}-nvm0";
          nvm1.device = "/dev/disk/by-label/${hostName}-nvm1";
          
          hdd0.device = "/dev/disk/by-label/${hostName}-hdd0";
          hdd1.device = "/dev/disk/by-label/${hostName}-hdd1";
          hdd2.device = "/dev/disk/by-label/${hostName}-hdd2";
          hdd3.device = "/dev/disk/by-label/${hostName}-hdd3";
          hdd4.device = "/dev/disk/by-label/${hostName}-hdd4";
          hdd5.device = "/dev/disk/by-label/${hostName}-hdd5";
        };

        network.flushBeforeStage2 = false;
      };
      
      supportedFilesystems = [ "zfs" ];
      zfs = {
        enableUnstable = true;
      };
    };

    fileSystems = {
      "/" = {
        fsType = "tmpfs";
        options = [ "mode=0755" ];
      };
    };

    networking = {
      hostName = "vidhar";
      domain = "yggdrasil";
      search = [ "yggdrasil" ];

      useDHCP = false;
      useNetworkd = true;

      interfaces."eno1" = {
        ipv4.addresses = [
          { address = "10.141.0.1"; prefixLength = 24; }
        ];
      };
      interfaces."mgmt" = {
        ipv4.addresses = [
          { address = "10.141.1.1"; prefixLength = 24; }
        ];
      };

      vlans = {
        mgmt = {
          id = 2;
          interface = "eno2";
        };
      };

      firewall.enable = false;
      nftables = {
        enable = true;
        rulesetFile = ./ruleset.nft;
      };
    };

    services.resolved = {
      llmnr = "false";
    };

    services.dhcpd4 = {
      enable = true;
      interfaces = [ "eno1" "mgmt" ];
      extraConfig = ''
        subnet 10.141.0.0 netmask 255.255.255.0 {
          range 10.141.0.128 10.141.0.254;
          option domain-name-servers 10.141.0.1;
          option broadcast-address 10.141.0.255;
          option routers 10.141.0.1;
          option domain-name "yggdrasil";
        }

        subnet 10.141.1.0 netmask 255.255.255.0 {
          range 10.141.1.128 10.141.1.254;
        }
      '';
      machines = [
        {
          ethernetAddress = "50:d4:f7:f3:0f:7e";
          hostName = "gauss-ap01";
          ipAddress = "10.141.0.64";
        }
        {
          ethernetAddress = "60:a4:b7:53:94:b5";
          hostName = "switch01";
          ipAddress = "10.141.1.2";
        }
      ];
    };
    services.corerad = {
      enable = true;
      settings = {
        interfaces = [
          { name = config.networking.pppInterface;
            monitor = true;
            verbose = true;
          }
          { name = "eno1";
            advertise = true;
            verbose = true;
            prefix = [{ prefix = "::/64"; }];
            route = [{ prefix = "::/0"; }];
            rdnss = [{ servers = ["::"]; }];
            dnssl = [{ domain_names = ["yggdrasil"]; }];
          }
        ];
      };
    };
    services.ndppd = {
      enable = true;
      proxies = {
        ${config.networking.pppInterface} = {
          router = true;
          rules.lan = {
            method = "iface";
            interface = "eno1";
            network = "::/0";
          };
        };
      };
    };
    boot.kernel.sysctl = {
      "net.ipv6.conf.all.forwarding" = true;
      "net.ipv6.conf.default.forwarding" = true;
      "net.ipv4.conf.all.forwarding" = true;
      "net.ipv4.conf.default.forwarding" = true;

      "net.core.rmem_max" = "4194304";
      "net.core.wmem_max" = "4194304";
    };
    systemd.network.networks = {
      "eno2" = {
        matchConfig.Name = "eno2";
        networkConfig.LinkLocalAddressing = "no";
      };
      "telekom" = {
        matchConfig.Name = "telekom";
        networkConfig.LinkLocalAddressing = "no";
      };
    };
    systemd.services."pppd-telekom" = {
      bindsTo = [ "sys-subsystem-net-devices-telekom.device" ];
      after = [ "sys-subsystem-net-devices-telekom.device" ];
    };
    systemd.services."dhcpcd-telekom" = {
      wantedBy = [ "multi-user.target" "network-online.target" ];
      bindsTo = [ "pppd-telekom.service" ];
      after = [ "pppd-telekom.service" ];
      wants = [ "network.target" ];
      before = [ "network-online.target" ];

      path = with pkgs; [ dhcpcd nettools openresolv ];
      unitConfig.ConditionCapability = "CAP_NET_ADMIN";

      stopIfChanged = false;

      serviceConfig = let
        dhcpcdConf = pkgs.writeText "dhcpcd.conf" ''
          duid
          vendorclassid
          ipv6only

          nooption domain_name_servers, domain_name, domain_search
          option classless_static_routes
          option interface_mtu

          option host_name
          option rapid_commit
          require dhcp_server_identifier
          slaac private

          noipv6rs                 # disable routing solicitation
          nohook resolv.conf
          allowinterfaces dsl
          interface dsl
            ipv6ra_autoconf
            iaid 1195061668
            ipv6rs                 # enable routing solicitation for WAN adapter
            ia_pd 1 eno1/0/64/0    # request a PD and assign it to the LAN

          waitip 6
        '';
      in {
        Type = "forking";
        PIDFile = "/run/dhcpcd/pid";
        RuntimeDirectory = "dhcpcd";
        ExecStart = "@${pkgs.dhcpcd}/sbin/dhcpcd dhcpcd -q --config ${dhcpcdConf}";
        ExecReload = "${pkgs.dhcpcd}/sbin/dhcpcd --rebind";
        Restart = "always";
      };
    };
    users.users.dhcpcd = {
      isSystemUser = true;
      group = "dhcpcd";
    };
    users.groups.dhcpcd = {};
    
    services.timesyncd.enable = false;
    services.chrony = {
      enable = true;
      servers = [];
      extraConfig = ''
        allow 10.141.1.0/24
        local

        pool time.cloudflare.com iburst nts
        pool nts.ntp.se iburst nts
        server nts.sth1.ntp.se iburst nts
        server nts.sth2.ntp.se iburst nts
        server ptbtime1.ptb.de iburst nts
        server ptbtime2.ptb.de iburst nts
        server ptbtime3.ptb.de iburst nts

        leapsectz right/UTC

        makestep 0.1 3

        cmdport 0
      '';
    };

    services.openssh = {
      enable = true;
      passwordAuthentication = false;
      challengeResponseAuthentication = false;
      extraConfig = ''
        AllowGroups ssh
      '';
    };
    users.groups."ssh" = {
      members = ["root"];
    };

    security.sudo.extraConfig = ''
      Defaults lecture = never
    '';

    nix = {
      daemonCPUSchedPolicy = "batch";
      daemonIOSchedClass = "idle";

      gc = {
        automatic = true;
        options = "--delete-older-than 30d";
      };
    };

    powerManagement = {
      enable = true;

      cpuFreqGovernor = "schedutil";
    };

    services.unbound = {
      enable = true;
      resolveLocalQueries = false;
      stateDir = "/var/lib/unbound";
      localControlSocketPath = "/run/unbound/unbound.ctl";
      settings = {
        server = {
          interface = ["127.0.0.1" "10.141.0.1" "::0"];
          access-control = ["0.0.0.0/0 allow" "::/0 allow"];
          root-hints = "${pkgs.dns-root-data}/root.hints";

          num-threads = 12;
          so-reuseport = true;
          msg-cache-slabs = 16;
          rrset-cache-slabs = 16;
          infra-cache-slabs = 16;
          key-cache-slabs = 16;

          rrset-cache-size = "100m";
          msg-cache-size = "50m";
          outgoing-range = 8192;
          num-queries-per-thread = 4096;

          so-rcvbuf = "4m";
          so-sndbuf = "4m";

          serve-expired = true;
          serve-expired-ttl = 86400;
          serve-expired-reply-ttl = 0;

          prefetch = true;
          prefetch-key = true;

          minimal-responses = false;

          extended-statistics = true;

          rrset-roundrobin = true;
          use-caps-for-id = true;
        };
      };
    };

    services.samba = {
      enable = true;
      securityType = "user";
      extraConfig = ''
        domain master = yes
        workgroup = WORKGROUP
        load printers = no
        printing = bsd
        printcap name = /dev/null
        disable spoolss = yes
        guest account = nobody
      '';
      shares = {
        homes = {
          comment = "Home Directories";
          path = "/home/%S";
          browseable = "no";
          "valid users" = "%S";
          "read only" = "no";
          "create mask" = "0700";
          "directory mask" = "0700";
          "vfs objects" = "shadow_copy2";
          "shadow:snapdir" = ".zfs/snapshot";
          "shadow:sort" = "desc";
          "shadow:format" = "%Y-%m-%d-%Hh%MU";
          "shadow:snapprefix" = "^zfs-auto-snap_\(frequent\)\{0,1\}\(hourly\)\{0,1\}\(daily\)\{0,1\}\(monthly\)\{0,1\}";
          "shadow:delimiter" = "-";
        };
        eos = {
          comment = "Disk image of eos";
          browseable = true;
          "valid users" = "mherold";
          writeable = "true";
          path = "/srv/eos";
        };
      };
    };
    services.samba-wsdd = {
      enable = true;
      workgroup = "WORKGROUP";
    };

    fileSystems."/srv/eos.lower" = {
      device = "/dev/zvol/hdd-raid6/safe/home/mherold/eos/base";
      fsType = "ntfs3";
      options = [ "ro" "uid=mherold" "gid=users" "fmask=0177" "dmask=0077" "nofail" "noauto" ];
    };

    fileSystems."/srv/eos.upper" = {
      device = "/dev/zvol/hdd-raid6/safe/home/mherold/eos/upper";
      fsType = "ext4";
      options = [ "nofail" "noauto" ];
    };

    systemd.mounts = [
      {
        wantedBy = [ "samba-smbd.service" ];
        before = [ "samba-smbd.service" ];

        where = "/srv/eos";
        what = "overlay";
        type = "overlay";
        options = lib.concatStringsSep ","
          [ "lowerdir=/srv/eos.lower"
            "upperdir=/srv/eos.upper/upper"
            "workdir=/srv/eos.upper/work"
          ];

        unitConfig = {
          RequiresMountsFor = [ "/srv/eos.lower" "/srv/eos.upper" ];
        };
      }
    ];
  };
}