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

with lib;

let
  luaPam = pkgs.callPackage ./custom/luaPam.nix {};
  luaPosix = pkgs.callPackage ./custom/luaPosix.nix {};
  luaSha2 = pkgs.callPackage ./custom/luaSha2.nix {};
  myDomains = [ "dirty-haskell.org" "www.dirty-haskell.org" "lists.dirty-haskell.org" "l.dirty-haskell.org"
                "online.141.li" "o.141.li" "ftp.141.li" "files.141.li" "f.141.li" "ymir.141.li" "141.li" "www.141.li" "lists.141.li" "l.141.li" "rpg.141.li" "odin.141.li"
                "ymir.xmpp.li" "xmpp.li" "www.xmpp.li" "lists.xmpp.li" "l.xmpp.li" "muc.xmpp.li" "proxy.xmpp.li"
                "online.yggdrasil.li" "o.yggdrasil.li" "ftp.yggdrasil.li" "files.yggdrasil.li" "f.yggdrasil.li" "ymir.yggdrasil.li" "git.yggdrasil.li" "www.yggdrasil.li" "yggdrasil.li" "lists.yggdrasil.li" "l.yggdrasil.li" "rpg.yggdrasil.li" "odin.yggdrasil.li"
                "online.praseodym.org" "o.praseodym.org" "ftp.praseodym.org" "files.praseodym.org" "f.praseodym.org" "ymir.praseodym.org" "praseodym.org" "www.praseodym.org" "lists.praseodym.org" "l.praseodym.org" "rpg.praseodym.org"
                "ymir.kleen.li" "kleen.li" "www.kleen.li"
                "ymir.nights.email" "nights.email" "www.nights.email"
              ];

   dnsZoneDir = ./ymir/zones;
   dnsZones = listToAttrs (flatten (mapAttrsToList dnsZone (builtins.readDir dnsZoneDir)));
   dnsZone = fName: type: optional (type == "regular" || type == "symlink") (nameValuePair (dnsZoneName fName) {
     data = readFile (dnsZoneDir + ("/" + fName));
   });
   dnsZoneName = fName: concatStringsSep "." (reverseList (splitString "." (removeSuffix ".soa" fName)));
in rec {
  imports =
    [
      ./nixpkgs.nix
      ./ymir/hw.nix
      ./ymir/mlmmj-expose.nix
      ./custom/zsh.nix
      ./users.nix
      ./custom/tinc/def.nix
      ./custom/tinc/yggdrasil.nix
      ./custom/ymir-nginx.nix
      ./custom/uucp.nix
      ./custom/unit-status-mail.nix
      ./utils/nix/module.nix
    ];

  networking.hostId = "1c5c994e";
  environment.etc."machine-id".text = "34f0d2df31f8634d8c08d47b15419d26";

  boot.loader.grub = {
    enable = true;
    version = 2;
    device = "/dev/vda";
  };

  boot.tmpOnTmpfs = true;

  boot.kernel.sysctl = {
    "net.ipv4.tcp_keepalive_time" = 60;
    "net.ipv4.tcp_keepalive_intvl" = 10;
    "net.ipv4.tcp_keepalive_probes" = 6;
  };

  nixpkgs.config.allowUnfree = true;

  nixpkgs.overlays = [
    (self: super: {
      # uwsgi = pkgs.callPackage ./customized/uwsgi.nix {
      #   extraPlugins = {
      #     cgi = {
      #       name = "cgi";
      #       interpreter = pkgs.python3.interpreter;
      #       path = "plugins/cgi";
      #       inputs = [ pkgs.python3 ];
      #       install = ''
      #         ${pkgs.python3.executable} -m compileall $out/${pkgs.python3.sitePackages}/
      #         ${pkgs.python3.executable} -O -m compileall $out/${pkgs.python3.sitePackages}/
      #       '';
      #     };
      #   };
      #   plugins = [];
      # };
      cgit = super.lib.overrideDerivation super.cgit (oldAttrs : {
        buildInputs = oldAttrs.buildInputs ++ [
          self.perl
          self.python3
          self.makeWrapper
        ];
        postInstall = let
          pythonEnv = self.python3.buildEnv.override { extraLibs = with self.python3Packages; [ pygments markdown ]; };
        in ''
          wrapProgram $out/lib/cgit/filters/syntax-highlighting.py --prefix PYTHONPATH ':' ${pythonEnv}/lib/*/site-packages
          wrapProgram $out/lib/cgit/filters/about-formatting.sh --prefix PATH ':' ${self.coreutils}/bin
          tmpFile=$(mktemp)
          chmod +x $tmpFile
          echo "#!${pythonEnv}/bin/python3" >$tmpFile
          tail -n +2 $out/lib/cgit/filters/html-converters/md2html >>$tmpFile
          mv -v $tmpFile $out/lib/cgit/filters/html-converters/md2html
          wrapProgram $out/lib/cgit/filters/html-converters/md2html --prefix PYTHONPATH ':' ${pythonEnv}/lib/*/site-packages
          wrapProgram $out/lib/cgit/filters/html-converters/man2html --prefix PATH ':' ${self.groff}/bin
        '';
      });
      push2bin = super.writeScriptBin "push2bin" ''
        #!${self.zsh}/bin/zsh

        PATH=${self.coreutils}/bin:${self.gawk}/bin

        baseDir=/srv/www/files
        baseUrl="https://f.141.li"

        tmpFile=$(mktemp "''${baseDir}/.upload.XXXXXXXXXX")

        function zshexit() { [[ -n "''${tmpFile}" && -e "''${tmpFile}" ]] && rm -f "''${tmpFile}" }

        prefix=$(tee "''${tmpFile}" | sha512sum | awk '{ print $1; }' | head -c 10)
        prefix=''${prefix:l}
        filename="$1"
 
        [[ -z "''${prefix}" || -z "''${filename}" ]] && exit 2
        [[ ! -f "''${tmpFile}" || $(stat -c '%s' "''${tmpFile}") == "0" ]] && exit 3
 
        mkdir -p "''${baseDir}/''${prefix}"
        mv "''${tmpFile}" "''${baseDir}/''${prefix}/''${filename}"
 
        chmod 755 "''${baseDir}/''${prefix}"
        chmod 644 "''${baseDir}/''${prefix}/''${filename}"
 
        printf "%s/%s/%s" "''${baseUrl}" "''${prefix}" "''${filename}"
      '';
      pam_pwdfile = super.stdenv.mkDerivation rec {
        name = "pam-pwdfile-${version}";
        version = "1.0";
        src = super.fetchFromGitHub {
          owner = "tiwe-de";
          repo = "libpam-pwdfile";
          rev = "v${version}";
          sha256 = "0sjzwsnlf1g0xbingmjvb9gh8lnwzkkfzw10194ibnppdn4gy0zy";
        };

        buildInputs = with self; [ pam ];

        installFlags = [ "DESTDIR=$(out)" ];
      };
    })
  ];

  environment.systemPackages = with pkgs; [
    git
    mosh
    rsync
    tmux
    zsh
    mlmmj
    rebuild-system
    rxvt_unicode.terminfo alacritty.terminfo
  ];

  networking = {
    hostName = "ymir";
    firewall = {
      enable = true;
      allowPing = true;
      allowedTCPPorts = [ 21 # ftp
                          22 # ssh
                          25 # smtp
                          143 # imap
                          993 # imaps
                          5000 # xmpp proxy
                          5222 # xmpp.s2c
                          5269 # xmpp.s2s
                          655 # tinc.yggdrasil
                          656 # tinc.laeradhr
                          80 # http
                          443 # https
                          9418 # git
                          53 # DNS
                          6523 # Obby
                          4190 # Managesieve
                        ];
      allowedUDPPorts = [ 53 # DNS
                        ];
      allowedTCPPortRanges = [ { from = 20000; to = 21000; } # ftp
                             ];
      allowedUDPPortRanges = [ { from = 60000; to = 61000; } # mosh
                             ];

      interfaces.yggdrasil.allowedTCPPorts =
        [ 11332 # rspamd
        ];
    };
    enableIPv6 = true;
    interfaces."ens3" = {
      useDHCP = true;
      ipv6.addresses = [
          { address = "2a03:4000:6:d004::";
            prefixLength = 64;
          }
        ];
    };
    resolvconf.dnsExtensionMechanism = true;
    nameservers = [ "::1" "127.0.0.1" "10.141.1.1" "8.8.8.8" "8.8.4.4" ];
    domain = "niflheim.yggdrasil";
    search = [ "niflheim.yggdrasil" "yggdrasil" "asgard.yggdrasil" ];
  };

  users.extraUsers.root = let
    template = (import users/gkleen.nix);
    in {
        inherit (template) shell;
        openssh.authorizedKeys.keyFiles = template.openssh.authorizedKeys.keyFiles;
      };

  # List services that you want to enable:

  services.openssh = {
    enable = true;
    passwordAuthentication = false;
    challengeResponseAuthentication = false;
    extraConfig = ''
      AllowGroups ssh

      HostCertificate /etc/ssh/ssh_host_ed25519_key-cert.pub
      HostCertificate /etc/ssh/ssh_host_rsa_key-cert.pub
      RevokedKeys /etc/ssh/krl.bin
    '';
    knownHosts = import ./knownHosts.nix;
    hostKeys = [
      { bits = 4096; path = "/etc/ssh/ssh_host_rsa_key"; type = "rsa"; }
      { path = "/etc/ssh/ssh_host_ed25519_key"; type = "ed25519"; }
    ];
  };
  environment.etc."ssh/ssh_host_rsa_key-cert.pub".source = ./ymir/rsa-cert.pub;
  environment.etc."ssh/ssh_host_ed25519_key-cert.pub".source = ./ymir/ed25519-cert.pub;
  environment.etc."ssh/krl.bin".source = ./krl.bin;
  users.groups."ssh" = {
    members = ["gitolite" "uucp" "root"];
  };

  services.fcron = {
    enable = true;
    systab = ''
      %weekly,erroronlymail  * *   nix-collect-garbage --delete-older-than '7d'
    '';
  };

  users.groups."ssl" = {
    members = [ "nginx"
                config.services.postfix.user
                "murmur"
                "infinoted"
              ];
  };

  users.groups."rspamd" = {
    members = [ config.services.rspamd.user
                config.services.postfix.user
              ];
  };

  services.journald = {
    rateLimitBurst = 0;
    extraConfig = ''
      SystemMaxUse=100M 
    '';
  };

  services.yggdrasilTinc = {
    enable = true;
    connect = false;
    useDNS = false;
    interfaceConfig = {
      ipv4 = {
        addresses = [ { address = "10.141.5.1"; prefixLength = 16; } ];
        routes = [ { address = "10.141.1.0"; prefixLength = 24; via = "10.141.1.1"; } ];
      };
      macAddress = "2e:1b:73:b2:49:6d";
    };
  };

  users.extraUsers."nginx".extraGroups = ["uwsgi"];

  services.uwsgi = {
    enable = true;
    plugins = ["python3" "cgi"];
    instance = {
      type = "emperor";
      uid = "root"; gid = "root";
      vassals = {
        "git.yggdrasil.li" =  {
          type = "normal";
          processes = 1;
          threads = 8;
          chdir = "${pkgs.cgit}/cgit";
          cgi = "${pkgs.cgit}/cgit/cgit.cgi";
          env = [
            "CGIT_CONFIG=/etc/cgit/git.yggdrasil.li"
          ];
          socket = "/run/git.yggdrasil.li.sock";
          chmod-socket = "660";
          chown-socket = "uwsgi:nginx";
          uid = "uwsgi"; gid = "uwsgi";
        };
      };
    };
  };

  systemd.services."uwsgi" = {
    wantedBy = [ "nginx.service" ];
    before = [ "nginx.service" ];
    serviceConfig = {
      User = lib.mkForce null;
      Group = lib.mkForce null;
    };
  };
  
  users.extraUsers."uwsgi".extraGroups = ["gitolite"];

  environment.etc."cgit/git.yggdrasil.li" = {
    enable = true;
    text = ''
      robots=noindex, nofollow
      virtual-root=/
      enable-git-config=1
      remove-suffix=1

      root-title=git.yggdrasil.li
      root-desc=

      enable-http-clone=1

      enable-commit-graph=1
      snapshots=tar tar.gz tar.bz2 tar.xz zip
      side-by-side-diffs=1

      source-filter=${pkgs.cgit}/lib/cgit/filters/syntax-highlighting.py
      about-filter=${pkgs.cgit}/lib/cgit/filters/about-formatting.sh

      readme=:README.md
      readme=:README.txt
      readme=:README
      readme=:readme.md
      readme=:readme.txt
      readme=:readme

      clone-prefix=git://git.yggdrasil.li https://git.yggdrasil.li

      strict-export=git-daemon-export-ok
      section-from-path=2
      scan-path=${config.services.gitolite.dataDir}/repositories
    '';
  };

  services.gitolite = {
    enable = true;
    adminPubkey = builtins.readFile (builtins.head (import ./users/gkleen.nix).openssh.authorizedKeys.keyFiles);
    dataDir = "/srv/git";
    user = "gitolite";
    extraGitoliteRc = ''
      $RC{UMASK} = 0027;
      $RC{GIT_CONFIG_KEYS} = 'gitweb\.(owner|description|category)';
      $RC{LOG_DEST} = 'syslog';
      $RC{ROLES}{AUTHORS} = 1;
      $RC{GROUPLIST_PGM} = 'printf "@self-key-managers"';
      $RC{HOSTNAME} = '${networking.hostName}';
      $RC{LOCAL_CODE} = "$rc{GL_ADMIN_BASE}/local";
      push(@{$RC{ENABLE}}, qw(create fork D cgit repo-specific-hooks macros));
    '';
  };

  services.gitDaemon = {
    enable = true;
    basePath = services.gitolite.dataDir + "/repositories";
    user = "gitolite";
    group = "gitolite";
  };

  services.postfix = {
    enable = true;
    hostname = "ymir.yggdrasil.li";
    recipientDelimiter = "+";
    setSendmail = true;
    postmasterAlias = ""; rootAlias = ""; extraAliases = "";
    virtual = ''
      blog@dirty-haskell.org dirty-haskell@lists.yggdrasil.li
      @nights.email some@nights.email
    '';
    #destination = ["yggdrasil.li" "ymir.yggdrasil.li" "praseodym.org" "ymir.praseodym.org" "141.li" "ymir.141.li" "xmpp.li" "ymir.xmpp.li" "dirty-haskell.org" "explainuxul.de" "www.explainuxul.de" "lmu.li" "www.lmu.li" "localhost.yggdrasil.li" "localhost"];
    destination = [''regexp:${pkgs.writeText "destination" ''
        /\.?yggdrasil\.li$/ ACCEPT
        /\.?praseodym\.org$/ ACCEPT
        /\.?141\.li$/ ACCEPT
        /\.?xmpp\.li$/ ACCEPT
        /\.?kleen\.li$/ ACCEPT
        /\.?dirty-haskell\.org$/ ACCEPT
        /\.?nights\.email$/ ACCEPT
        /\.?yggdrasil$/ ACCEPT
        /\.?localdomain$/ ACCEPT
        /^localhost$/ ACCEPT
        /\.?ymir$/ ACCEPT
      ''}''];
    sslCert = "/var/lib/acme/yggdrasil.li/fullchain.pem";
    sslKey = "/var/lib/acme/yggdrasil.li/key.pem";
    useDane = true;
    config = {
      #the dh params
      smtpd_tls_dh1024_param_file = toString config.security.dhparams.params."postfix-1024".path;
      smtpd_tls_dh512_param_file = toString config.security.dhparams.params."postfix-512".path;
      #enable ECDH
      smtpd_tls_eecdh_grade = "strong";
      #enabled SSL protocols, don't allow SSLv2 and SSLv3
      smtpd_tls_protocols = [ "!SSLv2" "!SSLv3"];
      smtpd_tls_mandatory_protocols = ["!SSLv2" "!SSLv3"];
      #allowed ciphers for smtpd_tls_security_level=encrypt
      smtpd_tls_mandatory_ciphers = "high";
      #allowed ciphers for smtpd_tls_security_level=may
      #smtpd_tls_ciphers = high
      #enforce the server cipher preference
      tls_preempt_cipherlist = true;
      #disable following ciphers for smtpd_tls_security_level=encrypt
      smtpd_tls_mandatory_exclude_ciphers = ["aNULL" "MD5" "DES" "ADH" "RC4" "PSD" "SRP" "3DES" "eNULL"];
      #disable following ciphers for smtpd_tls_security_level=may
      smtpd_tls_exclude_ciphers = ["aNULL" "MD5" "DES" "ADH" "RC4" "PSD" "SRP" "3DES" "eNULL"];
      #enable TLS logging to see the ciphers for inbound connections
      smtpd_tls_loglevel = "1";
      #enable TLS logging to see the ciphers for outbound connections
      smtp_tls_loglevel = "1";

      smtp_dns_support_level = "dnssec";

      transport_maps = ''regexp:${pkgs.writeText "transport" ''
        /@(rpgs?|lists?|l)\.(.*\.)?(yggdrasil\.li|praseodym\.org|141\.li|xmpp\.li|kleen\.li|dirty-haskell\.org|nights\.email|yggdrasil|localdomain|localhost|ymir)$/ mlmmj:
        /@subs?\.(rpgs?|lists?|l)\.(.*\.)?(yggdrasil\.li|praseodym\.org|141\.li|xmpp\.li|kleen\.li|dirty-haskell\.org|nights\.email|yggdrasil|localdomain|localhost|ymir)$/ mlmmj-subs:
        /@odin(\.asgard\.yggdrasil)?$/ uucp:odin
      ''} regexp:/srv/mail/transport pipemap:{texthash:/srv/mail/discard,static:{discard:}}'';

      local_recipient_maps = "";

      luser_relay = ''gkleen+''${local}'';
      
      # 10 GiB
      message_size_limit = "10737418240";
      # 10 GiB
      mailbox_size_limit = "10737418240";

      mailbox_transport_maps = "pipemap:{unix:passwd.byname, static:{lmtp:unix:private/dovecot-lmtp}}";
      #mailbox_command = ${pkgs.dovecot}/libexec/dovecot/dovecot-lda -f "$SENDER" -a "$RECIPIENT"

      smtpd_sasl_type = "dovecot";
      smtpd_sasl_path = "private/dovecot-auth";

      smtpd_sasl_auth_enable = true;
      smtpd_sasl_security_options = ["noanonymous" "noplaintext"];
      smtpd_sasl_tls_security_options = "noanonymous";
      smtpd_tls_auth_only = true;

      smtpd_delay_reject = true;
      smtpd_helo_required = true;
      smtpd_helo_restrictions = "permit";

      smtpd_recipient_restrictions = [
        "reject_unauth_pipelining"
        "reject_non_fqdn_recipient"
        "reject_unknown_recipient_domain"
        "permit_mynetworks"
        "permit_sasl_authenticated"
        "reject_non_fqdn_helo_hostname"
        "reject_invalid_helo_hostname"
        "reject_unauth_destination"
        "reject_unknown_recipient_domain"
        "reject_unverified_recipient"
      ];

      smtpd_relay_restrictions = [
        "permit_mynetworks"
        "permit_sasl_authenticated"
        "reject_unauth_destination"
      ];

      mlmmj_destination_recipient_limit = "1";
      mlmmj-subs_destination_recipient_limit = "1";
      propagate_unmatched_extensions = ["canonical" "virtual" "alias"];
      smtpd_authorized_verp_clients = "$authorized_verp_clients";
      authorized_verp_clients = "$mynetworks";

      milter_default_action = "accept";
      smtpd_milters = ["local:/run/opendkim/opendkim.sock" "local:/run/rspamd/rspamd-milter.sock"];
      non_smtpd_milters = ["local:/run/opendkim/opendkim.sock" "local:/run/rspamd/rspamd-milter.sock"];

      alias_maps = ''texthash:${pkgs.writeText "aliases" ''
        postmaster gkleen
        webmaster gkleen
        abuse gkleen
        noc gkleen
        security gkleen
        hostmaster gkleen
        usenet gkleen
        news gkleen
        www gkleen
        uucp gkleen
        ftp gkleen
        root gkleen
      ''} texthash:/srv/mail/spm
      '';

      queue_run_delay = "10s";
      minimal_backoff_time = "1m";
      maximal_backoff_time = "10m";
      maximal_queue_lifetime = "100m";
      bounce_queue_lifetime = "20m";

      sender_canonical_maps = "tcp:localhost:10001";
      sender_canonical_classes = "envelope_sender";
      recipient_canonical_maps = "tcp:localhost:10002";
      recipient_canonical_classes = ["envelope_recipient" "header_recipient"];

      smtpd_discard_ehlo_keyword_address_maps = "cidr:${pkgs.writeText "esmtp_access" ''
        # Allow DSN requests from local subnet only
        192.168.0.0/16      silent-discard
        172.16.0.0/12       silent-discard
        10.0.0.0/8          silent-discard
        0.0.0.0/0           silent-discard, dsn
        fd00::/8            silent-discard
        ::/0                silent-discard, dsn
      ''}";

      recipient_bcc_maps = "texthash:/srv/mail/recip_bcc";
      sender_bcc_maps = "texthash:/srv/mail/sender_bcc";
    };
    masterConfig = {
      uucp = {
        type = "unix";
        private = true;
        privileged = true;
        chroot = false;
        command = "pipe";
        args = [ "flags=Fqhu" "user=uucp" ''argv=${config.security.wrapperDir}/uux -z -a $sender - $nexthop!rmail ($recipient)'' ];
      };
      mlmmj = {
        type = "unix";
        private = true;
        privileged = true;
        chroot = false;
        command = "pipe";
        args = [ "flags=XORhu" "user=mlmmj" ''argv=${pkgs.mlmmj}/bin/mlmmj-receive -F -L /srv/mail/lists/''${user} -s ''${sender} -e ''${extension}'' ];
      };
      mlmmj-subs = {
        type = "unix";
        private = true;
        privileged = true;
        chroot = false;
        command = "pipe";
        args = [ "flags=Fqhu" "user=mlmmj" ''argv=${pkgs.mlmmj-exposed}/bin/mlmmj-exposed /srv/mail/lists/''${user} ''${extension}'' ];
      };
    };
    networks = ["127.0.0.0/8" "[::ffff:127.0.0.0]/104" "[::1]/128" "10.141.0.0/16"];
  };

  services.postsrsd = {
    enable = true;
    domain = "srs.141.li";
    separator = "+";
    excludeDomains = [ ".yggdrasil.li" "yggdrasil.li"
                       ".praseodym.org" "praseodym.org"
                       ".141.li" "141.li"
                       ".xmpp.li" "xmpp.li"
                       ".kleen.li" "kleen.li"
                       ".nights.email" "nights.email"
                       ".lmu.li" "lmu.li"
                       ".dirty-haskell.org" "dirty-haskell.org"
                     ];
  };

  systemd.services."mlmmj-maintd" = {
    description = "mlmmj maintenance daemon";

    serviceConfig = {
      User = "mlmmj";
      Group = "mlmmj";
      ExecStart = "${pkgs.mlmmj}/bin/mlmmj-maintd -F -d /srv/mail/lists";
    };
  };

  services.opendkim = {
    enable = true;
    user = "postfix"; group = "postfix";
    socket = "local:/run/opendkim/opendkim.sock";
    domains = ''csl:${concatStringsSep "," myDomains}'';
    keyPath = "/var/lib/dkim/";
    selector = "ymir";
    configFile = builtins.toFile "opendkim.conf" ''
      Syslog true
      MTACommand ${config.security.wrapperDir}/sendmail
      LogResults true
    '';
  };

  services.dovecot2 = {
    enable = true;
    enableImap = true;
    enableLmtp = true;
    enablePop3 = false;
    enablePAM = false; # do that manualy
    sslServerCert = "/var/lib/acme/yggdrasil.li/fullchain.pem";
    sslServerKey = "/var/lib/acme/yggdrasil.li/key.pem";
    mailLocation = "maildir:~/mail:LAYOUT=index:UTF-8";
    modules = with pkgs; [ dovecot_pigeonhole ];
    protocols = [ "sieve" ];
    extraConfig = ''
      userdb {
        driver = passwd
      }

      passdb {
        driver = pam
        args = dovecot2

        result_success = continue-ok
      }

      passdb {
        driver = passwd-file
        args = /srv/mail/dovecot.passwd
      
        result_success = continue-ok
      }
    
      mail_plugins = $mail_plugins quota
      mailbox_list_index = yes
      postmaster_address = postmaster@yggdrasil.li
      recipient_delimiter = +
      auth_username_format = %Ln

      service auth {
        unix_listener /var/lib/postfix/queue/private/dovecot-auth {
          mode = 0600
          user = postfix
          group = postfix
        }
      }

      service lmtp {
        vsz_limit=1G

        unix_listener /var/lib/postfix/queue/private/dovecot-lmtp {
          mode = 0600
          user = postfix
          group = postfix
        }
      }

      protocol lmtp {
        mail_plugins = $mail_plugins sieve
      }

      protocol lda {
        mail_plugins = $mail_plugins sieve
      }

      namespace inbox {
        separator = /
        inbox = yes
        prefix = 
      }

      plugin {
        quota = maildir:User quota
        quota_rule = *:storage=5GB
        quota_rule2 = Trash:storage=+10%%
        quota_status_overquota = "552 5.2.2 Mailbox is full"
        quota_status_success = DUNNO
        quota_status_nouser = DUNNO
        quota_grace = 10%%
      }

      protocol imap {
        mail_max_userip_connections = 50
        mail_plugins = $mail_plugins imap_quota
      }

      service managesieve-login {
        inet_listener sieve {
          port = 4190
        }
      }

      plugin {
        sieve = file:~/sieve;active=~/.dovecot.sieve
        sieve_redirect_envelope_from = orig_recipient
      }
    '';
  };
  security.pam.services.dovecot2.text = ''
    auth requisite  pam_succeed_if.so user ingroup mail
    auth required   pam_unix.so audit
    account sufficient pam_unix.so
  '';
  users.groups."mail" = {};

  users.extraUsers."mlmmj" = {
    isSystemUser = true;
    group = "mlmmj";
    extraGroups = [ "mail" ];
  };

  users.extraGroups."mlmmj" = {};

  users.extraGroups."mladmin" = {
    members = [ "gkleen" ];
  };
  
  users.extraGroups."infinoted" = {
    members = [ "infinoted" "gitolite" ];
  };

  security.sudo.extraConfig = ''
    %mladmin ALL=(mlmmj) NOPASSWD: ALL
    %infinoted ALL=(infinoted) NOPASSWD: ALL
  '';

  security.polkit = {
      enable = true;
      extraConfig = ''
        polkit.addRule(function(action, subject) {
          if (    action.id == "org.freedesktop.systemd1.manage-units"
               && action.lookup("unit") == "infinoted.service"
               && subject.isInGroup("infinoted")
             ) {
              return polkit.Result.YES;
          }
        });
      '';
    };

  security.wrappers = { "newgrp".source = "${pkgs.shadow}/bin/newgrp"; };

  security.acme = {
    acceptTerms = true;
    certs = {
      "yggdrasil.li" = {
        group = "ssl";
        email = "phikeebaogobaegh@141.li";
        keyType = "rsa4096";
        dnsProvider = "rfc2136";
        credentialsFile = pkgs.writeText "rfc2136-credentials.env" ''
          RFC2136_NAMESERVER=202.61.241.61:53
          RFC2136_TSIG_ALGORITHM=hmac-sha256.
          RFC2136_TSIG_KEY=ymir_acme_key
          RFC2136_TSIG_SECRET_FILE=/etc/acme_tsig_secret
          RFC2136_TTL=0
          RFC2136_PROPAGATION_TIMEOUT=60
          RFC2136_POLLING_INTERVAL=2
          RFC2136_SEQUENCE_INTERVAL=1
        '';
        dnsResolver = "127.0.0.1";
        extraDomainNames = [
          "dirty-haskell.org" "*.dirty-haskell.org"
          "141.li" "*.141.li"
          "xmpp.li" "*.xmpp.li"
          "*.yggdrasil.li"
          "praseodym.org" "*.praseodym.org"
          "kleen.li" "*.kleen.li"
          "nights.email" "*.nights.email"
        ];
        postRun = ''
          systemctl try-reload-or-restart nginx.service dovecot2.service postfix.service vsftpd.service infinoted.service
        '';
      };
    };
  };

  systemd.services."acme-yggdrasil.li" = {
    requires = [ "nginx.service" ]; 
    serviceConfig = {
      ReadWritePaths = [ "/srv/www/acme" ];
      RuntimeDirectory = [ "nginx/webdav" ];
      RuntimeDirectoryMode = "0700";
    };
  };
  systemd.tmpfiles.rules
    = let mkAcmeDir = domain: "d /srv/www/acme 0775 root ssl 10d -";
      in map mkAcmeDir myDomains ++ [
        "L /etc/nixos - - - - /root/nixos"
      ];

  services.uucp = {
    enable = true;
    nodeName = "ymir";
    remoteNodes = {
      "odin" = {
        publicKeys = ["ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIKT/BsAMLJs9NYhKIso4J3EF+VzRBm3c+qCQ5ONKc/1s uucp@odin"];
        hostnames = ["odin.asgard.yggdrasil"];
      };
      "hel" = {
        publicKeys = ["ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOWBybBQKbPucqBgULQ1phv7IKFWl1Xc4drkCx3D5mIz uucp@hel"];
        hostnames = ["hel.midgard.yggdrasil"];
      };
      "sif" = {
        publicKeys = ["ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAINDLcU8Qi+Ogu+jBSd4hJ5XO6HhRYs6/Y4mVAtTwdime root@sif"];
        hostnames = ["sif.midgard.yggdrasil"];
      };
    };

    commandPath = ["${pkgs.rmail}/bin" "${pkgs.push2bin}/bin" "${pkgs.rspamd}/bin"];
    defaultCommands = ["rmail" "push2bin" "rspamc"];
  };

  services.atd = {
    enable = true;
  };

  users.groups."filebin" = {
    members = ["gkleen" "uucp"];
  };

  services.nsd = {
    enable = false;
    verbosity = 3;
    interfaces = [ "10.142.0.3" "188.68.51.254" "2a03:4000:6:d004::" ];
    ipTransparent = true;
    remoteControl = {
      enable = true;
    };
    zones = {
      "inwx" = {
        notify = [ "185.181.104.96 NOKEY"
                 ];
        provideXFR = [ "185.181.104.96 NOKEY"
                     ];
        outgoingInterface = "188.68.51.254";
        children = dnsZones;
        dnssec = true;
        dnssecPolicy = {
          coverage = "2mo";
        };
      };
    };
  };

  services.unbound = {
    enable = true;
    allowedAccess = ["127.0.0.0/8" "::ffff:127.0.0.0/104" "::1/128" "10.141.0.0/16"];
    interfaces = ["127.0.0.1" "::1" "10.141.5.1"];
  };

  services.dhcpd4 = {
    enable = true;
    interfaces = [ "yggdrasil" ];
    machines = [
      { hostName = "hel"; ethernetAddress = "ee:10:15:9a:cc:1f"; ipAddress = "hel.midgard.yggdrasil"; }
      { hostName = "sif"; ethernetAddress = "5c:93:21:c3:61:39"; ipAddress = "sif.midgard.yggdrasil"; }
    ];
    extraConfig = ''
      option rfc3442-classless-static-routes code 121 = array of integer 8;
      option ms-classless-static-routes code 249 = array of integer 8;

      subnet 10.141.0.0 netmask 255.255.0.0 {
        range 10.141.255.0 10.141.255.254;

        option rfc3442-classless-static-routes 24, 10, 141, 4, 10, 141, 1, 5, 24, 10, 141, 1, 10, 141, 1, 1, 24, 192, 168, 178, 10, 141, 1, 1;
        option ms-classless-static-routes 24, 10, 141, 4, 10, 141, 1, 5, 24, 10, 141, 1, 10, 141, 1, 1, 24, 192, 168, 178, 10, 141, 1, 1;

        option domain-name "yggdrasil";
        option domain-name-servers 8.8.8.8, 8.8.4.4, 192.168.178.1;
      }
    '';
  };

  services.infinoted = {
    enable = true;
    keyFile = "/var/lib/acme/yggdrasil.li/key.pem";
    certificateFile = "/var/lib/acme/yggdrasil.li/fullchain.pem";
    plugins = [ "note-text" "note-chat" "logging" "autosave" "certificate-auth" "directory-sync" ];
    extraConfig = ''
      [certificate-auth]
      ca-list=/var/lib/infinoted/ca.cert.pem
      ca-key=/var/lib/infinoted/ca.key.pem
      accept-unauthenticated-clients=true

      [autosave]
      interval=5

      [directory-sync]
      directory=/var/lib/infinoted/dirsync
      interval=5
      hook=${pkgs.writeScript "git-sync.sh" ''
        #!${pkgs.zsh}/bin/zsh

        git -C ''${2:h} rev-parse --is-inside-work-tree &>/dev/null || exit 0

        repository=$(git -C ''${2:h} rev-parse --show-toplevel)
        [[ $? -ne 0 ]] && exit $?

        git() {
            $(whence -cp git) -C ''${repository} ''${@}
        }

        typeset -a changeSet
        changeSet=()
        git diff -z --name-only | \
            while IFS= read -r -d $'\0' change; do changeSet=(''${changeSet} ''${change}); done

        [[ ''${changeSet[(i)$(realpath ''${2} --relative-to=''${repository})]} -le ''${#changeSet} ]] || exit 0

        commitMessage=$(printf "%s modified via infinoted" $(realpath ''${2} --relative-to=''${repository}))
        git add ''${2}
        git commit -m ''${commitMessage} --no-edit ''${2}
        git push
      ''}
    '';
  };

  systemd.services."infinoted".serviceConfig.ExecReload = "${pkgs.coreutils}/bin/kill -HUP $MAINPID";

  users.extraUsers."infinoted" = {
    isSystemUser = true;
  };

  services.haveged = {
    enable = true;
  };

  system.autoUpgrade.enable = true;
  system.stateVersion = "17.09";

  systemd.services."nixos-upgrade".path = with pkgs; [ git ];
  systemd.services."nixos-upgrade".preStart = ''
    git -C /etc/nixos pull
    git -C /etc/nixos submodule update
  '';

  systemd.status-mail = {
    onFailure = [ "nixos-upgrade" "postfix" "dovecot2" "opendkim" "unbound" "tinc@yggdrasil" "postsrsd" ];
  };

  services.vsftpd = {
    enable = true;
    forceLocalLoginsSSL = true;
    forceLocalDataSSL = true;
    localUsers = true;
    writeEnable = true;
    chrootlocalUser = true;
    rsaKeyFile = "/var/lib/acme/yggdrasil.li/key.pem";
    rsaCertFile = "/var/lib/acme/yggdrasil.li/fullchain.pem";
    extraConfig = ''
      log_ftp_protocol=YES
      ssl_ciphers=HIGH:!aNULL:!eNULL:!NULL

      local_umask=022
    
      log_ftp_protocol=NO
      xferlog_enable=YES
    
      pam_service_name=vsftpd

      port_enable=NO

      pasv_enable=YES
      pasv_max_port=21000
      pasv_min_port=20000

      allow_writeable_chroot=YES

      guest_enable=YES
      guest_username=vsftpd
      virtual_use_local_privs=YES
      user_sub_token=$USER
      local_root=/srv/ftp/$USER
      hide_ids=YES
    '';
  };

  systemd.services."vsftpd".serviceConfig.ExecReload = "${pkgs.coreutils}/bin/kill -HUP $MAINPID";

  security.pam.services."vsftpd".text = ''
    auth required ${pkgs.pam_pwdfile}/lib/security/pam_pwdfile.so pwdfile=/srv/ftp.htpasswd
    account required pam_permit.so
  '';

  users.extraUsers."vsftpd" = {
    home = mkForce "/srv/ftp";
    extraGroups = [ "ssl" ];
  };

  security.dhparams = {
    enable = true;
    stateful = false;
    params = {
      nginx.bits = 3072;
      "postfix-512".bits = 512;
      "postfix-1024".bits = 1024;
      "dovecot2".bits = 2048;
    };
  };

  services.rspamd = {
    enable = true;
    workers = {
      controller = {};
      external = {
        type = "rspamd_proxy";
        bindSockets = [
          { mode = "0660";
            socket = "/run/rspamd/rspamd-milter.sock";
            owner = config.services.rspamd.user;
            group = config.services.rspamd.group;
          }
        ];
        extraConfig = ''
          milter = yes;

          upstream "local" {
            default = yes;
            self_scan = yes;
          }
        '';
      };
      internal = {
        type = "rspamd_proxy";
        bindSockets = [
          "ymir.niflheim.yggdrasil:11332"
        ];
        extraConfig = ''
          milter = yes;

          upstream "local" {
            default = yes;
            self_scan = yes;
            settings_id = "internal";
          }
        '';
      };
    };
    locals = {
      "milter_headers.conf".text = ''
        use = ["authentication-results", "x-spamd-result", "x-rspamd-queue-id", "x-rspamd-server", "x-spam-level", "x-spam-status"];
        extended_headers_rcpt = ["@odin.asgard.yggdrasil"];
      '';
      "actions.conf".text = ''
        reject = 15;
        add_header = 10;
        greylist = 5;
      '';
      "groups.conf".text = ''
        symbols {
          "BAYES_SPAM" {
            weight = 2.0;
          }
        }
      '';
      "dmarc.conf".text = ''
        reporting = true;
        send_reports = true;
        report_settings {
          org_name = "Yggdrasil.li";
          domain = "yggdrasil.li";
          email = "postmaster@yggdrasil.li";
        }
      '';
      "redis.conf".text = ''
        servers = "localhost";
      '';
      "dkim_signing.conf".text = "enabled = false;";
      "neural.conf".text = "enabled = false;";
      "classifier-bayes.conf".text = ''
        enable = true;
        expire = 8640000;
        new_schema = true;
        backend = "redis";
        per_user = true;
        min_learns = 0;

        autolearn = [0, 10];
        
        statfile {
            symbol = "BAYES_HAM";
            spam = false;
        }
        statfile {
            symbol = "BAYES_SPAM";
            spam = true;
        }
      '';
      "settings.conf".text = ''
        internal {
          priority = high;

          apply {
            milter_headers {
              skip_local = false;
              skip_authenticated = false;
              authenticated_headers = ["authentication-results", "x-spamd-result", "x-rspamd-queue-id", "x-rspamd-server", "x-spam-level", "x-spam-status"];
            }

            actions {
              reject = null;
              greylist = null;
              add_header = 10;
            }

            rules_disabled = ["FORGED_RECIPIENTS", "RCVD_NO_TLS_LAST"];
          }
        }
      '';
      "redirectors.inc".text = ''
        visit.creeper.host
      '';
    };
  };

  systemd.services.rspamd = {
    requires = [ "redis.service" ];
    bindsTo = [ "redis.service" ];
  };

  services.redis = {
    enable = true;
    vmOverCommit = true;
    bind = "127.0.0.1 ::1";
  };

  services.qemuGuest.enable = true;

  systemd.services."borgbackup@" = {
    path = with pkgs; [ lvm2 borgbackup utillinux (python3.withPackages (p: with p; [dateutil python-unshare])) ];

    serviceConfig = {
      ExecStart = "${./snap.py} %I";
      ExecCondition = "${pkgs.stdenv.shell} -c \"! systemctl is-active 'borgbackup@*.service' | ${pkgs.gnugrep}/bin/grep -q activating\"";
      Environment = [
        "BORG_CACHE_DIR=/var/lib/borg/cache"
      ];
      Type = "oneshot";
      Nice = 15;
      IOSchedulingClass = 2;
      IOSchedulingPriority = 7;
      SuccessExitStatus = [0 1];
      LogRateLimitIntervalSec = 0;
    };
  };
  systemd.timers = {
    "mlmmj-maintd" = {
      description = "run mlmmj maintenance daemon";
      wantedBy = [ "multi-user.target" ];

      timerConfig = {
        OnActiveSec = "10m";
        OnUnitActiveSec = "10m";
      };
    };
  } // listToAttrs (map (t: nameValuePair "borgbackup@${t}" {
    requiredBy = ["multi-user.target"];

    timerConfig = {
      Persistent = false;
      OnCalendar = "*-*-* 01/6:00:00 Europe/Berlin";
      RandomizedDelaySec = "1h";
    };
  }) ["ymir-home" "ymir-root" "ymir-root\\x2dhome" "ymir-srv"]);
}