/*
Gonna use a priper nixos module for this
*/
{
  config,
  pkgs,
  lib,
  inputs,
  ...
}:
with lib; let
  cfg = config.services.skynet_ldap;
  domain = "${cfg.domain.sub}.${cfg.domain.base}.${cfg.domain.tld}";
in {
  # these are needed for teh program in question
  imports = [
    ../acme.nix
    ../dns.nix
    ../nginx.nix
    ./backend.nix
  ];

  options.services.skynet_ldap = {
    # options that need to be passed in to make this work

    enable = mkEnableOption "Skynet LDAP service";

    host = {
      ip = mkOption {
        type = types.str;
      };

      name = mkOption {
        type = types.str;
      };
    };

    domain = {
      tld = mkOption {
        type = types.str;
        default = "ie";
      };

      base = mkOption {
        type = types.str;
        default = "skynet";
      };

      sub = mkOption {
        type = types.str;
        default = "account";
      };
    };

    frontend.port = mkOption {
      type = types.port;
      default = 8888;
    };

    base = mkOption {
      type = types.str;
      default = "dc=skynet,dc=ie";
    };
  };

  config = mkIf cfg.enable {
    # passthrough to the backend
    services.ldap_backend = {
      enable = true;
      host.ip = cfg.host.ip;
      host.name = cfg.host.name;
    };

    # after changing teh password openldap.service has to be restarted
    age.secrets.ldap_pw = {
      file = ../../secrets/ldap/pw.age;
      mode = "440";
      owner = "openldap";
      group = "openldap";
    };

    skynet_acme.domains = [
      domain
    ];

    skynet_dns.records = [
      {
        record = cfg.domain.sub;
        r_type = "CNAME";
        value = cfg.host.name;
      }
    ];

    # firewall on teh computer itself
    networking.firewall.allowedTCPPorts = [
      389
      636
    ];

    services.nginx.virtualHosts = {
      ${domain} = {
        forceSSL = true;
        useACMEHost = "skynet";
        locations."/" = {
          root = "${inputs.skynet_ldap_frontend.defaultPackage."x86_64-linux"}";
          # https://stackoverflow.com/a/38238001
          extraConfig = ''
            if ($request_uri ~ ^/(.*)\.html) {
              return 302 /$1;
            }
            try_files $uri $uri.html $uri/ =404;
          '';
        };
      };
    };

    # using https://nixos.wiki/wiki/OpenLDAP for base config

    systemd.services.openldap = {
      wants = ["acme-${cfg.domain.base}.service"];
      after = ["acme-${cfg.domain.base}.service"];
    };

    users.groups.acme.members = ["openldap"];

    services.openldap = {
      # backup /var/lib/openldap/slapd.d

      enable = true;

      /*
      enable plain and secure connections
      */
      urlList = ["ldap:///" "ldaps:///"];

      settings = {
        attrs = {
          olcLogLevel = "conns config";

          /*
          settings for acme ssl
          */
          olcTLSCACertificateFile = "/var/lib/acme/${cfg.domain.base}/full.pem";
          olcTLSCertificateFile = "/var/lib/acme/${cfg.domain.base}/cert.pem";
          olcTLSCertificateKeyFile = "/var/lib/acme/${cfg.domain.base}/key.pem";
          # got teh ciphers from https://access.redhat.com/articles/1474813
          # the ones provided on the nixos page didnt work
          olcTLSCipherSuite = "ECDHE-RSA-AES256-SHA384:AES256-SHA256:!RC4:HIGH:!MD5:!aNULL:!EDH:!EXP:!SSLV2:!eNULL";
          olcTLSCRLCheck = "none";
          olcTLSVerifyClient = "never";
          olcTLSProtocolMin = "3.3";

          # make it so it can return up to 2000 results ar once, more than twice our total records for users
          olcSizeLimit = "2000";
        };

        children = {
          "cn=schema".includes = [
            "${pkgs.openldap}/etc/schema/core.ldif"
            "${pkgs.openldap}/etc/schema/cosine.ldif"
            "${pkgs.openldap}/etc/schema/inetorgperson.ldif"
            "${pkgs.openldap}/etc/schema/nis.ldif"
            ./openssh-lpk.ldif
            ./skMemberOf.ldif
          ];

          "cn=modules".attrs = {
            objectClass = ["olcModuleList"];
            cn = "modules";
            olcModuleLoad = ["dynlist" "memberof" "refint" "pw-sha2"];
          };

          "olcDatabase={-1}frontend".attrs = {
            objectClass = ["olcDatabaseConfig" "olcFrontendConfig"];

            olcPasswordHash = "{SSHA512}";
          };

          "olcDatabase={1}mdb" = {
            attrs = {
              objectClass = ["olcDatabaseConfig" "olcMdbConfig"];

              olcDatabase = "{1}mdb";
              olcDbDirectory = "/var/lib/openldap/data";

              olcSuffix = cfg.base;

              /*
              your admin account, do not use writeText on a production system
              */
              olcRootDN = "cn=admin,${cfg.base}";
              olcRootPW.path = config.age.secrets.ldap_pw.path;

              olcAccess = [
                /*
                custom access rules for userPassword attributes
                */
                ''
                  {0}to attrs=userPassword
                    by dn.exact="uid=ldap_api,ou=users,dc=skynet,dc=ie" manage
                    by self write
                    by anonymous auth
                    by * none
                ''

                ''
                  {1}to attrs=mail,sshPublicKey,cn,sn
                    by dn.exact="uid=ldap_api,ou=users,dc=skynet,dc=ie" manage
                    by self write
                    by * read
                ''

                /*
                allow read on anything else
                */
                ''
                  {2}to *
                    by dn.exact="uid=ldap_api,ou=users,dc=skynet,dc=ie" manage
                    by * read
                ''
              ];
            };

            # https://blog.oddbit.com/post/2013-07-22-generating-a-membero/
            children = {
              "olcOverlay=dynlist".attrs = {
                objectClass = ["olcOverlayConfig" "olcDynamicList"];
                olcOverlay = "dynlist";
                olcDlAttrSet = "skPerson labeledURI skMemberOf";
              };

              "olcOverlay=memberof".attrs = {
                objectClass = ["olcOverlayConfig" "olcMemberOf" "olcConfig" "top"];
                olcOverlay = "memberof";

                olcMemberOfDangling = "ignore";
                olcMemberOfRefInt = "TRUE";
                olcMemberOfGroupOC = "groupOfNames";
                olcMemberOfMemberAD = "member";
                olcMemberOfMemberOfAD = "memberOf";
              };
            };
          };
        };
      };
    };
  };
}