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

let
  inherit (lib) types;

  cfg = config.services.lldap;
  format = pkgs.formats.json { };

  # helpers
  _configFile = {
    user_attributes = lib.mapAttrsToList (n: v: v) cfg.provision.user_attributes;
    group_attributes = lib.mapAttrsToList (n: v: v) cfg.provision.group_attributes;
    users = lib.mapAttrsToList (n: v: v) cfg.provision.users;
    groups = lib.mapAttrsToList (n: v: v) cfg.provision.groups;
    # users = lib.mapAttrsToList (n: v: v // {
    #   user_id = if v ? user_id then v.user_id else n;
    # }) cfg.users;
    # groups = lib.mapAttrsToList (n: v: v // {
    #   display_name = if v ? display_name then v.display_name else n;
    # }) cfg.groups;
  };
  configFile = format.generate "lldap-declarative.json" _configFile;

  # opts
  optsAttributes = { name, config, ... }: {
    options = {
      name = lib.mkOption {
        type = types.str;
        default = name;
        description = "The name of the attribute";
      };

      attributeType = lib.mkOption {
        type = types.enum [ "STRING" "INTEGER" "JPEG_PHOTO" "DATE_TIME" ];
        description = "Type of the attribute";
      };

      isList = lib.mkOption {
        type = types.bool;
        default = false;
        description = "Is this attribute a list (multiple values for this attribute)";
      };

      isEditable = lib.mkOption {
        type = types.bool;
        default = false;
        description = "Should the user be able to edit this value?";
      };

      isVisible = lib.mkOption {
        type = types.bool;
        default = false;
        description = "Should the user be able to see this value?";
      };
    };
  };

  optsUser = { name, config, ... }: {
    freeformType = format.type;
    options = {
      user_id = lib.mkOption {
        type = types.str;
        default = name;
        description = "The name of the user";
      };
    };
  };

  optsGroup = { name, config, ... }: {
    freeformType = format.type;
    options = {
      display_name = lib.mkOption {
        type = types.str;
        default = name;
        description = "The display name of the group";
      };
    };
  };
    
in {
  options = {
    services.lldap = {
      provisionUsername = lib.mkOption {
        type = types.str;
        description = "Username to use when signing into lldap";
      };

      provisionPasswordFile = lib.mkOption {
        type = types.path;
        description = "Path for the password file to authenticate the user";
      };

      provision = {
        group_attributes = lib.mkOption {
          type = types.attrsOf (types.submodule optsAttributes);
          default = {};
        };
  
        user_attributes = lib.mkOption {
          type = types.attrsOf (types.submodule optsAttributes);
          default = {};
        };
  
        users = lib.mkOption {
          type = types.attrsOf (types.submodule optsUser);
          default = {};
          example = {
            user1 = {
              password = "env:LLDAP_USER1_PASSWORD";
              mail = "something@something.dk";
  
              foo = "value for user attribute foo";
              bar = "value for user attribute bar";
              groups = [ "group1" "group2" ];
            };
            user2 = { user_id = "superuserawesome"; };
          };
        };
  
        groups = lib.mkOption {
          type = types.attrsOf (types.submodule optsGroup);
          default = {};
          example = {
            base_member = {
              foo = "value for group attribute foo";
              bar = "value for group attribute bar";
            };
            system = {
              display_name = "system_service - override display_name";
            };
            testgroup = {};
          };
        };
      };
    };
  };

  config = lib.mkIf (cfg.enable && cfg.provision != {}) {
    systemd.services.lldapsetup = {
      description = "setup lldap declaratively";
      wantedBy = [ config.systemd.services.lldap.name "multi-user.target" ];
      after = [ config.systemd.services.lldap.name ];
  
      environment = {
        LLDAP_URL = "${cfg.settings.http_url}:${builtins.toString cfg.settings.http_port}";
        LLDAP_USERNAME = cfg.provisionUsername;
        LLDAP_PASSWORD = "file:${cfg.provisionPasswordFile}";
      };

      path = with pkgs; [
        lldap
      ];

      script = let
          pythonEnv = pkgs.python3.withPackages(ps: with ps; [ gql aiohttp requests ]);
          pythonDir = pkgs.runCommand "lldap-bootstrap" {} ''
            mkdir -p $out/bootstrap
            cp -a ${./bootstrap}/. $out/bootstrap
          '';
      in ''
        cd ${pythonDir}
        ${pythonEnv}/bin/python -m bootstrap.main ${configFile}
      '';
    };
  };
}