%%--------------------------------------------------------------------
%% Copyright (c) 2020-2022 EMQ Technologies Co., Ltd. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%%     http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%--------------------------------------------------------------------

-module(emqx_lwm2m_xml_object).

-include("emqx_lwm2m.hrl").
-include_lib("xmerl/include/xmerl.hrl").

-export([ get_obj_def/2
        , get_obj_def_assertive/2
        , get_object_id/1
        , get_object_name/1
        , get_object_and_resource_id/2
        , get_resource_type/2
        , get_resource_name/2
        , get_resource_operations/2
        ]).

-define(LOG(Level, Format, Args),
    logger:Level("LWM2M-OBJ: " ++ Format, Args)).

get_obj_def_assertive(ObjectId, IsInt) ->
    case get_obj_def(ObjectId, IsInt) of
        {error, no_xml_definition} ->
            erlang:throw({bad_request, {unknown_object_id, ObjectId}});
        Xml ->
            Xml
    end.

get_obj_def(ObjectIdInt, true) ->
    emqx_lwm2m_xml_object_db:find_objectid(ObjectIdInt);
get_obj_def(ObjectNameStr, false) ->
    emqx_lwm2m_xml_object_db:find_name(ObjectNameStr).

get_object_id(ObjDefinition) ->
    [#xmlText{value=ObjectId}] = xmerl_xpath:string("ObjectID/text()", ObjDefinition),
    ObjectId.

get_object_name(ObjDefinition) ->
    [#xmlText{value=ObjectName}] = xmerl_xpath:string("Name/text()", ObjDefinition),
    ObjectName.


get_object_and_resource_id(ResourceNameBinary, ObjDefinition) ->
    ResourceNameString = binary_to_list(ResourceNameBinary),
    [#xmlText{value=ObjectId}] = xmerl_xpath:string("ObjectID/text()", ObjDefinition),
    [#xmlAttribute{value=ResourceId}] = xmerl_xpath:string("Resources/Item/Name[.=\""++ResourceNameString++"\"]/../@ID", ObjDefinition),
    ?LOG(debug, "get_object_and_resource_id ObjectId=~p, ResourceId=~p", [ObjectId, ResourceId]),
    {ObjectId, ResourceId}.


get_resource_type(ResourceIdInt, ObjDefinition) ->
    ResourceIdString = integer_to_list(ResourceIdInt),
    [#xmlText{value=DataType}] = xmerl_xpath:string("Resources/Item[@ID=\""++ResourceIdString++"\"]/Type/text()", ObjDefinition),
    DataType.

get_resource_name(ResourceIdInt, ObjDefinition) ->
    ResourceIdString = integer_to_list(ResourceIdInt),
    [#xmlText{value=Name}] = xmerl_xpath:string("Resources/Item[@ID=\""++ResourceIdString++"\"]/Name/text()", ObjDefinition),
    Name.

get_resource_operations(ResourceIdInt, ObjDefinition) ->
    ResourceIdString = integer_to_list(ResourceIdInt),
    [#xmlText{value=Operations}] = xmerl_xpath:string("Resources/Item[@ID=\""++ResourceIdString++"\"]/Operations/text()", ObjDefinition),
    Operations.