%% @author Marc Worrell <marc@worrell.nl>
%% @copyright 2012-2020 Marc Worrell
%% @doc Format a resource record for a browser diff function.

%% Copyright 2012-2020 Marc Worrell
%%
%% 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(admin_rsc_diff).

-export([
    format/3
    ]).

% These fields are shown in this order, any other fields are shown after these.
-define(FIELDS, [
    <<"title">>,

    <<"category_id">>,
    <<"creator_id">>,
    <<"modifier_id">>,

    <<"created">>,
    <<"modified">>,

    <<"publication_start">>,
    <<"publication_end">>,
    <<"org_pubdate">>,

    <<"is_published">>,
    <<"is_featured">>,
    <<"is_protected">>,
    <<"is_dependent">>,

    <<"visible_for">>,
    <<"content_group_id">>,

    <<"language">>,

    <<"chapeau">>,
    <<"subtitle">>,
    <<"short_title">>,
    <<"summary">>,

    <<"name_prefix">>,
    <<"name_first">>,
    <<"name_surname_prefix">>,
    <<"name_surname">>,

    <<"phone">>,
    <<"phone_mobile">>,
    <<"phone_alt">>,
    <<"phone_emergency">>,

    <<"email">>,
    <<"website">>,
    <<"is_website_redirect">>,

    <<"date_start">>,
    <<"date_end">>,
    <<"date_remarks">>,
    <<"date_is_all_day">>,

    <<"address_street_1">>,
    <<"address_street_2">>,
    <<"address_city">>,
    <<"address_state">>,
    <<"address_postcode">>,
    <<"address_country">>,

    <<"mail_street_1">>,
    <<"mail_street_2">>,
    <<"mail_city">>,
    <<"mail_state">>,
    <<"mail_postcode">>,
    <<"mail_country">>,

    <<"location_lng">>,
    <<"location_lat">>,

    <<"body">>,
    <<"body_extra">>,
    <<"blocks">>,

    <<"uri">>,
    <<"page_path">>,
    <<"is_page_path_multiple">>,
    <<"name">>,

    <<"seo_noindex">>,
    <<"slug">>,
    <<"custom_slug">>,
    <<"seo_desc">>
]).

-include_lib("zotonic_core/include/zotonic.hrl").

format(L, B, Context) when is_list(L) ->
    format(z_props:from_props(L), B, Context);
format(A, L, Context) when is_list(L) ->
    format(A, z_props:from_props(L), Context);
format(undefined, B, Context) ->
    format(#{}, B, Context);
format(A, undefined, Context) ->
    format(A, #{}, Context);
format(A, B, Context) when is_map(A), is_map(B) ->
    AllKeys = lists:usort( maps:keys(A) ++ maps:keys(B) ),
    Extra = AllKeys -- ?FIELDS,
    Ks = lists:reverse(?FIELDS ++ Extra),
    fetch(Ks, A, B, [], Context).

fetch([], _A, _B, Acc, _Context) ->
    Acc;
fetch([K|Ks], MapA, MapB, Acc, Context) ->
    A = normalize(K, maps:get(K, MapA, undefined)),
    B = normalize(K, maps:get(K, MapB, undefined)),
    case A of
        B ->
            fetch(Ks, MapA, MapB, Acc, Context);
        _ ->
            case {format_value(K, A, Context),
                  format_value(K, B, Context)}
            of
                {X,X} ->
                    fetch(Ks, MapA, MapB, Acc, Context);
                {FA,FB} ->
                    Acc1 = [ {K, FA, FB} | Acc ],
                    fetch(Ks, MapA, MapB, Acc1, Context)
            end
    end.

normalize(_K, #trans{ tr = Tr }) -> #trans{ tr = lists:sort(Tr) };
normalize(<<"language">>, L) when is_list(L) -> lists:sort(L);
normalize(_K, V) -> V.

format_value(_K, undefined, _Context) ->
    <<>>;
format_value(_K, <<>>, _Context) ->
    <<>>;
format_value(_K, [], _Context) ->
    <<>>;
format_value(_K, #trans{ tr = [] }, _Context) ->
    <<>>;
format_value(_K, {{_,_,_},{_,_,_}} = V, Context) ->
    z_datetime:format(V, "Y-m-d H:i:s", Context);
format_value(uri, Uri, _Context) when is_binary(Uri) ->
    z_html:escape(Uri);
format_value(_K, V, _Context) when is_binary(V) ->
    V;
format_value(<<"category_id">>, Id, Context) ->
    by_id(Id, Context);
format_value(<<"creator_id">>, Id, Context) ->
    by_id(Id, Context);
format_value(<<"modifier_id">>, Id, Context) ->
    by_id(Id, Context);
format_value(<<"rsc_id">>, Id, Context) ->
    by_id(Id, Context);
format_value(<<"content_group_id">>, Id, Context) ->
    by_id(Id, Context);
format_value(<<"blocks">>, Blocks, Context) when is_list(Blocks) ->
    format_blocks(Blocks, Context);
format_value(<<"blocks">>, _, _Context) ->
    <<>>;
format_value(_, #trans{ tr = Tr }, _Context) ->
    iolist_to_binary([
        [ z_convert:to_binary(Iso), $:, 32, V, <<"\n">> ]
        || {Iso, V} <- Tr, is_binary(V), V =/= <<>>
    ]);
format_value(_K, V, _Context) when is_tuple(V) ->
    z_html:escape(iolist_to_binary(io_lib:format("~p", [V])));
format_value(_K, V, Context) when is_list(V) ->
    iolist_to_binary(
        lists:join(
            ", ",
            [ format_value(none, A, Context) || A <- V ]));
format_value(_K, M, _Context) when is_map(M) ->
    iolist_to_binary(io_lib:format("~p", [ M ]));
format_value(_K, A, _Context) ->
    try
        z_convert:to_binary(A)
    catch
        _:_ -> iolist_to_binary(io_lib:format("~p", [ A ]))
    end.


by_id(Id, Context) when is_integer(Id) ->
    iolist_to_binary([
        z_trans:lookup_fallback(m_rsc:p(Id, title, Context), Context),
        32,
        $(, integer_to_list(Id), $)
    ]).


format_blocks(Blocks, Context) ->
    iolist_to_binary(lists:join("\n\n--\n\n", [ format_block(B, Context) || B <- Blocks ])).

format_block(B, Context) when is_map(B) ->
    format_block(lists:sort( maps:to_list(B) ), Context);
format_block(B, Context) ->
    iolist_to_binary(lists:join(
            "\n",
            [
                iolist_to_binary([z_convert:to_binary(K), ": ", format_value(K,V,Context)])
                || {K,V} <- B
            ])).