%% Copyright (c) 2021 Robert Virding
%%
%% 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.

%% File    : lfe_shell_docs.erl
%% Author  : Robert Virding
%% Purpose : Render LFE docs for output in shell.

%% The interface is loosely modelled on the shell_docs module.

-module(lfe_shell_docs).

-export([render/2,render/3,render/4]).

-include("lfe.hrl").
-include("lfe_docs.hrl").

%% Coloured strings for the LFE banner, red, green, yellow and blue.
-define(RED(Str), "\e[31m" ++ Str ++ "\e[0m").
-define(GRN(Str), "\e[1;32m" ++ Str ++ "\e[0m").
-define(YLW(Str), "\e[1;33m" ++ Str ++ "\e[0m").
-define(BLU(Str), "\e[1;34m" ++ Str ++ "\e[0m").

%% render(Module, Docs) -> unicode:chardata().

render(Bin, Docs) when is_binary(Bin) ->
    {ok,{Mod,_}} = beam_lib:chunks(Bin, [], []), %Sneaky!
    render(Mod, Docs);
render(Mod, #docs_v1{format = ?LFE_FORMAT, module_doc=Mdoc}) ->
    [lfe_io:format1(?BLU("~p")++"\n\n", [Mod]), return_doc(Mdoc)].

%% render(Module, Function, Docs) -> unicode:chardata().

render(_Mod, Name, #docs_v1{format = ?LFE_FORMAT, docs = Docs}) ->
    Fns = [ F || {{_,N,_},_,_,_,_}=F <- Docs, N =:= Name ],
    Ret = lists:map(fun ({{function,_,_},_,Sig,Doc,_}) ->
			    [lfe_io:format1(?BLU("defun ~s")++"\n\n", [Sig]),
			     return_doc(Doc)];
			({{macro,_,_},_,Sig,Doc,_}) ->
			    [lfe_io:format1(?BLU("defmacro ~s")++"\n\n", [Sig]),
			     return_doc(Doc)]
		    end, Fns),
    return_render(Ret, function_missing).

%% render(Module, Function, Arity, Docs) -> unicode:chardata().

render(_Mod, Name, Arity, #docs_v1{format = ?LFE_FORMAT, docs = Docs}) ->
    Fns = [ F || {{function,N,A},_,_,_,_}=F <- Docs, N =:= Name, A =:= Arity ],
    Ret = lists:map(fun ({{function,_,_},_,Sig,Doc,_}) ->
			    [lfe_io:format1(?BLU("defun ~s")++"\n\n", [Sig]),
			     return_doc(Doc)]
		    end, Fns),
    return_render(Ret, function_missing).

return_doc(#{<<"en">> := Dv}) -> lfe_io:format1("~s\n\n", [Dv]);
return_doc(_) -> "\n".

return_render([], Error) -> {error,Error};
return_render(FDocs, _Error) -> FDocs.