%% @author author <author@example.com>
%% @copyright YYYY author.

%% @doc Web server for test.

-module(test_web).
-author('author <author@example.com>').

-export([start/1, stop/0, loop/2]).

%% External API

start(Options) ->
    {DocRoot, Options1} = get_option(docroot, Options),
    Loop = fun (Req) ->
                   ?MODULE:loop(Req, DocRoot)
           end,
    mochiweb_http:start([{name, ?MODULE}, {loop, Loop} | Options1]).

stop() ->
    mochiweb_http:stop(?MODULE).

loop(Req, DocRoot) ->
    "/" ++ Path = Req:get(path),
    case Req:get(method) of
        Method when Method =:= 'GET'; Method =:= 'HEAD' ->
            case Path of
                "timer" ->	%% 新增了 /timer 这个 URL，它是一个 HTTP Chunked 的例子
                    Response = Req:ok({"text/plain", chunked}),
                    timer(Response);
                _ ->
                    Req:serve_file(Path, DocRoot)
            end;
        'POST' ->
            case Path of
                _ ->
                    Req:not_found()
            end;
        _ ->
            Req:respond({501, [], []})
    end.

%% Internal API

get_option(Option, Options) ->
    {proplists:get_value(Option, Options), proplists:delete(Option, Options)}.

%% 打印当前时间，间隔一秒，再在已经打开的 http 连接之上，再次打印，这也就是所谓 HTTP长连接/ServerPush 的一种
timer(Response) ->
    Response:write_chunk(io_lib:format("The time is: ~p~n",
                                       [calendar:local_time()])),
    timer:sleep(1000),
    timer(Response).