-module(filespy).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).

-export([new/0, add_dir/2, add_dirs/2, set_actor_handler/2, set_initial_state/2, set_handler/2, set_initializer/2, selector/0, spec/1, start/1]).
-export_type([no_directories/0, has_directories/0, no_handler/0, has_handler/0, no_initial_state/0, has_initial_state/0, event/0, change/1, builder/5]).

-if(?OTP_RELEASE >= 27).
-define(MODULEDOC(Str), -moduledoc(Str)).
-define(DOC(Str), -doc(Str)).
-else.
-define(MODULEDOC(Str), -compile([])).
-define(DOC(Str), -compile([])).
-endif.

?MODULEDOC(
    " This module is a wrapper around the erlang [FS](https://fs.n2o.dev/)\n"
    " library. It allows you to create a listener for file change events for any\n"
    " operating system.\n"
    "\n"
    " Note: on Linux and BSD, you need `inotify-tools` installed.\n"
).

-type no_directories() :: any().

-type has_directories() :: any().

-type no_handler() :: any().

-type has_handler() :: any().

-type no_initial_state() :: any().

-type has_initial_state() :: any().

-type event() :: created |
    modified |
    closed |
    deleted |
    renamed |
    attribute |
    {unknown, gleam@erlang@atom:atom_()}.

-type change(HXB) :: {change, binary(), list(event())} | {custom, HXB}.

-opaque builder(HXC, HXD, HXE, HXF, HXG) :: {builder,
        list(binary()),
        gleam@option:option(fun((change(HXG), HXC) -> gleam@otp@actor:next(change(HXG), HXC))),
        gleam@option:option(fun(() -> HXC))} |
    {gleam_phantom, HXD, HXE, HXF}.

-file("src/filespy.gleam", 78).
?DOC(
    " Create a new builder\n"
    "\n"
    " Use this with the `add_dir` and `handler` functions to configure the\n"
    " watcher\n"
).
-spec new() -> builder(any(), no_directories(), no_handler(), no_initial_state(), nil).
new() ->
    {builder, [], none, none}.

-file("src/filespy.gleam", 90).
?DOC(
    " Add a directory to watch\n"
    "\n"
    " # Examples\n"
    "\n"
    " ```gleam\n"
    " filespy.new()\n"
    " |> filespy.add_dir(\"./watched\")\n"
    " ```\n"
).
-spec add_dir(builder(HXV, any(), HXX, HXY, HXZ), binary()) -> builder(HXV, has_directories(), HXX, HXY, HXZ).
add_dir(Builder, Directory) ->
    {builder,
        [Directory | erlang:element(2, Builder)],
        erlang:element(3, Builder),
        erlang:element(4, Builder)}.

-file("src/filespy.gleam", 101).
?DOC(" Add multiple directories at once\n").
-spec add_dirs(builder(HYK, any(), HYM, HYN, HYO), list(binary())) -> builder(HYK, has_directories(), HYM, HYN, HYO).
add_dirs(Builder, Directories) ->
    {builder,
        lists:append(Directories, erlang:element(2, Builder)),
        erlang:element(3, Builder),
        erlang:element(4, Builder)}.

-file("src/filespy.gleam", 154).
?DOC(
    " Set the actor handler\n"
    "\n"
    " Use this if you want to have a more thorough control over the generated\n"
    " actor. You will also need to set an initial state, with `set_initial_state`.\n"
).
-spec set_actor_handler(
    builder(HZM, HZN, no_handler(), HZO, HZP),
    fun((change(HZP), HZM) -> gleam@otp@actor:next(change(HZP), HZM))
) -> builder(HZM, HZN, has_handler(), HZO, HZP).
set_actor_handler(Builder, Handler) ->
    {builder,
        erlang:element(2, Builder),
        {some, Handler},
        erlang:element(4, Builder)}.

-file("src/filespy.gleam", 170).
?DOC(
    " Set the initial state\n"
    "\n"
    " Use this if you want to have a more thorough control over the generated\n"
    " actor. You'll only have access to this state if you set your handler with\n"
    " `set_actor_handler`.\n"
).
-spec set_initial_state(builder(IAC, IAD, IAE, no_initial_state(), IAF), IAC) -> builder(IAC, IAD, IAE, has_initial_state(), IAF).
set_initial_state(Builder, State) ->
    {builder,
        erlang:element(2, Builder),
        erlang:element(3, Builder),
        {some, fun() -> State end}}.

-file("src/filespy.gleam", 129).
?DOC(
    " Set the handler\n"
    "\n"
    " # Examples\n"
    "\n"
    " ```gleam\n"
    " filespy.new()\n"
    " |> filespy.add_dir(\"./watched\")\n"
    " |> filespy.set_handler(fn (path: String, event: filespy.Event) {\n"
    "     case event {\n"
    "       filespy.Created -> {\n"
    "         io.println(\"File \" <> path <> \" created\")\n"
    "       }\n"
    "       _ -> {\n"
    "         io.println(\"Something else happened to \" <> path)\n"
    "       }\n"
    "   }\n"
    " })\n"
).
-spec set_handler(
    builder(nil, HZA, no_handler(), no_initial_state(), HZB),
    fun((binary(), event()) -> nil)
) -> builder(nil, HZA, has_handler(), has_initial_state(), HZB).
set_handler(Builder, Handler) ->
    Wrapped_handler = fun(Event, _) ->
        case Event of
            {change, Path, Events} ->
                gleam@list:each(Events, fun(Ev) -> Handler(Path, Ev) end);

            _ ->
                nil
        end,
        gleam@otp@actor:continue(nil)
    end,
    _pipe = Builder,
    _pipe@1 = set_actor_handler(_pipe, Wrapped_handler),
    set_initial_state(_pipe@1, nil).

-file("src/filespy.gleam", 186).
?DOC(
    " Set the initializer\n"
    "\n"
    " Use this if you want to, for example, return a subject in the state. The\n"
    " initializer will run in the actor's `on_init`, so it'll run under the\n"
    " watcher process\n"
).
-spec set_initializer(
    builder(IAQ, IAR, IAS, no_initial_state(), IAT),
    fun(() -> IAQ)
) -> builder(IAQ, IAR, IAS, has_initial_state(), IAT).
set_initializer(Builder, Initializer) ->
    {builder,
        erlang:element(2, Builder),
        erlang:element(3, Builder),
        {some, Initializer}}.

-file("src/filespy.gleam", 204).
?DOC(" Decode an atom to an `Event`.\n").
-spec event_decoder() -> gleam@dynamic@decode:decoder(event()).
event_decoder() ->
    gleam@dynamic@decode:then(
        {decoder, fun gleam@dynamic@decode:decode_dynamic/1},
        fun(Content) -> case gleam_erlang_ffi:atom_from_dynamic(Content) of
                {error, _} ->
                    gleam@dynamic@decode:failure(created, <<"Event"/utf8>>);

                {ok, Event} ->
                    Created = erlang:binary_to_atom(<<"created"/utf8>>),
                    Deleted = erlang:binary_to_atom(<<"deleted"/utf8>>),
                    Modified = erlang:binary_to_atom(<<"modified"/utf8>>),
                    Closed = erlang:binary_to_atom(<<"closed"/utf8>>),
                    Renamed = erlang:binary_to_atom(<<"renamed"/utf8>>),
                    Attrib = erlang:binary_to_atom(<<"attribute"/utf8>>),
                    Removed = erlang:binary_to_atom(<<"removed"/utf8>>),
                    case Event of
                        Ev when Ev =:= Created ->
                            gleam@dynamic@decode:success(created);

                        Ev@1 when Ev@1 =:= Deleted ->
                            gleam@dynamic@decode:success(deleted);

                        Ev@2 when Ev@2 =:= Modified ->
                            gleam@dynamic@decode:success(modified);

                        Ev@3 when Ev@3 =:= Closed ->
                            gleam@dynamic@decode:success(closed);

                        Ev@4 when Ev@4 =:= Renamed ->
                            gleam@dynamic@decode:success(renamed);

                        Ev@5 when Ev@5 =:= Removed ->
                            gleam@dynamic@decode:success(deleted);

                        Ev@6 when Ev@6 =:= Attrib ->
                            gleam@dynamic@decode:success(attribute);

                        Other ->
                            gleam@dynamic@decode:success({unknown, Other})
                    end
            end end
    ).

-file("src/filespy.gleam", 232).
?DOC(
    " Decode a [`charlist`](https://hexdocs.pm/gleam_erlang/gleam/erlang/charlist.html#Charlist)\n"
    " from a `Dynamic` value, and convert it to `String`.\n"
).
-spec charlist_decoder() -> gleam@dynamic@decode:decoder(binary()).
charlist_decoder() ->
    gleam@dynamic@decode:map(
        {decoder, fun gleam@dynamic@decode:decode_dynamic/1},
        fun(Chars) ->
            unicode:characters_to_binary(filespy_ffi:identity(Chars))
        end
    ).

-file("src/filespy.gleam", 238).
?DOC(" Decode `fs` events. Return type is `#(Pid, FileEvent, #(Path, List(Event)))`.\n").
-spec change_decoder() -> gleam@dynamic@decode:decoder({gleam@dynamic:dynamic_(),
    gleam@dynamic:dynamic_(),
    {binary(), list(event())}}).
change_decoder() ->
    gleam@dynamic@decode:field(
        0,
        {decoder, fun gleam@dynamic@decode:decode_dynamic/1},
        fun(Pid) ->
            gleam@dynamic@decode:field(
                1,
                {decoder, fun gleam@dynamic@decode:decode_dynamic/1},
                fun(File_event) ->
                    gleam@dynamic@decode:field(
                        2,
                        begin
                            gleam@dynamic@decode:field(
                                0,
                                charlist_decoder(),
                                fun(Path) ->
                                    gleam@dynamic@decode:field(
                                        1,
                                        gleam@dynamic@decode:list(
                                            event_decoder()
                                        ),
                                        fun(Events) ->
                                            gleam@dynamic@decode:success(
                                                {Path, Events}
                                            )
                                        end
                                    )
                                end
                            )
                        end,
                        fun(All_events) ->
                            gleam@dynamic@decode:success(
                                {Pid, File_event, All_events}
                            )
                        end
                    )
                end
            )
        end
    ).

-file("src/filespy.gleam", 250).
?DOC(" Get a `Selector` which can be used to select for filesystem events.\n").
-spec selector() -> gleam@erlang@process:selector(change(any())).
selector() ->
    gleam@erlang@process:selecting_anything(
        gleam_erlang_ffi:new_selector(),
        fun(Event) -> case gleam@dynamic@decode:run(Event, change_decoder()) of
                {ok, {_, _, {Path, Events}}} ->
                    {change, Path, Events};

                _ ->
                    {change, <<""/utf8>>, []}
            end end
    ).

-file("src/filespy.gleam", 259).
?DOC(" Get an actor `Spec` for the watcher\n").
-spec spec(
    builder(IBK, has_directories(), has_handler(), has_initial_state(), IBL)
) -> gleam@otp@actor:spec(IBK, change(IBL)).
spec(Builder) ->
    _assert_subject = erlang:element(3, Builder),
    {some, Handler} = case _assert_subject of
        {some, _} -> _assert_subject;
        _assert_fail ->
            erlang:error(#{gleam_error => let_assert,
                        message => <<"Pattern match failed, no pattern matched the value."/utf8>>,
                        value => _assert_fail,
                        module => <<"filespy"/utf8>>,
                        function => <<"spec"/utf8>>,
                        line => 262})
    end,
    _assert_subject@1 = erlang:element(4, Builder),
    {some, Initializer} = case _assert_subject@1 of
        {some, _} -> _assert_subject@1;
        _assert_fail@1 ->
            erlang:error(#{gleam_error => let_assert,
                        message => <<"Pattern match failed, no pattern matched the value."/utf8>>,
                        value => _assert_fail@1,
                        module => <<"filespy"/utf8>>,
                        function => <<"spec"/utf8>>,
                        line => 263})
    end,
    {spec,
        fun() ->
            {Oks, Errs} = begin
                _pipe = erlang:element(2, Builder),
                _pipe@2 = gleam@list:map(
                    _pipe,
                    fun(Dir) ->
                        Atom = erlang:binary_to_atom(
                            <<"fs_watcher"/utf8, Dir/binary>>
                        ),
                        _pipe@1 = fs:start_link(Atom, Dir),
                        gleam@result:map(_pipe@1, fun(Pid) -> {Pid, Atom} end)
                    end
                ),
                gleam@result:partition(_pipe@2)
            end,
            case Errs of
                [] ->
                    _pipe@3 = Oks,
                    gleam@list:each(
                        _pipe@3,
                        fun(Res) ->
                            {_, Atom@1} = Res,
                            fs:subscribe(Atom@1)
                        end
                    ),
                    {ready, Initializer(), selector()};

                Errs@1 ->
                    gleam@list:each(
                        Oks,
                        fun(Res@1) ->
                            {Pid@1, _} = Res@1,
                            gleam@erlang@process:kill(Pid@1)
                        end
                    ),
                    {failed,
                        <<"Failed to start watcher: "/utf8,
                            (gleam@string:inspect(Errs@1))/binary>>}
            end
        end,
        5000,
        Handler}.

-file("src/filespy.gleam", 305).
?DOC(
    " Start an actor which will receive filesystem events\n"
    "\n"
    " In order for this to work, you'll need to have set some directories to be\n"
    " watched, with `add_dir`, and set a handler with either `set_handler` or\n"
    " `set_actor_handler` and `set_initial_state`.\n"
).
-spec start(
    builder(any(), has_directories(), has_handler(), has_initial_state(), IBV)
) -> {ok, gleam@erlang@process:subject(change(IBV))} |
    {error, gleam@otp@actor:start_error()}.
start(Builder) ->
    _pipe = spec(Builder),
    gleam@otp@actor:start_spec(_pipe).