telega

-module(telega@flow@storage).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/telega/flow/storage.gleam").
-export([generate_id/3, create_ets_storage/0, create_noop_storage/0]).

-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(" Storage utilities for flow persistence.\n").

-file("src/telega/flow/storage.gleam", 12).
?DOC(" Generate a flow instance ID from user, chat, and flow name\n").
-spec generate_id(integer(), integer(), binary()) -> binary().
generate_id(User_id, Chat_id, Flow_name) ->
    <<<<<<<<Flow_name/binary, "_"/utf8>>/binary,
                (erlang:integer_to_binary(Chat_id))/binary>>/binary,
            "_"/utf8>>/binary,
        (erlang:integer_to_binary(User_id))/binary>>.

-file("src/telega/flow/storage.gleam", 16).
-spec user_index_key(integer(), integer()) -> binary().
user_index_key(User_id, Chat_id) ->
    <<<<<<"_idx:"/utf8, (erlang:integer_to_binary(Chat_id))/binary>>/binary,
            ":"/utf8>>/binary,
        (erlang:integer_to_binary(User_id))/binary>>.

-file("src/telega/flow/storage.gleam", 24).
?DOC(
    " Create ETS-backed storage for flow instances.\n"
    "\n"
    " Data persists in memory for the lifetime of the VM but does NOT survive VM restarts.\n"
    " For persistent storage across restarts, implement a custom `FlowStorage` with a database backend.\n"
).
-spec create_ets_storage() -> {ok, telega@flow@types:flow_storage(any())} |
    {error, telega@error:telega_error()}.
create_ets_storage() ->
    gleam@result:'try'(
        telega@internal@flow_storage:start(),
        fun(Storage) ->
            {ok,
                {flow_storage,
                    fun(Instance) ->
                        telega@internal@flow_storage:save(
                            Storage,
                            erlang:element(2, Instance),
                            Instance
                        ),
                        Index_key = user_index_key(
                            erlang:element(4, Instance),
                            erlang:element(5, Instance)
                        ),
                        telega@internal@flow_storage:add_to_index(
                            Storage,
                            Index_key,
                            erlang:element(2, Instance)
                        ),
                        {ok, nil}
                    end,
                    fun(Id) ->
                        {ok, telega@internal@flow_storage:load(Storage, Id)}
                    end,
                    fun(Id@1) ->
                        Instance@1 = telega@internal@flow_storage:load(
                            Storage,
                            Id@1
                        ),
                        telega@internal@flow_storage:delete(Storage, Id@1),
                        case Instance@1 of
                            {some, Inst} ->
                                Index_key@1 = user_index_key(
                                    erlang:element(4, Inst),
                                    erlang:element(5, Inst)
                                ),
                                telega@internal@flow_storage:remove_from_index(
                                    Storage,
                                    Index_key@1,
                                    Id@1
                                );

                            none ->
                                nil
                        end,
                        {ok, nil}
                    end,
                    fun(User_id, Chat_id) ->
                        Index_key@2 = user_index_key(User_id, Chat_id),
                        Instance_ids = telega@internal@flow_storage:lookup_index(
                            Storage,
                            Index_key@2
                        ),
                        {ok,
                            gleam@list:filter_map(
                                Instance_ids,
                                fun(Id@2) ->
                                    case telega@internal@flow_storage:load(
                                        Storage,
                                        Id@2
                                    ) of
                                        {some, Instance@2} ->
                                            {ok, Instance@2};

                                        none ->
                                            {error, nil}
                                    end
                                end
                            )}
                    end}}
        end
    ).

-file("src/telega/flow/storage.gleam", 65).
?DOC(
    " Create no-op storage that discards all data.\n"
    " Useful for testing or stateless flows that don't need persistence.\n"
).
-spec create_noop_storage() -> telega@flow@types:flow_storage(any()).
create_noop_storage() ->
    {flow_storage,
        fun(_) -> {ok, nil} end,
        fun(_) -> {ok, none} end,
        fun(_) -> {ok, nil} end,
        fun(_, _) -> {ok, []} end}.