eventsourcing

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

-export([new/2, execute/3]).
-export_type([aggregate/4, aggregate_context/4, event_envelop/1, event_sourcing/6, event_store/5]).

-type aggregate(NRA, NRB, NRC, NRD) :: {aggregate,
        NRA,
        fun((NRA, NRB) -> {ok, list(NRC)} | {error, NRD}),
        fun((NRA, NRC) -> NRA)}.

-type aggregate_context(NRE, NRF, NRG, NRH) :: {aggregate_context,
        binary(),
        aggregate(NRE, NRF, NRG, NRH),
        integer()}.

-type event_envelop(NRI) :: {memory_store_event_envelop,
        binary(),
        integer(),
        NRI} |
    {serialized_event_envelop,
        binary(),
        integer(),
        NRI,
        binary(),
        binary(),
        binary()}.

-opaque event_sourcing(NRJ, NRK, NRL, NRM, NRN, NRO) :: {event_sourcing,
        event_store(NRJ, NRK, NRL, NRM, NRN),
        list(fun((binary(), list(event_envelop(NRM))) -> nil))} |
    {gleam_phantom, NRO}.

-type event_store(NRP, NRQ, NRR, NRS, NRT) :: {event_store,
        NRP,
        fun((NRP, binary()) -> aggregate_context(NRQ, NRR, NRS, NRT)),
        fun((NRP, aggregate_context(NRQ, NRR, NRS, NRT), list(NRS)) -> list(event_envelop(NRS)))}.

-spec new(
    event_store(NVB, NVC, NVD, NVE, NVF),
    list(fun((binary(), list(event_envelop(NVE))) -> nil))
) -> event_sourcing(NVB, NVC, NVD, NVE, NVF, any()).
new(Event_store, Queries) ->
    {event_sourcing, Event_store, Queries}.

-spec execute(
    event_sourcing(any(), any(), NSL, any(), NSN, any()),
    binary(),
    NSL
) -> {ok, nil} | {error, NSN}.
execute(Event_sourcing, Aggregate_id, Command) ->
    Aggregate_context = (erlang:element(3, erlang:element(2, Event_sourcing)))(
        erlang:element(2, erlang:element(2, Event_sourcing)),
        Aggregate_id
    ),
    Aggregate = erlang:element(3, Aggregate_context),
    Entity = erlang:element(2, Aggregate),
    gleam@result:map(
        (erlang:element(3, Aggregate))(Entity, Command),
        fun(Events) ->
            _pipe = Events,
            gleam@list:map(
                _pipe,
                fun(_capture) ->
                    (erlang:element(4, Aggregate))(Entity, _capture)
                end
            ),
            Commited_events = (erlang:element(
                4,
                erlang:element(2, Event_sourcing)
            ))(
                erlang:element(2, erlang:element(2, Event_sourcing)),
                Aggregate_context,
                Events
            ),
            _pipe@1 = erlang:element(3, Event_sourcing),
            gleam@list:map(
                _pipe@1,
                fun(Query) -> Query(Aggregate_id, Commited_events) end
            ),
            nil
        end
    ).