-module(oaspec@openapi@resolver).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/oaspec/openapi/resolver.gleam").
-export([ref_to_name/1, resolve_schema_ref/2]).
-export_type([resolve_error/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.

-type resolve_error() :: {unresolved_ref, binary()} | {circular_ref, binary()}.

-file("src/oaspec/openapi/resolver.gleam", 20).
?DOC(
    " Resolve a $ref string to its schema name.\n"
    " Example: \"#/components/schemas/User\" -> \"User\"\n"
).
-spec ref_to_name(binary()) -> binary().
ref_to_name(Ref) ->
    _pipe = Ref,
    _pipe@1 = gleam@string:split(_pipe, <<"/"/utf8>>),
    _pipe@2 = gleam@list:last(_pipe@1),
    gleam@result:unwrap(_pipe@2, <<"Unknown"/utf8>>).

-file("src/oaspec/openapi/resolver.gleam", 37).
?DOC(" Internal resolver that tracks visited refs for cycle detection.\n").
-spec resolve_schema_ref_with_seen(
    oaspec@openapi@schema:schema_ref(),
    oaspec@openapi@spec:open_api_spec(oaspec@openapi@spec:resolved()),
    gleam@set:set(binary())
) -> {ok, oaspec@openapi@schema:schema_object()} | {error, resolve_error()}.
resolve_schema_ref_with_seen(Schema_ref, Spec, Seen) ->
    case Schema_ref of
        {inline, Schema} ->
            {ok, Schema};

        {reference, Ref, Name} ->
            case gleam@set:contains(Seen, Ref) of
                true ->
                    {error, {circular_ref, Ref}};

                false ->
                    New_seen = gleam@set:insert(Seen, Ref),
                    case erlang:element(5, Spec) of
                        {some, Components} ->
                            case gleam_stdlib:map_get(
                                erlang:element(2, Components),
                                Name
                            ) of
                                {ok, {inline, Schema@1}} ->
                                    {ok, Schema@1};

                                {ok, {reference, Inner_ref, Inner_name}} ->
                                    resolve_schema_ref_with_seen(
                                        {reference, Inner_ref, Inner_name},
                                        Spec,
                                        New_seen
                                    );

                                {error, _} ->
                                    {error, {unresolved_ref, Ref}}
                            end;

                        none ->
                            {error, {unresolved_ref, Ref}}
                    end
            end
    end.

-file("src/oaspec/openapi/resolver.gleam", 29).
?DOC(
    " Resolve a SchemaRef to a SchemaObject, looking up $ref in components.\n"
    " Tracks seen refs to detect circular references.\n"
).
-spec resolve_schema_ref(
    oaspec@openapi@schema:schema_ref(),
    oaspec@openapi@spec:open_api_spec(oaspec@openapi@spec:resolved())
) -> {ok, oaspec@openapi@schema:schema_object()} | {error, resolve_error()}.
resolve_schema_ref(Schema_ref, Spec) ->
    resolve_schema_ref_with_seen(Schema_ref, Spec, gleam@set:new()).