-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, resolve_schema_refs_in_schema/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", 21).
?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", 38).
?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(),
    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} ->
            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} ->
                            Name = ref_to_name(Ref),
                            case gleam_stdlib:map_get(
                                erlang:element(2, Components),
                                Name
                            ) of
                                {ok, {inline, Schema@1}} ->
                                    {ok, Schema@1};

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

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

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

-file("src/oaspec/openapi/resolver.gleam", 30).
?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()
) -> {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()).

-file("src/oaspec/openapi/resolver.gleam", 126).
?DOC(" Try to resolve a single ref, keeping it as-is if resolution fails.\n").
-spec resolve_one_ref(
    oaspec@openapi@schema:schema_ref(),
    oaspec@openapi@spec:open_api_spec()
) -> oaspec@openapi@schema:schema_ref().
resolve_one_ref(Schema_ref, Spec) ->
    case Schema_ref of
        {reference, Ref} ->
            case resolve_schema_ref(Schema_ref, Spec) of
                {ok, Schema} ->
                    {inline, Schema};

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

        Inline ->
            Inline
    end.

-file("src/oaspec/openapi/resolver.gleam", 138).
?DOC(" Map a list of schema refs, resolving each.\n").
-spec list_map_ref(
    list(oaspec@openapi@schema:schema_ref()),
    oaspec@openapi@spec:open_api_spec()
) -> list(oaspec@openapi@schema:schema_ref()).
list_map_ref(Refs, Spec) ->
    gleam@list:map(Refs, fun(R) -> resolve_one_ref(R, Spec) end).

-file("src/oaspec/openapi/resolver.gleam", 73).
?DOC(" Resolve all $ref in a schema object's nested schemas (one level).\n").
-spec resolve_schema_refs_in_schema(
    oaspec@openapi@schema:schema_object(),
    oaspec@openapi@spec:open_api_spec()
) -> oaspec@openapi@schema:schema_object().
resolve_schema_refs_in_schema(Schema, Spec) ->
    case Schema of
        {object_schema,
            Description,
            Properties,
            Required,
            Additional_properties,
            Additional_properties_untyped,
            Nullable} ->
            Resolved_props = gleam@dict:map_values(
                Properties,
                fun(_, V) -> resolve_one_ref(V, Spec) end
            ),
            Resolved_ap = case Additional_properties of
                {some, Ap} ->
                    {some, resolve_one_ref(Ap, Spec)};

                none ->
                    none
            end,
            {object_schema,
                Description,
                Resolved_props,
                Required,
                Resolved_ap,
                Additional_properties_untyped,
                Nullable};

        {array_schema, Description@1, Items, Min_items, Max_items, Nullable@1} ->
            {array_schema,
                Description@1,
                resolve_one_ref(Items, Spec),
                Min_items,
                Max_items,
                Nullable@1};

        {all_of_schema, Description@2, Schemas} ->
            Resolved = list_map_ref(Schemas, Spec),
            {all_of_schema, Description@2, Resolved};

        {one_of_schema, Description@3, Schemas@1, Discriminator} ->
            Resolved@1 = list_map_ref(Schemas@1, Spec),
            {one_of_schema, Description@3, Resolved@1, Discriminator};

        {any_of_schema, Description@4, Schemas@2} ->
            Resolved@2 = list_map_ref(Schemas@2, Spec),
            {any_of_schema, Description@4, Resolved@2};

        Other ->
            Other
    end.