-module(starfuzz@resolver).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/starfuzz/resolver.gleam").
-export([new/1, with_threshold/2, with_confidence_thresholds/3, component/3, resolve/3]).
-export_type([confidence/0, resolution/1, resolver/2]).

-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(
    " A module providing declarative entity resolution matching capabilities.\n"
    " Structured records can be compared using weighted components, outputting matched status\n"
    " and confidence levels (High, Medium, Low) for each candidate.\n"
).

-type confidence() :: high | medium | low.

-type resolution(DYO) :: {resolution,
        DYO,
        float(),
        list(starfuzz@rank:component_score()),
        confidence(),
        boolean()}.

-type resolver(DYP, DYQ) :: {resolver,
        fun((DYP, DYQ) -> list(starfuzz@rank:component_score())),
        float(),
        {float(), float()}}.

-file("src/starfuzz/resolver.gleam", 38).
?DOC(
    " Creates a new Resolver with a composite scoring function.\n"
    " Defaults to a threshold of 0.7, medium confidence at 0.75, and high confidence at 0.9.\n"
).
-spec new(fun((DYR, DYS) -> list(starfuzz@rank:component_score()))) -> resolver(DYR, DYS).
new(Scorer) ->
    {resolver, Scorer, 0.7, {0.75, 0.9}}.

-file("src/starfuzz/resolver.gleam", 47).
?DOC(" Configures the minimum score threshold to consider a record \"matched\".\n").
-spec with_threshold(resolver(DYW, DYX), float()) -> resolver(DYW, DYX).
with_threshold(Resolver, Threshold) ->
    {resolver,
        erlang:element(2, Resolver),
        Threshold,
        erlang:element(4, Resolver)}.

-file("src/starfuzz/resolver.gleam", 52).
?DOC(" Configures the thresholds for Medium and High confidence tiers.\n").
-spec with_confidence_thresholds(resolver(DZC, DZD), float(), float()) -> resolver(DZC, DZD).
with_confidence_thresholds(Resolver, Medium, High) ->
    {resolver,
        erlang:element(2, Resolver),
        erlang:element(3, Resolver),
        {Medium, High}}.

-file("src/starfuzz/resolver.gleam", 57).
?DOC(" Helper function to construct a ComponentScore inside the resolver scorer.\n").
-spec component(binary(), float(), float()) -> starfuzz@rank:component_score().
component(Name, Weight, Score) ->
    {component_score, Name, Score, Weight}.

-file("src/starfuzz/resolver.gleam", 63).
?DOC(
    " Resolves a query entity against a list of candidates.\n"
    " Returns resolution records sorted descending by composite score, with stable ordering.\n"
).
-spec resolve(resolver(DZI, DZJ), DZI, list(DZJ)) -> {ok, list(resolution(DZJ))} |
    {error, starfuzz@rank:rank_error()}.
resolve(Resolver, Query, Candidates) ->
    Candidates_indexed = gleam@list:index_map(
        Candidates,
        fun(C, I) -> {C, I} end
    ),
    Result = gleam@list:fold(
        Candidates_indexed,
        {ok, []},
        fun(Acc_state, Item) -> case Acc_state of
                {error, E} ->
                    {error, E};

                {ok, Acc} ->
                    {Candidate, _} = Item,
                    Components = (erlang:element(2, Resolver))(Query, Candidate),
                    case starfuzz@rank:combine(Components) of
                        {error, E@1} ->
                            {error, E@1};

                        {ok, Score} ->
                            Matched = Score >= erlang:element(3, Resolver),
                            {Med_th, High_th} = erlang:element(4, Resolver),
                            Confidence = case Score >= High_th of
                                true ->
                                    high;

                                false ->
                                    case Score >= Med_th of
                                        true ->
                                            medium;

                                        false ->
                                            low
                                    end
                            end,
                            {ok,
                                [{resolution,
                                        Candidate,
                                        Score,
                                        Components,
                                        Confidence,
                                        Matched} |
                                    Acc]}
                    end
            end end
    ),
    case Result of
        {error, E@2} ->
            {error, E@2};

        {ok, Resolutions} ->
            Indexed = gleam@list:index_map(
                lists:reverse(Resolutions),
                fun(R, Idx) -> {R, Idx} end
            ),
            Sorted = gleam@list:sort(
                Indexed,
                fun(A, B) ->
                    case erlang:element(3, erlang:element(1, A)) > erlang:element(
                        3,
                        erlang:element(1, B)
                    ) of
                        true ->
                            lt;

                        false ->
                            case erlang:element(3, erlang:element(1, A)) < erlang:element(
                                3,
                                erlang:element(1, B)
                            ) of
                                true ->
                                    gt;

                                false ->
                                    case erlang:element(2, A) < erlang:element(
                                        2,
                                        B
                                    ) of
                                        true ->
                                            lt;

                                        false ->
                                            gt
                                    end
                            end
                    end
                end
            ),
            {ok, gleam@list:map(Sorted, fun(X) -> erlang:element(1, X) end)}
    end.