gleamy_structures

-module(structures@red_black_tree_kv).
-compile([no_auto_import, nowarn_unused_vars]).

-export([new/1, clear/1, insert/3, delete/2, find/2, fold/3, foldr/3, draw/2]).
-export_type([color/0, node_/2, tree/2, min_del/2]).

-type color() :: r | b | bb.

-type node_(FCI, FCJ) :: e |
    ee |
    {t, color(), node_(FCI, FCJ), {FCI, FCJ}, node_(FCI, FCJ)}.

-opaque tree(FCK, FCL) :: {tree,
        node_(FCK, FCL),
        fun((FCK, FCK) -> gleam@order:order())}.

-type min_del(FCM, FCN) :: {min, {FCM, FCN}, node_(FCM, FCN)} | none.

-spec new(fun((FCO, FCO) -> gleam@order:order())) -> tree(FCO, any()).
new(Compare) ->
    {tree, e, Compare}.

-spec clear(tree(FCS, FCT)) -> tree(FCS, FCT).
clear(Tree) ->
    {tree, e, erlang:element(3, Tree)}.

-spec blacken(node_(FEK, FEL)) -> node_(FEK, FEL).
blacken(Node) ->
    case Node of
        {t, r, {t, r, _, _, _} = L, Y, C} ->
            {t, b, L, Y, C};

        {t, r, K, X, {t, r, _, _, _} = R} ->
            {t, b, K, X, R};

        T ->
            T
    end.

-spec balance(color(), node_(FEQ, FER), {FEQ, FER}, node_(FEQ, FER)) -> node_(FEQ, FER).
balance(C, L, V, R) ->
    case {C, L, V, R} of
        {b, {t, r, {t, r, K, X, B}, Y, C@1}, Z, D} ->
            {t, r, {t, b, K, X, B}, Y, {t, b, C@1, Z, D}};

        {b, {t, r, K@1, X@1, {t, r, B@1, Y@1, C@2}}, Z@1, D@1} ->
            {t, r, {t, b, K@1, X@1, B@1}, Y@1, {t, b, C@2, Z@1, D@1}};

        {b, K@2, X@2, {t, r, {t, r, B@2, Y@2, C@3}, Z@2, D@2}} ->
            {t, r, {t, b, K@2, X@2, B@2}, Y@2, {t, b, C@3, Z@2, D@2}};

        {b, K@3, X@3, {t, r, B@3, Y@3, {t, r, C@4, Z@3, D@3}}} ->
            {t, r, {t, b, K@3, X@3, B@3}, Y@3, {t, b, C@4, Z@3, D@3}};

        {bb, K@4, X@4, {t, r, {t, r, B@4, Y@4, C@5}, Z@4, D@4}} ->
            {t, b, {t, b, K@4, X@4, B@4}, Y@4, {t, b, C@5, Z@4, D@4}};

        {bb, {t, r, K@5, X@5, {t, r, B@5, Y@5, C@6}}, Z@5, D@5} ->
            {t, b, {t, b, K@5, X@5, B@5}, Y@5, {t, b, C@6, Z@5, D@5}};

        {C@7, K@6, X@6, B@6} ->
            {t, C@7, K@6, X@6, B@6}
    end.

-spec redden(node_(FEY, FEZ)) -> node_(FEY, FEZ).
redden(Node) ->
    case Node of
        {t, b, {t, b, _, _, _} = L, Y, {t, b, _, _, _} = R} ->
            {t, r, L, Y, R};

        T ->
            T
    end.

-spec rotate(color(), node_(FFK, FFL), {FFK, FFL}, node_(FFK, FFL)) -> node_(FFK, FFL).
rotate(C, L, V, R) ->
    case {C, L, V, R} of
        {r, {t, bb, K, X, B}, Y, {t, b, C@1, Z, D}} ->
            balance(b, {t, r, {t, b, K, X, B}, Y, C@1}, Z, D);

        {r, ee, Y@1, {t, b, C@2, Z@1, D@1}} ->
            balance(b, {t, r, e, Y@1, C@2}, Z@1, D@1);

        {r, {t, b, K@1, X@1, B@1}, Y@2, {t, bb, C@3, Z@2, D@2}} ->
            balance(b, K@1, X@1, {t, r, B@1, Y@2, {t, b, C@3, Z@2, D@2}});

        {r, {t, b, K@2, X@2, B@2}, Y@3, ee} ->
            balance(b, K@2, X@2, {t, r, B@2, Y@3, e});

        {b, {t, bb, K@3, X@3, B@3}, Y@4, {t, b, C@4, Z@3, D@3}} ->
            balance(bb, {t, r, {t, b, K@3, X@3, B@3}, Y@4, C@4}, Z@3, D@3);

        {b, ee, Y@5, {t, b, C@5, Z@4, D@4}} ->
            balance(bb, {t, r, e, Y@5, C@5}, Z@4, D@4);

        {b, {t, b, K@4, X@4, B@4}, Y@6, {t, bb, C@6, Z@5, D@5}} ->
            balance(bb, K@4, X@4, {t, r, B@4, Y@6, {t, b, C@6, Z@5, D@5}});

        {b, {t, b, K@5, X@5, B@5}, Y@7, ee} ->
            balance(bb, K@5, X@5, {t, r, B@5, Y@7, e});

        {b, {t, bb, K@6, W, B@6}, X@6, {t, r, {t, b, C@7, Y@8, D@6}, Z@6, E}} ->
            {t,
                b,
                balance(b, {t, r, {t, b, K@6, W, B@6}, X@6, C@7}, Y@8, D@6),
                Z@6,
                E};

        {b, ee, X@7, {t, r, {t, b, C@8, Y@9, D@7}, Z@7, E@1}} ->
            {t, b, balance(b, {t, r, e, X@7, C@8}, Y@9, D@7), Z@7, E@1};

        {b,
            {t, r, K@7, W@1, {t, b, B@7, X@8, C@9}},
            Y@10,
            {t, bb, D@8, Z@8, E@2}} ->
            {t,
                b,
                K@7,
                W@1,
                balance(b, B@7, X@8, {t, r, C@9, Y@10, {t, b, D@8, Z@8, E@2}})};

        {b, {t, r, K@8, W@2, {t, b, B@8, X@9, C@10}}, Y@11, ee} ->
            {t, b, K@8, W@2, balance(b, B@8, X@9, {t, r, C@10, Y@11, e})};

        {C@11, K@9, X@10, B@9} ->
            {t, C@11, K@9, X@10, B@9}
    end.

-spec ins(node_(FEE, FEF), {FEE, FEF}, fun((FEE, FEE) -> gleam@order:order())) -> node_(FEE, FEF).
ins(Node, X, Compare) ->
    case Node of
        e ->
            {t, r, e, X, e};

        {t, C, K, Y, B} ->
            case Compare(erlang:element(1, X), erlang:element(1, Y)) of
                lt ->
                    balance(C, ins(K, X, Compare), Y, B);

                gt ->
                    balance(C, K, Y, ins(B, X, Compare));

                eq ->
                    {t, C, K, X, B}
            end;

        _ ->
            Node
    end.

-spec insert(tree(FCY, FCZ), FCY, FCZ) -> tree(FCY, FCZ).
insert(Tree, Key, Value) ->
    {tree,
        blacken(
            ins(erlang:element(2, Tree), {Key, Value}, erlang:element(3, Tree))
        ),
        erlang:element(3, Tree)}.

-spec del(node_(FFE, FFF), FFE, fun((FFE, FFE) -> gleam@order:order())) -> node_(FFE, FFF).
del(Node, X, Compare) ->
    case Node of
        e ->
            Node;

        {t, r, e, Y, e} ->
            case Compare(X, erlang:element(1, Y)) of
                eq ->
                    e;

                _ ->
                    Node
            end;

        {t, b, e, Y@1, e} ->
            case Compare(X, erlang:element(1, Y@1)) of
                eq ->
                    ee;

                _ ->
                    Node
            end;

        {t, b, {t, r, e, Y@2, e} = L, Z, e} ->
            case Compare(X, erlang:element(1, Z)) of
                lt ->
                    {t, b, del(L, X, Compare), Z, e};

                gt ->
                    Node;

                eq ->
                    {t, b, e, Y@2, e}
            end;

        {t, C, K, Y@3, B} ->
            case Compare(X, erlang:element(1, Y@3)) of
                lt ->
                    rotate(C, del(K, X, Compare), Y@3, B);

                gt ->
                    rotate(C, K, Y@3, del(B, X, Compare));

                eq ->
                    case min_del(B) of
                        {min, Y1, B1} ->
                            rotate(C, K, Y1, B1);

                        none ->
                            e
                    end
            end;

        _ ->
            Node
    end.

-spec delete(tree(FDE, FDF), FDE) -> tree(FDE, FDF).
delete(Tree, Key) ->
    {tree,
        del(redden(erlang:element(2, Tree)), Key, erlang:element(3, Tree)),
        erlang:element(3, Tree)}.

-spec do_find(node_(FFY, FFZ), FFY, fun((FFY, FFY) -> gleam@order:order())) -> {ok,
        {FFY, FFZ}} |
    {error, nil}.
do_find(Node, Key, Compare) ->
    case Node of
        {t, _, L, K, R} ->
            case Compare(Key, erlang:element(1, K)) of
                lt ->
                    do_find(L, Key, Compare);

                gt ->
                    do_find(R, Key, Compare);

                eq ->
                    {ok, K}
            end;

        _ ->
            {error, nil}
    end.

-spec find(tree(FDK, FDL), FDK) -> {ok, {FDK, FDL}} | {error, nil}.
find(Tree, Key) ->
    do_find(erlang:element(2, Tree), Key, erlang:element(3, Tree)).

-spec do_fold(node_(FGE, FGF), FGI, fun((FGI, FGE, FGF) -> FGI)) -> FGI.
do_fold(Node, Acc, Fun) ->
    case Node of
        {t, _, R, V, L} ->
            Acc@1 = do_fold(R, Acc, Fun),
            Acc@2 = Fun(Acc@1, erlang:element(1, V), erlang:element(2, V)),
            Acc@3 = do_fold(L, Acc@2, Fun),
            Acc@3;

        _ ->
            Acc
    end.

-spec fold(tree(FDQ, FDR), FDU, fun((FDU, FDQ, FDR) -> FDU)) -> FDU.
fold(Tree, Acc, Fun) ->
    do_fold(erlang:element(2, Tree), Acc, Fun).

-spec do_foldr(node_(FGJ, FGK), FGN, fun((FGN, FGJ, FGK) -> FGN)) -> FGN.
do_foldr(Node, Acc, Fun) ->
    case Node of
        {t, _, R, V, L} ->
            Acc@1 = do_foldr(L, Acc, Fun),
            Acc@2 = Fun(Acc@1, erlang:element(1, V), erlang:element(2, V)),
            Acc@3 = do_foldr(R, Acc@2, Fun),
            Acc@3;

        _ ->
            Acc
    end.

-spec foldr(tree(FDV, FDW), FDZ, fun((FDZ, FDV, FDW) -> FDZ)) -> FDZ.
foldr(Tree, Acc, Fun) ->
    do_foldr(erlang:element(2, Tree), Acc, Fun).

-spec do_draw(node_(FGO, FGP), integer(), fun((FGO, FGP) -> binary())) -> binary().
do_draw(Node, Indent, To_string) ->
    case Node of
        {t, _, L, K, R} ->
            Ls = do_draw(L, Indent + 1, To_string),
            Ks = do_indent(
                <<(To_string(erlang:element(1, K), erlang:element(2, K)))/binary,
                    "\n"/utf8>>,
                Indent
            ),
            Rs = do_draw(R, Indent + 1, To_string),
            <<<<Ls/binary, Ks/binary>>/binary, Rs/binary>>;

        _ ->
            <<""/utf8>>
    end.

-spec draw(tree(FEA, FEB), fun((FEA, FEB) -> binary())) -> binary().
draw(Tree, To_string) ->
    do_draw(erlang:element(2, Tree), 0, To_string).

-spec min_del(node_(FFS, FFT)) -> min_del(FFS, FFT).
min_del(Node) ->
    case Node of
        {t, r, e, X, e} ->
            {min, X, e};

        {t, b, e, X@1, e} ->
            {min, X@1, ee};

        {t, b, e, X@2, {t, r, e, Y, e}} ->
            {min, X@2, {t, b, e, Y, e}};

        {t, C, K, X@3, B} ->
            case min_del(K) of
                {min, X1, A1} ->
                    {min, X1, rotate(C, A1, X@3, B)};

                none ->
                    none
            end;

        _ ->
            none
    end.

-spec do_indent(binary(), integer()) -> binary().
do_indent(Acc, I) ->
    case I of
        0 ->
            Acc;

        I@1 ->
            do_indent(<<".  "/utf8, Acc/binary>>, I@1 - 1)
    end.