glib

-module(glib@tree).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).

-export([to_list/1, size/1, is_balanced/1, remove/2, add/2, main/0]).
-export_type([tree/1, tree_node/1]).

-opaque tree(GTA) :: {tree,
        gleam@option:option(tree_node(GTA)),
        fun((GTA, GTA) -> gleam@order:order())}.

-type tree_node(GTB) :: {tree_node,
        GTB,
        integer(),
        gleam@option:option(tree_node(GTB)),
        gleam@option:option(tree_node(GTB))}.

-spec do_to_list(tree_node(GTF)) -> list(GTF).
do_to_list(Tree) ->
    gleam@list:concat([case erlang:element(4, Tree) of
                none ->
                    [];

                {some, Node} ->
                    do_to_list(Node)
            end, gleam@list:repeat(
                erlang:element(2, Tree),
                erlang:element(3, Tree)
            ), case erlang:element(5, Tree) of
                none ->
                    [];

                {some, Node@1} ->
                    do_to_list(Node@1)
            end]).

-spec to_list(tree(GTC)) -> list(GTC).
to_list(Tree) ->
    case erlang:element(2, Tree) of
        none ->
            [];

        {some, Node} ->
            do_to_list(Node)
    end.

-spec get_size(integer(), gleam@option:option(tree_node(any()))) -> integer().
get_size(Size, Node) ->
    case Node of
        none ->
            Size + 1;

        {some, Tn} ->
            get_size(Size, erlang:element(4, Tn)) + get_size(
                Size,
                erlang:element(5, Tn)
            )
    end.

-spec size(tree(any())) -> integer().
size(Tree) ->
    get_size(0, erlang:element(2, Tree)).

-spec get_height(integer(), gleam@option:option(tree_node(any()))) -> integer().
get_height(Height, Node) ->
    case Node of
        none ->
            Height;

        {some, Tn} ->
            gleam@int:max(
                get_height(Height + 1, erlang:element(4, Tn)),
                get_height(Height + 1, erlang:element(5, Tn))
            )
    end.

-spec is_balanced(tree(any())) -> boolean().
is_balanced(Tree) ->
    case erlang:element(2, Tree) of
        none ->
            true;

        {some, Root} ->
            Left = get_height(1, erlang:element(4, Root)),
            Right = get_height(1, erlang:element(5, Root)),
            gleam@int:absolute_value(Left - Right) =< gleam@result:unwrap(
                gleam@int:modulo(size(Tree) - 1, 2),
                0
            )
    end.

-spec move_node(tree(GUH), tree_node(GUH), tree_node(GUH)) -> tree_node(GUH).
move_node(Tree, Root_node, Moved_node) ->
    case (erlang:element(3, Tree))(
        erlang:element(2, Root_node),
        erlang:element(2, Moved_node)
    ) of
        eq ->
            erlang:error(#{gleam_error => panic,
                    message => <<"panic expression evaluated"/utf8>>,
                    module => <<"glib/tree"/utf8>>,
                    function => <<"move_node"/utf8>>,
                    line => 177});

        lt ->
            case erlang:element(4, Root_node) of
                none ->
                    erlang:setelement(4, Root_node, {some, Moved_node});

                {some, Lnode} ->
                    move_node(Tree, Lnode, Moved_node)
            end;

        gt ->
            case erlang:element(5, Root_node) of
                none ->
                    erlang:setelement(5, Root_node, {some, Moved_node});

                {some, Rnode} ->
                    move_node(Tree, Rnode, Moved_node)
            end
    end.

-spec do_remove(tree(GTS), tree_node(GTS), GTS) -> gleam@option:option(tree_node(GTS)).
do_remove(Tree, Node, Value) ->
    case (erlang:element(3, Tree))(Value, erlang:element(2, Node)) of
        eq ->
            case erlang:element(3, Node) > 1 of
                true ->
                    {some,
                        erlang:setelement(3, Node, erlang:element(3, Node) - 1)};

                false ->
                    case erlang:element(4, Node) of
                        none ->
                            case erlang:element(5, Node) of
                                none ->
                                    none;

                                {some, _} ->
                                    erlang:element(5, Node)
                            end;

                        {some, Lnode} ->
                            case erlang:element(5, Node) of
                                none ->
                                    erlang:element(4, Node);

                                {some, Rnode} ->
                                    {some, move_node(Tree, Lnode, Rnode)}
                            end
                    end
            end;

        lt ->
            case erlang:element(4, Node) of
                none ->
                    {some, Node};

                {some, Leftnode} ->
                    {some,
                        erlang:setelement(
                            4,
                            Node,
                            do_remove(Tree, Leftnode, Value)
                        )}
            end;

        gt ->
            case erlang:element(5, Node) of
                none ->
                    {some, Node};

                {some, Rightnode} ->
                    {some,
                        erlang:setelement(
                            5,
                            Node,
                            do_remove(Tree, Rightnode, Value)
                        )}
            end
    end.

-spec remove(tree(GTP), GTP) -> tree(GTP).
remove(Tree, Value) ->
    case erlang:element(2, Tree) of
        none ->
            Tree;

        {some, Root} ->
            erlang:setelement(2, Tree, do_remove(Tree, Root, Value))
    end.

-spec new_node(GUM) -> tree_node(GUM).
new_node(Value) ->
    {tree_node, Value, 1, none, none}.

-spec do_add(tree(GTL), tree_node(GTL), GTL) -> tree_node(GTL).
do_add(Tree, Node, Value) ->
    case (erlang:element(3, Tree))(Value, erlang:element(2, Node)) of
        eq ->
            erlang:setelement(3, Node, erlang:element(3, Node) + 1);

        lt ->
            case erlang:element(4, Node) of
                none ->
                    erlang:setelement(4, Node, {some, new_node(Value)});

                {some, Leftnode} ->
                    erlang:setelement(
                        4,
                        Node,
                        {some, do_add(Tree, Leftnode, Value)}
                    )
            end;

        gt ->
            case erlang:element(5, Node) of
                none ->
                    erlang:setelement(5, Node, {some, new_node(Value)});

                {some, Rightnode} ->
                    erlang:setelement(
                        5,
                        Node,
                        {some, do_add(Tree, Rightnode, Value)}
                    )
            end
    end.

-spec add(tree(GTI), GTI) -> tree(GTI).
add(Tree, Value) ->
    case erlang:element(2, Tree) of
        none ->
            erlang:setelement(2, Tree, {some, new_node(Value)});

        {some, Root} ->
            erlang:setelement(2, Tree, {some, do_add(Tree, Root, Value)})
    end.

-spec main() -> nil.
main() ->
    _pipe = {tree, none, fun gleam@int:compare/2},
    _pipe@1 = to_list(_pipe),
    _pipe@2 = gleam@string:inspect(_pipe@1),
    gleam@io:println(_pipe@2),
    _pipe@3 = {tree, none, fun gleam@int:compare/2},
    _pipe@4 = add(_pipe@3, 123),
    _pipe@5 = to_list(_pipe@4),
    _pipe@6 = gleam@string:inspect(_pipe@5),
    gleam@io:println(_pipe@6).