yog

-module(yog@pathfinding@utils).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/yog/pathfinding/utils.gleam").
-export([compare_frontier/3, compare_distance_frontier/3, compare_a_star_frontier/3, should_explore_node/4]).
-export_type([path/1]).

-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(" Shared types and utilities for pathfinding algorithms.\n").

-type path(KHJ) :: {path, list(integer()), KHJ}.

-file("src/yog/pathfinding/utils.gleam", 12).
-spec compare_frontier(
    {KHK, list(integer())},
    {KHK, list(integer())},
    fun((KHK, KHK) -> gleam@order:order())
) -> gleam@order:order().
compare_frontier(A, B, Cmp) ->
    Cmp(erlang:element(1, A), erlang:element(1, B)).

-file("src/yog/pathfinding/utils.gleam", 20).
-spec compare_distance_frontier(
    {KHN, integer()},
    {KHN, integer()},
    fun((KHN, KHN) -> gleam@order:order())
) -> gleam@order:order().
compare_distance_frontier(A, B, Cmp) ->
    Cmp(erlang:element(1, A), erlang:element(1, B)).

-file("src/yog/pathfinding/utils.gleam", 28).
-spec compare_a_star_frontier(
    {KHO, KHO, list(integer())},
    {KHO, KHO, list(integer())},
    fun((KHO, KHO) -> gleam@order:order())
) -> gleam@order:order().
compare_a_star_frontier(A, B, Cmp) ->
    Cmp(erlang:element(1, A), erlang:element(1, B)).

-file("src/yog/pathfinding/utils.gleam", 38).
?DOC(
    " Helper to determine if a node should be explored based on distance comparison.\n"
    " Returns True if the node hasn't been visited or if the new distance is shorter.\n"
).
-spec should_explore_node(
    gleam@dict:dict(KHR, KHS),
    KHR,
    KHS,
    fun((KHS, KHS) -> gleam@order:order())
) -> boolean().
should_explore_node(Visited, Node, New_dist, Compare) ->
    case gleam_stdlib:map_get(Visited, Node) of
        {ok, Prev_dist} ->
            case Compare(New_dist, Prev_dist) of
                lt ->
                    true;

                _ ->
                    false
            end;

        {error, nil} ->
            true
    end.