-module(day4).

-export([solve/1]).

solve(InputData) ->
	Lines = binary:split(InputData, <<$\n>>, [trim_all, global]),
	{part1(Lines), none}.

part1([]) -> 0;
part1([Entry | Rest]) ->
	Ranges = binary:split(Entry, <<",">>, [trim_all, global]),
	[[F1, F2], [S1, S2]] = lists:map(fun(Range) -> binary:split(Range, <<"-">>, [trim_all, global]) end, Ranges),
	First = {binary_to_integer(F1), binary_to_integer(F2)},
	Second = {binary_to_integer(S1), binary_to_integer(S2)},
	io:format("~n~p ~p", [First, Second]),
	case range_intersect(First, Second) of
		First -> 1;
		Second -> 1;
		_SomethingElse -> io:format(" out"), 0
	end + part1(Rest).

range_empty() -> {0, -1}.
range_is_empty({Bottom, Top}) -> Top < Bottom.
range_intersect({B1, T1}, {B2, T2}) -> {max(B1, B2), min(T1, T2)}.