package {{context.group}}.{{context.project}}.ext;

import lombok.Data;
import lombok.AllArgsConstructor;

import java.util.Optional;
import java.util.function.Function;

@Data
@AllArgsConstructor
public class MayFail<T> {
    Exception ex;
    T result;

    public static <T> MayFail<T> from(T result) {
        return new MayFail<>(null, result);
    }

    public static <T> MayFail<T> from(Exception error) {
        return new MayFail<>(error, null);
    }

    public interface MayFailProvider<R> {
        R func() throws Exception;
    }

    public static <T> MayFail<T> from(MayFailProvider<T> mayFailProvider) {
        try {
            return MayFail.from(mayFailProvider.func());
        } catch (Exception ex) {
            return MayFail.from(ex);
        }
    }

    public boolean isSuccess() {
        return ex == null;
    }

    public T get() {
        return result;
    }

    public T getOrDefault(T defaultResult) {
        return ex == null ?  result : defaultResult;
    }

    public <R> MayFail<R> map(Function<T, R> mapFunc) {
        if (ex == null) {
            return MayFail.from(mapFunc.apply(result));
        } else {
            return MayFail.from(ex);
        }
    }

    public <R> Optional<R> mapOption(Function<T, R> mapFunc) {
        return Optional.ofNullable(mapFunc.apply(result));
    }
}