package org.warp.commonutils.functional;

import java.util.Objects;
import java.util.StringJoiner;

public final class OperationResult<T> {

	private final boolean cancel;
	private final T value;

	private OperationResult(boolean cancel, T value) {
		this.cancel = cancel;
		this.value = value;
	}

	public static <T> OperationResult<T> cancelNext(T value) {
		return new OperationResult<>(true, value);
	}

	public static <T> OperationResult<T> result(T value) {
		return new OperationResult<>(false, value);
	}

	public static <T> OperationResult<T> of(boolean cancel, T value) {
		return new OperationResult<>(cancel, value);
	}

	public boolean isCancelled() {
		return cancel;
	}

	public T getValue() {
		return value;
	}

	@Override
	public boolean equals(Object o) {
		if (this == o) {
			return true;
		}
		if (o == null || getClass() != o.getClass()) {
			return false;
		}

		OperationResult<?> that = (OperationResult<?>) o;

		if (cancel != that.cancel) {
			return false;
		}
		return Objects.equals(value, that.value);
	}

	@Override
	public int hashCode() {
		int result = (cancel ? 1 : 0);
		result = 31 * result + (value != null ? value.hashCode() : 0);
		return result;
	}

	@Override
	public String toString() {
		return new StringJoiner(", ", OperationResult.class.getSimpleName() + "[", "]")
				.add("cancel=" + cancel)
				.add("value=" + value)
				.toString();
	}

	public <X> OperationResult<X> copyStatusWith(X newResults) {
		if (cancel) {
			return OperationResult.cancelNext(newResults);
		} else {
			return OperationResult.result(newResults);
		}
	}
}