package civitas.common;
   
   import java.util.function.Function;
   
   import org.mockito.invocation.InvocationOnMock;
   
   import civitas.util.CivitasBigInteger;
   
   public class TestUtil {
  
  	static int n = 0;
  
  	public static void fakeRandomToArray(final InvocationOnMock invocation, final CivitasBigInteger random) {
  		byte[] array = invocation.getArgument(0);
  		java.util.Arrays.fill(array, (byte) 0);
  		byte[] aBytes = random.toByteArray();
  		int diff = aBytes.length - array.length;
  		for (int i = 0; i < array.length; i++) {
  			array[i] = aBytes[i + diff];
  		}
  	}
  
  	public static <T> T construct(final Class<T> klass, final Object... params) {
  		Class<?>[] types = new Class<?>[params.length];
  
  		for (int i = 0; i < types.length; i++) {
  			Class<?> cl = params[i].getClass();
  			types[i] = cl;
  		}
  		try {
  			return klass.getDeclaredConstructor(types).newInstance(params);
  		} catch (Exception e) {
  			throw new Error(e);
  		}
  	}
  
  	public static Function<CivitasBigInteger, CivitasBigInteger> pick(final int mod) {
  		n = 0;
  		return s -> {
  			if (n < 8 && mod == n++ % 2) {
  				return s;
  			} else {
  				return null;
  			}
  		};
  	}
  }