/*
 * Copyright (c) 2014, 2015, Dynatrace and/or its affiliates. All rights reserved.
 * 
 * This file is part of the Lock Contention Tracing Subsystem for the HotSpot
 * Virtual Machine, which is developed at Christian Doppler Laboratory on
 * Monitoring and Evolution of Very-Large-Scale Software Systems. Please
 * contact us at <http://mevss.jku.at/> if you need additional information
 * or have any questions.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work. If not, see <http://www.gnu.org/licenses/>.
 *
 */ 
package sun.evtracing.processing;

import static java.lang.System.err;

import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.HashMap;

public class Sanity {

	private static final boolean PRINT_INDIVIDUAL_WARNINGS = Boolean.parseBoolean(System.getProperty("sun.evtracing.printIndividualWarnings"));

	private static class Counter {
		private int value = 0;
		public void inc() { value++; }
		public int get() { return value; }
	}
	private static HashMap<String, Counter> WARNINGS;

	public static boolean isEnabled() {
		boolean ea = false;
		assert (ea = true);
		return ea;
	}

	/**
	 * Non-failing assert for conditions that we expect to be true, but might be
	 * violated in rare cases, especially because of magic happening during VM
	 * startup.
	 */
	public static void warnIf(boolean condition, String format, Object... args) {
		if (condition) {
			warn(format, args);
		}
	}

	/**
	 * Print a warning if assertions are enabled.
	 */
	public static void warn(String format, Object... args) {
		if (isEnabled()) {
			if (PRINT_INDIVIDUAL_WARNINGS) {
				err.printf(format, args);
				err.println();
			} else {
				if (WARNINGS == null) {
					WARNINGS = new HashMap<>();
				}
				Counter ctr = WARNINGS.computeIfAbsent(format, f -> new Counter());
				ctr.inc();
			}
		}
	}

	public static void printCollectedWarnings() {
		if (WARNINGS != null) {
			WARNINGS.entrySet().stream()
				.sorted((x, y) -> y.getValue().get() - x.getValue().get())
				.forEach(e -> err.printf("%6d  %s%n", e.getValue().get(), e.getKey()));
		}
	}

	public static void assertNoInheritedAbstractMethods(Class<?> clazz) {
		for (Method m : clazz.getMethods()) {
			if (Modifier.isAbstract(m.getModifiers()) && !clazz.equals(m.getDeclaringClass())) {
				throw new AssertionError("class must implement all abstract methods from superclasses", null);
			}
		}
	}
}