package junit.runner;

/*-
 * #%L
 * org.eclipse.jdt.ui.junit.sampleproject
 * %%
 * Copyright (C) 2020 Eclipse Foundation
 * %%
 * This program and the accompanying materials are made available under the terms of the Eclipse Public License v1.0
 * and Eclipse Distribution License v. 1.0 which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 * #L%
 */

import junit.framework.*;
import java.lang.reflect.*;
import java.text.NumberFormat;
import java.io.*;
import java.util.*;

/**
 * Base class for all test runners. This class was born live on stage in
 * Sardinia during XP2000.
 */
public abstract class BaseTestRunner implements TestListener {
	public static final String SUITE_METHODNAME = "suite";

	private static Properties fPreferences;
	static int fgMaxMessageLength = 500;
	static boolean fgFilterStack = true;
	boolean fLoading = true;

	/*
	 * Implementation of TestListener
	 */
	public synchronized void startTest(Test test) {
		testStarted(test.toString());
	}

	protected static void setPreferences(Properties preferences) {
		fPreferences = preferences;
	}

	protected static Properties getPreferences() {
		if (fPreferences == null) {
			fPreferences = new Properties();
			fPreferences.put("loading", "true");
			fPreferences.put("filterstack", "true");
			readPreferences();
		}
		return fPreferences;
	}

	public static void savePreferences() throws IOException {
		FileOutputStream fos = new FileOutputStream(getPreferencesFile());
		try {
			getPreferences().store(fos, "");
		} finally {
			fos.close();
		}
	}

	public void setPreference(String key, String value) {
		getPreferences().setProperty(key, value);
	}

	public synchronized void endTest(Test test) {
		testEnded(test.toString());
	}

	public synchronized void addError(final Test test, final Throwable t) {
		testFailed(TestRunListener.STATUS_ERROR, test, t);
	}

	public synchronized void addFailure(final Test test, final AssertionFailedError t) {
		testFailed(TestRunListener.STATUS_FAILURE, test, t);
	}

	// TestRunListener implementation

	public abstract void testStarted(String testName);

	public abstract void testEnded(String testName);

	public abstract void testFailed(int status, Test test, Throwable t);

	/**
	 * Returns the Test corresponding to the given suite. This is a template method,
	 * subclasses override runFailed(), clearStatus().
	 */
	public Test getTest(String suiteClassName) {
		if (suiteClassName.length() <= 0) {
			clearStatus();
			return null;
		}
		Class testClass = null;
		try {
			testClass = loadSuiteClass(suiteClassName);
		} catch (ClassNotFoundException e) {
			String clazz = e.getMessage();
			if (clazz == null)
				clazz = suiteClassName;
			runFailed("Class not found \"" + clazz + "\"");
			return null;
		} catch (Exception e) {
			runFailed("Error: " + e.toString());
			return null;
		}
		Method suiteMethod = null;
		try {
			suiteMethod = testClass.getMethod(SUITE_METHODNAME, new Class[0]);
		} catch (Exception e) {
			// try to extract a test suite automatically
			clearStatus();
			return new TestSuite(testClass);
		}
		if (!Modifier.isStatic(suiteMethod.getModifiers())) {
			runFailed("Suite() method must be static");
			return null;
		}
		Test test = null;
		try {
			test = (Test) suiteMethod.invoke(null, new Class[0]); // static method
			if (test == null)
				return test;
		} catch (InvocationTargetException e) {
			runFailed("Failed to invoke suite():" + e.getTargetException().toString());
			return null;
		} catch (IllegalAccessException e) {
			runFailed("Failed to invoke suite():" + e.toString());
			return null;
		}

		clearStatus();
		return test;
	}

	/**
	 * Returns the formatted string of the elapsed time.
	 */
	public String elapsedTimeAsString(long runTime) {
		return NumberFormat.getInstance().format((double) runTime / 1000);
	}

	/**
	 * Processes the command line arguments and returns the name of the suite class
	 * to run or null
	 */
	protected String processArguments(String[] args) {
		String suiteName = null;
		for (int i = 0; i < args.length; i++) {
			if (args[i].equals("-noloading")) {
				setLoading(false);
			} else if (args[i].equals("-nofilterstack")) {
				fgFilterStack = false;
			} else if (args[i].equals("-c")) {
				if (args.length > i + 1)
					suiteName = extractClassName(args[i + 1]);
				else
					System.out.println("Missing Test class name");
				i++;
			} else {
				suiteName = args[i];
			}
		}
		return suiteName;
	}

	/**
	 * Sets the loading behaviour of the test runner
	 */
	public void setLoading(boolean enable) {
		fLoading = enable;
	}

	/**
	 * Extract the class name from a String in VA/Java style
	 */
	public String extractClassName(String className) {
		if (className.startsWith("Default package for"))
			return className.substring(className.lastIndexOf(".") + 1);
		return className;
	}

	/**
	 * Truncates a String to the maximum length.
	 */
	public static String truncate(String s) {
		if (fgMaxMessageLength != -1 && s.length() > fgMaxMessageLength)
			s = s.substring(0, fgMaxMessageLength) + "...";
		return s;
	}

	/**
	 * Override to define how to handle a failed loading of a test suite.
	 */
	protected abstract void runFailed(String message);

	/**
	 * Returns the loaded Class for a suite name.
	 */
	protected Class loadSuiteClass(String suiteClassName) throws ClassNotFoundException {
		return getLoader().load(suiteClassName);
	}

	/**
	 * Clears the status message.
	 */
	protected void clearStatus() { // Belongs in the GUI TestRunner class
	}

	/**
	 * Returns the loader to be used.
	 */
	public TestSuiteLoader getLoader() {
		if (useReloadingTestSuiteLoader())
			return new ReloadingTestSuiteLoader();
		return new StandardTestSuiteLoader();
	}

	protected boolean useReloadingTestSuiteLoader() {
		return getPreference("loading").equals("true") && !inVAJava() && fLoading;
	}

	private static File getPreferencesFile() {
		String home = System.getProperty("user.home");
		return new File(home, "junit.properties");
	}

	private static void readPreferences() {
		try (InputStream is = new FileInputStream(getPreferencesFile())) {
			setPreferences(new Properties(getPreferences()));
			getPreferences().load(is);
		} catch (IOException e) {
			// ignore
		}
	}

	public static String getPreference(String key) {
		return getPreferences().getProperty(key);
	}

	public static int getPreference(String key, int dflt) {
		String value = getPreference(key);
		int intValue = dflt;
		if (value == null)
			return intValue;
		try {
			intValue = Integer.parseInt(value);
		} catch (NumberFormatException ne) {
		}
		return intValue;
	}

	public static boolean inVAJava() {
		try {
			Class.forName("com.ibm.uvm.tools.DebugSupport");
		} catch (Exception e) {
			return false;
		}
		return true;
	}

	/**
	 * Returns a filtered stack trace
	 */
	public static String getFilteredTrace(Throwable t) {
		StringWriter stringWriter = new StringWriter();
		PrintWriter writer = new PrintWriter(stringWriter);
		t.printStackTrace(writer);
		StringBuffer buffer = stringWriter.getBuffer();
		String trace = buffer.toString();
		return BaseTestRunner.getFilteredTrace(trace);
	}

	/**
	 * Filters stack frames from internal JUnit classes
	 */
	public static String getFilteredTrace(String stack) {
		if (showStackRaw())
			return stack;

		StringWriter sw = new StringWriter();
		PrintWriter pw = new PrintWriter(sw);
		StringReader sr = new StringReader(stack);
		BufferedReader br = new BufferedReader(sr);

		String line;
		try {
			while ((line = br.readLine()) != null) {
				if (!filterLine(line))
					pw.println(line);
			}
		} catch (Exception IOException) {
			return stack; // return the stack unfiltered
		}
		return sw.toString();
	}

	protected static boolean showStackRaw() {
		return !getPreference("filterstack").equals("true") || fgFilterStack == false;
	}

	static boolean filterLine(String line) {
		String[] patterns = new String[] { "junit.framework.TestCase", "junit.framework.TestResult",
				"junit.framework.TestSuite", "junit.framework.Assert.", // don't filter AssertionFailure
				"junit.swingui.TestRunner", "junit.awtui.TestRunner", "junit.textui.TestRunner",
				"java.lang.reflect.Method.invoke(" };
		for (String pattern : patterns) {
			if (line.indexOf(pattern) > 0)
				return true;
		}
		return false;
	}

	static {
		fgMaxMessageLength = getPreference("maxmessage", fgMaxMessageLength);
	}

}
