/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.log4j;

import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import java.util.Random;

/*
  Stress test the Logger class.

*/

class StressCategory {

    static Level[] level = new Level[] { Level.DEBUG, Level.INFO, Level.WARN, Level.ERROR, Level.FATAL };

    static Level defaultLevel = Logger.getRootLogger().getLevel();

    static int LENGTH;
    static String[] names;
    static Logger[] cat;
    static CT[] ct;

    static Random random = new Random(10);

    public static void main(String[] args) {

	LENGTH = args.length;

	if (LENGTH == 0) {
	    System.err.println("Usage: java " + StressCategory.class.getName() + " name1 ... nameN\n.");
	    System.exit(1);
	}
	if (LENGTH >= 7) {
	    System.err.println("This stress test suffers from combinatorial explosion.\n"
		    + "Invoking with seven arguments takes about 90 minutes even on fast machines");
	}

	names = new String[LENGTH];
	for (int i = 0; i < LENGTH; i++) {
	    names[i] = args[i];
	}
	cat = new Logger[LENGTH];
	ct = new CT[LENGTH];

	permute(0);

	// If did not exit, then passed all tests.
    }

    // Loop through all permutations of names[].
    // On each possible permutation call createLoop
    static void permute(int n) {
	if (n == LENGTH)
	    createLoop(0);
	else
	    for (int i = n; i < LENGTH; i++) {
		swap(names, n, i);
		permute(n + 1);
		swap(names, n, i);
	    }
    }

    static void swap(String[] names, int i, int j) {
	String t = names[i];
	names[i] = names[j];
	names[j] = t;
    }

    public static void permutationDump() {
	System.out.print("Current permutation is - ");
	for (int i = 0; i < LENGTH; i++) {
	    System.out.print(names[i] + " ");
	}
	System.out.println();
    }

    // Loop through all possible 3^n combinations of not instantiating,
    // instantiating and setting/not setting a level.

    static void createLoop(int n) {
	if (n == LENGTH) {
	    // System.out.println("..............Creating cat[]...........");
	    for (int i = 0; i < LENGTH; i++) {
		if (ct[i] == null)
		    cat[i] = null;
		else {
		    cat[i] = Logger.getLogger(ct[i].catstr);
		    cat[i].setLevel(ct[i].level);
		}
	    }
	    test();
	    // Clear hash table for next round
	    Hierarchy h = (Hierarchy) LogManager.getLoggerRepository();
	    h.clear();
	} else {
	    ct[n] = null;
	    createLoop(n + 1);

	    ct[n] = new CT(names[n], null);
	    createLoop(n + 1);

	    int r = random.nextInt();
	    if (r < 0)
		r = -r;
	    ct[n] = new CT(names[n], level[r % 5]);
	    createLoop(n + 1);
	}
    }

    static void test() {
	// System.out.println("++++++++++++TEST called+++++++++++++");
	// permutationDump();
	// catDump();

	for (int i = 0; i < LENGTH; i++) {
	    if (!checkCorrectness(i)) {
		System.out.println("Failed stress test.");
		permutationDump();

		// Hierarchy._default.fullDump();
		ctDump();
		catDump();
		System.exit(1);
	    }
	}
    }

    static void ctDump() {
	for (int j = 0; j < LENGTH; j++) {
	    if (ct[j] != null)
		System.out.println("ct [" + j + "] = (" + ct[j].catstr + "," + ct[j].level + ")");
	    else
		System.out.println("ct [" + j + "] = undefined");
	}
    }

    static void catDump() {
	for (int j = 0; j < LENGTH; j++) {
	    if (cat[j] != null)
		System.out.println("cat[" + j + "] = (" + cat[j].name + "," + cat[j].getLevel() + ")");
	    else
		System.out.println("cat[" + j + "] = undefined");
	}
    }

    // static
    // void provisionNodesDump() {
    // for (Enumeration e = CategoryFactory.ht.keys(); e.hasMoreElements() ;) {
    // CategoryKey key = (CategoryKey) e.nextElement();
    // Object c = CategoryFactory.ht.get(key);
    // if(c instanceof ProvisionNode)
    // ((ProvisionNode) c).dump(key.name);
    // }
    // }

    static boolean checkCorrectness(int i) {
	CT localCT = ct[i];

	// Can't perform test if logger is not instantiated
	if (localCT == null)
	    return true;

	// find expected level
	Level expected = getExpectedPrioriy(localCT);

	Level purported = cat[i].getEffectiveLevel();

	if (expected != purported) {
	    System.out.println("Expected level for " + localCT.catstr + " is " + expected);
	    System.out.println("Purported level for " + cat[i].name + " is " + purported);
	    return false;
	}
	return true;

    }

    static Level getExpectedPrioriy(CT ctParam) {
	Level level = ctParam.level;
	if (level != null)
	    return level;

	String catstr = ctParam.catstr;

	for (int i = catstr.lastIndexOf('.', catstr.length() - 1); i >= 0; i = catstr.lastIndexOf('.', i - 1)) {
	    String substr = catstr.substring(0, i);

	    // find the level of ct corresponding to substr
	    for (int j = 0; j < LENGTH; j++) {
		if (ct[j] != null && substr.equals(ct[j].catstr)) {
		    Level p = ct[j].level;
		    if (p != null)
			return p;
		}
	    }
	}
	return defaultLevel;
    }

    static class CT {
	public String catstr;
	public Level level;

	CT(String catstr, Level level) {
	    this.catstr = catstr;
	    this.level = level;
	}
    }
}
