/*
 * 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.util;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.File;

public class Compare {

    static final int B1_NULL = -1;
    static final int B2_NULL = -2;

    static public boolean compare(String file1, String file2) throws FileNotFoundException, IOException {

	BufferedReader in1 = null;
	BufferedReader in2 = null;
	try {
	    in1 = new BufferedReader(new FileReader(file1));
	    in2 = new BufferedReader(new FileReader(file2));

	    String s1;
	    int lineCounter = 0;
	    while ((s1 = in1.readLine()) != null) {
		lineCounter++;
		String s2 = in2.readLine();
		if (!s1.equals(s2)) {
		    System.out.println("Files [" + file1 + "] and [" + file2 + "] differ on line " + lineCounter);
		    System.out.println("One reads:  [" + s1 + "].");
		    System.out.println("Other reads:[" + s2 + "].");
		    return false;
		}
	    }

	    // the second file is longer
	    if (in2.read() != -1) {
		System.out.println("File [" + file2 + "] longer than file [" + file1 + "].");
		return false;
	    }
	} finally {
	    close(in1);
	    close(in2);
	}
	return true;
    }

    private static void close(BufferedReader in) {
	if (in == null)
	    return;
	try {
	    in.close();
	} catch (IOException ioe) {

	}

    }

    private static final InputStream open(final Class<?> testClass, final String fileName) throws IOException {
	String resourceName = fileName;
	if (fileName.startsWith("witness/")) {
	    resourceName = fileName.substring(fileName.lastIndexOf('/') + 1);
	}
	InputStream is = testClass.getResourceAsStream(resourceName);
	if (is == null) {
	    File file = new File(fileName);
	    if (file.exists()) {
		is = new FileInputStream(file);
	    } else {
		throw new FileNotFoundException("Resource " + resourceName + " not found");
	    }
	}
	return is;
    }

    public static boolean compare(Class<?> testClass, final String file1, final String file2) throws IOException {
	BufferedReader in1 = new BufferedReader(new FileReader(file1));
	BufferedReader in2 = new BufferedReader(new InputStreamReader(open(testClass, file2)));
	try {
	    return compare(testClass, file1, file2, in1, in2);
	} finally {
	    in1.close();
	    in2.close();
	}
    }

    public static boolean compare(Class<?> testClass, String file1, String file2, BufferedReader in1,
	    BufferedReader in2) throws IOException {

	String s1;
	int lineCounter = 0;

	while ((s1 = in1.readLine()) != null) {
	    lineCounter++;

	    String s2 = in2.readLine();

	    if (!s1.equals(s2)) {
		System.out.println("Files [" + file1 + "] and [" + file2 + "] differ on line " + lineCounter);
		System.out.println("One reads:  [" + s1 + "].");
		System.out.println("Other reads:[" + s2 + "].");
		outputFile(testClass, file1);
		outputFile(testClass, file2);

		return false;
	    }
	}

	// the second file is longer
	if (in2.read() != -1) {
	    System.out.println("File [" + file2 + "] longer than file [" + file1 + "].");
	    outputFile(testClass, file1);
	    outputFile(testClass, file2);

	    return false;
	}

	return true;
    }

    /**
     * 
     * Prints file on the console.
     *
     */
    private static void outputFile(Class<?> testClass, String file) throws IOException {
	InputStream is = open(testClass, file);
	BufferedReader in1 = new BufferedReader(new InputStreamReader(is));

	String s1;
	int lineCounter = 0;
	System.out.println("--------------------------------");
	System.out.println("Contents of " + file + ":");

	while ((s1 = in1.readLine()) != null) {
	    lineCounter++;
	    System.out.print(lineCounter);

	    if (lineCounter < 10) {
		System.out.print("   : ");
	    } else if (lineCounter < 100) {
		System.out.print("  : ");
	    } else if (lineCounter < 1000) {
		System.out.print(" : ");
	    } else {
		System.out.print(": ");
	    }

	    System.out.println(s1);
	}
	in1.close();
    }

}
