/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at legal-notices/CDDLv1_0.txt
 * or http://forgerock.org/license/CDDLv1.0.html.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at legal-notices/CDDLv1_0.txt.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information:
 *      Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 *
 *
 *      Copyright 2012-2013 ForgeRock AS
 */

package com.forgerock.opendj.ldap.tools;

import static com.forgerock.opendj.ldap.tools.ToolConstants.OPTION_LONG_HELP;
import static com.forgerock.opendj.ldap.tools.ToolConstants.OPTION_LONG_OUTPUT_LDIF_FILENAME;
import static com.forgerock.opendj.ldap.tools.ToolConstants.OPTION_SHORT_HELP;
import static com.forgerock.opendj.ldap.tools.ToolConstants.OPTION_SHORT_OUTPUT_LDIF_FILENAME;
import static com.forgerock.opendj.ldap.tools.ToolsMessages.*;
import static com.forgerock.opendj.ldap.tools.Utils.filterExitCode;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.List;

import org.forgerock.i18n.LocalizableException;
import org.forgerock.i18n.LocalizableMessage;
import org.forgerock.opendj.ldap.ResultCode;
import org.forgerock.opendj.ldif.LDIF;
import org.forgerock.opendj.ldif.LDIFChangeRecordWriter;
import org.forgerock.opendj.ldif.LDIFEntryReader;

/**
 * This utility can be used to compare two LDIF files and report the differences
 * in LDIF format.
 */
public final class LDIFDiff extends ConsoleApplication {

    /**
     * The main method for LDIFDiff tool.
     *
     * @param args
     *            The command-line arguments provided to this program.
     */
    public static void main(final String[] args) {
        final int retCode = new LDIFDiff().run(args);
        System.exit(filterExitCode(retCode));
    }

    private LDIFDiff() {
        // Nothing to do.
    }

    private int run(final String[] args) {
        // Create the command-line argument parser for use with this
        // program.

        final LocalizableMessage toolDescription = INFO_LDIFDIFF_TOOL_DESCRIPTION.get();
        final ArgumentParser argParser =
                new ArgumentParser(LDIFDiff.class.getName(), toolDescription, false, true, 2, 2,
                        "source target");

        final BooleanArgument showUsage;
        final StringArgument outputFilename;

        try {
            outputFilename =
                    new StringArgument("outputFilename", OPTION_SHORT_OUTPUT_LDIF_FILENAME,
                            OPTION_LONG_OUTPUT_LDIF_FILENAME, false, false, true,
                            INFO_OUTPUT_LDIF_FILE_PLACEHOLDER.get(), "stdout", null,
                            INFO_LDIFDIFF_DESCRIPTION_OUTPUT_FILENAME
                                    .get(INFO_OUTPUT_LDIF_FILE_PLACEHOLDER.get()));
            argParser.addArgument(outputFilename);

            showUsage =
                    new BooleanArgument("showUsage", OPTION_SHORT_HELP, OPTION_LONG_HELP,
                            INFO_DESCRIPTION_SHOWUSAGE.get());
            argParser.addArgument(showUsage);
            argParser.setUsageArgument(showUsage, getOutputStream());
        } catch (final ArgumentException ae) {
            final LocalizableMessage message = ERR_CANNOT_INITIALIZE_ARGS.get(ae.getMessage());
            println(message);
            return ResultCode.CLIENT_SIDE_PARAM_ERROR.intValue();
        }

        // Parse the command-line arguments provided to this program.
        try {
            argParser.parseArguments(args);

            // If we should just display usage or version information,
            // then print it and exit.
            if (argParser.usageOrVersionDisplayed()) {
                return ResultCode.SUCCESS.intValue();
            }
        } catch (final ArgumentException ae) {
            final LocalizableMessage message = ERR_ERROR_PARSING_ARGS.get(ae.getMessage());
            println(message);
            return ResultCode.CLIENT_SIDE_PARAM_ERROR.intValue();
        }

        InputStream sourceInputStream = null;
        InputStream targetInputStream = null;
        OutputStream outputStream = null;
        LDIFEntryReader sourceReader = null;
        LDIFEntryReader targetReader = null;
        LDIFChangeRecordWriter outputWriter = null;

        try {
            // First source file.
            final List<String> trailingArguments = argParser.getTrailingArguments();
            if (!trailingArguments.get(0).equals("-")) {
                try {
                    sourceInputStream = new FileInputStream(trailingArguments.get(0));
                } catch (final FileNotFoundException e) {
                    final LocalizableMessage message =
                            ERR_LDIF_FILE_CANNOT_OPEN_FOR_READ.get(trailingArguments.get(0), e
                                    .getLocalizedMessage());
                    println(message);
                    return ResultCode.CLIENT_SIDE_PARAM_ERROR.intValue();
                }
            }

            // Patch file.
            if (!trailingArguments.get(1).equals("-")) {
                try {
                    targetInputStream = new FileInputStream(trailingArguments.get(1));
                } catch (final FileNotFoundException e) {
                    final LocalizableMessage message =
                            ERR_LDIF_FILE_CANNOT_OPEN_FOR_READ.get(trailingArguments.get(1), e
                                    .getLocalizedMessage());
                    println(message);
                    return ResultCode.CLIENT_SIDE_PARAM_ERROR.intValue();
                }
            }

            // Output file.
            if (outputFilename.isPresent() && !outputFilename.getValue().equals("-")) {
                try {
                    outputStream = new FileOutputStream(outputFilename.getValue());
                } catch (final FileNotFoundException e) {
                    final LocalizableMessage message =
                            ERR_LDIF_FILE_CANNOT_OPEN_FOR_WRITE.get(outputFilename.getValue(), e
                                    .getLocalizedMessage());
                    println(message);
                    return ResultCode.CLIENT_SIDE_PARAM_ERROR.intValue();
                }
            }

            // Default to stdin/stdout for all streams if not specified.
            if (sourceInputStream == null) {
                // Command line parameter was "-".
                sourceInputStream = System.in;
            }

            if (targetInputStream == null) {
                targetInputStream = System.in;
            }

            if (outputStream == null) {
                outputStream = System.out;
            }

            // Check that we are not attempting to read both the source and
            // target from stdin.
            if (sourceInputStream == targetInputStream) {
                final LocalizableMessage message = ERR_LDIFDIFF_MULTIPLE_USES_OF_STDIN.get();
                println(message);
                return ResultCode.CLIENT_SIDE_PARAM_ERROR.intValue();
            }

            // Perform the diff.
            sourceReader = new LDIFEntryReader(sourceInputStream);
            targetReader = new LDIFEntryReader(targetInputStream);
            outputWriter = new LDIFChangeRecordWriter(outputStream);
            LDIF.copyTo(LDIF.diff(sourceReader, targetReader), outputWriter);
        } catch (final IOException e) {
            if (e instanceof LocalizableException) {
                println(ERR_LDIFDIFF_DIFF_FAILED.get(((LocalizableException) e).getMessageObject()));
            } else {
                println(ERR_LDIFDIFF_DIFF_FAILED.get(e.getLocalizedMessage()));
            }
            return ResultCode.CLIENT_SIDE_LOCAL_ERROR.intValue();
        } finally {
            closeIfNotNull(sourceReader, targetReader, outputWriter);
            closeIfNotNull(sourceInputStream, targetInputStream, outputStream);
        }

        return ResultCode.SUCCESS.intValue();
    }
}