/*
 * Copyright (C) 2021 Christian Pierre MOMON <christian@momon.org>
 * 
 * This file is part of Logar, simple tool to manage http log files.
 * 
 * Logar is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 * 
 * Logar 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 Affero General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with Logar.  If not, see <http://www.gnu.org/licenses/>.
 */
package fr.devinsy.logar.app;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.time.LocalDateTime;
import java.time.YearMonth;
import java.time.format.DateTimeFormatter;
import java.time.format.DateTimeParseException;
import java.util.Locale;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.zip.GZIPOutputStream;

import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.StringUtils;
import org.april.logar.util.Files;
import org.april.logar.util.FilesUtils;
import org.april.logar.util.LineIterator;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import fr.devinsy.logar.app.anonymizer.Anonymizer;
import fr.devinsy.logar.app.log.LogUtils;

/**
 * The Class Logar.
 */
public final class Logar
{
    private static Logger logger = LoggerFactory.getLogger(Logar.class);

    public static Pattern nginxAccessLogLinePattern = Pattern.compile("^\\S+ - [^\\[]+ \\[(?<time>[^\\]]+)\\] .*$");
    public static Pattern nginxErrorLogLinePattern = Pattern.compile("^(?<time>\\S+\\s\\S+)\\s\\[(?<level>[^\\]]*)\\]\\s.*$");

    /**
     * Instantiates a new log tool.
     */
    private Logar()
    {
    }

    /**
     * Anonymize.
     *
     * @param source
     *            the source
     * @param target
     *            the target
     */
    public static void anonymize(final File source)
    {
        anonymize(source, null);
    }

    /**
     * Anonymize.
     *
     * @param source
     *            the source
     * @param target
     *            the target
     */
    public static void anonymize(final File source, final File mapFile)
    {
        if (source == null)
        {
            throw new IllegalArgumentException("Null source file.");
        }
        else if (!source.exists())
        {
            throw new IllegalArgumentException("Source file does not exist.");
        }
        else
        {
            Anonymizer anonymizer = new Anonymizer();
            anonymizer.loadMapTable(mapFile);
            System.out.println("Table size=" + anonymizer.getMapTable().size());

            Files files = FilesUtils.searchFileRecursively(source, ".log", ".log.gz").removeContaining("-anon.log");
            logger.info("file count={}", files.size());
            for (File file : files)
            {
                if (file.getName().contains("access"))
                {
                    anonymizer.anonymizeAccessFile(file);
                }
                else if (file.getName().contains("error"))
                {
                    //
                }
            }

            if (mapFile != null)
            {
                System.out.println("Table size=" + anonymizer.getMapTable().size());
                anonymizer.SaveMapTable(mapFile);
            }
        }
    }

    /**
     * Archive.
     *
     * @param source
     *            the source
     * @param target
     *            the target
     * @throws IOException
     */
    public static void archive(final File source, final File target) throws IOException
    {
        archiveAccessFiles(source, target);
        archiveErrorFiles(source, target);
    }

    /**
     * Test archive access files.
     *
     * @param source
     *            the source
     * @throws IOException
     */
    public static void archiveAccessFiles(final File source, final File target) throws IOException
    {
        if (source == null)
        {
            throw new IllegalArgumentException("Null parameter [source]");
        }
        else if (!source.isDirectory())
        {
            throw new IllegalArgumentException("Source parameter is not a directory.");
        }
        else if (!target.isDirectory())
        {
            throw new IllegalArgumentException("Target parameter is not a directory.");
        }
        else
        {
            YearMonth targetYearMonth = YearMonth.now().minusMonths(1);
            Stats counter = new Stats();

            for (File directory : Files.of(source).sortByName())
            {
                if ((directory.isDirectory()) && (!StringUtils.equalsAny(directory.getName(), ".", "..")))
                {
                    String targetFileName = String.format("%s-access-%s.log.gz", directory.getName(), targetYearMonth.toString());
                    File targetDirectory = new File(target, directory.getName());
                    targetDirectory.mkdirs();
                    File targetFile = new File(targetDirectory, targetFileName);
                    logger.info("== {} -> {}", directory.getName(), targetFile.getAbsoluteFile());
                    PrintWriter out = new PrintWriter(new GZIPOutputStream(new FileOutputStream(targetFile)));

                    for (File file : Files.of(directory).sortByName())
                    {
                        if ((!file.isDirectory()) && (file.getName().contains("access")))
                        {
                            logger.info(file.getName());
                            try
                            {
                                LineIterator iterator = new LineIterator(file);
                                while (iterator.hasNext())
                                {
                                    String line = iterator.next();
                                    counter.incLineCount();

                                    Matcher matcher = nginxAccessLogLinePattern.matcher(line);
                                    if (matcher.matches())
                                    {
                                        String value = matcher.group("time");
                                        try
                                        {
                                            LocalDateTime date = LocalDateTime.parse(value, DateTimeFormatter.ofPattern("dd/MMM/yyyy:HH:mm:ss Z").withLocale(Locale.ENGLISH));
                                            counter.incSuccessLineCount();

                                            if (YearMonth.from(date).equals(targetYearMonth))
                                            {
                                                out.println(line);
                                            }
                                        }
                                        catch (DateTimeParseException exception)
                                        {
                                            System.err.println("Date format problem with [" + line + "]");
                                            counter.incErrorLineCount();
                                        }
                                    }
                                    else
                                    {
                                        System.err.println("Not matching line [" + line + "]");
                                        counter.incErrorLineCount();
                                    }
                                }

                                counter.incSuccessFileCount();
                            }
                            catch (IOException exception)
                            {
                                System.err.println("Error with file [" + file.getAbsolutePath() + "]");
                                exception.printStackTrace();
                                counter.incErrorFileCount();
                            }
                            finally
                            {
                                counter.incFileCount();
                            }
                        }
                    }

                    IOUtils.closeQuietly(out);
                }
            }

            System.out.println("=====================================================");
            counter.stop();
            System.out.println(counter.toString());
        }
    }

    /**
     * Archive error files.
     *
     * @param source
     *            the source
     * @param target
     *            the target
     * @throws IOException
     *             Signals that an I/O exception has occurred.
     */
    public static void archiveErrorFiles(final File source, final File target) throws IOException
    {
        if (source == null)
        {
            throw new IllegalArgumentException("Null parameter [source]");
        }
        else if (!source.isDirectory())
        {
            throw new IllegalArgumentException("Source parameter is not a directory.");
        }
        else if (!target.isDirectory())
        {
            throw new IllegalArgumentException("Target parameter is not a directory.");
        }
        else
        {
            YearMonth targetYearMonth = YearMonth.now().minusMonths(1);
            Stats counter = new Stats();
            counter.start();

            for (File directory : Files.of(source).sortByName())
            {
                if ((directory.isDirectory()) && (!StringUtils.equalsAny(directory.getName(), ".", "..")))
                {
                    String targetFileName = String.format("%s-error-%s.log.gz", directory.getName(), targetYearMonth.toString());
                    File targetDirectory = new File(target, directory.getName());
                    targetDirectory.mkdirs();
                    File targetFile = new File(targetDirectory, targetFileName);
                    logger.info("== {} -> {}", directory.getName(), targetFile.getAbsoluteFile());
                    PrintWriter out = new PrintWriter(new GZIPOutputStream(new FileOutputStream(targetFile)));

                    for (File file : Files.of(directory).sortByName())
                    {
                        if ((!file.isDirectory()) && (file.getName().contains("error")))
                        {
                            // logger.info(file.getName());
                            try
                            {
                                LineIterator iterator = new LineIterator(file);
                                while (iterator.hasNext())
                                {
                                    String line = iterator.next();
                                    counter.incLineCount();

                                    Matcher matcher = nginxErrorLogLinePattern.matcher(line);
                                    if (matcher.matches())
                                    {
                                        String value = matcher.group("time");
                                        try
                                        {
                                            LocalDateTime date = LocalDateTime.parse(value, DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm:ss").withLocale(Locale.ENGLISH));
                                            counter.incSuccessLineCount();

                                            if (YearMonth.from(date).equals(targetYearMonth))
                                            {
                                                out.println(line);
                                            }
                                        }
                                        catch (DateTimeParseException exception)
                                        {
                                            System.err.println("Date format problem with [" + line + "]");
                                            counter.incErrorLineCount();
                                        }
                                    }
                                    else
                                    {
                                        System.err.println("Not matching line [" + line + "]");
                                        counter.incErrorLineCount();
                                    }
                                }

                                counter.incSuccessLineCount();
                            }
                            catch (IOException exception)
                            {
                                System.err.println("Error with file [" + file.getAbsolutePath() + "]");
                                exception.printStackTrace();
                                counter.incErrorFileCount();
                            }
                            finally
                            {
                                counter.incFileCount();
                            }
                        }
                    }

                    IOUtils.closeQuietly(out);
                }
            }

            System.out.println("=====================================================");
            counter.stop();
            System.out.println(counter.toString());
        }
    }

    /**
     * Check.
     *
     * @param source
     *            the source
     */
    public static void check(final File source)
    {
        if (source != null)
        {
            if (source.isFile())
            {
                if (source.getName().contains("access"))
                {
                    checkAccessFiles(source);
                }
                else if (source.getName().contains("error"))
                {
                    checkErrorFiles(source);
                }
            }
            else
            {
                for (File file : Files.of(source).removeHidden().sortByName())
                {
                    if (file.isDirectory())
                    {
                        check(file);
                    }
                    else if (StringUtils.endsWithAny(file.getName(), ".log", ".gz", ".1", ".2"))
                    {
                        check(file);
                    }
                }
            }
        }
    }

    /**
     * Check access files.
     *
     * @param file
     *            the source
     */
    public static void checkAccessFiles(final File file)
    {
        if (file == null)
        {
            throw new IllegalArgumentException("Null parameter.");
        }
        else if (!file.isFile())
        {
            throw new IllegalArgumentException("Parameter is not a file.");
        }
        else
        {
            System.out.println("== Check access log for [" + file.getName() + "]");

            int lineCount = 0;
            int badLineCount = 0;
            try
            {
                LineIterator iterator = new LineIterator(file);
                while (iterator.hasNext())
                {
                    String line = iterator.next();
                    lineCount += 1;

                    try
                    {
                        LogUtils.parseAccessLog(line).getDatetime();
                    }
                    catch (IllegalArgumentException exception)
                    {
                        System.out.println("Bad format line: " + line);
                        badLineCount += 1;
                        exception.printStackTrace();
                    }
                    catch (DateTimeParseException exception)
                    {
                        System.out.println("Bad datetime format: " + line);
                        badLineCount += 1;
                    }
                }
            }
            catch (IOException exception)
            {
                System.err.println("Error with file [" + file.getAbsolutePath() + "]");
                exception.printStackTrace();
            }

            if (badLineCount > 0)
            {
                System.out.println("Bad line count: " + badLineCount + "/" + lineCount);
            }
        }
    }

    /**
     * Check error files.
     *
     * @param file
     *            the file
     */
    public static void checkErrorFiles(final File file)
    {
        if (file == null)
        {
            throw new IllegalArgumentException("Null parameter.");
        }
        else if (!file.isFile())
        {
            throw new IllegalArgumentException("Parameter is not a file.");
        }
        else
        {
            System.out.println("== Check error log for [" + file.getName() + "]");

            int lineCount = 0;
            int badLineCount = 0;
            try
            {
                LineIterator iterator = new LineIterator(file);
                while (iterator.hasNext())
                {
                    String line = iterator.next();
                    lineCount += 1;

                    try
                    {
                        LogUtils.parseErrorLog(line).getDatetime();
                    }
                    catch (IllegalArgumentException exception)
                    {
                        System.out.println("Bad format line: " + line);
                        badLineCount += 1;
                    }
                    catch (DateTimeParseException exception)
                    {
                        System.out.println("Bad datetime format: " + line);
                        badLineCount += 1;
                    }
                }
            }
            catch (IOException exception)
            {
                System.err.println("Error with file [" + file.getAbsolutePath() + "]");
                exception.printStackTrace();
            }

            if (badLineCount > 0)
            {
                System.out.println("Bad line count: " + badLineCount + "/" + lineCount);
            }
        }
    }

    /**
     * Check sort.
     *
     * @param source
     *            the source
     * @throws IOException
     */
    public static void checkSort(final File source) throws IOException
    {
        if (source != null)
        {
            if (source.isFile())
            {
                if (source.getName().contains("access"))
                {
                    checkSortForAccessFiles(source);
                }
                else if (source.getName().contains("error"))
                {
                    checkSortForErrorFiles(source);
                }
            }
            else
            {
                for (File file : Files.of(source).removeHidden().sortByName())
                {
                    checkSort(file);
                }
            }
        }
    }

    /**
     * Check sort for access files.
     *
     * @param source
     *            the source
     * @throws IOException
     */
    public static void checkSortForAccessFiles(final File file) throws IOException
    {
        if (file == null)
        {
            throw new IllegalArgumentException("Null parameter [source]");
        }
        else if (!file.isFile())
        {
            throw new IllegalArgumentException("Source parameter is not a file.");
        }
        else
        {
            System.out.println("== Check sort for [" + file.getName() + "]");
            LocalDateTime currentDate = null;
            int lineCount = 0;
            int badLineCount = 0;
            LineIterator iterator = new LineIterator(file);
            while (iterator.hasNext())
            {
                String line = iterator.next();
                lineCount += 1;
                LocalDateTime date = LogUtils.parseAccessLog(line).getDatetime();
                if ((currentDate != null) && (date.isBefore(currentDate)))
                {
                    System.out.println(String.format("break detected: %d %s", lineCount, currentDate.toString()));
                    badLineCount += 1;
                }
                currentDate = date;
            }

            if (badLineCount > 0)
            {
                System.out.println("Bad line count: " + badLineCount + "/" + lineCount);
            }
        }
    }

    /**
     * Check sort for error files.
     *
     * @param source
     *            the source
     * @throws IOException
     */
    public static void checkSortForErrorFiles(final File file) throws IOException
    {
        if (file == null)
        {
            throw new IllegalArgumentException("Null parameter [source]");
        }
        else if (!file.isFile())
        {
            throw new IllegalArgumentException("Source parameter is not a file.");
        }
        else
        {
            System.out.println("== Check sort for [" + file.getName() + "]");
            LocalDateTime currentDate = null;
            int lineCount = 0;
            int badLineCount = 0;
            LineIterator iterator = new LineIterator(file);
            while (iterator.hasNext())
            {
                String line = iterator.next();
                lineCount += 1;
                LocalDateTime date = LogUtils.parseErrorLog(line).getDatetime();
                if ((currentDate != null) && (date.isBefore(currentDate)))
                {
                    System.out.println(String.format("break detected: %d %s", lineCount, currentDate.toString()));
                    badLineCount += 1;
                }
                currentDate = date;
            }

            if (badLineCount > 0)
            {
                System.out.println("Bad line count: " + badLineCount + "/" + lineCount);
            }
        }
    }

    /**
     * Sort.
     *
     * @param source
     *            the source
     * @throws IOException
     *             Signals that an I/O exception has occurred.
     */
    public static void sort(final File source) throws IOException
    {
        if (source != null)
        {
            if (source.isFile())
            {
                if (source.getName().contains("access"))
                {
                    sortAccessFiles(source);
                }
                else if (source.getName().contains("error"))
                {
                    sortErrorFiles(source);
                }
            }
            else
            {
                for (File file : Files.of(source).removeHidden().sortByName())
                {
                    sort(file);
                }
            }
        }
    }

    /**
     * Sort access files.
     *
     * @param file
     *            the file
     * @throws IOException
     *             Signals that an I/O exception has occurred.
     */
    public static void sortAccessFiles(final File file) throws IOException
    {
        if (file == null)
        {
            throw new IllegalArgumentException("Null parameter [source]");
        }
        else if (!file.isFile())
        {
            throw new IllegalArgumentException("Source parameter is not a file.");
        }
        else
        {
            System.out.println("== Sort for [" + file.getName() + "]");
            LogUtils.sortAccessLog(file);
        }
    }

    /**
     * Sort error files.
     *
     * @param file
     *            the file
     * @throws IOException
     */
    public static void sortErrorFiles(final File file) throws IOException
    {
        if (file == null)
        {
            throw new IllegalArgumentException("Null parameter [source]");
        }
        else if (!file.isFile())
        {
            throw new IllegalArgumentException("Source parameter is not a file.");
        }
        else
        {
            System.out.println("== Sort for [" + file.getName() + "]");
            LogUtils.sortErrorLog(file);
        }
    }

    /**
     * Test parsing.
     *
     * @param source
     *            the source
     */
    public static void testParsing(final File source)
    {
        testParsingAccessFiles(source);
        testParsingErrorFiles(source);
    }

    /**
     * Test parsing access files.
     *
     * @param source
     *            the source
     */
    public static void testParsingAccessFiles(final File source)
    {
        if (source == null)
        {
            throw new IllegalArgumentException("Null parameter [source]");
        }
        else if (!source.isDirectory())
        {
            throw new IllegalArgumentException("Source parameter is not a directory.");
        }
        else
        {
            System.out.println("== Test access log for [" + source.getName() + "]");
            Stats counter = new Stats();

            for (File directory : source.listFiles())
            {
                if ((directory.isDirectory()) && (!StringUtils.equalsAny(directory.getName(), ".", "..")))
                {
                    logger.info("== {}", directory.getName());

                    for (File file : directory.listFiles())
                    {
                        if ((!file.isDirectory()) && (file.getName().contains("access")))
                        {
                            // logger.info(file.getName());

                            try
                            {
                                LineIterator iterator = new LineIterator(file);
                                while (iterator.hasNext())
                                {
                                    String line = iterator.next();
                                    counter.incLineCount();

                                    Matcher matcher = nginxAccessLogLinePattern.matcher(line);
                                    if (matcher.matches())
                                    {
                                        String value = matcher.group("time");
                                        try
                                        {
                                            LocalDateTime date = LocalDateTime.parse(value, DateTimeFormatter.ofPattern("dd/MMM/yyyy:HH:mm:ss Z").withLocale(Locale.ENGLISH));
                                            counter.incSuccessLineCount();
                                        }
                                        catch (DateTimeParseException exception)
                                        {
                                            System.err.println("Date format error with [" + line + "]");
                                            counter.incErrorLineCount();
                                        }
                                    }
                                    else
                                    {
                                        System.err.println("Not matching line [" + line + "]");
                                        counter.incErrorLineCount();
                                    }
                                }

                                counter.incSuccessFileCount();
                            }
                            catch (IOException exception)
                            {
                                System.err.println("Error with file [" + file.getAbsolutePath() + "]");
                                exception.printStackTrace();
                                counter.incErrorFileCount();
                            }
                            finally
                            {
                                counter.incFileCount();
                            }
                        }
                    }
                }
            }

            counter.stop();
            System.out.println(counter.toString());
        }
    }

    /**
     * Test parsing error files.
     *
     * @param source
     *            the source
     */
    public static void testParsingErrorFiles(final File source)
    {
        if (source == null)
        {
            throw new IllegalArgumentException("Null parameter [source]");
        }
        else if (!source.isDirectory())
        {
            throw new IllegalArgumentException("Source parameter is not a directory.");
        }
        else
        {
            System.out.println("== Test error log for [" + source.getName() + "]");
            Stats counter = new Stats();

            for (File directory : source.listFiles())
            {
                if ((directory.isDirectory()) && (!StringUtils.equalsAny(directory.getName(), ".", "..")))
                {
                    logger.info("== {}", directory.getName());

                    for (File file : directory.listFiles())
                    {
                        if ((!file.isDirectory()) && (file.getName().contains("error")))
                        {
                            // logger.info(file.getName());
                            try
                            {
                                LineIterator iterator = new LineIterator(file);
                                while (iterator.hasNext())
                                {
                                    String line = iterator.next();
                                    counter.incLineCount();

                                    Matcher matcher = nginxErrorLogLinePattern.matcher(line);
                                    if (matcher.matches())
                                    {
                                        String value = matcher.group("time");
                                        try
                                        {
                                            LocalDateTime date = LocalDateTime.parse(value, DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm:ss").withLocale(Locale.ENGLISH));
                                            counter.incSuccessLineCount();
                                        }
                                        catch (DateTimeParseException exception)
                                        {
                                            System.err.println("Date format problem with [" + line + "]");
                                            counter.incErrorLineCount();
                                        }
                                    }
                                    else
                                    {
                                        System.err.println("Not matching line [" + line + "]");
                                        counter.incErrorLineCount();
                                    }
                                }

                                counter.incSuccessFileCount();
                            }
                            catch (IOException exception)
                            {
                                System.err.println("Error with file [" + file.getAbsolutePath() + "]");
                                exception.printStackTrace();
                                counter.incErrorFileCount();
                            }
                            finally
                            {
                                counter.incFileCount();
                            }
                        }
                    }
                }
            }

            System.out.println("=====================================================");
            counter.stop();
            System.out.println(counter.toString());
        }
    }
}