/**
 *
 * Copyright 2004 The Apache Software Foundation
 *
 * Licensed 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.codehaus.plexus.archiver;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Locale;
import java.util.concurrent.atomic.AtomicInteger;

import org.codehaus.plexus.archiver.util.ArchiveEntryUtils;
import org.codehaus.plexus.components.io.attributes.SymlinkUtils;
import org.codehaus.plexus.components.io.filemappers.FileMapper;
import org.codehaus.plexus.components.io.fileselectors.FileSelector;
import org.codehaus.plexus.components.io.resources.PlexusIoResource;
import org.codehaus.plexus.util.FileUtils;
import org.codehaus.plexus.util.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import static java.nio.file.StandardCopyOption.REPLACE_EXISTING;

// TODO there should really be constructors which take the source file.

/**
 * @author <a href="mailto:evenisse@codehaus.org">Emmanuel Venisse</a>
 */
public abstract class AbstractUnArchiver implements UnArchiver, FinalizerEnabled {
    private final Logger logger = LoggerFactory.getLogger(getClass());

    protected Logger getLogger() {
        return logger;
    }

    private File destDirectory;

    private File destFile;

    private File sourceFile;

    private boolean overwrite = true;

    private FileMapper[] fileMappers;

    private List<ArchiveFinalizer> finalizers;

    private FileSelector[] fileSelectors;

    /**
     * since 2.3 is on by default
     *
     * @since 1.1
     */
    private boolean useJvmChmod = true;

    /**
     * @since 1.1
     */
    private boolean ignorePermissions = false;

    public AbstractUnArchiver() {
        // no op
    }

    public AbstractUnArchiver(final File sourceFile) {
        this.sourceFile = sourceFile;
    }

    @Override
    public File getDestDirectory() {
        return destDirectory;
    }

    @Override
    public void setDestDirectory(final File destDirectory) {
        this.destDirectory = destDirectory;
    }

    @Override
    public File getDestFile() {
        return destFile;
    }

    @Override
    public void setDestFile(final File destFile) {
        this.destFile = destFile;
    }

    @Override
    public File getSourceFile() {
        return sourceFile;
    }

    @Override
    public void setSourceFile(final File sourceFile) {
        this.sourceFile = sourceFile;
    }

    @Override
    public boolean isOverwrite() {
        return overwrite;
    }

    @Override
    public void setOverwrite(final boolean b) {
        overwrite = b;
    }

    @Override
    public FileMapper[] getFileMappers() {
        return fileMappers;
    }

    @Override
    public void setFileMappers(final FileMapper[] fileMappers) {
        this.fileMappers = fileMappers;
    }

    @Override
    public final void extract() throws ArchiverException {
        validate();
        execute();
        runArchiveFinalizers();
    }

    @Override
    public final void extract(final String path, final File outputDirectory) throws ArchiverException {
        validate(path, outputDirectory);
        execute(path, outputDirectory);
        runArchiveFinalizers();
    }

    @Override
    public void addArchiveFinalizer(final ArchiveFinalizer finalizer) {
        if (finalizers == null) {
            finalizers = new ArrayList<>();
        }

        finalizers.add(finalizer);
    }

    @Override
    public void setArchiveFinalizers(final List<ArchiveFinalizer> archiveFinalizers) {
        finalizers = archiveFinalizers;
    }

    private void runArchiveFinalizers() throws ArchiverException {
        if (finalizers != null) {
            for (ArchiveFinalizer finalizer : finalizers) {
                finalizer.finalizeArchiveExtraction(this);
            }
        }
    }

    protected void validate(final String path, final File outputDirectory) {}

    protected void validate() throws ArchiverException {
        if (sourceFile == null) {
            throw new ArchiverException("The source file isn't defined.");
        }

        if (sourceFile.isDirectory()) {
            throw new ArchiverException("The source must not be a directory.");
        }

        if (!sourceFile.exists()) {
            throw new ArchiverException("The source file " + sourceFile + " doesn't exist.");
        }

        if (destDirectory == null && destFile == null) {
            throw new ArchiverException("The destination isn't defined.");
        }

        if (destDirectory != null && destFile != null) {
            throw new ArchiverException("You must choose between a destination directory and a destination file.");
        }

        if (destDirectory != null && !destDirectory.isDirectory()) {
            destFile = destDirectory;
            destDirectory = null;
        }

        if (destFile != null && destFile.isDirectory()) {
            destDirectory = destFile;
            destFile = null;
        }
    }

    @Override
    public void setFileSelectors(final FileSelector[] fileSelectors) {
        this.fileSelectors = fileSelectors;
    }

    @Override
    public FileSelector[] getFileSelectors() {
        return fileSelectors;
    }

    protected boolean isSelected(final String fileName, final PlexusIoResource fileInfo) throws ArchiverException {
        if (fileSelectors != null) {
            for (FileSelector fileSelector : fileSelectors) {
                try {

                    if (!fileSelector.isSelected(fileInfo)) {
                        return false;
                    }
                } catch (final IOException e) {
                    throw new ArchiverException(
                            "Failed to check, whether " + fileInfo.getName() + " is selected: " + e.getMessage(), e);
                }
            }
        }
        return true;
    }

    protected abstract void execute() throws ArchiverException;

    protected abstract void execute(String path, File outputDirectory) throws ArchiverException;

    /**
     * @since 1.1
     */
    @Override
    public boolean isUseJvmChmod() {
        return useJvmChmod;
    }

    /**
     * <b>jvm chmod won't set group level permissions !</b>
     *
     * @since 1.1
     */
    @Override
    public void setUseJvmChmod(final boolean useJvmChmod) {
        this.useJvmChmod = useJvmChmod;
    }

    /**
     * @since 1.1
     */
    @Override
    public boolean isIgnorePermissions() {
        return ignorePermissions;
    }

    /**
     * @since 1.1
     */
    @Override
    public void setIgnorePermissions(final boolean ignorePermissions) {
        this.ignorePermissions = ignorePermissions;
    }

    protected void extractFile(
            final File srcF,
            final File dir,
            final InputStream compressedInputStream,
            String entryName,
            final Date entryDate,
            final boolean isDirectory,
            final Integer mode,
            String symlinkDestination,
            final FileMapper[] fileMappers)
            throws IOException, ArchiverException {
        if (fileMappers != null) {
            for (final FileMapper fileMapper : fileMappers) {
                entryName = fileMapper.getMappedFileName(entryName);
            }
        }

        // Hmm. Symlinks re-evaluate back to the original file here. Unsure if this is a good thing...
        final File targetFileName = FileUtils.resolveFile(dir, entryName);

        // Make sure that the resolved path of the extracted file doesn't escape the destination directory
        // getCanonicalFile().toPath() is used instead of getCanonicalPath() (returns String),
        // because "/opt/directory".startsWith("/opt/dir") would return false negative.
        Path canonicalDirPath = dir.getCanonicalFile().toPath();
        Path canonicalDestPath = targetFileName.getCanonicalFile().toPath();

        if (!canonicalDestPath.startsWith(canonicalDirPath)) {
            throw new ArchiverException("Entry is outside of the target directory (" + entryName + ")");
        }

        // don't allow override target symlink by standard file
        if (StringUtils.isEmpty(symlinkDestination) && Files.isSymbolicLink(canonicalDestPath)) {
            throw new ArchiverException("Entry is outside of the target directory (" + entryName + ")");
        }

        try {
            if (!shouldExtractEntry(dir, targetFileName, entryName, entryDate)) {
                return;
            }

            // create intermediary directories - sometimes zip don't add them
            final File dirF = targetFileName.getParentFile();
            if (dirF != null) {
                dirF.mkdirs();
            }

            if (!StringUtils.isEmpty(symlinkDestination)) {
                SymlinkUtils.createSymbolicLink(targetFileName, new File(symlinkDestination));
            } else if (isDirectory) {
                targetFileName.mkdirs();
            } else {
                Files.copy(compressedInputStream, targetFileName.toPath(), REPLACE_EXISTING);
            }

            targetFileName.setLastModified(entryDate.getTime());

            if (!isIgnorePermissions() && mode != null && !isDirectory) {
                ArchiveEntryUtils.chmod(targetFileName, mode);
            }
        } catch (final FileNotFoundException ex) {
            getLogger().warn("Unable to expand to file " + targetFileName.getPath());
        }
    }

    /**
     * Counter for casing message emitted, visible for testing.
     */
    final AtomicInteger casingMessageEmitted = new AtomicInteger(0);

    // Visible for testing
    protected boolean shouldExtractEntry(File targetDirectory, File targetFileName, String entryName, Date entryDate)
            throws IOException {
        //     entryname  | entrydate | filename   | filedate | behavior
        // (1) readme.txt | 1970      | -          | -        | always extract if the file does not exist
        // (2) readme.txt | 1970      | readme.txt | 2020     | do not overwrite unless isOverwrite() is true
        // (3) readme.txt | 2020      | readme.txt | 1970     | always override when the file is older than the archive
        // entry
        // (4) README.txt | 1970      | readme.txt | 2020     | case-insensitive filesystem: warn + do not overwrite
        // unless isOverwrite()
        //                                                      case-sensitive filesystem: extract without warning
        // (5) README.txt | 2020      | readme.txt | 1970     | case-insensitive filesystem: warn + overwrite because
        // entry is newer
        //                                                      case-sensitive filesystem: extract without warning

        // The canonical file name follows the name of the archive entry, but takes into account the case-
        // sensitivity of the filesystem. So on a case-sensitive file system, file.exists() returns false for
        // scenario (4) and (5).
        // No matter the case sensitivity of the file system, file.exists() returns false when there is no file with the
        // same name (1).
        if (!targetFileName.exists()) {
            return true;
        }

        boolean entryIsDirectory =
                entryName.endsWith("/"); // directory entries always end with '/', regardless of the OS.
        String canonicalDestPath = targetFileName.getCanonicalPath();
        String suffix = (entryIsDirectory ? "/" : "");
        String relativeCanonicalDestPath =
                canonicalDestPath.replace(targetDirectory.getCanonicalPath() + File.separatorChar, "") + suffix;
        boolean fileOnDiskIsOlderThanEntry = targetFileName.lastModified() < entryDate.getTime();
        boolean differentCasing =
                !normalizedFileSeparator(entryName).equals(normalizedFileSeparator(relativeCanonicalDestPath));

        // Warn for case (4) and (5) if the file system is case-insensitive
        if (differentCasing) {
            String casingMessage = String.format(
                    Locale.ENGLISH,
                    "Archive entry '%s' and existing file '%s' names differ only by case."
                            + " This may lead to an unexpected outcome on case-insensitive filesystems.",
                    entryName,
                    canonicalDestPath);
            getLogger().warn(casingMessage);
            casingMessageEmitted.incrementAndGet();
        }

        // Override the existing file if isOverwrite() is true or if the file on disk is older than the one in the
        // archive
        return isOverwrite() || fileOnDiskIsOlderThanEntry;
    }

    private String normalizedFileSeparator(String pathOrEntry) {
        return pathOrEntry.replace("/", File.separator);
    }
}
