/*
 *  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.commons.compress.archivers.zip;

import java.io.File;
import java.util.Date;
import java.util.LinkedHashMap;
import java.util.zip.ZipException;
import org.apache.commons.compress.archivers.ArchiveEntry;

/**
 * Extension that adds better handling of extra fields and provides
 * access to the internal and external file attributes.
 *
 * @NotThreadSafe
 */
public class ZipArchiveEntry extends java.util.zip.ZipEntry
    implements ArchiveEntry, Cloneable {

    public static final int PLATFORM_UNIX = 3;
    public static final int PLATFORM_FAT  = 0;
    private static final int SHORT_MASK = 0xFFFF;
    private static final int SHORT_SHIFT = 16;

    private int internalAttributes = 0;
    private int platform = PLATFORM_FAT;
    private long externalAttributes = 0;
    private LinkedHashMap/*<ZipShort, ZipExtraField>*/ extraFields = null;
    private String name = null;

    /**
     * Creates a new zip entry with the specified name.
     * @param name the name of the entry
     */
    public ZipArchiveEntry(String name) {
        super(name);
    }

    /**
     * Creates a new zip entry with fields taken from the specified zip entry.
     * @param entry the entry to get fields from
     * @throws ZipException on error
     */
    public ZipArchiveEntry(java.util.zip.ZipEntry entry) throws ZipException {
        super(entry);
        setName(entry.getName());
        byte[] extra = entry.getExtra();
        if (extra != null) {
            setExtraFields(ExtraFieldUtils.parse(extra));
        } else {
            // initializes extra data to an empty byte array
            setExtra();
        }
    }

    /**
     * Creates a new zip entry with fields taken from the specified zip entry.
     * @param entry the entry to get fields from
     * @throws ZipException on error
     */
    public ZipArchiveEntry(ZipArchiveEntry entry) throws ZipException {
        this((java.util.zip.ZipEntry) entry);
        setInternalAttributes(entry.getInternalAttributes());
        setExternalAttributes(entry.getExternalAttributes());
        setExtraFields(entry.getExtraFields());
    }

    /**
     */
    protected ZipArchiveEntry() {
        super("");
    }

    public ZipArchiveEntry(File inputFile, String entryName) {
        this(entryName);
        if (inputFile.isFile()){
            setSize(inputFile.length());
        }
        setTime(inputFile.lastModified());
        // TODO are there any other fields we can set here?
    }

    /**
     * Overwrite clone.
     * @return a cloned copy of this ZipArchiveEntry
     */
    public Object clone() {
        ZipArchiveEntry e = (ZipArchiveEntry) super.clone();

        e.extraFields = extraFields != null ? (LinkedHashMap) extraFields.clone() : null;
        e.setInternalAttributes(getInternalAttributes());
        e.setExternalAttributes(getExternalAttributes());
        e.setExtraFields(getExtraFields());
        return e;
    }

    /**
     * Retrieves the internal file attributes.
     *
     * @return the internal file attributes
     */
    public int getInternalAttributes() {
        return internalAttributes;
    }

    /**
     * Sets the internal file attributes.
     * @param value an <code>int</code> value
     */
    public void setInternalAttributes(int value) {
        internalAttributes = value;
    }

    /**
     * Retrieves the external file attributes.
     * @return the external file attributes
     */
    public long getExternalAttributes() {
        return externalAttributes;
    }

    /**
     * Sets the external file attributes.
     * @param value an <code>long</code> value
     */
    public void setExternalAttributes(long value) {
        externalAttributes = value;
    }

    /**
     * Sets Unix permissions in a way that is understood by Info-Zip's
     * unzip command.
     * @param mode an <code>int</code> value
     */
    public void setUnixMode(int mode) {
        // CheckStyle:MagicNumberCheck OFF - no point
        setExternalAttributes((mode << SHORT_SHIFT)
                              // MS-DOS read-only attribute
                              | ((mode & 0200) == 0 ? 1 : 0)
                              // MS-DOS directory flag
                              | (isDirectory() ? 0x10 : 0));
        // CheckStyle:MagicNumberCheck ON
        platform = PLATFORM_UNIX;
    }

    /**
     * Unix permission.
     * @return the unix permissions
     */
    public int getUnixMode() {
        return platform != PLATFORM_UNIX ? 0 :
            (int) ((getExternalAttributes() >> SHORT_SHIFT) & SHORT_MASK);
    }

    /**
     * Platform specification to put into the &quot;version made
     * by&quot; part of the central file header.
     *
     * @return PLATFORM_FAT unless {@link #setUnixMode setUnixMode}
     * has been called, in which case PLATORM_UNIX will be returned.
     */
    public int getPlatform() {
        return platform;
    }

    /**
     * Set the platform (UNIX or FAT).
     * @param platform an <code>int</code> value - 0 is FAT, 3 is UNIX
     */
    protected void setPlatform(int platform) {
        this.platform = platform;
    }

    /**
     * Replaces all currently attached extra fields with the new array.
     * @param fields an array of extra fields
     */
    public void setExtraFields(ZipExtraField[] fields) {
        extraFields = new LinkedHashMap();
        for (int i = 0; i < fields.length; i++) {
            extraFields.put(fields[i].getHeaderId(), fields[i]);
        }
        setExtra();
    }

    /**
     * Retrieves extra fields.
     * @return an array of the extra fields
     */
    public ZipExtraField[] getExtraFields() {
        if (extraFields == null) {
            return new ZipExtraField[0];
        }
        ZipExtraField[] result = new ZipExtraField[extraFields.size()];
        return (ZipExtraField[]) extraFields.values().toArray(result);
    }

    /**
     * Adds an extra fields - replacing an already present extra field
     * of the same type.
     *
     * <p>If no extra field of the same type exists, the field will be
     * added as last field.</p>
     * @param ze an extra field
     */
    public void addExtraField(ZipExtraField ze) {
        if (extraFields == null) {
            extraFields = new LinkedHashMap();
        }
        extraFields.put(ze.getHeaderId(), ze);
        setExtra();
    }

    /**
     * Adds an extra fields - replacing an already present extra field
     * of the same type.
     *
     * <p>The new extra field will be the first one.</p>
     * @param ze an extra field
     */
    public void addAsFirstExtraField(ZipExtraField ze) {
        LinkedHashMap copy = extraFields;
        extraFields = new LinkedHashMap();
        extraFields.put(ze.getHeaderId(), ze);
        if (copy != null) {
            copy.remove(ze.getHeaderId());
            extraFields.putAll(copy);
        }
        setExtra();
    }

    /**
     * Remove an extra fields.
     * @param type the type of extra field to remove
     */
    public void removeExtraField(ZipShort type) {
        if (extraFields == null) {
            throw new java.util.NoSuchElementException();
        }
        if (extraFields.remove(type) == null) {
            throw new java.util.NoSuchElementException();
        }
        setExtra();
    }

    /**
     * Looks up an extra field by its header id.
     *
     * @return null if no such field exists.
     */
    public ZipExtraField getExtraField(ZipShort type) {
        if (extraFields != null) {
            return (ZipExtraField) extraFields.get(type);
        }
        return null;
    }

    /**
     * Throws an Exception if extra data cannot be parsed into extra fields.
     * @param extra an array of bytes to be parsed into extra fields
     * @throws RuntimeException if the bytes cannot be parsed
     * @throws RuntimeException on error
     */
    public void setExtra(byte[] extra) throws RuntimeException {
        try {
            ZipExtraField[] local = ExtraFieldUtils.parse(extra, true);
            mergeExtraFields(local, true);
        } catch (ZipException e) {
            throw new RuntimeException(e.getMessage(), e);
        }
    }

    /**
     * Unfortunately {@link java.util.zip.ZipOutputStream
     * java.util.zip.ZipOutputStream} seems to access the extra data
     * directly, so overriding getExtra doesn't help - we need to
     * modify super's data directly.
     */
    protected void setExtra() {
        super.setExtra(ExtraFieldUtils.mergeLocalFileDataData(getExtraFields()));
    }

    /**
     * Sets the central directory part of extra fields.
     */
    public void setCentralDirectoryExtra(byte[] b) {
        try {
            ZipExtraField[] central = ExtraFieldUtils.parse(b, false);
            mergeExtraFields(central, false);
        } catch (ZipException e) {
            throw new RuntimeException(e.getMessage(), e);
        }
    }

    /**
     * Retrieves the extra data for the local file data.
     * @return the extra data for local file
     */
    public byte[] getLocalFileDataExtra() {
        byte[] extra = getExtra();
        return extra != null ? extra : new byte[0];
    }

    /**
     * Retrieves the extra data for the central directory.
     * @return the central directory extra data
     */
    public byte[] getCentralDirectoryExtra() {
        return ExtraFieldUtils.mergeCentralDirectoryData(getExtraFields());
    }

    /**
     * Get the name of the entry.
     * @return the entry name
     */
    public String getName() {
        return name == null ? super.getName() : name;
    }

    /**
     * Is this entry a directory?
     * @return true if the entry is a directory
     */
    public boolean isDirectory() {
        return getName().endsWith("/");
    }

    /**
     * Set the name of the entry.
     * @param name the name to use
     */
    protected void setName(String name) {
        this.name = name;
    }

    /**
     * Get the hashCode of the entry.
     * This uses the name as the hashcode.
     * @return a hashcode.
     */
    public int hashCode() {
        // this method has severe consequences on performance. We cannot rely
        // on the super.hashCode() method since super.getName() always return
        // the empty string in the current implemention (there's no setter)
        // so it is basically draining the performance of a hashmap lookup
        return getName().hashCode();
    }

    /**
     * If there are no extra fields, use the given fields as new extra
     * data - otherwise merge the fields assuming the existing fields
     * and the new fields stem from different locations inside the
     * archive.
     * @param f the extra fields to merge
     * @param local whether the new fields originate from local data
     */
    private void mergeExtraFields(ZipExtraField[] f, boolean local)
        throws ZipException {
        if (extraFields == null) {
            setExtraFields(f);
        } else {
            for (int i = 0; i < f.length; i++) {
                ZipExtraField existing = getExtraField(f[i].getHeaderId());
                if (existing == null) {
                    addExtraField(f[i]);
                } else {
                    if (local) {
                        byte[] b = f[i].getLocalFileDataData();
                        existing.parseFromLocalFileData(b, 0, b.length);
                    } else {
                        byte[] b = f[i].getCentralDirectoryData();
                        existing.parseFromCentralDirectoryData(b, 0, b.length);
                    }
                }
            }
            setExtra();
        }
    }

    /** {@inheritDocs} */
    public Date getLastModifiedDate() {
        return new Date(getTime());
    }

    /* (non-Javadoc)
     * @see java.lang.Object#equals(java.lang.Object)
     */
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj == null || getClass() != obj.getClass()) {
            return false;
        }
        ZipArchiveEntry other = (ZipArchiveEntry) obj;
        if (name == null) {
            if (other.name != null) {
                return false;
            }
        } else if (!name.equals(other.name)) {
            return false;
        }
        return true;
    }
}