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/* ====================================================================
   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.poi.openxml4j.opc.internal;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
import org.apache.poi.openxml4j.exceptions.OpenXML4JException;
import org.apache.poi.openxml4j.opc.OPCPackage;
import org.apache.poi.openxml4j.opc.PackagePart;
import org.apache.poi.openxml4j.opc.PackagePartName;
import org.apache.poi.openxml4j.opc.internal.marshallers.ZipPartMarshaller;
import org.apache.poi.util.Beta;
import org.apache.poi.util.IOUtils;
import org.apache.poi.util.TempFile;

import java.io.*;

/**
 * (Experimental) Temp File version of a package part.
 *
 * @since POI 5.1.0
 */
@Beta
public final class TempFilePackagePart extends PackagePart {
    private static final Logger LOG = LogManager.getLogger(TempFilePackagePart.class);

    /**
     * Storage for the part data.
     */
    private File tempFile;

    /**
     * Constructor.
     *
     * @param pack
     *            The owner package.
     * @param partName
     *            The part name.
     * @param contentType
     *            The content type.
     * @throws InvalidFormatException
     *             If the specified URI is not OPC compliant.
     * @throws IOException
     *             If temp file cannot be created.
     */
    public TempFilePackagePart(OPCPackage pack, PackagePartName partName,
                               String contentType) throws InvalidFormatException, IOException {
        this(pack, partName, contentType, true);
    }

    /**
     * Constructor.
     *
     * @param pack
     *            The owner package.
     * @param partName
     *            The part name.
     * @param contentType
     *            The content type.
     * @param loadRelationships
     *            Specify if the relationships will be loaded.
     * @throws InvalidFormatException
     *             If the specified URI is not OPC compliant.
     * @throws IOException
     *             If temp file cannot be created.
     */
    public TempFilePackagePart(OPCPackage pack, PackagePartName partName,
                               String contentType, boolean loadRelationships)
            throws InvalidFormatException, IOException {
        super(pack, partName, new ContentType(contentType), loadRelationships);
        tempFile = TempFile.createTempFile("poi-package-part", ".tmp");
    }

    @Override
    protected InputStream getInputStreamImpl() throws IOException {
        return new FileInputStream(tempFile);
    }

    @Override
    protected OutputStream getOutputStreamImpl() throws IOException {
        return new FileOutputStream(tempFile);
    }

    @Override
    public long getSize() {
        return tempFile.length();
    }

    @Override
    public void clear() {
        try(OutputStream os = getOutputStreamImpl()) {
            os.write(new byte[0]);
        } catch (IOException e) {
            LOG.atWarn().log("Failed to clear data in temp file", e);
        }
    }

    @Override
    public boolean save(OutputStream os) throws OpenXML4JException {
        return new ZipPartMarshaller().marshall(this, os);
    }

    @Override
    public boolean load(InputStream is) throws InvalidFormatException {
       try (OutputStream os = getOutputStreamImpl()) {
            IOUtils.copy(is, os);
       } catch(IOException e) {
            throw new InvalidFormatException(e.getMessage(), e);
       }

       // All done
       return true;
    }

    @Override
    public void close() {
        if (!tempFile.delete()) {
            LOG.atInfo().log("Failed to delete temp file; may already have been closed and deleted");
        }
    }

    @Override
    public void flush() {
        // Do nothing
    }
}