/*
 * Copyright 2002-2017 Drew Noakes
 *
 *    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.
 *
 * More information about this project is available at:
 *
 *    https://drewnoakes.com/code/exif/
 *    https://github.com/drewnoakes/metadata-extractor
 */
package com.drew.metadata;

import com.drew.imaging.ImageMetadataReader;
import com.drew.imaging.ImageProcessingException;
import com.drew.imaging.jpeg.JpegMetadataReader;
import com.drew.imaging.jpeg.JpegProcessingException;
import com.drew.imaging.jpeg.JpegSegmentMetadataReader;
import com.drew.metadata.exif.ExifReader;
import com.drew.metadata.iptc.IptcReader;

import java.io.File;
import java.io.IOException;
import java.util.Arrays;

/**
 * Showcases the most popular ways of using the metadata-extractor library.
 * <p>
 * For more information, see the project wiki: https://github.com/drewnoakes/metadata-extractor/wiki/GettingStarted
 *
 * @author Drew Noakes https://drewnoakes.com
 */
public class SampleUsage
{
    public static void main(String[] args)
    {
        File file = new File("Tests/Data/withIptcExifGps.jpg");

        // There are multiple ways to get a Metadata object for a file

        //
        // SCENARIO 1: UNKNOWN FILE TYPE
        //
        // This is the most generic approach.  It will transparently determine the file type and invoke the appropriate
        // readers.  In most cases, this is the most appropriate usage.  This will handle JPEG, TIFF, GIF, BMP and RAW
        // (CRW/CR2/NEF/RW2/ORF) files and extract whatever metadata is available and understood.
        //
        try {
            Metadata metadata = ImageMetadataReader.readMetadata(file);

            print(metadata, "Using ImageMetadataReader");
        } catch (ImageProcessingException e) {
            print(e);
        } catch (IOException e) {
            print(e);
        }

        //
        // SCENARIO 2: SPECIFIC FILE TYPE
        //
        // If you know the file to be a JPEG, you may invoke the JpegMetadataReader, rather than the generic reader
        // used in approach 1.  Similarly, if you knew the file to be a TIFF/RAW image you might use TiffMetadataReader,
        // PngMetadataReader for PNG files, BmpMetadataReader for BMP files, or GifMetadataReader for GIF files.
        //
        // Using the specific reader offers a very, very slight performance improvement.
        //
        try {
            Metadata metadata = JpegMetadataReader.readMetadata(file);

            print(metadata, "Using JpegMetadataReader");
        } catch (JpegProcessingException e) {
            print(e);
        } catch (IOException e) {
            print(e);
        }

        //
        // APPROACH 3: SPECIFIC METADATA TYPE
        //
        // If you only wish to read a subset of the supported metadata types, you can do this by
        // passing the set of readers to use.
        //
        // This currently only applies to JPEG file processing.
        //
        try {
            // We are only interested in handling
            Iterable<JpegSegmentMetadataReader> readers = Arrays.asList(new ExifReader(), new IptcReader());

            Metadata metadata = JpegMetadataReader.readMetadata(file, readers);

            print(metadata, "Using JpegMetadataReader for Exif and IPTC only");
        } catch (JpegProcessingException e) {
            print(e);
        } catch (IOException e) {
            print(e);
        }
    }

    /**
     * Write all extracted values to stdout.
     */
    private static void print(Metadata metadata, String method)
    {
        System.out.println();
        System.out.println("-------------------------------------------------");
        System.out.print(' ');
        System.out.print(method);
        System.out.println("-------------------------------------------------");
        System.out.println();

        //
        // A Metadata object contains multiple Directory objects
        //
        for (Directory directory : metadata.getDirectories()) {

            //
            // Each Directory stores values in Tag objects
            //
            for (Tag tag : directory.getTags()) {
                System.out.println(tag);
            }

            //
            // Each Directory may also contain error messages
            //
            for (String error : directory.getErrors()) {
                System.err.println("ERROR: " + error);
            }
        }
    }

    private static void print(Exception exception)
    {
        System.err.println("EXCEPTION: " + exception);
    }
}