+/*
+ * Sonitus - MetadataBlock.java - Copyright © 2013 David Roden
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.pterodactylus.sonitus.io.flac;
+
+import static com.google.common.io.ByteStreams.readFully;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.List;
+
+import com.google.common.base.Optional;
+import com.google.common.base.Predicate;
+import com.google.common.collect.FluentIterable;
+import com.google.common.collect.Lists;
+
+/**
+ * Parser and container for information about a FLAC stream.
+ *
+ * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+ */
+public class Stream {
+
+ /** The metadata blocks of the stream. */
+ private final List<MetadataBlock> metadataBlocks = Lists.newArrayList();
+
+ /**
+ * Creates a new FLAC stream containing the given metadata blocks.
+ *
+ * @param metadataBlocks
+ * The metadata blocks in order of appearance
+ */
+ private Stream(List<MetadataBlock> metadataBlocks) {
+ this.metadataBlocks.addAll(metadataBlocks);
+ }
+
+ //
+ // ACCESSORS
+ //
+
+ /**
+ * Returns all metadata blocks of the given block type, in the order they
+ * appear in this stream.
+ *
+ * @param blockType
+ * The block type to get all metadata blocks for
+ * @return The metadata blocks of the given block type
+ */
+ public Collection<MetadataBlock> metadataBlocks(final BlockType blockType) {
+ return FluentIterable.from(metadataBlocks).filter(new Predicate<MetadataBlock>() {
+
+ @Override
+ public boolean apply(MetadataBlock metadataBlock) {
+ return metadataBlock.header().blockType() == blockType;
+ }
+ }).toList();
+ }
+
+ //
+ // STATIC METHODS
+ //
+
+ /**
+ * Parses the given input stream and returns information about the stream if it
+ * can be successfully parsed as a FLAC stream.
+ *
+ * @param inputStream
+ * The input stream containing the FLAC stream
+ * @return The parsed FLAC stream, or {@link Optional#absent()} if no FLAC
+ * stream could be found at the stream’s current position
+ * @throws IOException
+ * if an I/O error occurs
+ */
+ public static Optional<Stream> parse(InputStream inputStream) throws IOException {
+ byte[] streamTag = new byte[4];
+ readFully(inputStream, streamTag);
+ if (!Arrays.equals(streamTag, new byte[] { 'f', 'L', 'a', 'C' })) {
+ return Optional.absent();
+ }
+ List<MetadataBlock> metadataBlocks = Lists.newArrayList();
+ while (true) {
+ MetadataBlock metadataBlock = MetadataBlock.parse(inputStream);
+ metadataBlocks.add(metadataBlock);
+ if (metadataBlock.header().isLastMetadataBlock()) {
+ break;
+ }
+ }
+ return Optional.of(new Stream(metadataBlocks));
+ }
+
+}