/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package sun.nio.cs;

public class StreamEncoder extends Writer

{

    private static final int DEFAULT_BYTE_BUFFER_SIZE = 8192;

    private volatile boolean closed;

    private void ensureOpen() throws IOException {

        if (closed)

            throw new IOException("Stream closed");

    }

    // Factories for java.io.OutputStreamWriter

    public static StreamEncoder forOutputStreamWriter(OutputStream out,

                                                      Object lock,

                                                      String charsetName)

        throws UnsupportedEncodingException

    {

        String csn = charsetName;

        if (csn == null)

            csn = Charset.defaultCharset().name();

        try {

            if (Charset.isSupported(csn))

                return new StreamEncoder(out, lock, Charset.forName(csn));

        } catch (IllegalCharsetNameException x) { }

        throw new UnsupportedEncodingException (csn);

    }

    public static StreamEncoder forOutputStreamWriter(OutputStream out,

                                                      Object lock,

                                                      Charset cs)

    {

        return new StreamEncoder(out, lock, cs);

    }

    public static StreamEncoder forOutputStreamWriter(OutputStream out,

                                                      Object lock,

                                                      CharsetEncoder enc)

    {

        return new StreamEncoder(out, lock, enc);

    }

    // Factory for java.nio.channels.Channels.newWriter

    public static StreamEncoder forEncoder(WritableByteChannel ch,

                                           CharsetEncoder enc,

                                           int minBufferCap)

    {

        return new StreamEncoder(ch, enc, minBufferCap);

    }

    // -- Public methods corresponding to those in OutputStreamWriter --

    // All synchronization and state/argument checking is done in these public

    // methods; the concrete stream-encoder subclasses defined below need not

    // do any such checking.

    public String getEncoding() {

        if (isOpen())

            return encodingName();

        return null;

    }

    public void flushBuffer() throws IOException {

        synchronized (lock) {

            if (isOpen())

                implFlushBuffer();

            else

                throw new IOException("Stream closed");

        }

    }

    public void write(int c) throws IOException {

        char cbuf[] = new char[1];

        cbuf[0] = (char) c;

        write(cbuf, 0, 1);

    }

    public void write(char cbuf[], int off, int len) throws IOException {

        synchronized (lock) {

            ensureOpen();

            if ((off < 0) || (off > cbuf.length) || (len < 0) ||

                ((off + len) > cbuf.length) || ((off + len) < 0)) {

                throw new IndexOutOfBoundsException();

            } else if (len == 0) {

                return;

            }

            implWrite(cbuf, off, len);

        }

    }

    public void write(String str, int off, int len) throws IOException {

        /* Check the len before creating a char buffer */

        if (len < 0)

            throw new IndexOutOfBoundsException();

        char cbuf[] = new char[len];

        str.getChars(off, off + len, cbuf, 0);

        write(cbuf, 0, len);

    }

    public void write(CharBuffer cb) throws IOException {

        int position = cb.position();

        try {

            synchronized (lock) {

                ensureOpen();

                implWrite(cb);

            }

        } finally {

            cb.position(position);

        }

    }

    public void flush() throws IOException {

        synchronized (lock) {

            ensureOpen();

            implFlush();

        }

    }

    public void close() throws IOException {

        synchronized (lock) {

            if (closed)

                return;

        }

    }

    private boolean isOpen() {

        return !closed;

    }

    // -- Charset-based stream encoder impl --

    private Charset cs;

    private CharsetEncoder encoder;

    private ByteBuffer bb;

    // Exactly one of these is non-null

    private final OutputStream out;

    private WritableByteChannel ch;

    // Leftover first char in a surrogate pair

    private boolean haveLeftoverChar = false;

    private char leftoverChar;

    private CharBuffer lcb = null;

    private StreamEncoder(OutputStream out, Object lock, Charset cs) {

        this(out, lock,

         cs.newEncoder()

         .onMalformedInput(CodingErrorAction.REPLACE)

         .onUnmappableCharacter(CodingErrorAction.REPLACE));

    }

    private StreamEncoder(OutputStream out, Object lock, CharsetEncoder enc) {

        super(lock);

        this.out = out;

        this.ch = null;

        this.cs = enc.charset();

        this.encoder = enc;

        // This path disabled until direct buffers are faster

        if (false && out instanceof FileOutputStream) {

                ch = ((FileOutputStream)out).getChannel();

        if (ch != null)

                    bb = ByteBuffer.allocateDirect(DEFAULT_BYTE_BUFFER_SIZE);

        }

            if (ch == null) {

        bb = ByteBuffer.allocate(DEFAULT_BYTE_BUFFER_SIZE);

        }

    }

    private StreamEncoder(WritableByteChannel ch, CharsetEncoder enc, int mbc) {

        this.out = null;

        this.ch = ch;

        this.cs = enc.charset();

        this.encoder = enc;

        this.bb = ByteBuffer.allocate(mbc < 0

                                  ? DEFAULT_BYTE_BUFFER_SIZE

                                  : mbc);

    }

    private void writeBytes() throws IOException {

        bb.flip();

        int lim = bb.limit();

        int pos = bb.position();

        assert (pos <= lim);

        int rem = (pos <= lim ? lim - pos : 0);

            if (rem > 0) {

        if (ch != null) {

            if (ch.write(bb) != rem)

                assert false : rem;

        } else {

            out.write(bb.array(), bb.arrayOffset() + pos, rem);

        }

        }

        bb.clear();

        }

    private void flushLeftoverChar(CharBuffer cb, boolean endOfInput)

        throws IOException

    {

        if (!haveLeftoverChar && !endOfInput)

            return;

        if (lcb == null)

            lcb = CharBuffer.allocate(2);

        else

            lcb.clear();

        if (haveLeftoverChar)

            lcb.put(leftoverChar);

        if ((cb != null) && cb.hasRemaining())

            lcb.put(cb.get());

        lcb.flip();

        while (lcb.hasRemaining() || endOfInput) {

            CoderResult cr = encoder.encode(lcb, bb, endOfInput);

            if (cr.isUnderflow()) {

                if (lcb.hasRemaining()) {

                    leftoverChar = lcb.get();

                    if (cb != null && cb.hasRemaining()) {

                        lcb.clear();

                        lcb.put(leftoverChar).put(cb.get()).flip();

                        continue;

                    }

                    return;

                }

                break;

            }

            if (cr.isOverflow()) {

                assert bb.position() > 0;

                writeBytes();

                continue;

            }

            cr.throwException();

        }

        haveLeftoverChar = false;

    }

    void implWrite(char cbuf[], int off, int len)

        throws IOException

    {

        CharBuffer cb = CharBuffer.wrap(cbuf, off, len);

        implWrite(cb);

    }

    void implWrite(CharBuffer cb)

        throws IOException

    {

        if (haveLeftoverChar) {

            flushLeftoverChar(cb, false);

        }

        while (cb.hasRemaining()) {

            CoderResult cr = encoder.encode(cb, bb, false);

            if (cr.isUnderflow()) {

                assert (cb.remaining() <= 1) : cb.remaining();

                if (cb.remaining() == 1) {

                    haveLeftoverChar = true;

                    leftoverChar = cb.get();

                }

                break;

            }

            if (cr.isOverflow()) {

                assert bb.position() > 0;

                writeBytes();

                continue;

            }

            cr.throwException();

        }

    }

    void implFlushBuffer() throws IOException {

        if (bb.position() > 0)

        writeBytes();

    }

    void implFlush() throws IOException {

        implFlushBuffer();

        if (out != null)

        out.flush();

    }

    void implClose() throws IOException {

        flushLeftoverChar(null, true);

        try {

            for (;;) {

                CoderResult cr = encoder.flush(bb);

                if (cr.isUnderflow())

                    break;

                if (cr.isOverflow()) {

                    assert bb.position() > 0;

                    writeBytes();

                    continue;

                }

                cr.throwException();

            }

            if (bb.position() > 0)

                writeBytes();

            if (ch != null)

                ch.close();

        } catch (IOException x) {

            encoder.reset();

            throw x;

        }

    }

    String encodingName() {

        return ((cs instanceof HistoricallyNamedCharset)

            ? ((HistoricallyNamedCharset)cs).historicalName()

            : cs.name());

    }

}