/*
 *  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.
 */
/**
 * @author Rustem V. Rafikov
 * @version $Revision: 1.3 $
 */

package javax.imageio.stream;

import java.io.EOFException;
import java.io.IOException;
import java.nio.ByteOrder;

/**
 * The ImageInputStreamImpl abstract class implements the ImageInputStream
 * interface.
 * 
 * @since Android 1.0
 */
public abstract class ImageInputStreamImpl implements ImageInputStream {

    /**
     * The byte order.
     */
    protected ByteOrder byteOrder = ByteOrder.BIG_ENDIAN;

    /**
     * The stream position.
     */
    protected long streamPos = 0;

    /**
     * The flushed position.
     */
    protected long flushedPos = 0;

    /**
     * The bit offset.
     */
    protected int bitOffset = 0;

    /**
     * The closed.
     */
    private boolean closed = false;

    /**
     * The position stack.
     */
    private final PositionStack posStack = new PositionStack();

    /**
     * Instantiates a new ImageInputStreamImpl.
     */
    public ImageInputStreamImpl() {
    }

    /**
     * Check if the stream is closed and if true, throws an IOException.
     * 
     * @throws IOException
     *             if the stream is closed.
     */
    protected final void checkClosed() throws IOException {
        if (closed) {
            throw new IOException("stream is closed");
        }
    }

    public void setByteOrder(ByteOrder byteOrder) {
        this.byteOrder = byteOrder;
    }

    public ByteOrder getByteOrder() {
        return byteOrder;
    }

    public abstract int read() throws IOException;

    public int read(byte[] b) throws IOException {
        return read(b, 0, b.length);
    }

    public abstract int read(byte[] b, int off, int len) throws IOException;

    public void readBytes(IIOByteBuffer buf, int len) throws IOException {
        if (buf == null) {
            throw new NullPointerException("buffer is NULL");
        }

        byte[] b = new byte[len];
        len = read(b, 0, b.length);

        buf.setData(b);
        buf.setOffset(0);
        buf.setLength(len);
    }

    public boolean readBoolean() throws IOException {
        int b = read();
        if (b < 0) {
            throw new EOFException("EOF reached");
        }
        return b != 0;
    }

    public byte readByte() throws IOException {
        int b = read();
        if (b < 0) {
            throw new EOFException("EOF reached");
        }
        return (byte)b;
    }

    public int readUnsignedByte() throws IOException {
        int b = read();
        if (b < 0) {
            throw new EOFException("EOF reached");
        }
        return b;
    }

    public short readShort() throws IOException {
        int b1 = read();
        int b2 = read();

        if (b1 < 0 || b2 < 0) {
            throw new EOFException("EOF reached");
        }

        return byteOrder == ByteOrder.BIG_ENDIAN ? (short)((b1 << 8) | (b2 & 0xff))
                : (short)((b2 << 8) | (b1 & 0xff));
    }

    public int readUnsignedShort() throws IOException {
        // -- TODO implement
        throw new UnsupportedOperationException("Not implemented yet");
    }

    public char readChar() throws IOException {
        // -- TODO implement
        throw new UnsupportedOperationException("Not implemented yet");
    }

    public int readInt() throws IOException {
        // -- TODO implement
        throw new UnsupportedOperationException("Not implemented yet");
    }

    public long readUnsignedInt() throws IOException {
        // -- TODO implement
        throw new UnsupportedOperationException("Not implemented yet");
    }

    public long readLong() throws IOException {
        // -- TODO implement
        throw new UnsupportedOperationException("Not implemented yet");
    }

    public float readFloat() throws IOException {
        // -- TODO implement
        throw new UnsupportedOperationException("Not implemented yet");
    }

    public double readDouble() throws IOException {
        // -- TODO implement
        throw new UnsupportedOperationException("Not implemented yet");
    }

    public String readLine() throws IOException {
        // -- TODO implement
        throw new UnsupportedOperationException("Not implemented yet");
    }

    public String readUTF() throws IOException {
        // -- TODO implement
        throw new UnsupportedOperationException("Not implemented yet");
    }

    public void readFully(byte[] b, int off, int len) throws IOException {
        // -- TODO implement
        throw new UnsupportedOperationException("Not implemented yet");
    }

    public void readFully(byte[] b) throws IOException {
        readFully(b, 0, b.length);
    }

    public void readFully(short[] s, int off, int len) throws IOException {
        // -- TODO implement
        throw new UnsupportedOperationException("Not implemented yet");
    }

    public void readFully(char[] c, int off, int len) throws IOException {
        // -- TODO implement
        throw new UnsupportedOperationException("Not implemented yet");
    }

    public void readFully(int[] i, int off, int len) throws IOException {
        // -- TODO implement
        throw new UnsupportedOperationException("Not implemented yet");
    }

    public void readFully(long[] l, int off, int len) throws IOException {
        // -- TODO implement
        throw new UnsupportedOperationException("Not implemented yet");
    }

    public void readFully(float[] f, int off, int len) throws IOException {
        // -- TODO implement
        throw new UnsupportedOperationException("Not implemented yet");
    }

    public void readFully(double[] d, int off, int len) throws IOException {
        // -- TODO implement
        throw new UnsupportedOperationException("Not implemented yet");
    }

    public long getStreamPosition() throws IOException {
        checkClosed();
        return streamPos;
    }

    public int getBitOffset() throws IOException {
        checkClosed();
        return bitOffset;
    }

    public void setBitOffset(int bitOffset) throws IOException {
        checkClosed();
        this.bitOffset = bitOffset;
    }

    public int readBit() throws IOException {
        // -- TODO implement
        throw new UnsupportedOperationException("Not implemented yet");
    }

    public long readBits(int numBits) throws IOException {
        // -- TODO implement
        throw new UnsupportedOperationException("Not implemented yet");
    }

    public long length() {
        return -1L;
    }

    public int skipBytes(int n) throws IOException {
        // -- TODO implement
        throw new UnsupportedOperationException("Not implemented yet");
    }

    public long skipBytes(long n) throws IOException {
        // -- TODO implement
        throw new UnsupportedOperationException("Not implemented yet");
    }

    public void seek(long pos) throws IOException {
        checkClosed();
        if (pos < getFlushedPosition()) {
            throw new IllegalArgumentException("trying to seek before flushed pos");
        }
        bitOffset = 0;
        streamPos = pos;
    }

    public void mark() {
        try {
            posStack.push(getStreamPosition());
        } catch (IOException e) {
            e.printStackTrace();
            throw new RuntimeException("Stream marking error");
        }
    }

    public void reset() throws IOException {
        // -- TODO bit pos
        if (!posStack.isEmpty()) {
            long p = posStack.pop();
            if (p < flushedPos) {
                throw new IOException("marked position lies in the flushed portion of the stream");
            }
            seek(p);
        }
    }

    public void flushBefore(long pos) throws IOException {
        if (pos > getStreamPosition()) {
            throw new IndexOutOfBoundsException("Trying to flush outside of current position");
        }
        if (pos < flushedPos) {
            throw new IndexOutOfBoundsException("Trying to flush within already flushed portion");
        }
        flushedPos = pos;
        // -- TODO implement
    }

    public void flush() throws IOException {
        flushBefore(getStreamPosition());
    }

    public long getFlushedPosition() {
        return flushedPos;
    }

    public boolean isCached() {
        return false; // def
    }

    public boolean isCachedMemory() {
        return false; // def
    }

    public boolean isCachedFile() {
        return false; // def
    }

    public void close() throws IOException {
        checkClosed();
        closed = true;

    }

    /**
     * Finalizes this object.
     * 
     * @throws Throwable
     *             if an error occurs.
     */
    @Override
    protected void finalize() throws Throwable {
        if (!closed) {
            try {
                close();
            } finally {
                super.finalize();
            }
        }
    }

    /**
     * The Class PositionStack.
     */
    private static class PositionStack {

        /**
         * The Constant SIZE.
         */
        private static final int SIZE = 10;

        /**
         * The values.
         */
        private long[] values = new long[SIZE];

        /**
         * The pos.
         */
        private int pos = 0;

        /**
         * Push.
         * 
         * @param v
         *            the v.
         */
        void push(long v) {
            if (pos >= values.length) {
                ensure(pos + 1);
            }
            values[pos++] = v;
        }

        /**
         * Pop.
         * 
         * @return the long.
         */
        long pop() {
            return values[--pos];
        }

        /**
         * Checks if is empty.
         * 
         * @return true, if is empty.
         */
        boolean isEmpty() {
            return pos == 0;
        }

        /**
         * Ensure.
         * 
         * @param size
         *            the size.
         */
        private void ensure(int size) {
            long[] arr = new long[Math.max(2 * values.length, size)];
            System.arraycopy(values, 0, arr, 0, values.length);
            values = arr;
        }
    }
}