/*******************************************************************************
 * Copyright (c) 2010, 2017 SAP AG and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 * 
 * Contributors:
 *     Lazar Kirchev, SAP AG - initial API and implementation
 *******************************************************************************/
package org.eclipse.equinox.console.common;

import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;

/**
 * This class serves as an input stream, which wraps the actual input (e.g. from the telnet) and buffers the lines.
 */
public class ConsoleInputStream extends InputStream {

    private final ArrayList<byte[]> buffer = new ArrayList<>();
    private byte[] current;
    private int pos;
    private boolean isClosed;

    @Override
	public synchronized int read() {
        while (current == null && buffer.isEmpty() && !isClosed) {
            try {
                wait();
            } catch (InterruptedException e) {
                return -1;
            }
        }
        if (isClosed) {
            return -1;
        }

        try {
            if (current == null) {
                current = buffer.remove(0);
                return current[pos++] & 0xFF;
            } else {

                return current[pos++] & 0xFF;
            }
        } finally {
            if (current != null) {
                if (pos == current.length) {
                    current = null;
                    pos = 0;
                }
            }
        }

    }

    /*public int read(byte b[], int off, int len) throws IOException {
        if (len == 0) {
            return len;
        }
        int i = read();
        if (i == -1) {
            return -1;
        }
        b[off] = (byte) i;
        return 1;
    }*/
    
    /*public synchronized int read(byte b[], int off, int len) throws IOException {
        if (len == 0) {
            return len;
        }
        
        int currOff = off;
        int readCnt = 0;
        
        if (current != null) {
        	int i;
        	while (pos > 0 && readCnt < len) {
        		i = read();
        		if (i == -1) {
        			return (readCnt > 0) ? readCnt : i;
        		}
        		b[currOff] = (byte) i;
        		currOff++;
        		readCnt++;
        	}
        } else {
        	int i = read();
        	if (i == -1) {
        		return i;
        	}
        	b[currOff] = (byte) i;
        	currOff++;
        	readCnt++;
        	while (pos > 0 && readCnt < len) {
        		i = read();
        		if (i == -1) {
        			return (readCnt > 0) ? readCnt : i;
        		}
        		b[currOff] = (byte) i;
        		currOff++;
        		readCnt++;
        	}
        }
        
        return readCnt;
    }*/
    
    @Override
	public synchronized int read(byte b[], int off, int len) throws IOException {
        if (len == 0) {
            return len;
        }
        
        int currOff = off;
        int readCnt = 0;
        int i;
        
        if (current == null) {
        	i = read();
        	if (i == -1) {
        		return i;
        	}
        	b[currOff] = (byte) i;
        	currOff++;
        	readCnt++;
        }
        
        while ((pos > 0 || !buffer.isEmpty()) && readCnt < len) {
    		i = read();
    		if (i == -1) {
    			return (readCnt > 0) ? readCnt : i;
    		}
    		b[currOff] = (byte) i;
    		currOff++;
    		readCnt++;
    	}
        
        return readCnt;
    }

    @Override
	public synchronized void close() throws IOException {
        isClosed = true;
        notifyAll();
    }

    public synchronized void add(byte[] data) {
        if (data.length > 0) {
            buffer.add(data);
            notify();
        }
    }

}
