BEGIN LICENSE BLOCK *****
Version: EPL 2.0/GPL 2.0/LGPL 2.1
The contents of this file are subject to the Eclipse Public
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.eclipse.org/legal/epl-v20.html
Software distributed under the License is distributed on an "AS
IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
implied. See the License for the specific language governing
rights and limitations under the License.
Copyright (C) 2006 Ola Bini 
Alternatively, the contents of this file may be used under the terms of
either of the GNU General Public License Version 2 or later (the "GPL"),
or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
in which case the provisions of the GPL or the LGPL are applicable instead
of those above. If you wish to allow use of your version of this file only
under the terms of either the GPL or the LGPL, and not to allow others to
use your version of this file under the terms of the EPL, indicate your
decision by deleting the provisions above and replace them with the notice
and other provisions required by the GPL or the LGPL. If you do not delete
the provisions above, a recipient may use your version of this file under
the terms of any one of the EPL, the GPL or the LGPL.
END LICENSE BLOCK /***** BEGIN LICENSE BLOCK *****
 * Version: EPL 2.0/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Eclipse Public
 * 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.eclipse.org/legal/epl-v20.html
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * Copyright (C) 2006 Ola Bini <Ola.Bini@ki.se>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the EPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the EPL, the GPL or the LGPL.
 ***** END LICENSE BLOCK *****/

package org.jruby.util;

import java.io.OutputStream;
import java.io.IOException;
import org.jcodings.Encoding;
import org.jcodings.specific.ASCIIEncoding;
import org.jruby.Ruby;
import org.jruby.RubyIO;
import org.jruby.RubyString;
import org.jruby.runtime.CallSite;
import org.jruby.runtime.builtin.IRubyObject;
import org.jruby.runtime.MethodIndex;

This class wraps a IRubyObject in an OutputStream. Depending on which messages
the IRubyObject answers to, it will have different functionality.
The point is that the IRubyObject could exhibit duck typing, in the style of IO versus StringIO, for example.
At the moment, the only functionality supported is writing, and the only requirement on the io-object is
that it responds to write() and close() like IO.
Author:
Ola Bini/**
 * This class wraps a IRubyObject in an OutputStream. Depending on which messages
 * the IRubyObject answers to, it will have different functionality.
 * 
 * The point is that the IRubyObject could exhibit duck typing, in the style of IO versus StringIO, for example.
 *
 * At the moment, the only functionality supported is writing, and the only requirement on the io-object is
 * that it responds to write() and close() like IO.
 * 
 * @author <a href="mailto:Ola.Bini@ki.se">Ola Bini</a>
 */
public class IOOutputStream extends OutputStream {
    private final IRubyObject io;
    private final OutputStream out;
    private final CallSite writeAdapter;
    private final CallSite closeAdapter = MethodIndex.getFunctionalCallSite("close");
    private final Encoding encoding;

    
Creates a new OutputStream with the object provided.
Params:
io – the ruby object/**
     * Creates a new OutputStream with the object provided.
     *
     * @param io the ruby object
     */
    public IOOutputStream(final IRubyObject io, Encoding encoding, boolean checkAppend, boolean verifyCanWrite) {
        this.io = io;
        this.out = ( io instanceof RubyIO && !((RubyIO) io).isClosed() &&
                ((RubyIO) io).isBuiltin("write") ) ?
                    ((RubyIO) io).getOutStream() : null;
        if (out == null || verifyCanWrite) {
            final String site;
            if (io.respondsTo("write")) {
                site = "write";
            } else if (checkAppend && io.respondsTo("<<")) {
                site = "<<";
            } else if (verifyCanWrite) {
                throw io.getRuntime().newArgumentError("Object: " + io + " is not a legal argument to this wrapper, " +
                        "cause it doesn't respond to \"write\".");
            } else {
                site = "write";
            }
            writeAdapter = MethodIndex.getFunctionalCallSite(site);
        }
        else {
            writeAdapter = null; // won't be used
        }
        this.encoding = encoding;
    }
    
    public IOOutputStream(final IRubyObject io, boolean checkAppend, boolean verifyCanWrite) {
        this(io, ASCIIEncoding.INSTANCE, checkAppend, verifyCanWrite);
    }    

    
Creates a new OutputStream with the object provided.
Params:
io – the ruby object/**
     * Creates a new OutputStream with the object provided.
     *
     * @param io the ruby object
     */
    public IOOutputStream(final IRubyObject io) {
        this(io, true, true);
    }
    
    public IOOutputStream(final IRubyObject io, Encoding encoding) {
        this(io, encoding, true, true);
    }    

    @Override
    public void write(final int bite) throws IOException {
        if (out != null) {
            out.write(bite);
        } else {
            final Ruby runtime = io.getRuntime();
            writeAdapter.call(runtime.getCurrentContext(), io, io,
                    RubyString.newStringLight(runtime, new ByteList(new byte[] { (byte) bite }, encoding, false)));
        }
    }

    @Override
    public void write(final byte[] b) throws IOException {
        write(b, 0, b.length);
    }

    @Override
    public void write(final byte[] b,final int off, final int len) throws IOException {
        if (out != null) {
            out.write(b, off, len);
        } else {
            final Ruby runtime = io.getRuntime();
            writeAdapter.call(runtime.getCurrentContext(), io, io,
                    RubyString.newStringLight(runtime, new ByteList(b, off, len, encoding, false)));
        }
    }
    
    @Override
    public void close() throws IOException {
        if (out != null) {
            out.close();
        } else if (io.respondsTo("close")) {
            closeAdapter.call(io.getRuntime().getCurrentContext(), io, io);
        }
    }
}