SquirrelJME/SquirrelJME

// -*- Mode: Java; indent-tabs-mode: t; tab-width: 4 -*-
// ---------------------------------------------------------------------------
// SquirrelJME
//     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
// ---------------------------------------------------------------------------
// SquirrelJME is under the Mozilla Public License Version 2.0.
// See license.mkd for licensing and copyright information.
// ---------------------------------------------------------------------------

package java.io;

import cc.squirreljme.runtime.cldc.annotation.Api;
import cc.squirreljme.runtime.cldc.debug.Debugging;
import cc.squirreljme.runtime.cldc.io.CodecFactory;
import cc.squirreljme.runtime.cldc.io.Encoder;

/**
 * This class maps character based output to a byte based output, encoding
 * any written characters to the output.
 * 
 * @since 2022/07/12
 */
@Api
public class OutputStreamWriter
    extends Writer
{
    /** The encoder used to encode bytes. */
    private final Encoder _encoder;
    
    /** The stream to write to. */
    private final OutputStream _out;
    
    /** The internal working buffer for the encoder. */
    private final byte[] _workBuf;
    
    /**
     * Initializes the writer, using the default character set.
     * 
     * @param __out The stream to write to.
     * @throws NullPointerException On null arguments.
     * @since 2022/07/12
     */
    @Api
    public OutputStreamWriter(OutputStream __out)
        throws NullPointerException
    {
        this(__out, CodecFactory.defaultEncoder());
    }
    
    /**
     * Initializes the writer.
     * 
     * @param __out The stream to write to.
     * @param __charset The character set to use for encoding.
     * @throws NullPointerException On null arguments.
     * @throws UnsupportedEncodingException If the encoding is not supported.
     * @since 2022/07/12
     */
    @Api
    public OutputStreamWriter(OutputStream __out, String __charset)
        throws NullPointerException, UnsupportedEncodingException
    {
        this(__out, CodecFactory.encoder(__charset));
    }
    
    /**
     * Initializes the writer, using the specified internal encoder.
     * 
     * @param __out The stream to write to.
     * @throws NullPointerException On null arguments.
     * @since 2022/07/12
     */
    @Api
    private OutputStreamWriter(OutputStream __out, Encoder __encoder)
        throws NullPointerException
    {
        if (__out == null || __encoder == null)
            throw new NullPointerException("NARG");
        
        this._out = __out;
        this._encoder = __encoder;
        this._workBuf = new byte[__encoder.maximumSequenceLength()];
    }
    
    /**
     * {@inheritDoc}
     * @since 2022/07/12
     */
    @Override
    public void close()
        throws IOException
    {
        // Forward
        this._out.close();
    }
    
    /**
     * {@inheritDoc}
     * @since 2022/07/12
     */
    @Override
    public void flush()
        throws IOException
    {
        // Forward
        this._out.flush();
    }
    
    /**
     * Returns the name of the encoding.
     * 
     * @return The encoding name.
     * @since 2022/07/12
     */
    @Api
    public String getEncoding()
    {
        return this._encoder.encodingName();
    }
    
    /**
     * {@inheritDoc}
     * @since 2022/07/12
     */
    @Override
    public void write(int __c)
        throws IOException
    {
        this.__write((char)__c);
    }
    
    /**
     * {@inheritDoc}
     * @since 2022/07/12
     */
    @Override
    public void write(char[] __c, int __o, int __l)
        throws IndexOutOfBoundsException, IOException, NullPointerException
    {
        if (__c == null)
            throw new NullPointerException("NARG");
        if (__o < 0 || __l < 0 || (__o + __l) < 0 ||
            (__o + __l) > __c.length)
            throw new IndexOutOfBoundsException("IOOB");
        
        for (int i = 0; i < __l; i++)
            this.__write(__c[__o + i]);
    }
    
    /**
     * {@inheritDoc}
     * @since 2022/07/12
     */
    @Override
    public void write(String __str, int __off, int __len)
        throws IndexOutOfBoundsException, IOException, NullPointerException
    {
        if (__str == null)
            throw new NullPointerException("NARG");
        if (__off < 0 || __len < 0 || (__off + __len) < 0 ||
            (__off + __len) > __str.length())
            throw new IndexOutOfBoundsException("IOOB");
        
        for (int i = 0; i < __len; i++)
            this.__write(__str.charAt(__off + i));
    }
    
    /**
     * Writes the given character.
     * 
     * @param __c The character to write.
     * @throws IOException On write errors.
     * @since 2022/07/12
     */
    private void __write(char __c)
        throws IOException
    {
        byte[] workBuf = this._workBuf;
        int len = this._encoder.encode(__c, workBuf, 0, workBuf.length);
        
        // Should never happen!
        if (len < 0)
            throw Debugging.oops();
        
        this._out.write(workBuf, 0, len);
    }
}