/*
 * 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.
 */

package org.apache.jena.atlas.io;

import java.io.IOException ;
import java.io.InputStream ;
import java.io.Reader ;

import org.apache.jena.atlas.AtlasException ;

/** Fast and streaming.
 */
public final class InStreamASCII extends Reader implements CharStream
{
    private InputStreamBuffered input ;
    private long count = 0 ;

    public InStreamASCII(InputStream in)
    {
        if ( in instanceof InputStreamBuffered )
        {
            input = (InputStreamBuffered)in ;
            return ;
        }
        input = new InputStreamBuffered(in) ;
    }
    
    public InStreamASCII(InputStreamBuffered in) { input = in ; }

    @Override
    public boolean ready() throws IOException
    {
        return input.available() > 0 ;
    }
    
    @Override
    public void close() throws IOException
    { input.close() ; }

    @Override
    public void closeStream()
    { IO.close(input) ; }

    @Override
    public int read(char[] cbuf, int off, int len)
    {
        for ( int i = off ; i < off+len ; i++ )
        {
            int x = read() ;
            if ( x == -1 )
            {
                if ( i == off )
                    return -1 ;
                return (i-off) ;
            }
            if ( x > 128 )
                throw new AtlasException("Illegal ASCII character : "+x) ;
            cbuf[i] = (char)x ;
        }
        return len ; 
    }

    @Override
    public int read()
    { return advance() ; }
    
    @Override
    public int advance()
    {
        count++ ;
        return input.advance() ;
    }
}