package com.darwinsys.io;

import java.io.*;

/**
 * Some simple file I-O primitives reimplemented in Java.
 * All methods are static, since there is no state.
 * @version $Id: FileIO.java,v 1.18 2004/05/30 01:39:27 ian Exp $
 */
public class FileIO {

	/** Nobody should need to create an instance; all methods are static */
	private FileIO() {
		// Nothing to do
	}

    /** Copy a file from one filename to another */
    public static void copyFile(String inName, String outName)
	throws FileNotFoundException, IOException {
		BufferedInputStream is = 
			new BufferedInputStream(new FileInputStream(inName));
		BufferedOutputStream os = 
			new BufferedOutputStream(new FileOutputStream(outName));
		copyFile(is, os, true);
	}

	/** Copy a file from an opened InputStream to opened OutputStream */
	public static void copyFile(InputStream is, OutputStream os, boolean close) 
	throws IOException {
		byte[] b = new byte[BLKSIZ];				// the byte read from the file
		int i;
		while ((i = is.read(b)) != -1) {
			os.write(b, 0, i);
		}
		is.close();
		if (close)
			os.close();
    }

	/** Copy a file from an opened Reader to opened Writer */
	public static void copyFile(Reader is, Writer os, boolean close) 
	throws IOException {
		int b;				// the byte read from the file
		BufferedReader bis = new BufferedReader(is);
		while ((b = is.read()) != -1) {
			os.write(b);
		}
		is.close();
		if (close)
			os.close();
    }

	/** Copy a file from a filename to a PrintWriter. */
	public static void copyFile(String inName, PrintWriter pw, boolean close) 
	throws FileNotFoundException, IOException {
		BufferedReader ir = new BufferedReader(new FileReader(inName));
		copyFile(ir, pw, close);
	}

	/** Open a file and read the first line from it. */
	public static String readLine(String inName)
	throws FileNotFoundException, IOException {
		BufferedReader is = new BufferedReader(new FileReader(inName));
		String line = null;
		line = is.readLine();
		is.close();
		return line;
	}

	/** The size of blocking to use */
	protected static final int BLKSIZ = 16384;

	/** Copy a data file from one filename to another, alternate method.
	 * As the name suggests, use my own buffer instead of letting
	 * the BufferedReader allocate and use the buffer.
	 */
	public void copyFileBuffered(String inName, String outName) throws
			FileNotFoundException, IOException {
		InputStream is = new FileInputStream(inName);
		OutputStream os = new FileOutputStream(outName);
		int count = 0;		// the byte count
		byte[] b = new byte[BLKSIZ];	// the bytes read from the file
		while ((count = is.read(b)) != -1) {
			os.write(b, 0, count);
		}
		is.close();
		os.close();
	}

	/** Read the entire content of a Reader into a String */
	public static String readerToString(Reader is) throws IOException {
		StringBuffer sb = new StringBuffer();
		char[] b = new char[BLKSIZ];
		int n;

		// Read a block. If it gets any chars, append them.
		while ((n = is.read(b)) > 0) {
			sb.append(b, 0, n);
		}

		// Only construct the String object once, here.
		return sb.toString();
	}

	/** Read the content of a Stream into a String */
	public static String inputStreamToString(InputStream is)
	throws IOException {
		return readerToString(new InputStreamReader(is));
	}

	/** Write a String as the entire content of a File */
	public static void stringToFile(String text, String fileName)
	throws IOException {
		BufferedWriter os = new BufferedWriter(new FileWriter(fileName));
		os.write(text);
		os.flush();
		os.close();
	}

	/** Open a BufferedReader from a named file. */
	public static BufferedReader openFile(String fileName)
	throws IOException {
		return new BufferedReader(new FileReader(fileName));
	}
}