/*************************************************************************
 *  Compilation:  javac In.java
 *  Execution:    java In
 *  
 *  Reads in data of various types from: stdin, file, URL.
 *
 *  Reads in a string, rest of line, or rest of file and returns
 *  it as a String or null if there is no more data.
 *
 *  The client can use Integer.parseInt(in.readString()) to read
 *  in an int.
 *
 *  Typically this class is used with another client, but main()
 *  provides a testing routine.
 *
 *  % java In
 *  Test if In.java works.
 *  Second line.
 *  
 *  Test 
 *  if
 *  In.java 
 *  works.
 *  Second
 *  line.
 *
 *  Test if In.java works.
 *  Second line.
 *
 *************************************************************************/


import java.net.URLConnection;
import java.net.URL;
import java.net.Socket;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.BufferedReader;
import java.io.FileReader;


class In {
    private BufferedReader br;

    // system independent
    private final static String NEWLINE = System.getProperty("line.separator");

    // for stdin
    public In() {
        InputStreamReader isr = new InputStreamReader(System.in);
        br = new BufferedReader(isr);
    }

    // for stdin
    public In(Socket socket) {
        try {
            InputStream is        = socket.getInputStream();
            InputStreamReader isr = new InputStreamReader(is);
            br                    = new BufferedReader(isr);
        } catch (IOException ioe) { ioe.printStackTrace(); }
    }
 
    // for URLs
    public In(URL url) {
        try {
            URLConnection site    = url.openConnection();
            InputStream is        = site.getInputStream();
            InputStreamReader isr = new InputStreamReader(is);
            br                    = new BufferedReader(isr);
        } catch (IOException ioe) { ioe.printStackTrace(); }
    }


    // for files and web pages
    public In(String s) {

        try {

            // first try to read file from local file system
            File file = new File(s);
            if (file.exists()) {
                FileReader fr = new FileReader(s);
                br = new BufferedReader(fr);
                return;
            }

            // next try for files included in jar
            URL url = getClass().getResource(s);

            // or URL from web
            if (url == null) url = new URL(s);

            URLConnection site    = url.openConnection();
            InputStream is        = site.getInputStream();
            InputStreamReader isr = new InputStreamReader(is);
            br = new BufferedReader(isr);
        } catch(IOException ioe) { throw new RuntimeException("Could not open " + s); }
    }


    // note read() returns -1 if EOF
    private int readChar() {
        int c = -1;
        try { c = br.read(); }
        catch(IOException ioe) { ioe.printStackTrace(); }
        return c;
    }

    // read a token - delete preceding whitespace and one trailing whitespace character
    public String readString() {
        int c;
        while ((c = readChar()) != -1)
            if (!Character.isWhitespace((char) c)) break;

        if (c == -1) return null;
 
        String s = "" + (char) c;
        while ((c = readChar()) != -1)
            if (Character.isWhitespace((char) c)) break;
            else s += (char) c;

        return s;
    }

    // return rest of line as string and return it, not including newline 
    public String readLine() {
        if (br == null) return null;
        String s = null;
        try { s = br.readLine(); }
        catch(IOException ioe) { ioe.printStackTrace(); }
        return s;
    }


    // return rest of input as string, use StringBuffer to avoid quadratic run time
    // don't include NEWLINE at very end
    public String readAll() {
        StringBuffer sb = new StringBuffer();
        String s = readLine();
        if (s == null) return null;
        sb.append(s);
        while ((s = readLine()) != null) {
            sb.append(NEWLINE).append(s);
        }   
        return sb.toString();
    }


    public void close() { 
        try { br.close(); }
        catch (IOException e) { e.printStackTrace(); }
    }


    // This method is just here to test the class
    public static void main (String args[]) {
        In in;
        String s;

        // read from a URL
        in = new In("http://www.cs.princeton.edu/IntroCS/24inout/InTest.txt");
        System.out.println(in.readAll());
        System.out.println();

        // read one line at a time from URL
        in = new In("http://www.cs.princeton.edu/IntroCS/24inout/InTest.txt");
        while ((s = in.readLine()) != null)
            System.out.println(s);
        System.out.println();

        // read one string at a time from URL
        in = new In("http://www.cs.princeton.edu/IntroCS/24inout/InTest.txt");
        while ((s = in.readString()) != null)
            System.out.println(s);
        System.out.println();


        // read one line at a time from file in current directory
        in = new In("InTest.txt");
        while ((s = in.readLine()) != null)
            System.out.println(s);
        System.out.println();

        // read one line at a time from absolute path
        in = new In("/csinfo/www/introcs/24inout/InTest.txt");
        //// in = new In("C:\\csinfo\\www\\introcs\\24inout\\InTest.txt");  // Windows
        while ((s = in.readLine()) != null)
            System.out.println(s);
        System.out.println();

        // read one line at a time from file using relative path
        in = new In("../24inout/InTest.txt");
        while ((s = in.readLine()) != null)
            System.out.println(s);
        System.out.println();
    }

}