/*
 * TextSearcherUtils.java
 *
 * Created on January 14, 2003, 1:20 PM
 */

package project1;

import java.io.*;
import java.util.LinkedList;
import java.util.Iterator;
import java.net.URL;

/** A static method used by the Text Search Oracle.
 *  DON'T CHANGE THIS FILE!  You won't be able to hand it it for Project1.
 *  Your turned-in project must run with our original version of the file.
 *
 *  This method is in a separate file for Project 1 mainly so it won't
 *  be accidentally changed and handed it.  It might be better packaged elsewhere,
 *  such as a method of TextSearcher.
 *
 * @author  dickey cse143
 */
public class TextSearcherUtils {
    
    /** Name of the file containing the text to be searched.
     * It would make more sense for this data to be in the TextSearcher class.
     * It is here just to make testing more convenient.
     */
    private static final String bookName = "ws-sonnets.txt"; 
                    //don't change this file name,
                    //or your program won't work when we test it.
    public static String[] readTextIntoArray() {
        return readTextIntoArray(bookName);        
    }
    
     /* There is little or no need even read this code for Project 1.
     *  It is here to be called to help construct a TextSearcher oracle.
     *  DON'T CHANGE IT, or your program may not run on our system.
     */
     /** Read a text file into an array of strings.
     * @param bookName The name of the text file.  The file needs to be somewhere
     *   where the class loader can find it (i.e., in the class path).  Try
      *  putting the file in the directory of this package, or in the directory
      *  above that.
     * @return an array of strings, each string corresponding to a line of
     *      the file, in the same order as on the file.  A null array is returned
      *     in case the file cannot be located or opened.  An array of length
            0 is a legal return value, meaning that the file existed but no
            data was read from it.  Some of the individual lines (strings)
      *     may be empty strings, but none will be null.
     */
    private static String[] readTextIntoArray(String bookName) {
        ClassLoader cLoader = ClassLoader.getSystemClassLoader();
        /*  //a bit of debug code
         URL bookURL = cLoader.getResource(bookName);
            if (bookURL == null) {
                System.out.println("Can't even get the URL");
            } else {
                //System.out.println("URL is " + bookURL);
            }
         */
        InputStream originalStream = cLoader.getResourceAsStream(bookName);
        if (originalStream == null) {
            System.out.println("Can't find the file " + bookName);
            return null;
        }
        //Get a buffered reader so it is easy to get one line at a time.
        BufferedReader textLines = new BufferedReader(new 
                                        InputStreamReader(originalStream));
        if (textLines == null) {
            System.out.println("Unable to open buffered reader from stream " +
                                            originalStream + 
                                            " from file " + bookName);
            return null;
        }
        //We don't know how many lines there will be,
            //so we store them first in a list.
        LinkedList linesList = new LinkedList();
        while (true) { //read each line of the file and save in the list.
            //stay in the loop until an exception or end of file occurs
            //save each line of the file, without examining it.
            try {
                String thisLine = textLines.readLine();
                if (thisLine == null) {
                    //must be end of file
                    break;
                }
                linesList.add(thisLine);
            } catch (IOException e) {
                System.out.println("Stream exception; no more data will be read.\n\t"
                            + e);
                break; //leave the while loop
            } catch (Throwable e) {
                System.out.println("Highly unexpected error: " + e);
                linesList = new LinkedList(); //set the list back to empty, in case the
                                    //error was something like "out of memory"
                break; //one way to leave the while loop
            }
        } //end while
        int lineCount = linesList.size();
        System.out.println("\nNo more data on " + bookName +
                        " after " + lineCount + " lines.");        
        //copy the list to a string array
        String[] retArray = new String[lineCount];
        Iterator listIter = linesList.iterator();
        for (int line = 0; line < lineCount; line++) {
            assert listIter.hasNext();
            retArray[line] = (String) listIter.next();
            assert retArray[line] != null;
        }
        return retArray;
    //end readTextToArray    
    }

    
}