package textfile;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.Reader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
/* 
 * Created on Apr 28, 2004
 * Originally created for CSE142-04sp Assignment 4 (Movie Data Base)
 */
/** A buffered reader for text files with fields delimited by some 
 * regular expression
 * (for example, by a TAB character).
 * @author dickey
 */
public class DelimitedTextReader extends BufferedReader {
	
	/**tab character is the default delimiter. */	
	public static final String DEFAULT_DELIMITER = "/t";
	
	private String delimiter = DEFAULT_DELIMITER;
	
	/** Create a reader with the default delimiter.
	 * @param in a reader; same assumptions as for the constuctor of 
	 * BufferedReader.
	 */
	public DelimitedTextReader(Reader in) {
		super(in);
	}
	
	/** Create a reader with an arbitrary string as delimiter.
	 * 
	 * @param in a reader; same assumptions as for the constuctor of 
	 * BufferedReader.
	 * @param delimiter a regular expression defining the string used to
	 * separate fields on each line.  Although this can be any regular
	 * expression in principle, it is expected that it will normally be
	 * something simple, like a single character.
	 */
	public DelimitedTextReader(Reader in, final String delimiter) {
		this(in);
		this.delimiter = delimiter;
	}
	
	
	/** Create a reader with the default delimiter.
	 * @param in see BufferedReader
	 * @param sz see BufferedReader
	 */
	public DelimitedTextReader(Reader in, int sz) {
		super(in, sz);
	}

	/** Create a reader with an arbitrary string as delimiter.
	 * @param in see BufferedReader
	 * @param sz see BufferedReader
	 * @param delimiter see DelimitedTextReader(in, delimiter).
	 */
	public DelimitedTextReader(Reader in, int sz, String delimiter) {
		this(in, sz);
		this.delimiter = delimiter;
	}

	
	/** Read the next line of the file and give it back as a list of
	 * Strings.  The strings in the list were separated on the original
	 * line by the delimiter string.
	 * @return a list containing all the fields of the line, or null if
	 * end of file has been reached.
	 * @throws IOException
	 */
	public ArrayList readLineAsFieldList() throws IOException {
		String[] fields = readLineAsFieldArray();
		if (fields == null) {
			return null;
		}
		List flist = Arrays.asList(fields);
		ArrayList alist = new ArrayList(flist);
		return alist;
	}
	
	/** Read the next line of the file and give it back as an array of
	 * Strings.  The strings in the array were separated on the original
	 * line by the delimiter string.
	 * @return an array containing all the fields of the line, or null if
	 * end of file has been reached.
	 * @throws IOException
	 */
	public String[] readLineAsFieldArray()throws IOException {
		String thisLine = this.readLine();
		if (thisLine == null) {
			//end of file has been reached
			return null;
		}
		//split as many times as possible around the delimiter
		String[] fields = thisLine.split(this.delimiter, -1);
		return fields;
	}
}