/*
 * Created on Jun 23, 2004
 */
package wordFinderPuzzle;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

import textfile.FileOrURLInputStream;

/** Read a text file which contains a representation of a word finder puzzle.
 * The format of the file is as follows:
 * <br /> Line 1 contains two integers, separated by a space.  These
 * are number of rows (r) and number of columns (c) of the puzzle.
 * <br /> The next r lines each contain a string of exactly c characters.
 * These lines represent the rows of characters of the puzzle.
 * <br />The next line contains a single number, which is the number (w) of
 *  words
 * which are to be looked for in the puzzle.
 * <br /> The next w lines each contain one word to be searched for.
 * <br /> Any lines beyond this are ignored.
 * <br /> For example, the following represents a 3x3 puzzle with
 * two words to be searched for:
<br />3 3
<br />cat
<br />ack
<br />rtx
<br />2
<br />cat
<br />act
<br /> There is a minimum number of rows and columns that a puzzle must be.
The number of rows and columns does not have to be the same.
 * 
 * @author dickey
 */
public class WFPuzzleReader {
	
	/** Minimum number of rows a puzzle may have. */
	public static final int MIN_ROWS = 2;
	/** Minimum number of columns a puzzle may have. */
	public static final int MIN_COLS = 2;
	
	/** The 2-D array of puzzle letters. */
	private char[][] matrix;
	
	/** The words to look for in the puzzle. */
	private String[] words;
	
	/** Read in a file from a file.
	 * 
	 * @param fileID Identifies a file, which may be local, or may
	 * be a URL of a remote file.  If local, the file should be on
	 * the classpath, in the user directory, or someplace else likely.
	 * <br /> The original case of all letters and words is preserved.  There
	 * is no check for legality of characters or words.
	 * @throws IOException if there is any error reading the file.
	 * @throws IllegalArgumentException if the file format is illegal.
	 */
	public WFPuzzleReader(String fileID) throws IOException {
		BufferedReader puzzfile = 
//			FileOrURLBufferedReader.createReader(fileID);
			new BufferedReader(new InputStreamReader(
					new FileOrURLInputStream(fileID)));
		int lineNum = 0; //how many lines of file have been read
		try {
			//The first line should have two numbers: 2-D array dimensions
			String firstLine = puzzfile.readLine();
			lineNum++;
			String[] nums = firstLine.split("\\s", -1); //split on whitespace
			int rowCount = Integer.parseInt(nums[0]);
			if (rowCount <= MIN_ROWS) {
				throw new IllegalArgumentException(
						"line #" + lineNum + ": row count " + rowCount + 
						" must be > " + MIN_ROWS);
				
			}
			int colCount = Integer.parseInt(nums[1]);
			if (colCount <= MIN_COLS) {
				throw new IllegalArgumentException(
						"line #" + lineNum + ": column count " + colCount + 
						" must be > " + MIN_COLS);		
			}
			//Now we know how big to expect the puzzle to be
			this.matrix = new char[rowCount][colCount];
			for (int row = 0; row < rowCount; row++) {
				String rowLine = puzzfile.readLine();
				lineNum++;
				if (rowLine.length() != colCount) {
					throw new IllegalArgumentException(
							"line #" + lineNum + " has " + rowLine.length() +
							", expected " + colCount);
				}
				this.matrix[row] = rowLine.toCharArray();
			}
			//all rows of the matrix have been read in
			//next line tells how many words to expect
			String wCountString = puzzfile.readLine();
			lineNum++;
			int wCount = Integer.parseInt(wCountString);
			if (wCount < 0) {
				throw new IllegalArgumentException("Line " + lineNum + ": " +
						"Number of words to search for " +
						" must be positive: " + wCount);
			}
			this.words = new String[wCount];
			for (int w = 0; w < wCount; w++) {
				String wLine = puzzfile.readLine();
				if (wLine == null) {
					throw new IllegalArgumentException("Premature end of file " +
							"after line " + lineNum);
				}
				lineNum++;
				this.words[w] = wLine.trim();		
				}
			//all expected data has been read
			String extraData = puzzfile.readLine();
			while (extraData != null) {
				lineNum++;
				System.out.println("Line " + lineNum + ": " +
						" unexpected data ignored: " + extraData);
				extraData = puzzfile.readLine();
			}
			System.out.println("Puzzle file " + fileID + " processed completely. " +
					lineNum + " lines read");
			System.out.println(this);
			//all done, successfully
		} catch (IOException e) {
			System.out.println("Error reading puzzle file, line " + lineNum +
					":\n\t" + e);
			throw e;
		}
	}
	
	/** Get the character matrix of the puzzle that was read in.
	 * 
	 * @return the character matrix.
	 */
	public char[][] getMatrix() {
		return this.matrix;
	}
	
	/** Get the list of words which are to be looked for in the puzzle.
	 * 
	 * @return an array of strings, each of which represents a word
	 * to be looked for.
	 */
	public String[] getWords() {
		return this.words;
	}
	
	/** Give a short summary of the puzzle that was read in.
	 * 
	 */
	public String toString() {
		String retVal = this.getClass().getName() + " " +
			this.matrix.length + "x" + this.matrix[0].length + " matrix, " +
			this.words.length + " words to find.";
		return retVal;
	}

}