package de.fhdw.wtf.common.token;
   
   import java.io.Serializable;
   
   /**
    * The position is the begin position of a token in the original input document.
    */
   public final class Position implements Serializable {
   	
  	/**
  	 * Serial Version UID.
  	 */
  	static final long serialVersionUID = 238623487L;
  	
  	/**
  	 * Line-Number in the model.
  	 */
  	private final int lineNumber;
  	
  	/**
  	 * Position in the model.
  	 */
  	private final int position;
  	
  	/**
  	 * Column-Number in the model.
  	 * 
  	 */
  	private final int columnNumber;
  	
  	/**
  	 * FilePath.
  	 */
  	private final String filePath;
  	
  	/**
  	 * Constructor for {@link Position}.
  	 * 
  	 * @param filePath
  	 *            initial file path
  	 * @param lineNumber
  	 *            initial line number
  	 * @param position
  	 *            start position of this comment in the original input
  	 * @param columnNumber
  	 *            initial column number
  	 */
  	private Position(final String filePath, final int lineNumber, final int columnNumber, final int position) {
  		this.lineNumber = lineNumber;
  		this.filePath = filePath;
  		this.columnNumber = columnNumber;
  		this.position = position;
  	}
  	
  	/**
  	 * Factory for a {@link Position}.
  	 * 
  	 * @param filePath
  	 *            initial file path
  	 * @param lineNumber
  	 *            initial line number
  	 * @param position
  	 *            start position in the original input
  	 * @param columnNumber
  	 *            initial column number
  	 * @return a new instance of this position
  	 */
  	public static Position create(final String filePath,
  			final int lineNumber,
  			final int columnNumber,
  			final int position) {
  		return new Position(filePath, lineNumber, columnNumber, position);
  	}
  	
  	/**
  	 * @return Returns the line number of a token in the original input document. Counting starts at 1.
  	 */
  	public int getLineNumber() {
  		return this.lineNumber;
  	}
  	
  	/**
  	 * @return Returns the position of a token in the document. (Zero-based counting, Control sequences are counted as
  	 *         one character)
  	 */
  	public int getPosition() {
  		return this.position;
  	}
  	
  	/**
  	 * @return Returns the position of a token in the line. The line is given in {@link #getLineNumber()
  	 *         getLineNumber()} Counting starts at 1.
  	 */
  	public int getColumnNumber() {
  		return this.columnNumber;
  	}
  	
  	/**
  	 * @return Returns the file path of a token.
 	 */
 	public String getFilePath() {
 		return this.filePath;
 	}
 	
 	@Override
 	public String toString() {
 		return "[FilePath:" + this.getFilePath() + ",LineNumber:" + this.getLineNumber() + ",ColumnNumber:"
 				+ this.getColumnNumber() + ",Position:" + this.getPosition() + "]";
 	}
 	
 	@Override
 	public boolean equals(final Object o) {
 		if (o instanceof Position) {
 			final Position p = (Position) o;
 			return this.getFilePath().equals(p.getFilePath()) && this.getLineNumber() == p.getLineNumber()
 					&& this.getPosition() == p.getPosition() && this.getColumnNumber() == p.getColumnNumber();
 		}
 		return false;
 	}
 	
 	@Override
 	public int hashCode() {
 		return this.getFilePath().hashCode() ^ this.getLineNumber() ^ this.getPosition() ^ this.getColumnNumber();
 	}
 	
 	/**
 	 * @return creates a non-existent position object
 	 */
 	public static Position createDummyPosition() {
 		return Position.create("", -1, -1, -1);
 	}
 }