import java.util.*;
import java.io.*;
/*
 * This class holds all the fields that are needed to be filled in
 * for a specific pdf template.  The Template is constructed by parsing
 * a pdf template document and finding which fields need to be filled.
 * The fields are initially empty.
 */
public class TemplateData{
	public TemplateData(File template){
		// read in and parse a pdf file making field objects that have only a field name
		myFileName = template.getAbsolutePath();
		System.out.println("TemplateData " + myFileName);
		myPosition = 0;
		myFields = new LinkedList();

		parsePDFTemplate(template);
	}

	/* This method sets a pointer to the first element in the collection of fields
	 */
	public void first(){
		myPosition = 0;
	}

	/* This method moves the pointer to the next element in the collection of fields.
	 */
	public void next(){
		myPosition++;
	}

	/* Returns true if the collection still has more elements to be visited.
	 */
	public boolean hasNext(){
		return myPosition < myFields.size();
	}

	/* Returns the element that is currently pointed to in the collection.
	 */
	public Object currentElement(){
		return myFields.get(myPosition);
	}

	/* This method allows the adding of another field object to the collection.
	 * @param Field j  -The field to be added.
	 * @return boolean successful - If the field already exists in the collection, it won't
	 *  be added.
	 */
	private boolean addField(Field j){
		// adds the field, j to the end of the collection, unless the field already exists.
		if(myFields.contains(j))
			return false;
		else{
			myFields.add(j);
			return true;
		}
	}

	public String getTemplateName ()
	{
		return myFileName;
	}

	private boolean parsePDFTemplate(File f){
		// Pre: f is a pdf template document
		// post: the file has been parsed and the empty fields have been
		//   represented by Field objects.
		try{

			BufferedReader br = new BufferedReader(new FileReader(f));
			StringTokenizer st;
			String line;
			String currentToken= "";
			while((line = br.readLine())!=null)
			{
				System.out.println(line);
				st = new StringTokenizer(line);
				while(st.hasMoreTokens())
				{
					currentToken = st.nextToken();
					if(currentToken.charAt(0) == '<')
						if(currentToken.charAt(currentToken.length()-1) != '>'){
							Field temp = new Field (currentToken.substring(1,currentToken.length()-2));
							System.out.println(temp);
							if(!myFields.contains(temp))
								myFields.add(temp);
						}
						else{
							Field temp = new Field (currentToken.substring(1,currentToken.length()-1));
							if(!myFields.contains(temp))
								myFields.add(temp);
						}
				}
			}
			br.close();
		}
		catch (Exception e)
		{
			System.err.println(e.getMessage());
		}

		return false;
	}



	private LinkedList myFields;
	private String myFileName;
	private int myPosition;
}