package gve.calc.formula;

import java.awt.*;
import gve.calc.formula.*;

public class RewriteRule extends Tabular {
	Part [] rules;	// naam regel, voorwaarden, conclusie

	public RewriteRule() {
		rules = new Part[1];
		rules[0] = new Identifier("");
		rules[0].setParent(this);
	}

	public String getName() {
		Part p = rules[0];
		if (p instanceof OperatorSpace)	// rule with parameters
			p = ((OperatorSpace)p).left;
		if (p instanceof Identifier)
			return ((Identifier)p).getString();
		return null;
	}

	
 How many parameters has this rule?
	  E.g. if the name is "G" then 0 params; "G x" has 1 param;
	  "S t x" has 2 etc 
	public int getParamCount() {
		int result = 0;
		Part p = rules[0];
		// Number of parameters is number of OperatorSpaces
		while (p instanceof OperatorSpace) {
			p = ((OperatorSpace)p).right;
			result++;
		}
		return result;
	}

	public Part getConclusion() {
		return rules[rules.length-1];
	}

	public Object clone() {
		RewriteRule result = new RewriteRule();
		result.rules = new Part[rules.length];
		for (int i = rules.length-1; i>=0; i--) {
			result.rules[i] = (Part)rules[i].clone();
			result.rules[i].setParent(result);
		}
		return result;
	}

	public int getHeight() { return rules.length; }
	public int getWidth() { return 1; }

	public Part elementAt(int i,int j) {
		return rules[i];
	}

	public void setElementAt(int i,int j,Part el) {
		rules[i] = el;
		el.setParent(this);
	}

	public void removeRow(int pos) {
		rules = removeRow(rules,pos);
		super.removeRow(pos);
	}

	public void insertRow(int pos) {
		rules = insertRow(rules,pos);
		super.insertRow(pos);
	}

	public void insertCol(int pos) {}

	public void write(java.io.Writer w) throws java.io.IOException {
		super.write(w);
		w.write(""+getHeight()); w.write("\n");
		writeTable(w);
	}

	public static Part read(java.io.BufferedReader r) throws java.io.IOException,
			ClassNotFoundException,NoSuchMethodException,
			java.lang.reflect.InvocationTargetException,IllegalAccessException {
		int height = Integer.parseInt(r.readLine());
		RewriteRule result = new RewriteRule();
		result.rules = new Part[height];
		result.readTable(r);
		return result;
	}

	public Component createView(FormulaView view) {
		return new RewriteRuleView(this,view);
	}
}