package org.simantics.modeling.ui.expression;

import java.util.Stack;

import org.simantics.basicexpression.analysis.DepthFirstAdapter;
import org.simantics.basicexpression.node.AConstantValue;
import org.simantics.basicexpression.node.ADivMultiplicative;
import org.simantics.basicexpression.node.AMultMultiplicative;
import org.simantics.basicexpression.node.APlusExpression;
import org.simantics.basicexpression.node.AStringValue;
import org.simantics.utils.datastructures.Triple;

public class InvertBasicExpressionVisitor extends DepthFirstAdapter {

	Stack<Object> stack = new Stack<Object>();

	public Object getResult() {
		return stack.pop();
	}

	public void outAConstantValue(AConstantValue node) {
		stack.push(Double.valueOf(node.toString()));
	}

	public void outAStringValue(AStringValue node) {
		String value = node.toString();
		stack.push(Triple.make(1.0, 0.0, value.substring(1, value.length() - 2).trim()));
	}

	@SuppressWarnings("unchecked")
    public void outAPlusExpression(APlusExpression node) {
		
		final Object o1 = stack.pop();
		final Object o2 = stack.pop();
		
		if(o1 instanceof Double && o2 instanceof Triple) {
			Triple<Double, Double, String> p = (Triple<Double, Double, String>)o2;
			stack.push(Triple.make(p.first, p.second + (Double)o1, p.third));
		} else if (o2 instanceof Double && o1 instanceof Triple) {
			Triple<Double, Double, String> p = (Triple<Double, Double, String>)o1;
			stack.push(Triple.make(p.first, p.second + (Double)o2, p.third));
		} else if (o2 instanceof Double && o1 instanceof Double) {
			stack.push((Double)o1 + (Double)o2);
		} else {
			stack.push(Double.NaN);
		}
		
	}

	@SuppressWarnings("unchecked")
    public void outAMinusExpression(APlusExpression node) {
		
		final Object o1 = stack.pop();
		final Object o2 = stack.pop();
		
		if(o1 instanceof Double && o2 instanceof Triple) {
			Triple<Double, Double, String> p = (Triple<Double, Double, String>)o2;
			stack.push(Triple.make(-p.first, (Double)o1 - p.second, p.third ));
		} else if (o2 instanceof Double && o1 instanceof Triple) {
			Triple<Double, Double, String> p = (Triple<Double, Double, String>)o1;
			stack.push(Triple.make(p.first, p.second - (Double)o2, p.third));
		} else if (o2 instanceof Double && o1 instanceof Double) {
			stack.push((Double)o1 - (Double)o2);
		} else {
			stack.push(Double.NaN);
		}
		
	}

	@SuppressWarnings("unchecked")
    public void outAMultMultiplicative(AMultMultiplicative node) {
		
		final Object o1 = stack.pop();
		final Object o2 = stack.pop();
		
		if(o1 instanceof Double && o2 instanceof Triple) {
			Triple<Double, Double, String> p = (Triple<Double, Double, String>)o2;
			stack.push(Triple.make(p.first * (Double)o1, p.second * (Double)o1, p.third));
		} else if (o2 instanceof Double && o1 instanceof Triple) {
			Triple<Double, Double, String> p = (Triple<Double, Double, String>)o1;
			stack.push(Triple.make(p.first * (Double)o2, p.second * (Double)o2, p.third));
		} else if (o2 instanceof Double && o1 instanceof Double) {
			stack.push((Double)o1 * (Double)o2);
		} else {
			stack.push(Double.NaN);
		}
		
	}

	@SuppressWarnings("unchecked")
    public void outADivMultiplicative(ADivMultiplicative node) {
		
		final Object o1 = stack.pop();
		final Object o2 = stack.pop();
		
		if(o1 instanceof Double && o2 instanceof Triple) {
			stack.push(Double.NaN);
		} else if (o2 instanceof Double && o1 instanceof Triple) {
			Triple<Double, Double, String> p = (Triple<Double,Double, String>)o1;
			stack.push(Triple.make(p.first / (Double)o2, p.second / (Double)o2, p.third));
		} else if (o2 instanceof Double && o1 instanceof Double) {
			stack.push((Double)o1 / (Double)o2);
		} else {
			stack.push(Double.NaN);
		}
		
	}
	
}