package org.apidesign.test.visitor;

import org.apidesign.test.visitor.PrintTest.PrintVisitor;

import static junit.framework.Assert.*;

import org.apidesign.visitor.Language.Expression;

import org.apidesign.visitor.Language.Minus;

import org.apidesign.visitor.Language.Number;

import org.apidesign.visitor.Language.Plus;

import org.apidesign.visitor.Language.Real;

import org.apidesign.visitor.Language.Visitor3_0;

import org.junit.Test;

public class PrintOfMinusStructureTest {

    @Test public void printOneMinusTwo() {

        Real one = new Real(1);

        Real two = new Real(2);

        Expression plus = new Minus(one, two);

        PrintVisitor print = new PrintVisitor();

        plus.visit(print);

        if (Boolean.getBoolean("no.failures")) {

            assertEquals(

                "Not defined how to handle Minus. We'll get wrong result",

                "unknown", print.sb.toString()

            );

            return;

        }

        assertEquals("1.0 - 2.0", print.sb.toString());

    }

    @Test public void visitorReadyForVersion3_0() {

        // BEGIN: visitor.nonmonotonic.print3

        class PrintVisitor3_0 implements Visitor3_0 {

            StringBuffer sb = new StringBuffer();

            public void visitUnknown(Expression exp) {

                sb.append("unknown");

            }

            public void visitPlus(Plus s) {

                s.getFirst().visit(this);

                sb.append(" + ");

                s.getSecond().visit(this);

            }

            public void visitNumber(Number n) {

                sb.append (n.getValue());

            }

            public void visitMinus(Minus m) {

                m.getFirst().visit(this);

                sb.append(" - ");

                m.getSecond().visit(this);

            }

            public void visitReal(Real r) {

                sb.append(r.getValue());

            }

        }

        Number one = new Number(1);

        Number two = new Number(2);

        Expression plus = new Minus(one, two);

        PrintVisitor3_0 print = new PrintVisitor3_0();

        plus.visit(print);

        assertEquals("1.0 - 2.0", print.sb.toString());

        // END: visitor.nonmonotonic.print3

        Real five = new Real(5);

        Real three = new Real(3);

        Expression realPlus = new Minus(five, three);

        PrintVisitor3_0 printReal = new PrintVisitor3_0();

        realPlus.visit(printReal);

        assertEquals("5.0 - 3.0", printReal.sb.toString());

    }

}