package com.seaofnodes.simple;

import com.seaofnodes.simple.evaluator.Evaluator;
import com.seaofnodes.simple.node.StopNode;
import org.junit.Test;


import static org.junit.Assert.assertEquals;
import static org.junit.Assert.fail;

public class Chapter12Test {
    @Test public void testSubZeroFloat() {
        var stop = new Parser("flt x = arg; return 0-x;").parse().iterate();
        // Compare strings so +0.0 and -0.0 remain distinct.
        assertEquals("0.0", Evaluator.evaluate(stop,0).toString());
        assertEquals("-1.0", Evaluator.evaluate(stop,1).toString());
    }

    @Test public void testDeadNumericReturns() {
        for( String[] test : new String[][] {
            {"if(1) return 7; else return 2.5;", "7"},
            {"if(0) return 7; else return 2.5;", "2.5"},
            {"return 7; return 2.5;", "7"},
            {"return 2.5; return 7;", "2.5"}
        } ) {
            String src = test[0];
            var stop = new Parser(src).parse().iterate();
            assertEquals(src,test[1],com.seaofnodes.simple.evaluator.Evaluator.evaluate(stop,0).toString());
        }
    }


    @Test
    public void testJig() {
        Parser parser = new Parser(
"""
return 3.14;
""");
        StopNode stop = parser.parse().iterate();
        assertEquals("return 3.14;", stop.toString());
        assertEquals(3.14, Evaluator.evaluate(stop,  0));
    }

    @Test
    public void testFloat() {
        Parser parser = new Parser(
"""
return 3.14;
""");
        StopNode stop = parser.parse().iterate();
        assertEquals("return 3.14;", stop.toString());
        assertEquals(3.14, Evaluator.evaluate(stop,  0));
    }

    @Test
    public void testSquareRoot() {
        Parser parser = new Parser(
"""
flt guess = arg;
while( 1 ) {
    flt next = (arg/guess + guess)/2;
    if( next == guess ) break;
    guess = next;
}
return guess;
""");
        StopNode stop = parser.parse().iterate();
        assertEquals("return Phi(Loop9,(flt)arg,(((ToFloat/Phi_guess)+Phi_guess)/2.0));", stop.toString());
        assertEquals(3.0, Evaluator.evaluate(stop,  9));
        assertEquals(1.414213562373095, Evaluator.evaluate(stop,  2));
    }

    @Test
    public void testFPOps() {
        Parser parser = new Parser(
"""
flt x = arg;
return x+1==x;
""");
        StopNode stop = parser.parse().iterate();
        assertEquals("return ((flt)arg==(ToFloat+1.0));", stop.toString());
        assertEquals(0L, Evaluator.evaluate(stop, 1));
    }

}