package com.seaofnodes.simple;

import com.seaofnodes.simple.codegen.CodeGen;
import org.junit.Test;
import static org.junit.Assert.assertEquals;

public class Chapter12Test {
    @Test public void testSubZeroFloat() {
        var code = new CodeGen("flt x = arg; return 0-x;").parse().opto().typeCheck();
        // Compare strings so +0.0 and -0.0 remain distinct.
        assertEquals("0.0", Eval2.eval(code,0));
        assertEquals("-1.0", Eval2.eval(code,1));
    }

    @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 code = new CodeGen(src).parse().opto().typeCheck();
            assertEquals(src,test[1],Eval2.eval(code,0));
        }
    }


    @Test
    public void testJig() {
        CodeGen code = new CodeGen(
"""
return 0;
""");
        code.parse().opto();
        assertEquals("return 0;", code.print());
        assertEquals("0", Eval2.eval(code,  0));
    }

    @Test
    public void testFloat() {
        CodeGen code = new CodeGen(
"""
flt x = 3.14;
return 0;
""");
        code.parse().opto();
        assertEquals("return 0;", code.print());
        assertEquals("0", Eval2.eval(code,  0));
    }

    @Test
    public void testSquareRoot() {
        CodeGen code = new CodeGen(
"""
flt guess = arg;
while( 1 ) {
    flt next = (arg/guess + guess)/2;
    if( next == guess ) break;
    guess = next;
}
return guess;
""");
        // TODO: One of the problems with <clinit> returning an OS error code,
        // is it chops all results to int.
        code.parse().opto();
        assertEquals("return Phi(Loop,(flt)arg,((Phi_guess+(ToFloat/Phi_guess))*0.5f));", code.print());
        assertEquals("3.0", Eval2.eval(code,  9));
        assertEquals("1.414213562373095", Eval2.eval(code,  2));
    }

    @Test
    public void testFPOps() {
        CodeGen code = new CodeGen(
"""
flt x = arg;
return x+1==x;
""");
        code.parse().opto();
        assertEquals("return ((flt)arg==(ToFloat+1.0f));", code.print());
        assertEquals("0", Eval2.eval(code, 1));
    }
}