import ch.bfh.parser.StatementParser;
import org.junit.Test;

import static org.junit.Assert.assertEquals;

public class StatementParserTest {

    StatementParser sp = new StatementParser();
    // Only testing correct expressions first
    @Test
    public void emptyExpression() {
        sp.parseStatement("");
        assertEquals(0.0, sp.getValue(), 0.0);
    }

    @Test
    public void oneFactor() {
        sp.parseStatement("10");
        assertEquals(10.0, sp.getValue(), 0.0);
    }

    @Test
    public void oneParenthesisedFactor() {
        sp.parseStatement("(10)");
        assertEquals(10.0, sp.getValue(), 0.0);
    }

    @Test
    public void oneNegativeFactor() {
        sp.parseStatement("-10");
        assertEquals(-10.0, sp.getValue(), 0.0);
    }

    @Test
    public void oneNegativeParenthesisedFactor() {
        sp.parseStatement("-(10)");
        assertEquals(-10.0, sp.getValue(), 0.0);
    }

    @Test
    public void oneNegativeParenthesisedNegativeFactor() {
        sp.parseStatement("-(-10)");
        assertEquals(10.0, sp.getValue(), 0.0);
    }

    @Test
    public void twoFactorSum() {
        sp.parseStatement("2+3");
        assertEquals(5.0, sp.getValue(), 0.0);
    }

    @Test
    public void twoFactorSub() {
        sp.parseStatement("2-3");
        assertEquals(-1.0, sp.getValue(), 0.0);
    }

    @Test
    public void twoFactorSumWithSub() {
        sp.parseStatement("2--3");
        assertEquals(5.0, sp.getValue(), 0.0);
    }

    @Test
    public void twoFactorSumWithSubParenthesised() {
        sp.parseStatement("2-(-3)");
        assertEquals(5.0, sp.getValue(), 0.0);
    }

    @Test
    public void twoFactorMul() {
        sp.parseStatement("2*3");
        assertEquals(6.0, sp.getValue(), 0.0);
    }

    @Test
    public void twoFactorDiv() {
        sp.parseStatement("11/4");
        assertEquals(2.75, sp.getValue(), 0.0);
    }

    @Test
    public void completeArithmeticOperationWithPriorities() {
        sp.parseStatement("(4+5)*3/4");
        assertEquals(6.75, sp.getValue(), 0.0);
    }

    @Test
    public void variableTest() {
        sp.parseStatement("let a = 5");
        assertEquals(5.0, sp.getValue(), 0.0);

        sp.parseStatement("a");
        assertEquals(5.0, sp.getValue(), 0.0);

        sp.parseStatement("(a)");
        assertEquals(5.0, sp.getValue(), 0.0);

        sp.parseStatement("-a");
        assertEquals(-5.0, sp.getValue(), 0.0);

        sp.parseStatement("-(a)");
        assertEquals(-5.0, sp.getValue(), 0.0);

        sp.parseStatement("-(-a)");
        assertEquals(5.0, sp.getValue(), 0.0);

        sp.parseStatement("let b=5*50");
        assertEquals(250.0, sp.getValue(), 0.0);

        sp.parseStatement("b/a");
        assertEquals(50.0, sp.getValue(), 0.0);

        sp.parseStatement("b+a/2");
        assertEquals(252.5, sp.getValue(), 0.0);

        sp.parseStatement("let z = b+a/2");
        assertEquals(252.5, sp.getValue(), 0.0);

        sp.parseStatement("let a = b+a");
        assertEquals(255.0, sp.getValue(), 0.0);
    }
    //TODO - test error detection

}