package com.seaofnodes.simple;

import com.seaofnodes.simple.node.*;
import org.junit.Test;

import static org.junit.Assert.*;

public class Chapter01Test {

    @Test
    public void testSimpleProgram() {
        Parser parser = new Parser("return 1;");
        ReturnNode ret = parser.parse();
        StartNode start = Parser.START;

        assertEquals(start, ret.ctrl());
        Node expr = ret.expr();
        if( expr instanceof ConstantNode con ) {
            assertEquals(start,con.in(0));
            assertEquals(1, con._value);
        } else {
            fail();
        }
    }

    @Test
    public void testZero() {
        Parser parser = new Parser("return 0;");
        parser.parse();
        StartNode start = Parser.START;
        for( Node use : start._outputs )
            if( use instanceof ConstantNode con )
                assertEquals(0,con._value);
    }

    @Test
    public void testBad1() {
        try {
            new Parser("ret").parse();
            fail();
        } catch( RuntimeException e ) {
            assertEquals("Syntax error, expected a statement: ret",e.getMessage());
        }
    }

    @Test
    public void testBad2() {
        try {
            new Parser("return 0123;").parse();
            fail();
        } catch( RuntimeException e ) {
            assertEquals("Syntax error: integer values cannot start with '0'",e.getMessage());
        }
    }

    @Test
    public void testBad3() {
        try {
            new Parser("return --12;").parse();
            fail();
        } catch( RuntimeException e ) {
            assertEquals("Syntax error, expected integer literal",e.getMessage());
        }
    }

    @Test
    public void testBad4() {
        try {
            new Parser("return 100").parse();
            fail();
        } catch( RuntimeException e ) {
            assertEquals("Syntax error, expected ;: ",e.getMessage());
        }
    }

    // Negative numbers require unary operator support that is not in scope
    @Test
    public void testBad5() {
        try {
            new Parser("return -100;").parse();
            fail();
        } catch( RuntimeException e ) {
            assertEquals("Syntax error, expected integer literal",e.getMessage());
        }
    }

    @Test
    public void testBad6() {
        try {
            new Parser("return100").parse();
            fail();
        } catch( RuntimeException e ) {
            assertEquals("Syntax error, expected a statement: return100",e.getMessage());
        }
    }

    @Test
    public void testBad7() {
        try {
            new Parser("return 1;}").parse();
            fail();
        } catch( RuntimeException e ) {
            assertEquals("Syntax error, unexpected }",e.getMessage());
        }
    }

}