package function.builtin.special;

import static org.junit.Assert.assertNull;
import static testutil.TestUtilities.*;

import org.junit.*;

import function.ArgumentValidator.*;
import function.builtin.EVAL.UndefinedSymbolException;
import sexpression.LispNumber;
import table.SymbolTable;

public class SETFTester {

    @Before
    public void setUp() {
        SETF.setSymbolTable(new SymbolTable());
    }

    @Test
    public void testSetf() {
        evaluateString("(setf a 23)");
        assertSExpressionsMatch(evaluateString("23"), evaluateString("a"));
    }

    @Test
    public void lookupDefinedSymbol() {
        evaluateString("(setf a 23)");
        assertSExpressionsMatch(evaluateString("23"), SETF.lookupSymbolValue("A"));
    }

    @Test
    public void lookupUndefinedSymbol() {
        assertNull(SETF.lookupSymbolValue("A"));
    }

    @Test
    public void setfGlobalVariable() {
        evaluateString("(setf a 23)");
        SymbolTable global = SETF.getSymbolTable();
        SETF.setSymbolTable(new SymbolTable(global));

        evaluateString("(setf a 94)");
        SETF.setSymbolTable(global);
        assertSExpressionsMatch(evaluateString("94"), evaluateString("a"));
    }

    @Test(expected = UndefinedSymbolException.class)
    public void setfLocalVariableDefined_DoesNotSetGlobal() {
        SymbolTable global = SETF.getSymbolTable();
        SymbolTable local = new SymbolTable(global);
        local.put("A", new LispNumber("99"));
        SETF.setSymbolTable(local);

        evaluateString("(setf a 94)");
        SETF.setSymbolTable(global);
        evaluateString("a");
    }

    @Test
    public void setfLocalVariableUndefined_SetsGlobal() {
        SymbolTable global = SETF.getSymbolTable();
        SymbolTable local = new SymbolTable(global);
        SETF.setSymbolTable(local);

        evaluateString("(setf a 94)");
        SETF.setSymbolTable(global);
        assertSExpressionsMatch(evaluateString("94"), evaluateString("a"));
    }

    @Test(expected = BadArgumentTypeException.class)
    public void testSetfWithNonSymbol() {
        evaluateString("(setf 1 2)");
    }

    @Test(expected = TooFewArgumentsException.class)
    public void testSetfWithTooFewArguments() {
        evaluateString("(setf x)");
    }

    @Test(expected = TooManyArgumentsException.class)
    public void testSetfWithTooManyArguments() {
        evaluateString("(setf a b c)");
    }

}