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.*;

public class SETFTester {
    
    private ExecutionContext executionContext;
    
    public SETFTester() {
        this.executionContext = ExecutionContext.getInstance();
    }

    @Before
    public void setUp() {
        executionContext.clearContext();
    }

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

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

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

    @Test
    public void setfGlobalVariable() {
        evaluateString("(setf a 23)");
        SymbolTable global = executionContext.getScope();
        executionContext.setScope(new SymbolTable(global));

        evaluateString("(setf a 94)");
        executionContext.setScope(global);
        assertSExpressionsMatch(new LispNumber("94"), evaluateString("a"));
    }

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

        evaluateString("(setf a 94)");
        executionContext.setScope(global);
        evaluateString("a");
    }

    @Test
    public void setfLocalVariableUndefined_SetsGlobal() {
        SymbolTable global = executionContext.getScope();
        SymbolTable local = new SymbolTable(global);
        executionContext.setScope(local);

        evaluateString("(setf a 94)");
        executionContext.setScope(global);
        assertSExpressionsMatch(new LispNumber("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)");
    }

}