/**
 * AmbientTalk/2 Project
 * TestParameterBinding.java created on 26-dec-2006 at 13:43:59
 * (c) Programming Technology Lab, 2006 - 2007
 * Authors: Tom Van Cutsem & Stijn Mostinckx
 * 
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */
package edu.vub.at.objects.natives.grammar;

import edu.vub.at.AmbientTalkTest;
import edu.vub.at.exceptions.InterpreterException;
import edu.vub.at.exceptions.XArityMismatch;
import edu.vub.at.exceptions.XIllegalParameter;
import edu.vub.at.objects.ATObject;
import edu.vub.at.objects.grammar.ATSymbol;
import edu.vub.at.objects.natives.NATContext;
import edu.vub.at.objects.natives.NATMethod;
import edu.vub.at.objects.natives.OBJNil;
import edu.vub.at.objects.natives.NATNumber;
import edu.vub.at.objects.natives.NATObject;
import edu.vub.at.objects.natives.NATTable;

/**
 * Unit test for parameter binding during e.g. function call.
 *
 * @author tvcutsem
 */
public class TestParameterBinding extends AmbientTalkTest {

	private void ensureBound(ATSymbol var, ATObject value) throws InterpreterException {
		assertEquals(value, bindScope_.impl_invokeAccessor(bindScope_, var, NATTable.EMPTY));
	}
	
	private void ensureBoundToTable(ATSymbol var, ATObject[] expected) throws InterpreterException {
		NATTable val = bindScope_.impl_invokeAccessor(bindScope_, var, NATTable.EMPTY).asNativeTable();
		ATObject[] values = val.elements_;
		assertEquals(expected.length, values.length);
		for (int i = 0; i < values.length; i++) {
			assertEquals(expected[i], values[i]);
		}
	}
	
	/**
	 * Given a name and parameters, returns a method
	 * def name(parameters) { nil }
	 */
	private NATMethod makeTestMethod(String nam, NATTable pars) {
		try {
			return new NATMethod(AGSymbol.jAlloc(nam), pars,
				new AGBegin(NATTable.atValue(new ATObject[] { OBJNil._INSTANCE_ })));
		} catch (InterpreterException e) {
			fail("unexpected exception while creating test fixture: " + e.getMessage());
			return null;
		}
	}
	
	private NATContext bindCtx_;
	private NATObject  bindScope_;
	
	private final AGSymbol at_a = AGSymbol.jAlloc("a");
	private final AGSymbol at_b = AGSymbol.jAlloc("b");
	private final AGSymbol at_rest = AGSymbol.jAlloc("rest");
	private final AGSymbol at_x = AGSymbol.jAlloc("x");
	private final AGSymbol at_y = AGSymbol.jAlloc("y");
	
	// TEST FUNCTIONS
	
	// def fun1() { nil }
	private NATMethod fun1 = makeTestMethod("fun1", NATTable.EMPTY);

	// def fun2(a,b) { nil }
	private NATMethod fun2 = makeTestMethod("fun2", NATTable.atValue(new ATObject[] { at_a, at_b }));
	
	// def fun3(a,b,x := 1) { nil }
	private NATMethod fun3 = makeTestMethod("fun3",
		NATTable.atValue(new ATObject[] { at_a, at_b, new AGAssignVariable(at_x, NATNumber.ONE) }));
	
	// def fun4(a, x:=a, @rest) { nil }
	private NATMethod fun4 = makeTestMethod("fun4",
		NATTable.atValue(new ATObject[] { at_a, new AGAssignVariable(at_x, at_a), new AGSplice(at_rest) }));
	
	// def fun5(x := self, y := 0) { nil }
	private NATMethod fun5 = makeTestMethod("fun5",
		NATTable.atValue(new ATObject[] { new AGAssignVariable(at_x, AGSelf._INSTANCE_), new AGAssignVariable(at_y, NATNumber.ZERO) }));

	// def fun6(a, @rest) { nil }
	private NATMethod fun6 = makeTestMethod("fun6", NATTable.atValue(new ATObject[] { at_a, new AGSplice(at_rest) }));
	
	// def fun7(@rest) { nil }
	private NATMethod fun7 = makeTestMethod("fun7", NATTable.atValue(new ATObject[] { new AGSplice(at_rest) }));


	public void setUp() throws InterpreterException {
		bindScope_ = new NATObject();
		bindCtx_ = new NATContext(bindScope_, bindScope_);
	}
	
	/**
	 * Tests parameter binding for 0-arity methods
	 */
	public void testZeroArity() throws InterpreterException {
		// fun1()
		fun1.base_applyInScope(NATTable.EMPTY, bindCtx_);
		
		// fun1(0) => arity mismatch
		try {
			fun1.base_applyInScope(NATTable.atValue(new ATObject[] { NATNumber.ZERO }), bindCtx_);
			fail("Expected XArityMismatch exception");
		} catch(XArityMismatch e) { }
	}
	
	/**
	 * Tests parameter binding for methods with mandatory arguments only.
	 */
	public void testMandatory() throws InterpreterException {
		// normal case: fun2(0,1)
		fun2.base_applyInScope(NATTable.atValue(new ATObject[] { NATNumber.ZERO, NATNumber.ONE }), bindCtx_);
		ensureBound(at_a, NATNumber.ZERO);
		ensureBound(at_b, NATNumber.ONE);
	}
	
	/**
	 * Tests for too few mandatory arguments
	 */
	public void testTooFewMandatory() throws InterpreterException {
		// too few arguments: fun2(0)
		try {
			fun2.base_applyInScope(NATTable.atValue(new ATObject[] { NATNumber.ZERO }), bindCtx_);
			fail("Expected XArityMismatch exception");
		} catch(XArityMismatch e) { }
	}
	
	/**
	 * Tests for too many mandatory arguments
	 */
	public void testTooManyMandatory() throws InterpreterException {
		// too many arguments: fun2(0,1,2)
		try {
			fun2.base_applyInScope(NATTable.atValue(new ATObject[] { NATNumber.ZERO, NATNumber.ONE, NATNumber.atValue(2) }), bindCtx_);
			fail("Expected XArityMismatch exception");
		} catch(XArityMismatch e) { }
	}
	
	/**
	 * Tests parameter binding for methods with mandatory arguments and optional arguments.
	 */
	public void testMandatoryAndOptional() throws InterpreterException {
		// normal case: fun3(0,1,2)
		fun3.base_applyInScope(NATTable.atValue(new ATObject[] { NATNumber.ZERO, NATNumber.ONE, NATNumber.atValue(2) }), bindCtx_);
		ensureBound(at_a, NATNumber.ZERO);
		ensureBound(at_b, NATNumber.ONE);
		ensureBound(at_x, NATNumber.atValue(2));
	}
	
	/**
	 * Tests parameter binding for methods with mandatory arguments and an
	 * optional argument that is not given.
	 */
	public void testMandatoryAndDefaultOptional() throws InterpreterException {
		// fun3(0,1) => ensure optional argument x is bound to default 1
		fun3.base_applyInScope(NATTable.atValue(new ATObject[] { NATNumber.ZERO, NATNumber.ONE }), bindCtx_);
		ensureBound(at_a, NATNumber.ZERO);
		ensureBound(at_b, NATNumber.ONE);
		ensureBound(at_x, NATNumber.ONE);
	}
	
	/**
	 * Tests whether parameter binding fails if given too many optional arguments.
	 */
	public void testMandatoryAndTooManyOptional() throws InterpreterException {
		// fun3(0,1,2,3)
		try {
			fun3.base_applyInScope(NATTable.atValue(new ATObject[] { NATNumber.ZERO, NATNumber.ONE, NATNumber.atValue(2), NATNumber.atValue(3) }), bindCtx_);
			fail("Expected XArityMismatch exception");
		} catch(XArityMismatch e) { }
	}
	
	/**
	 * Tests application with both mandatory, optional and rest arguments
	 */
	public void testMandOptAndRest() throws InterpreterException {
		// fun4(0,1,2,3)
		fun4.base_applyInScope(NATTable.atValue(new ATObject[] {
				NATNumber.ZERO, NATNumber.ONE, NATNumber.atValue(2), NATNumber.atValue(3) }), bindCtx_);
		ensureBound(at_a, NATNumber.ZERO);
		ensureBound(at_x, NATNumber.ONE);
		ensureBoundToTable(at_rest, new ATObject[] { NATNumber.atValue(2), NATNumber.atValue(3) });
	}
	
	/**
	 * Tests application with mandatory and optional arguments.
	 * The rest arguments should be []
	 */
	public void testMandOptAndNoRest() throws InterpreterException {
		// fun4(0,1)
		fun4.base_applyInScope(NATTable.atValue(new ATObject[] { NATNumber.ZERO, NATNumber.ONE }), bindCtx_);
		ensureBound(at_a, NATNumber.ZERO);
		ensureBound(at_x, NATNumber.ONE);
		ensureBound(at_rest, NATTable.EMPTY);
	}
	
	/**
	 * Tests application with mandatory arguments.
	 * The optional argument should be initialized to its default expression.
	 * Note that this default expression also tests for let*-like behaviour!
	 * The rest arguments should be []
	 */
	public void testMandNoOptAndNoRest() throws InterpreterException {
		// fun4(3)
		fun4.base_applyInScope(NATTable.atValue(new ATObject[] { NATNumber.atValue(3) }), bindCtx_);
		ensureBound(at_a, NATNumber.atValue(3));
		ensureBound(at_x, NATNumber.atValue(3));
		ensureBound(at_rest, NATTable.EMPTY);
	}
	
	/**
	 * Tests application with only optional arguments, all of which are given at call time.
	 */
	public void testOnlyOptionalArguments() throws InterpreterException {
		// fun5(0,1)
		fun5.base_applyInScope(NATTable.atValue(new ATObject[] { NATNumber.ZERO, NATNumber.ONE }), bindCtx_);
		ensureBound(at_x, NATNumber.ZERO);
		ensureBound(at_y, NATNumber.ONE);
	}
	
	/**
	 * Tests application with only optional arguments, only one of which is given at call time.
	 */
	public void testOnlyOptArgsWithOneFilledIn() throws InterpreterException {
		// fun5(0)
		fun5.base_applyInScope(NATTable.atValue(new ATObject[] { NATNumber.ZERO }), bindCtx_);
		ensureBound(at_x, NATNumber.ZERO);
		ensureBound(at_y, NATNumber.ZERO);
	}
	
	/**
	 * Tests application with only optional arguments, none of which are given at call time.
	 */
	public void testOnlyOptArgsWithNoneFilledIn() throws InterpreterException {
		// fun5()
		fun5.base_applyInScope(NATTable.EMPTY, bindCtx_);
		ensureBound(at_x, bindScope_);
		ensureBound(at_y, NATNumber.ZERO);
	}
	
	/**
	 * Tests application with one mandatory argument and zero rest arguments.
	 */
	public void testOneMandatoryAndNoRestArgs() throws InterpreterException {
		// fun6(0)
		fun6.base_applyInScope(NATTable.atValue(new ATObject[] { NATNumber.ZERO }), bindCtx_);
		ensureBound(at_a, NATNumber.ZERO);
		ensureBound(at_rest, NATTable.EMPTY);
	}
	
	/**
	 * Tests application with one mandatory argument and two rest arguments.
	 */
	public void testOneMandatoryAndTwoRestArgs() throws InterpreterException {
		// fun6(0,1,2)
		fun6.base_applyInScope(NATTable.atValue(
				new ATObject[] { NATNumber.ZERO, NATNumber.ONE, NATNumber.atValue(2) }), bindCtx_);
		ensureBound(at_a, NATNumber.ZERO);
		ensureBoundToTable(at_rest, new ATObject[] { NATNumber.ONE, NATNumber.atValue(2)});
	}
	
	/**
	 * Tests only rest arguments, with none given.
	 */
	public void testZeroRestArgs() throws InterpreterException {
		// fun7()
		fun7.base_applyInScope(NATTable.EMPTY, bindCtx_);
		ensureBound(at_rest, NATTable.EMPTY);
	}
	
	/**
	 * Tests only rest arguments, with one given.
	 */
	public void testOneRestArg() throws InterpreterException {
		// fun7(0)
		fun7.base_applyInScope(NATTable.atValue(new ATObject[] { NATNumber.ZERO }), bindCtx_);
		ensureBoundToTable(at_rest, new ATObject[] { NATNumber.ZERO });
	}
	
	
	/**
	 * Tests whether mandatory arguments specified after optional arguments
	 * results in a proper XIllegalParameter exception.
	 */
	public void testIllegalMandatoryAfterOptional() throws InterpreterException {
        // def fun8(x:=0, a) { nil }
		try {
		    new NATMethod(AGSymbol.jAlloc("fun8"),
				NATTable.atValue(new ATObject[] { new AGAssignVariable(at_x, NATNumber.ZERO), at_a }),
				new AGBegin(NATTable.atValue(new ATObject[] { OBJNil._INSTANCE_ })));
		    fail("Expected XIllegalParameter exception");
		} catch(XIllegalParameter e) { }
	}
	
	/**
	 * Tests whether mandatory arguments specified after the rest parameter
	 * results in a proper XIllegalParameter exception.
	 */
	public void testIllegalMandatoryAfterRest() throws InterpreterException {
        // def fun8(x:=0, a) { nil }
		try {
		    new NATMethod(AGSymbol.jAlloc("fun9"),
				NATTable.atValue(new ATObject[] { new AGSplice(at_rest), at_a }),
				new AGBegin(NATTable.atValue(new ATObject[] { OBJNil._INSTANCE_ })));
		    fail("Expected XIllegalParameter exception");
		} catch(XIllegalParameter e) { }
	}
	
	/**
	 * Tests whether optional arguments specified after the rest parameter
	 * results in a proper XIllegalParameter exception.
	 */
	public void testIllegalOptionalAfterRest() throws InterpreterException {
        // def fun8(x:=0, a) { nil }
		try {
		    new NATMethod(AGSymbol.jAlloc("fun10"),
				NATTable.atValue(new ATObject[] { new AGSplice(at_rest), new AGAssignVariable(at_x, NATNumber.ZERO) }),
				new AGBegin(NATTable.atValue(new ATObject[] { OBJNil._INSTANCE_ })));
		    fail("Expected XIllegalParameter exception");
		} catch(XIllegalParameter e) { }
	}
	
	/**
	 * Tests whether optional and rest parameters also work using multiple-definition
	 */
	public void testMultiAssignmentWithOptionalAndRestParameters() throws InterpreterException {
		// def [a,x:=a,@rest] := [0,1,2]
		AGMultiDefinition multiDef = new AGMultiDefinition(
				fun4.base_parameters(),
				NATTable.atValue(new ATObject[] { NATNumber.ZERO, NATNumber.ONE, NATNumber.atValue(2) }));
		multiDef.meta_eval(bindCtx_);
		ensureBound(at_a, NATNumber.ZERO);
		ensureBound(at_x, NATNumber.ONE);
		ensureBoundToTable(at_rest, new ATObject[] { NATNumber.atValue(2)});
	}

}