/**
 * AmbientTalk/2 Project
 * NATPatternType.java created on Jul 4, 2008 at 10:21:18 AM
 * (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;

import edu.vub.at.eval.Evaluator;
import edu.vub.at.exceptions.InterpreterException;
import edu.vub.at.exceptions.XArityMismatch;
import edu.vub.at.exceptions.XIllegalArgument;
import edu.vub.at.objects.ATClosure;
import edu.vub.at.objects.ATContext;
import edu.vub.at.objects.ATMethod;
import edu.vub.at.objects.ATObject;
import edu.vub.at.objects.ATTable;
import edu.vub.at.objects.ATTypeTag;
import edu.vub.at.objects.coercion.NativeTypeTags;
import edu.vub.at.objects.grammar.ATSymbol;
import edu.vub.at.objects.natives.grammar.AGApplication;
import edu.vub.at.signals.natives.NATLiftedBehavior;

/**
 * @author smostinc
 *
 */
public class NATPatternType extends NATTypeTag implements ATClosure {

	ATTable parameters;
	
	public NATPatternType(AGApplication pattern) throws InterpreterException {
		super(pattern.base_function().asSymbol(), NATTable.EMPTY);
		
		parameters = pattern.base_arguments();
	}
	
	public NATPatternType(ATSymbol typeName, ATTable typeArgs) {
		super(typeName, NATTable.EMPTY);
		
		parameters = typeArgs;
	}
	
	public ATObject base_apply(ATTable theArguments) throws InterpreterException {
		boolean		shouldBeLifted	= false;
		ATObject[] 	argumentsArray 	= theArguments.asNativeTable().elements_;

		for (int argIndex = 0; argIndex < argumentsArray.length; argIndex++) {
			ATObject currentArgument = argumentsArray[argIndex];
		
			if (currentArgument.isBehavior()) {
				shouldBeLifted = true;

				break;
			}
		}

		if(shouldBeLifted) {
			return NATLiftedBehavior.fromClosure(this, argumentsArray);
		} // else

		NATObject thePatternObject = new NATObject(new ATTypeTag[] { this, NativeTypeTags._ISOLATE_ });
		
		ATObject[] parameters = this.parameters.asNativeTable().elements_;
		ATObject[] arguments  = theArguments.asNativeTable().elements_;
		
		if(parameters.length != arguments.length)
			throw new XArityMismatch(typeName_.toString(), parameters.length, arguments.length);
		
		
		for (int i = 0; i < arguments.length; i++) {
			ATObject theValue = (ATObject) arguments[i];
			ATSymbol theName  = (ATSymbol) parameters[i];
			
			thePatternObject.meta_defineField(theName, theValue);
		}
		
		return thePatternObject;
		
	}
	
	public ATObject base_unapply(ATObject thePatternObject) throws InterpreterException {
		if(! thePatternObject.meta_isTaggedAs(this).asNativeBoolean().javaValue)
			throw new XIllegalArgument("Asked to unapply " + this + " on an object which does not have the proper type tag");
		
		ATObject[] parameters = this.parameters.asNativeTable().elements_;
		ATObject[] arguments  = new ATObject[parameters.length];
		
		for (int i = 0; i < arguments.length; i++) {
			ATSymbol theName  = (ATSymbol) parameters[i];
			ATObject theValue = thePatternObject.meta_invokeField(thePatternObject, theName);
			
			arguments[i] = theValue;
		}
		
		return NATTable.atValue(arguments);
		
	}
	
    public ATTable meta_typeTags() throws InterpreterException {
    	return NATTable.of(NativeTypeTags._TYPETAG_, NativeTypeTags._ISOLATE_, NativeTypeTags._CLOSURE_);
    }
    
    
    // BOGUS METHODS
    
	public ATObject base_applyInScope(ATTable args, ATObject scope)
			throws InterpreterException {
		// TODO Auto-generated method stub
		return null;
	}

	public ATContext base_context() throws InterpreterException {
		return new NATContext(Evaluator.getGlobalLexicalScope(), this);
	}

	public ATObject base_escape() throws InterpreterException {
		// TODO Auto-generated method stub
		return null;
	}

	public ATMethod base_method() throws InterpreterException {
		// TODO Auto-generated method stub
		return null;
	}

	public ATObject base_whileTrue_(ATClosure body) throws InterpreterException {
		// TODO Auto-generated method stub
		return null;
	}
	
	public ATClosure asClosure() throws InterpreterException {
		return this;
	}
}