/**
 * Copyright (c) 2014, the Railo Company Ltd.
 * Copyright (c) 2015, Lucee Assosication Switzerland
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either 
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public 
 * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 * 
 */
package lucee.transformer.bytecode.statement;

import lucee.runtime.util.ForEachUtil;
import lucee.transformer.Position;
import lucee.transformer.TransformerException;
import lucee.transformer.bytecode.Body;
import lucee.transformer.bytecode.BytecodeContext;
import lucee.transformer.bytecode.expression.var.VariableRef;
import lucee.transformer.bytecode.util.ExpressionUtil;
import lucee.transformer.bytecode.util.Types;
import lucee.transformer.bytecode.visitor.OnFinally;
import lucee.transformer.bytecode.visitor.TryFinallyVisitor;
import lucee.transformer.expression.Expression;
import lucee.transformer.expression.var.Variable;

import org.objectweb.asm.Label;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;
import org.objectweb.asm.commons.GeneratorAdapter;
import org.objectweb.asm.commons.Method;

public final class ForEach extends StatementBase implements FlowControlBreak,FlowControlContinue,HasBody {

	
	private Body body;
	private VariableRef key;
	private Expression value;

	private final static Method HAS_NEXT = 		new Method("hasNext",Types.BOOLEAN_VALUE,new Type[]{});
	private final static Method NEXT = 			new Method("next",Types.OBJECT,new Type[]{});
	private final static Method SET = 			new Method("set",Types.OBJECT,new Type[]{Types.PAGE_CONTEXT,Types.OBJECT});
	public static final Method LOOP_COLLECTION = new Method("loopCollection",Types.ITERATOR,new Type[]{Types.OBJECT});
	public static final Method FOR_EACH = new Method("forEach",Types.ITERATOR,new Type[]{Types.OBJECT});
	
	public static final Type FOR_EACH_UTIL = Type.getType(ForEachUtil.class);
	public static final Method RESET = new Method("reset",Types.VOID,new Type[]{Types.ITERATOR});

    //private static final Type COLLECTION_UTIL = Type.getType(CollectionUtil.class);

	private Label begin = new Label();
	private Label end = new Label();
	private FlowControlFinal fcf;
	private String label;

	/**
	 * Constructor of the class
	 * @param key
	 * @param value
	 * @param body
	 * @param line
	 */
	public ForEach(Variable key,Expression value,Body body,Position start, Position end,String label) {
		super(key.getFactory(),start,end);
		this.key=new VariableRef(key,false);
		this.value=value;
		this.body=body;
		this.label=label;
		body.setParent(this);
		
	}
	
	@Override
	public void _writeOut(BytecodeContext bc) throws TransformerException {
		GeneratorAdapter adapter = bc.getAdapter();
		final int it=adapter.newLocal(Types.ITERATOR);
		final int item=adapter.newLocal(Types.REFERENCE);
		
		//Value
			// ForEachUtil.toIterator(value)
			value.writeOut(bc, Expression.MODE_REF);
			adapter.invokeStatic(FOR_EACH_UTIL, FOR_EACH);
			//adapter.invokeStatic(COLLECTION_UTIL, TO_ITERATOR);
			// Iterator it=...
			adapter.storeLocal(it);
			TryFinallyVisitor tfv=new TryFinallyVisitor(new OnFinally() {
				
				@Override
				public void _writeOut(BytecodeContext bc) throws TransformerException {
					GeneratorAdapter a = bc.getAdapter();
					//if(fcf!=null && fcf.getAfterFinalGOTOLabel()!=null)ASMUtil.visitLabel(a,fcf.getFinalEntryLabel());
					a.loadLocal(it);
					a.invokeStatic(FOR_EACH_UTIL, RESET);
					/*if(fcf!=null){
						Label l=fcf.getAfterFinalGOTOLabel();
						if(l!=null)a.visitJumpInsn(Opcodes.GOTO, l);
					}*/
				}
			},getFlowControlFinal());
			tfv.visitTryBegin(bc);
			// Key
				// new VariableReference(...)
				key.writeOut(bc, Expression.MODE_REF);
				// VariableReference item=...
				adapter.storeLocal(item);
			
			// while
				ExpressionUtil.visitLine(bc, getStart());
				adapter.visitLabel(begin);
				
				// hasNext
				adapter.loadLocal(it);
				adapter.invokeInterface(Types.ITERATOR, HAS_NEXT);
				adapter.ifZCmp(Opcodes.IFEQ, end);
				
				// item.set(pc,it.next());
				adapter.loadLocal(item);
				adapter.loadArg(0);
				adapter.loadLocal(it);
				adapter.invokeInterface(Types.ITERATOR, NEXT);
				adapter.invokeInterface(Types.REFERENCE, SET);
				adapter.pop();
				
				// Body
				body.writeOut(bc);
				adapter.visitJumpInsn(Opcodes.GOTO, begin);
				adapter.visitLabel(end);
			tfv.visitTryEnd(bc);
		
	}

	@Override
	public Label getBreakLabel() {
		return end;
	}

	@Override
	public Label getContinueLabel() {
		return begin;
	}

	@Override
	public Body getBody() {
		return body;
	}

	@Override
	public FlowControlFinal getFlowControlFinal() {
		if(fcf==null) fcf=new FlowControlFinalImpl();
		return fcf;
	}

	@Override
	public String getLabel() {
		return label;
	}
}