//
// Copyright (C) 2006 United States Government as represented by the
// Administrator of the National Aeronautics and Space Administration
// (NASA).  All Rights Reserved.
//
// This software is distributed under the NASA Open Source Agreement
// (NOSA), version 1.3.  The NOSA has been approved by the Open Source
// Initiative.  See the file NOSA-1.3-JPF at the top of the distribution
// directory tree for the complete NOSA document.
//
// THE SUBJECT SOFTWARE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY OF ANY
// KIND, EITHER EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT
// LIMITED TO, ANY WARRANTY THAT THE SUBJECT SOFTWARE WILL CONFORM TO
// SPECIFICATIONS, ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR
// A PARTICULAR PURPOSE, OR FREEDOM FROM INFRINGEMENT, ANY WARRANTY THAT
// THE SUBJECT SOFTWARE WILL BE ERROR FREE, OR ANY WARRANTY THAT
// DOCUMENTATION, IF PROVIDED, WILL CONFORM TO THE SUBJECT SOFTWARE.
//
package gov.nasa.jpf.jvm.bytecode;

import java.util.function.BiFunction;
import cmu.conditional.Conditional;
import cmu.conditional.One;
import de.fosd.typechef.featureexpr.FeatureExpr;
import gov.nasa.jpf.vm.ArrayIndexOutOfBoundsExecutiveException;
import gov.nasa.jpf.vm.ElementInfo;
import gov.nasa.jpf.vm.Instruction;
import gov.nasa.jpf.vm.MJIEnv;
import gov.nasa.jpf.vm.StackFrame;
import gov.nasa.jpf.vm.ThreadInfo;

/**
 * abstraction for all array store instructions
 * 
 * ... array, index, <value> => ...
 */
public abstract class ArrayStoreInstruction extends ArrayElementInstruction implements StoreInstruction {

	@Override
	public Conditional<Instruction> execute(FeatureExpr ctx, final ThreadInfo ti) {
		Conditional<Integer> aref = peekArrayRef(ctx, ti); // need to be poly, could be LongArrayStore
		final ArrayStoreInstruction instruction = this;
		return aref.mapf(ctx, new BiFunction<FeatureExpr, Integer, Conditional<Instruction>>() {

			@Override
			public Conditional<Instruction> apply(FeatureExpr ctx, Integer aref) {
				if (aref == MJIEnv.NULL) {
					return new One<>(ti.createAndThrowException(ctx, "java.lang.NullPointerException"));
				}

				final ElementInfo e = ti.getModifiableElementInfoWithUpdatedSharedness(aref);
				if (isNewPorBoundary(e, ti)) {
					if (createAndSetArrayCG(e, ti, aref, peekIndex(ctx, ti), false)) {
						return new One<Instruction>(instruction);
					}
				}

				int esize = getElementSize();
				StackFrame frame = ti.getModifiableTopFrame();

				final Object attr = esize == 1 ? frame.getOperandAttr(ctx) : frame.getLongOperandAttr(ctx);

				popValue(ctx, frame);
				index = frame.pop(ctx);
				// don't set 'arrayRef' before we do the CG check (would kill loop optimization)
				arrayRef = frame.pop(ctx);

				Conditional<Instruction> xInsn = checkArrayStoreException(ctx, ti, e);
				return xInsn.mapf(ctx, new BiFunction<FeatureExpr, Instruction, Conditional<Instruction>>() {

					@Override
					public Conditional<Instruction> apply(FeatureExpr ctx, Instruction xInsn) {
						if (xInsn != null) {
							return new One<>(xInsn);
						}

						return index.mapf(ctx, new BiFunction<FeatureExpr, Integer, Conditional<Instruction>>() {

							@Override
							public Conditional<Instruction> apply(FeatureExpr ctx, Integer index) {
								try {
									setField(ctx, e, index);
									e.setElementAttrNoClone(index, attr); // <2do> what if the value is the same but not the attr?
									return getNext(ctx, ti);

								} catch (ArrayIndexOutOfBoundsException ex) { // at this point, the AIOBX is already processed
									return new One<Instruction>(new EXCEPTION(instruction, ArrayIndexOutOfBoundsException.class.getName(), "Array index out of range: " + index));
								}
							}

						});
					}

				});
			}
		});
	}

	/**
	 * this is for pre-exec use
	 */
	@Override
	public Conditional<Integer> peekArrayRef(FeatureExpr ctx, ThreadInfo ti) {
		return ti.getTopFrame().peek(ctx, 2);
	}

	@Override
	public Conditional<Integer> peekIndex(FeatureExpr ctx, ThreadInfo ti) {
		return ti.getTopFrame().peek(ctx, 1);
	}

	@SuppressWarnings("unchecked")
	protected Conditional<Instruction> checkArrayStoreException(FeatureExpr ctx, ThreadInfo ti, ElementInfo ei) {
		return (Conditional<Instruction>) One.NULL;
	}

	protected abstract void popValue(FeatureExpr ctx, StackFrame frame);

	protected abstract void setField(FeatureExpr ctx, ElementInfo e, int index) throws ArrayIndexOutOfBoundsExecutiveException;

	@Override
	public boolean isRead() {
		return false;
	}

	@Override
	public void accept(InstructionVisitor insVisitor) {
		insVisitor.visit(this);
	}

}