/*
 * FindBugs - Find bugs in Java programs
 * Copyright (C) 2004-2006 University of Maryland
 *
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package edu.umd.cs.findbugs.detect;

import edu.umd.cs.findbugs.BugInstance;
import edu.umd.cs.findbugs.BugReporter;
import edu.umd.cs.findbugs.OpcodeStack;
import edu.umd.cs.findbugs.OpcodeStack.Item;
import edu.umd.cs.findbugs.ba.AnalysisContext;
import edu.umd.cs.findbugs.ba.ClassContext;
import edu.umd.cs.findbugs.ba.interproc.ParameterProperty;
import edu.umd.cs.findbugs.bcel.OpcodeStackDetector;
import edu.umd.cs.findbugs.visitclass.PreorderVisitor;

public class IntCast2LongAsInstant extends OpcodeStackDetector {

    final BugReporter bugReporter;

    int lastConstantForSIPUSH;

    TrainLongInstantfParams.LongInstantParameterDatabase database = new TrainLongInstantfParams.LongInstantParameterDatabase();

    public IntCast2LongAsInstant(BugReporter bugReporter) {
        this.bugReporter = bugReporter;
        AnalysisContext.currentAnalysisContext().loadPropertyDatabaseFromResource(database, "longInstant.db",
                "long instant database");
    }

    @Override
    public void sawOpcode(int seen) {
        if (seen == SIPUSH) {
            lastConstantForSIPUSH = getIntConstant();
        }
        if (seen == INVOKEINTERFACE || seen == INVOKEVIRTUAL || seen == INVOKESPECIAL || seen == INVOKESTATIC) {
            String signature = getSigConstantOperand();

            int numberArguments = PreorderVisitor.getNumberArguments(signature);

            for (int i = 0; i < numberArguments; i++) {
                Item item = stack.getStackItem(numberArguments - 1 - i);
                if (item.getSpecialKind() == OpcodeStack.Item.RESULT_OF_I2L) {
                    ParameterProperty property = database.getProperty(getMethodDescriptorOperand());
                    if (property != null && property.hasProperty(i)) {
                        int priority = NORMAL_PRIORITY;

                        if (getPrevOpcode(1) == I2L && getPrevOpcode(2) == IMUL && getPrevOpcode(3) == SIPUSH
                                && lastConstantForSIPUSH == 1000) {
                            priority = HIGH_PRIORITY;

                        } else if (getPrevOpcode(1) == I2L && getPrevOpcode(2) == IMUL && getPrevOpcode(4) == SIPUSH
                                && lastConstantForSIPUSH == 1000) {
                            priority = HIGH_PRIORITY;
                        }
                        BugInstance bug = new BugInstance(this, "ICAST_INT_2_LONG_AS_INSTANT", priority).addClassAndMethod(this)
                                .addCalledMethod(this).addValueSource(item, this).addSourceLine(this);
                        bugReporter.reportBug(bug);
                    }

                }
            }

        }
    }

    /*
     * (non-Javadoc)
     * 
     * @see edu.umd.cs.findbugs.Detector#report()
     */
    @Override
    public void report() {

    }

    @Override
    public void visitClassContext(ClassContext classContext) {
        classContext.getJavaClass().accept(this);
    }

}
