/*
 * fb-contrib - Auxiliary detectors for Java programs
 * Copyright (C) 2005-2017 Dave Brosius
 *
 * 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 com.mebigfatguy.fbcontrib.detect;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import com.mebigfatguy.fbcontrib.utils.BugType;
import com.mebigfatguy.fbcontrib.utils.UnmodifiableSet;
import com.mebigfatguy.fbcontrib.utils.Values;

import edu.umd.cs.findbugs.BugInstance;
import edu.umd.cs.findbugs.BugReporter;
import edu.umd.cs.findbugs.OpcodeStack.CustomUserValue;

/**
 * looks for allocations of synchronized collections that are stored in local variables, and never stored in fields or returned from methods. As local variables
 * are by definition thread safe, using synchronized collections in this context makes no sense.
 */
@CustomUserValue
public class LocalSynchronizedCollection extends LocalTypeDetector {
    private static final Map<String, Integer> syncCtors = new HashMap<>();

    static {
        syncCtors.put("java/util/Vector", Values.JAVA_1_1);
        syncCtors.put("java/util/Hashtable", Values.JAVA_1_1);
        syncCtors.put(Values.SLASHED_JAVA_LANG_STRINGBUFFER, Values.JAVA_5);
    }

    private static final Map<String, Set<String>> synchClassMethods = new HashMap<>();

    static {
        Set<String> syncMethods = new HashSet<>();
        syncMethods.add("synchronizedCollection");
        syncMethods.add("synchronizedList");
        syncMethods.add("synchronizedMap");
        syncMethods.add("synchronizedSet");
        syncMethods.add("synchronizedSortedMap");
        syncMethods.add("synchronizedSortedSet");

        synchClassMethods.put("java/util/Collections", syncMethods);
    }

    private static final Set<String> selfReturningMethods = UnmodifiableSet.create("java/lang/StringBuffer.append");

    private BugReporter bugReporter;

    /**
     * constructs a LSYC detector given the reporter to report bugs on
     *
     * @param bugReporter
     *            the sync of bug reports
     */
    public LocalSynchronizedCollection(BugReporter bugReporter) {
        this.bugReporter = bugReporter;
    }

    @Override
    protected Map<String, Integer> getWatchedConstructors() {
        return syncCtors;
    }

    @Override
    protected Map<String, Set<String>> getWatchedClassMethods() {
        return synchClassMethods;
    }

    @Override
    protected Set<String> getSelfReturningMethods() {
        return selfReturningMethods;
    }

    @Override
    protected void reportBug(RegisterInfo cri) {
        bugReporter.reportBug(new BugInstance(this, BugType.LSYC_LOCAL_SYNCHRONIZED_COLLECTION.name(), cri.getPriority()).addClass(this).addMethod(this)
                .addSourceLine(cri.getSourceLineAnnotation()));
    }
}