/*
 * FindBugs - Find Bugs in Java programs
 * Copyright (C) 2005, 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 java.util.Iterator;
import java.util.Set;

import org.apache.bcel.classfile.Method;
import org.apache.bcel.generic.Instruction;
import org.apache.bcel.generic.InvokeInstruction;

import edu.umd.cs.findbugs.BugReporter;
import edu.umd.cs.findbugs.Detector;
import edu.umd.cs.findbugs.NonReportingDetector;
import edu.umd.cs.findbugs.SystemProperties;
import edu.umd.cs.findbugs.ba.CFG;
import edu.umd.cs.findbugs.ba.CFGBuilderException;
import edu.umd.cs.findbugs.ba.ClassContext;
import edu.umd.cs.findbugs.ba.DataflowAnalysisException;
import edu.umd.cs.findbugs.ba.Hierarchy;
import edu.umd.cs.findbugs.ba.JavaClassAndMethod;
import edu.umd.cs.findbugs.ba.Location;
import edu.umd.cs.findbugs.ba.SignatureConverter;

/**
 * This is just for debugging method call resolution.
 * 
 * @author David Hovemeyer
 */
public class CheckCalls implements Detector, NonReportingDetector {

    private static final String METHOD = SystemProperties.getProperty("checkcalls.method");

    private static final String TARGET_METHOD = SystemProperties.getProperty("checkcalls.targetmethod");

    BugReporter bugReporter;

    public CheckCalls(BugReporter bugReporter) {
        this.bugReporter = bugReporter;
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * edu.umd.cs.findbugs.Detector#visitClassContext(edu.umd.cs.findbugs.ba
     * .ClassContext)
     */
    public void visitClassContext(ClassContext classContext) {
        Method[] methodList = classContext.getJavaClass().getMethods();
        for (Method method : methodList) {
            if (method.getCode() == null)
                continue;

            // System.out.println("--> " + method.getName());
            if (METHOD != null && !method.getName().equals(METHOD))
                continue;

            try {
                System.out.println("Analyzing " + SignatureConverter.convertMethodSignature(classContext.getJavaClass(), method));
                analyzeMethod(classContext, method);
            } catch (CFGBuilderException e) {
                bugReporter.logError("Error", e);
            } catch (DataflowAnalysisException e) {
                bugReporter.logError("Error", e);
            } catch (ClassNotFoundException e) {
                bugReporter.reportMissingClass(e);
            }
        }
    }

    private void analyzeMethod(ClassContext classContext, Method method) throws CFGBuilderException, ClassNotFoundException,
            DataflowAnalysisException {
        CFG cfg = classContext.getCFG(method);
        for (Iterator<Location> i = cfg.locationIterator(); i.hasNext();) {
            Location location = i.next();
            Instruction ins = location.getHandle().getInstruction();

            if (ins instanceof InvokeInstruction) {
                if (TARGET_METHOD != null
                        && !((InvokeInstruction) ins).getMethodName(classContext.getConstantPoolGen()).equals(TARGET_METHOD))
                    continue;

                System.out.println("\n*******************************************************\n");

                System.out.println("Method invocation: " + location.getHandle());
                System.out.println("\tInvoking: "
                        + SignatureConverter.convertMethodSignature((InvokeInstruction) ins, classContext.getConstantPoolGen()));

                JavaClassAndMethod proto = Hierarchy.findInvocationLeastUpperBound((InvokeInstruction) ins,
                        classContext.getConstantPoolGen());
                if (proto == null) {
                    System.out.println("\tUnknown prototype method");
                } else {
                    System.out.println("\tPrototype method: class=" + proto.getJavaClass().getClassName() + ", method="
                            + proto.getMethod());
                }
                Set<JavaClassAndMethod> calledMethodSet = Hierarchy.resolveMethodCallTargets((InvokeInstruction) ins,
                        classContext.getTypeDataflow(method).getFactAtLocation(location), classContext.getConstantPoolGen());
                System.out.println("\tTarget method set: " + calledMethodSet);
            }
        }
    }

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

}