/*
 * Bytecode Analysis Framework
 * 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.ba.ca;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import org.apache.bcel.generic.ConstantPoolGen;
import org.apache.bcel.generic.Instruction;
import org.apache.bcel.generic.InstructionHandle;
import org.apache.bcel.generic.InvokeInstruction;

import edu.umd.cs.findbugs.ba.AbstractDataflowAnalysis;
import edu.umd.cs.findbugs.ba.BasicBlock;
import edu.umd.cs.findbugs.ba.BlockOrder;
import edu.umd.cs.findbugs.ba.CFG;
import edu.umd.cs.findbugs.ba.DataflowAnalysisException;
import edu.umd.cs.findbugs.ba.DepthFirstSearch;
import edu.umd.cs.findbugs.ba.Edge;
import edu.umd.cs.findbugs.ba.Location;
import edu.umd.cs.findbugs.ba.ReversePostOrder;

public class CallListAnalysis extends AbstractDataflowAnalysis<CallList> {
    private DepthFirstSearch dfs;

    // private ConstantPoolGen cpg;
    private Map<InstructionHandle, Call> callMap;

    public CallListAnalysis(CFG cfg, DepthFirstSearch dfs, ConstantPoolGen cpg) {
        this.dfs = dfs;
        // this.cpg = cpg;
        this.callMap = buildCallMap(cfg, cpg);
    }

    private static Map<InstructionHandle, Call> buildCallMap(CFG cfg, ConstantPoolGen cpg) {
        Map<InstructionHandle, Call> callMap = new HashMap<InstructionHandle, Call>();

        for (Iterator<Location> i = cfg.locationIterator(); i.hasNext();) {
            InstructionHandle handle = i.next().getHandle();
            Instruction ins = handle.getInstruction();

            if (ins instanceof InvokeInstruction) {
                InvokeInstruction inv = (InvokeInstruction) ins;
                Call call = new Call(inv.getClassName(cpg), inv.getName(cpg), inv.getSignature(cpg));
                callMap.put(handle, call);
            }
        }

        return callMap;
    }

    public void initEntryFact(CallList fact) {
        fact.clear();
    }

    // public void initResultFact(CallList fact) {
    // fact.setTop();
    // }

    public boolean isForwards() {
        return true;
    }

    public BlockOrder getBlockOrder(CFG cfg) {
        return new ReversePostOrder(cfg, dfs);
    }

    public void makeFactTop(CallList fact) {
        fact.setTop();
    }

    public boolean isTop(CallList fact) {
        return fact.isTop();
    }

    public CallList createFact() {
        return new CallList();
    }

    public boolean same(CallList a, CallList b) {
        return a.equals(b);
    }

    public void meetInto(CallList start, Edge edge, CallList result) throws DataflowAnalysisException {
        CallList merge = CallList.merge(start, result);
        result.copyFrom(merge);
    }

    public void copy(CallList source, CallList dest) {
        dest.copyFrom(source);
    }

    @Override
    public void transferInstruction(InstructionHandle handle, BasicBlock basicBlock, CallList fact)
            throws DataflowAnalysisException {
        Call call = callMap.get(handle);
        if (call != null) {
            fact.add(call);
        }
    }

    @Override
    public boolean isFactValid(CallList fact) {
        return fact.isValid();
    }

    // public static void main(String[] argv) throws Exception {
    // if (argv.length != 1) {
    // System.err.println("Usage: " + CallListAnalysis.class.getName() +
    // " <class file>");
    // System.exit(1);
    // }
    //
    // DataflowTestDriver<CallList, CallListAnalysis> driver =
    // new DataflowTestDriver<CallList, CallListAnalysis>() {
    // @Override
    // public Dataflow<CallList, CallListAnalysis> createDataflow(
    // ClassContext classContext,
    // Method method) throws CFGBuilderException, DataflowAnalysisException {
    // CallListAnalysis analysis = new CallListAnalysis(
    // classContext.getCFG(method),
    // classContext.getDepthFirstSearch(method),
    // classContext.getConstantPoolGen());
    // Dataflow<CallList, CallListAnalysis> dataflow =
    // new Dataflow<CallList, CallListAnalysis>(analysis.cfg, analysis);
    //
    // dataflow.execute();
    //
    // return dataflow;
    // }
    // };
    //
    // driver.execute(argv[0]);
    // }
}
