/*
 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
package com.sun.tools.sjavac.comp.dependencies;

import java.util.HashSet;
import java.util.Set;

import com.sun.source.tree.Tree;
import com.sun.source.util.TaskEvent;
import com.sun.source.util.TaskListener;
import com.sun.tools.javac.code.Symbol.ClassSymbol;
import com.sun.tools.javac.tree.JCTree.JCClassDecl;
import com.sun.tools.javac.tree.JCTree.JCCompilationUnit;
import com.sun.tools.javac.util.Context;
import com.sun.tools.javac.util.DefinedBy;
import com.sun.tools.javac.util.DefinedBy.Api;
import com.sun.tools.sjavac.comp.Dependencies;

public class PublicApiCollector implements TaskListener {

    private Context context;
    private final Set<ClassSymbol> classSymbols = new HashSet<>();

    public PublicApiCollector(Context context) {
        this.context = context;
    }

    @Override
    @DefinedBy(Api.COMPILER_TREE)
    public void finished(TaskEvent e) {
        switch (e.getKind()) {
        case ANALYZE:
            collectClassSymbols((JCCompilationUnit) e.getCompilationUnit());
            break;
        case COMPILATION:
            extractPubApis();
            break;
        }
    }

    private void collectClassSymbols(JCCompilationUnit cu) {
        for (Tree t : cu.getTypeDecls()) {
            if (t instanceof JCClassDecl)  // Can also be a JCSkip
                classSymbols.add(((JCClassDecl) t).sym);
        }
    }

    private void extractPubApis() {
        // For incremental builds we need to remember the public api of what
        // we depend upon.
        // Within a single compilation loop, we need to keep track of public
        // api of what we're compiling to decide if any dependants needs to
        // be tainted.
        Dependencies deps = Dependencies.instance(context);
        for (ClassSymbol cs : classSymbols)
            deps.visitPubapi(cs);
    }
}