/*

 * Copyright (c) 1999, 2013, 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;

import javax.lang.model.element.Element;

import java.util.Arrays;

import java.util.Comparator;

import java.util.HashMap;

import java.util.HashSet;

import java.util.Map;

import java.util.Set;

import com.sun.tools.javac.code.Symbol.ClassSymbol;

import com.sun.tools.javac.util.Context;

import com.sun.tools.javac.util.Log;

import com.sun.tools.javac.util.Name;

/** Utility class containing dependency information between packages

 *  and the pubapi for a package.

 *

 * <p><b>This is NOT part of any supported API.

 * If you write code that depends on this, you do so at your own

 * risk.  This code and its internal interfaces are subject to change

 * or deletion without notice.</b></p>

 */

public class Dependencies {

    // The log to be used for error reporting.

    protected Log log;

    // Map from package name to packages that the package depends upon.

    protected Map<Name,Set<Name>> deps;

    // This is the set of all packages that are supplied

    // through the java files at the command line.

    protected Set<Name> explicitPackages;

    // Map from a package name to its public api.

    // Will the Name encode the module in the future?

    // If not, this will have to change to map from Module+Name to public api.

    protected Map<Name,StringBuffer> publicApiPerClass;

    public static Dependencies instance(Context context) {

        Dependencies instance = context.get(dependenciesKey);

        if (instance == null)

            instance = new Dependencies(context);

        return instance;

    }

    private Dependencies(Context context) {

        context.put(dependenciesKey, this);

        log = Log.instance(context);

    }

    public void reset()

    {

    }

    /**

     * Fetch the set of dependencies that are relevant to the compile

     * that has just been performed. I.e. we are only interested in

     * dependencies for classes that were explicitly compiled.

     * @return

     */

    public Map<String,Set<String>> getDependencies() {

        if (explicitPackages == null) return new_deps;

        for (Name pkg : explicitPackages) {

            Set<Name> set = deps.get(pkg);

            if (set != null) {

                Set<String> new_set = new_deps.get(pkg.toString());

                if (new_set == null) {

                    // Modules beware....

                    new_deps.put(":"+pkg.toString(), new_set);

                }

                for (Name d : set) {

                    new_set.add(":"+d.toString());

                }

            }

        }

        return new_deps;

    }

    static class CompareNames implements Comparator<Name> {

         public int compare(Name a, Name b) {

             return a.toString().compareTo(b.toString());

         }

    }

    /**

     * Convert the map from class names to their pubapi to a map

     * from package names to their pubapi (which is the sorted concatenation

     * of all the class pubapis)

     */

    public Map<String,String> getPubapis() {

        if (publicApiPerClass == null) return publicApiPerPackage;

        Name[] keys = publicApiPerClass.keySet().toArray(new Name[0]);

        Arrays.sort(keys, new CompareNames());

        StringBuffer newPublicApi = new StringBuffer();

        int i=0;

        String prevPkg = "";

        for (Name k : keys) {

            String cn = k.toString();

            String pn = "";

            int dp = cn.lastIndexOf('.');

            if (dp != -1) {

                pn = cn.substring(0,dp);

            }

            if (!pn.equals(prevPkg)) {

                if (!prevPkg.equals("")) {

                    // Add default module name ":"

                    publicApiPerPackage.put(":"+prevPkg, newPublicApi.toString());

                }

                newPublicApi = new StringBuffer();

                prevPkg = pn;

            }

            newPublicApi.append(publicApiPerClass.get(k));

            i++;

        }

        if (!prevPkg.equals(""))

            publicApiPerPackage.put(":"+prevPkg, newPublicApi.toString());

        return publicApiPerPackage;

    }

    /**

     * Visit the api of a class and construct a pubapi string and

     * store it into the pubapi_perclass map.

     */

    public void visitPubapi(Element e) {

        Name n = ((ClassSymbol)e).fullname;

        Name p = ((ClassSymbol)e).packge().fullname;

        StringBuffer sb = publicApiPerClass.get(n);

        assert(sb == null);

        sb = new StringBuffer();

        PubapiVisitor v = new PubapiVisitor(sb);

        v.visit(e);

        if (sb.length()>0) {

            publicApiPerClass.put(n, sb);

        }

        explicitPackages.add(p);

     }

    /**

     * Collect a dependency. curr_pkg is marked as depending on dep_pkg.

     */

    public void collect(Name currPkg, Name depPkg) {

        if (!currPkg.equals(depPkg)) {

            Set<Name> theset = deps.get(currPkg);

            if (theset==null) {

                deps.put(currPkg, theset);

            }

            theset.add(depPkg);

        }

    }

}