/*

 * Copyright (c) 2011, 2015, 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.

 *

 * 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.

 */

/*

 * @test

 * @bug 7017664 7036906

 * @summary Basher for CompoundScopes

 * @modules jdk.compiler/com.sun.tools.javac.code

 *          jdk.compiler/com.sun.tools.javac.file

 *          jdk.compiler/com.sun.tools.javac.util

 */

import java.util.Random;

import java.util.Map;

import java.util.HashMap;

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

import com.sun.tools.javac.code.*;

import com.sun.tools.javac.code.Scope.*;

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

import com.sun.tools.javac.file.JavacFileManager;

public class CompoundScopeTest {

    public static void main(String... args) throws Exception {

        new CompoundScopeTest().run(args);

    }

    static final int MAX_SYMBOLS_COUNT = 20;

    static final int PASSES = 10;

    void run(String... args) throws Exception {

        int count = PASSES;

        for (int i = 0; i < args.length; i++) {

            String arg = args[i];

            if (arg.equals("-seed") && (i + 1 < args.length))

                seed = Long.parseLong(args[++i]);

            else if(arg.equals("-tests") && (i + 1 < args.length))

                count = Integer.parseInt(args[++i]);

            else

                throw new Exception("unknown arg: " + arg);

        }

        rgen = new Random(seed);

        for (int i = 0; i < count; i++) {

            Test t = new Test();

            t.run();

        }

        if (errors > 0)

            throw new Exception(errors + " errors found");

    }

    /**

     * Write a message to stderr.

     */

    void log(String msg) {

        System.err.println(msg);

    }

    /**

     * Write an error message to stderr.

     */

    void error(String msg) {

        System.err.println("Error: " + msg);

        errors++;

    }

    Random rgen;

    long seed = 0;

    int errors;

    /** Class to encapsulate a test run. */

    class Test {

        List<Symbol> elems = List.nil();

        Map<Name, List<Symbol>> shadowedMap = new HashMap<Name, List<Symbol>>();

        /** Run the test. */

        void run() throws Exception {

            log ("starting test");

            setup();

            Scope[] scopes = { createScope(rgen.nextInt(MAX_SYMBOLS_COUNT)),

                               createScope(rgen.nextInt(MAX_SYMBOLS_COUNT)),

                               createScope(rgen.nextInt(MAX_SYMBOLS_COUNT)) };

            boolean[][] scopeNesting = { {false, true, false, true},

                                   {false, true, true, true},

                                   {false, false, true, true} };

            /**

             * We want to generate (and check) the following compound scopes:

             * C1 = C(S1, S2, S3)

             * C2 = C((S1, S2), S3)

             * C3 = C(S1, (S2, S3))

             * C3 = C(C(S1, S2, S3))

             */

            for (int i = 0 ; i < 4 ; i ++) {

                CompoundScope root = new CompoundScope(symtab.noSymbol);

                CompoundScope sub = new CompoundScope(symtab.noSymbol);

                boolean subAdded = false;

                for (int sc = 0 ; sc < 3 ; sc ++) {

                    if (scopeNesting[sc][i]) {

                        sub.prependSubScope(scopes[sc]);

                        if (!subAdded) {

                            root.prependSubScope(sub);

                            subAdded = true;

                        }

                    } else {

                        root.prependSubScope(scopes[sc]);

                    }

                }

                log("testing scope: " + root);

                checkElems(root, null);

                checkElems(root, new OddFilter());

                checkShadowed(root, null);

                checkShadowed(root, new OddFilter());

            }

        }

        class OddFilter implements Filter<Symbol> {

            public boolean accepts(Symbol s) {

                Name numPart = s.name.subName(1, s.name.length());

                return Integer.parseInt(numPart.toString()) % 2 != 0;

            }

        }

        /**

         * Create a scope containing a given number of synthetic symbols

         */

        Scope createScope(int nelems) {

            WriteableScope s = WriteableScope.create(symtab.noSymbol);

            for (int i = 0 ; i < nelems ; i++) {

                Symbol sym = new TypeVariableSymbol(0, names.fromString("s" + i), null, null);

                s.enter(sym);

                elems = elems.prepend(sym);

                List<Symbol> shadowed = shadowedMap.get(sym.name);

                if (shadowed == null) {

                    shadowed = List.nil();

                }

                shadowedMap.put(sym.name, shadowed.prepend(sym));

            }

            return s;

        }

        /**

         * Setup compiler context

         */

        void setup() {

            log ("setup");

            context = new Context();

            JavacFileManager.preRegister(context); // required by ClassReader which is required by Symtab

            names = Names.instance(context);       // Name.Table impls tied to an instance of Names

            symtab = Symtab.instance(context);

        }

        /**

         * Check that CompoundScope.getElements() correctly visits all symbols

         * in all subscopes (in the correct order)

         */

        void checkElems(CompoundScope cs, Filter<Symbol> sf) {

            int count = 0;

            ListBuffer<Symbol> found = new ListBuffer<>();

            List<Symbol> allSymbols = sf == null ?

                    elems :

                    filter(elems, sf);

            int expectedCount = allSymbols.length();

            for (Symbol s : sf == null ? cs.getSymbols() : cs.getSymbols(sf)) {

                checkSameSymbols(s, allSymbols.head);

                allSymbols = allSymbols.tail;

                found.append(s);

                count++;

            }

            if (count != expectedCount) {

                error("CompoundScope.getElements() did not returned enough symbols");

            }

        }

        /**

         * Check that CompoundScope.getElements() correctly visits all symbols

         * with a given name in all subscopes (in the correct order)

         */

        void checkShadowed(CompoundScope cs, Filter<Symbol> sf) {

            for (Map.Entry<Name, List<Symbol>> shadowedEntry : shadowedMap.entrySet()) {

                int count = 0;

                List<Symbol> shadowed = sf == null ?

                    shadowedEntry.getValue() :

                    filter(shadowedEntry.getValue(), sf);

                int expectedCount = shadowed.length();

                Name name = shadowedEntry.getKey();

                for (Symbol s : sf == null ? cs.getSymbolsByName(name) : cs.getSymbolsByName(name, sf)) {

                    checkSameSymbols(s, shadowed.head);

                    shadowed = shadowed.tail;

                    count++;

                }

                if (count != expectedCount) {

                    error("CompoundScope.lookup() did not returned enough symbols for name " + name);

                }

            }

        }

        List<Symbol> filter(List<Symbol> elems, Filter<Symbol> sf) {

            ListBuffer<Symbol> res = new ListBuffer<>();

            for (Symbol s : elems) {

                if (sf.accepts(s)) {

                    res.append(s);

                }

            }

            return res.toList();

        }

        void checkSameSymbols(Symbol found, Symbol req) {

            if (found != req) {

                error("Symbol mismatch - found    : " + found + ":" + found.hashCode() + "\n" +

                      "                  required : " + req + ":" + req.hashCode());

            }

        }

        Context context;

        Symtab symtab;

        Names names;

    }

}