/*

 * Copyright (c) 2012, 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

 *

 * 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

 * @summary test access checking by java.lang.invoke.MethodHandles.Lookup

 * @library ../../../..

 * @build test.java.lang.invoke.AccessControlTest

 * @build test.java.lang.invoke.AccessControlTest_subpkg.Acquaintance_remote

 * @run testng/othervm test.java.lang.invoke.AccessControlTest

 */

package test.java.lang.invoke;

import java.lang.invoke.*;

import java.lang.reflect.*;

import java.util.*;

import org.testng.*;

import org.testng.annotations.*;

import static java.lang.invoke.MethodHandles.*;

import static java.lang.invoke.MethodHandles.Lookup.*;

import static java.lang.invoke.MethodType.*;

import static org.testng.Assert.*;

import test.java.lang.invoke.AccessControlTest_subpkg.Acquaintance_remote;

/**

 * Test many combinations of Lookup access and cross-class lookupStatic.

 * @author jrose

 */

public class AccessControlTest {

    static final Class<?> THIS_CLASS = AccessControlTest.class;

    // How much output?

    static int verbosity = 0;

    static {

        String vstr = System.getProperty(THIS_CLASS.getSimpleName()+".verbosity");

        if (vstr == null)

            vstr = System.getProperty(THIS_CLASS.getName()+".verbosity");

        if (vstr != null)  verbosity = Integer.parseInt(vstr);

    }

    private class LookupCase implements Comparable<LookupCase> {

        final Lookup   lookup;

        final Class<?> lookupClass;

        final int      lookupModes;

        public LookupCase(Lookup lookup) {

            this.lookup = lookup;

            this.lookupClass = lookup.lookupClass();

            this.lookupModes = lookup.lookupModes();

            assert(lookupString().equals(lookup.toString()));

            numberOf(lookupClass().getClassLoader()); // assign CL#

        }

        public LookupCase(Class<?> lookupClass, int lookupModes) {

            this.lookup = null;

            this.lookupClass = lookupClass;

            this.lookupModes = lookupModes;

            numberOf(lookupClass().getClassLoader()); // assign CL#

        }

        public final Class<?> lookupClass() { return lookupClass; }

        public final int      lookupModes() { return lookupModes; }

        public Lookup lookup() { lookup.getClass(); return lookup; }

        @Override

        public int compareTo(LookupCase that) {

            Class<?> c1 = this.lookupClass();

            Class<?> c2 = that.lookupClass();

            if (c1 != c2) {

                int cmp = c1.getName().compareTo(c2.getName());

                if (cmp != 0)  return cmp;

                cmp = numberOf(c1.getClassLoader()) - numberOf(c2.getClassLoader());

                assert(cmp != 0);

                return cmp;

            }

            return -(this.lookupModes() - that.lookupModes());

        }

        @Override

        public boolean equals(Object that) {

            return (that instanceof LookupCase && equals((LookupCase)that));

        }

        public boolean equals(LookupCase that) {

            return (this.lookupClass() == that.lookupClass() &&

                    this.lookupModes() == that.lookupModes());

        }

        @Override

        public int hashCode() {

            return lookupClass().hashCode() + (lookupModes() * 31);

        }

        /** Simulate all assertions in the spec. for Lookup.toString. */

        private String lookupString() {

            String name = lookupClass.getName();

            String suffix = "";

            if (lookupModes == 0)

                suffix = "/noaccess";

            else if (lookupModes == PUBLIC)

                suffix = "/public";

            else if (lookupModes == (PUBLIC|PACKAGE))

                suffix = "/package";

            else if (lookupModes == (PUBLIC|PACKAGE|PRIVATE))

                suffix = "/private";

            else if (lookupModes == (PUBLIC|PACKAGE|PRIVATE|PROTECTED))

                suffix = "";

            else

                suffix = "/#"+Integer.toHexString(lookupModes);

            return name+suffix;

        }

        /** Simulate all assertions from the spec. for Lookup.in:

         * <hr>

         * Creates a lookup on the specified new lookup class.

         * [A1] The resulting object will report the specified

         * class as its own {@link #lookupClass lookupClass}.

         * <p>

         * [A2] However, the resulting {@code Lookup} object is guaranteed

         * to have no more access capabilities than the original.

         * In particular, access capabilities can be lost as follows:<ul>

         * <li>[A3] If the new lookup class differs from the old one,

         * protected members will not be accessible by virtue of inheritance.

         * (Protected members may continue to be accessible because of package sharing.)

         * <li>[A4] If the new lookup class is in a different package

         * than the old one, protected and default (package) members will not be accessible.

         * <li>[A5] If the new lookup class is not within the same package member

         * as the old one, private members will not be accessible.

         * <li>[A6] If the new lookup class is not accessible to the old lookup class,

         * using the original access modes,

         * then no members, not even public members, will be accessible.

         * [A7] (In all other cases, public members will continue to be accessible.)

         * </ul>

         * Other than the above cases, the new lookup will have the same

         * access capabilities as the original. [A8]

         * <hr>

         */

        public LookupCase in(Class<?> c2) {

            Class<?> c1 = lookupClass();

            int m1 = lookupModes();

            int changed = 0;

            boolean samePackage = (c1.getClassLoader() == c2.getClassLoader() &&

                                   packagePrefix(c1).equals(packagePrefix(c2)));

            boolean sameTopLevel = (topLevelClass(c1) == topLevelClass(c2));

            boolean sameClass = (c1 == c2);

            assert(samePackage  || !sameTopLevel);

            assert(sameTopLevel || !sameClass);

            boolean accessible = sameClass;  // [A6]

            if ((m1 & PACKAGE) != 0)  accessible |= samePackage;

            if ((m1 & PUBLIC ) != 0)  accessible |= (c2.getModifiers() & PUBLIC) != 0;

            if (!accessible) {

                // Different package and no access to c2; lose all access.

                changed |= (PUBLIC|PACKAGE|PRIVATE|PROTECTED);  // [A6]

            }

            if (!samePackage) {

                // Different package; lose PACKAGE and lower access.

                changed |= (PACKAGE|PRIVATE|PROTECTED);  // [A4]

            }

            if (!sameTopLevel) {

                // Different top-level class.  Lose PRIVATE and lower access.

                changed |= (PRIVATE|PROTECTED);  // [A5]

            }

            if (!sameClass) {

                changed |= (PROTECTED);     // [A3]

            } else {

                assert(changed == 0);       // [A8] (no deprivation if same class)

            }

            if (accessible)  assert((changed & PUBLIC) == 0);  // [A7]

            int m2 = m1 & ~changed;

            LookupCase l2 = new LookupCase(c2, m2);

            assert(l2.lookupClass() == c2); // [A1]

            assert((m1 | m2) == m1);        // [A2] (no elevation of access)

            return l2;

        }

        @Override

        public String toString() {

            String s = lookupClass().getSimpleName();

            String lstr = lookupString();

            int sl = lstr.indexOf('/');

            if (sl >= 0)  s += lstr.substring(sl);

            ClassLoader cld = lookupClass().getClassLoader();

            if (cld != THIS_LOADER)  s += "/loader#"+numberOf(cld);

            return s;

        }

        /** Predict the success or failure of accessing this method. */

        public boolean willAccess(Method m) {

            Class<?> c1 = lookupClass();

            Class<?> c2 = m.getDeclaringClass();

            LookupCase lc = this.in(c2);

            int m1 = lc.lookupModes();

            int m2 = fixMods(m.getModifiers());

            // privacy is strictly enforced on lookups

            if (c1 != c2)  m1 &= ~PRIVATE;

            // protected access is sometimes allowed

            if ((m2 & PROTECTED) != 0) {

                int prev = m2;

                m2 |= PACKAGE;  // it acts like a package method also

                if ((lookupModes() & PROTECTED) != 0 &&

                    c2.isAssignableFrom(c1))

                    m2 |= PUBLIC;  // from a subclass, it acts like a public method also

            }

            if (verbosity >= 2)

                System.out.println(this+" willAccess "+lc+" m1="+m1+" m2="+m2+" => "+((m2 & m1) != 0));

            return (m2 & m1) != 0;

        }

    }

    private static Class<?> topLevelClass(Class<?> cls) {

        Class<?> c = cls;

        for (Class<?> ec; (ec = c.getEnclosingClass()) != null; )

            c = ec;

        assert(c.getEnclosingClass() == null);

        assert(c == cls || cls.getEnclosingClass() != null);

        return c;

    }

    private static String packagePrefix(Class<?> c) {

        while (c.isArray())  c = c.getComponentType();

        String s = c.getName();

        assert(s.indexOf('/') < 0);

        return s.substring(0, s.lastIndexOf('.')+1);

    }

    private final TreeSet<LookupCase> CASES = new TreeSet<>();

    private final TreeMap<LookupCase,TreeSet<LookupCase>> CASE_EDGES = new TreeMap<>();

    private final ArrayList<ClassLoader> LOADERS = new ArrayList<>();

    private final ClassLoader THIS_LOADER = this.getClass().getClassLoader();

    { if (THIS_LOADER != null)  LOADERS.add(THIS_LOADER); }  // #1

    private LookupCase lookupCase(String name) {

        for (LookupCase lc : CASES) {

            if (lc.toString().equals(name))

                return lc;

        }

        throw new AssertionError(name);

    }

    private int numberOf(ClassLoader cl) {

        if (cl == null)  return 0;

        int i = LOADERS.indexOf(cl);

        if (i < 0) {

            i = LOADERS.size();

            LOADERS.add(cl);

        }

        return i+1;

    }

    private void addLookupEdge(LookupCase l1, Class<?> c2, LookupCase l2) {

        TreeSet<LookupCase> edges = CASE_EDGES.get(l2);

        if (edges == null)  CASE_EDGES.put(l2, edges = new TreeSet<>());

        if (edges.add(l1)) {

            Class<?> c1 = l1.lookupClass();

            assert(l2.lookupClass() == c2); // [A1]

            int m1 = l1.lookupModes();

            int m2 = l2.lookupModes();

            assert((m1 | m2) == m1);        // [A2] (no elevation of access)

            LookupCase expect = l1.in(c2);

            if (!expect.equals(l2))

                System.out.println("*** expect "+l1+" => "+expect+" but got "+l2);

            assertEquals(expect, l2);

        }

    }

    private void makeCases(Lookup[] originalLookups) {

        // make initial set of lookup test cases

        CASES.clear(); LOADERS.clear(); CASE_EDGES.clear();

        ArrayList<Class<?>> classes = new ArrayList<>();

        for (Lookup l : originalLookups) {

            CASES.add(new LookupCase(l));

            classes.remove(l.lookupClass());  // no dups please

            classes.add(l.lookupClass());

        }

        System.out.println("loaders = "+LOADERS);

        int rounds = 0;

        for (int lastCount = -1; lastCount != CASES.size(); ) {

            lastCount = CASES.size();  // if CASES grow in the loop we go round again

            for (LookupCase lc1 : CASES.toArray(new LookupCase[0])) {

                for (Class<?> c2 : classes) {

                    LookupCase lc2 = new LookupCase(lc1.lookup().in(c2));

                    addLookupEdge(lc1, c2, lc2);

                    CASES.add(lc2);

                }

            }

            rounds++;

        }

        System.out.println("filled in "+CASES.size()+" cases from "+originalLookups.length+" original cases in "+rounds+" rounds");

        if (false) {

            System.out.println("CASES: {");

            for (LookupCase lc : CASES) {

                System.out.println(lc);

                Set<LookupCase> edges = CASE_EDGES.get(lc);

                if (edges != null)

                    for (LookupCase prev : edges) {

                        System.out.println("\t"+prev);

                    }

            }

            System.out.println("}");

        }

    }

    @Test public void test() {

        makeCases(lookups());

        if (verbosity > 0) {

            verbosity += 9;

            Method pro_in_self = targetMethod(THIS_CLASS, PROTECTED, methodType(void.class));

            testOneAccess(lookupCase("AccessControlTest/public"),  pro_in_self, "find");

            testOneAccess(lookupCase("Remote_subclass/public"),    pro_in_self, "find");

            testOneAccess(lookupCase("Remote_subclass"),           pro_in_self, "find");

            verbosity -= 9;

        }

        Set<Class<?>> targetClassesDone = new HashSet<>();

        for (LookupCase targetCase : CASES) {

            Class<?> targetClass = targetCase.lookupClass();

            if (!targetClassesDone.add(targetClass))  continue;  // already saw this one

            String targetPlace = placeName(targetClass);

            if (targetPlace == null)  continue;  // Object, String, not a target

            for (int targetAccess : ACCESS_CASES) {

                MethodType methodType = methodType(void.class);

                Method method = targetMethod(targetClass, targetAccess, methodType);

                // Try to access target method from various contexts.

                for (LookupCase sourceCase : CASES) {

                    testOneAccess(sourceCase, method, "find");

                    testOneAccess(sourceCase, method, "unreflect");

                }

            }

        }

        System.out.println("tested "+testCount+" access scenarios; "+testCountFails+" accesses were denied");

    }

    private int testCount, testCountFails;

    private void testOneAccess(LookupCase sourceCase, Method method, String kind) {

        Class<?> targetClass = method.getDeclaringClass();

        String methodName = method.getName();

        MethodType methodType = methodType(method.getReturnType(), method.getParameterTypes());

        boolean willAccess = sourceCase.willAccess(method);

        boolean didAccess = false;

        ReflectiveOperationException accessError = null;

        try {

            switch (kind) {

            case "find":

                if ((method.getModifiers() & Modifier.STATIC) != 0)

                    sourceCase.lookup().findStatic(targetClass, methodName, methodType);

                else

                    sourceCase.lookup().findVirtual(targetClass, methodName, methodType);

                break;

            case "unreflect":

                sourceCase.lookup().unreflect(method);

                break;

            default:

                throw new AssertionError(kind);

            }

            didAccess = true;

        } catch (ReflectiveOperationException ex) {

            accessError = ex;

        }

        if (willAccess != didAccess) {

            System.out.println(sourceCase+" => "+targetClass.getSimpleName()+"."+methodName+methodType);

            System.out.println("fail on "+method+" ex="+accessError);

            assertEquals(willAccess, didAccess);

        }

        testCount++;

        if (!didAccess)  testCountFails++;

    }

    static Method targetMethod(Class<?> targetClass, int targetAccess, MethodType methodType) {

        String methodName = accessName(targetAccess)+placeName(targetClass);

        if (verbosity >= 2)

            System.out.println(targetClass.getSimpleName()+"."+methodName+methodType);

        try {

            Method method = targetClass.getDeclaredMethod(methodName, methodType.parameterArray());

            assertEquals(method.getReturnType(), methodType.returnType());

            int haveMods = method.getModifiers();

            assert(Modifier.isStatic(haveMods));

            assert(targetAccess == fixMods(haveMods));

            return method;

        } catch (NoSuchMethodException ex) {

            throw new AssertionError(methodName, ex);

        }

    }

    static String placeName(Class<?> cls) {

        // return "self", "sibling", "nestmate", etc.

        if (cls == AccessControlTest.class)  return "self";

        String cln = cls.getSimpleName();

        int under = cln.lastIndexOf('_');

        if (under < 0)  return null;

        return cln.substring(under+1);

    }

    static String accessName(int acc) {

        switch (acc) {

        case PUBLIC:     return "pub_in_";

        case PROTECTED:  return "pro_in_";

        case PACKAGE:    return "pkg_in_";

        case PRIVATE:    return "pri_in_";

        }

        assert(false);

        return "?";

    }

    private static final int[] ACCESS_CASES = {

        PUBLIC, PACKAGE, PRIVATE, PROTECTED

    };

    /** Return one of the ACCESS_CASES. */

    static int fixMods(int mods) {

        mods &= (PUBLIC|PRIVATE|PROTECTED);

        switch (mods) {

        case PUBLIC: case PRIVATE: case PROTECTED: return mods;

        case 0:  return PACKAGE;

        }

        throw new AssertionError(mods);

    }

    static Lookup[] lookups() {

        ArrayList<Lookup> tem = new ArrayList<>();

        Collections.addAll(tem,

                           AccessControlTest.lookup_in_self(),

                           Inner_nestmate.lookup_in_nestmate(),

                           AccessControlTest_sibling.lookup_in_sibling());

        if (true) {

            Collections.addAll(tem,Acquaintance_remote.lookups());

        } else {

            try {

                Class<?> remc = Class.forName("test.java.lang.invoke.AccessControlTest_subpkg.Acquaintance_remote");

                Lookup[] remls = (Lookup[]) remc.getMethod("lookups").invoke(null);

                Collections.addAll(tem, remls);

            } catch (ReflectiveOperationException ex) {

                throw new LinkageError("reflection failed", ex);

            }

        }

        tem.add(publicLookup());

        tem.add(publicLookup().in(String.class));

        tem.add(publicLookup().in(List.class));

        return tem.toArray(new Lookup[0]);

    }

    static Lookup lookup_in_self() {

        return MethodHandles.lookup();

    }

    static public      void pub_in_self() { }

    static protected   void pro_in_self() { }

    static /*package*/ void pkg_in_self() { }

    static private     void pri_in_self() { }

    static class Inner_nestmate {

        static Lookup lookup_in_nestmate() {

            return MethodHandles.lookup();

        }

        static public      void pub_in_nestmate() { }

        static protected   void pro_in_nestmate() { }

        static /*package*/ void pkg_in_nestmate() { }

        static private     void pri_in_nestmate() { }

    }

}

class AccessControlTest_sibling {

    static Lookup lookup_in_sibling() {

        return MethodHandles.lookup();

    }

    static public      void pub_in_sibling() { }

    static protected   void pro_in_sibling() { }

    static /*package*/ void pkg_in_sibling() { }

    static private     void pri_in_sibling() { }

}

// This guy tests access from outside the package:

/*

package test.java.lang.invoke.AccessControlTest_subpkg;

public class Acquaintance_remote {

    public static Lookup[] lookups() { ...

    }

    ...

}

*/