/*

 * 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.

 *

 * 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.

 */

import com.sun.tools.classfile.Attribute;

import com.sun.tools.classfile.ClassFile;

import com.sun.tools.classfile.InnerClasses_attribute;

import com.sun.tools.classfile.InnerClasses_attribute.Info;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.HashMap;

import java.util.HashSet;

import java.util.List;

import java.util.Map;

import java.util.Set;

import java.util.stream.Collectors;

/**

 * Base class for tests of inner classes attribute.

 * The scenario of tests:

 *   1. set possible values of class modifiers.

 *   2. according to set class modifiers, a test generates sources

 * and golden data with {@code generateTestCases}.

 *   3. a test loops through all test cases and checks InnerClasses

 * attribute with {@code test}.

 *

 * Example, possible flags for outer class are {@code Modifier.PRIVATE and Modifier.PUBLIC},

 * possible flags for inner class are {@code Modifier.EMPTY}.

 * At the second step the test generates two test cases:

 *   1. public class A {

 *        public class B {

 *          class C {}

 *        }

 *      }

 *   2. public class A {

 *        private class B {

 *          class C {}

 *        }

 *      }

 */

public abstract class InnerClassesTestBase extends TestResult {

    private Modifier[] outerAccessModifiers = {Modifier.EMPTY, Modifier.PRIVATE, Modifier.PROTECTED, Modifier.PUBLIC};

    private Modifier[] outerOtherModifiers = {Modifier.EMPTY, Modifier.STATIC, Modifier.FINAL, Modifier.ABSTRACT};

    private Modifier[] innerAccessModifiers = outerAccessModifiers;

    private Modifier[] innerOtherModifiers = outerOtherModifiers;

    private boolean isForbiddenWithoutStaticInOuterMods = false;

    private ClassType outerClassType;

    private ClassType innerClassType;

    private boolean hasSyntheticClass;

    private String prefix = "";

    private String suffix = "";

    /**

     * Sets properties.

     *

     * Returns generated list of test cases. Method is called in {@code test()}.

     */

    public abstract void setProperties();

    /**

     * Runs the test.

     *

     * @param classToTest expected name of outer class

     * @param skipClasses classes that names should not be checked

     */

    public void test(String classToTest, String...skipClasses) throws TestFailedException {

        try {

            for (TestCase test : generateTestCases()) {

                addTestCase(test.getSource());

                test(classToTest, test, skipClasses);

            }

        } catch (Exception e) {

            addFailure(e);

        } finally {

            checkStatus();

        }

    }

    /**

     * If {@code flag} is {@code true} an outer class can not have static modifier.

     *

     * @param flag if {@code true} the outer class can not have static modifier

     */

    public void setForbiddenWithoutStaticInOuterMods(boolean flag) {

        isForbiddenWithoutStaticInOuterMods = flag;

    }

    /**

     * Sets the possible access flags of an outer class.

     *

     * @param mods the possible access flags of an outer class

     */

    public void setOuterAccessModifiers(Modifier...mods) {

        outerAccessModifiers = mods;

    }

    /**

     * Sets the possible flags of an outer class.

     *

     * @param mods the possible flags of an outer class

     */

    public void setOuterOtherModifiers(Modifier...mods) {

        outerOtherModifiers = mods;

    }

    /**

     * Sets the possible access flags of an inner class.

     *

     * @param mods the possible access flags of an inner class

     */

    public void setInnerAccessModifiers(Modifier...mods) {

        innerAccessModifiers = mods;

    }

    /**

     * Sets the possible flags of an inner class.

     *

     * @param mods the possible flags of an inner class

     */

    public void setInnerOtherModifiers(Modifier...mods) {

        innerOtherModifiers = mods;

    }

    /**

     * Sets the suffix for the generated source.

     *

     * @param suffix a suffix

     */

    public void setSuffix(String suffix) {

        this.suffix = suffix;

    }

    /**

     * Sets the prefix for the generated source.

     *

     * @param prefix a prefix

     */

    public void setPrefix(String prefix) {

        this.prefix = prefix;

    }

    /**

     * If {@code true} synthetic class is generated.

     *

     * @param hasSyntheticClass if {@code true} synthetic class is generated

     */

    public void setHasSyntheticClass(boolean hasSyntheticClass) {

        this.hasSyntheticClass = hasSyntheticClass;

    }

    /**

     * Sets the inner class type.

     *

     * @param innerClassType the inner class type

     */

    public void setInnerClassType(ClassType innerClassType) {

        this.innerClassType = innerClassType;

    }

    /**

     * Sets the outer class type.

     *

     * @param outerClassType the outer class type

     */

    public void setOuterClassType(ClassType outerClassType) {

        this.outerClassType = outerClassType;

    }

    private void test(String classToTest, TestCase test, String...skipClasses) {

        printf("Testing :\n%s\n", test.getSource());

        try {

            Map<String, Set<String>> class2Flags = test.getFlags();

            ClassFile cf = readClassFile(compile(test.getSource())

                    .getClasses().get(classToTest));

            InnerClasses_attribute innerClasses = (InnerClasses_attribute)

                    cf.getAttribute(Attribute.InnerClasses);

            int count = 0;

            for (Attribute a : cf.attributes.attrs) {

                if (a instanceof InnerClasses_attribute) {

                    ++count;

                }

            }

            assertEquals(1, count, "Number of inner classes attribute");

            if (innerClasses == null) {

                return;

            }

            assertEquals(cf.constant_pool.

                    getUTF8Info(innerClasses.attribute_name_index).value, "InnerClasses",

                    "innerClasses.attribute_name_index");

            // Inner Classes attribute consists of length (2 bytes)

            // and 8 bytes for each inner class's entry.

            assertEquals(innerClasses.attribute_length,

                    2 + 8 * class2Flags.size(), "innerClasses.attribute_length");

            assertEquals(innerClasses.number_of_classes,

                    class2Flags.size(), "innerClasses.number_of_classes");

            Set<String> visitedClasses = new HashSet<>();

            for (Info e : innerClasses.classes) {

                String baseName = cf.constant_pool.getClassInfo(

                        e.inner_class_info_index).getBaseName();

                if (cf.major_version >= 51 && e.inner_name_index == 0) {

                    assertEquals(e.outer_class_info_index, 0,

                        "outer_class_info_index "

                                + "in case of inner_name_index is zero : "

                                + baseName);

                }

                String className = baseName.replaceFirst(".*\\$", "");

                assertTrue(class2Flags.containsKey(className),

                        className);

                assertTrue(visitedClasses.add(className),

                        "there are no duplicates in attribute : " + className);

                assertEquals(e.inner_class_access_flags.getInnerClassFlags(),

                        class2Flags.get(className),

                        "inner_class_access_flags " + className);

                if (!Arrays.asList(skipClasses).contains(className)) {

                        assertEquals(

                            cf.constant_pool.getClassInfo(e.inner_class_info_index).getBaseName(),

                            classToTest + "$" + className,

                            "inner_class_info_index of " + className);

                    if (e.outer_class_info_index > 0) {

                        assertEquals(

                                cf.constant_pool.getClassInfo(e.outer_class_info_index).getName(),

                                classToTest,

                                "outer_class_info_index of " + className);

                    }

                }

            }

        } catch (Exception e) {

            addFailure(e);

        }

    }

    /**

     * Methods generates list of test cases. Method generates all possible combinations

     * of acceptable flags for nested inner classes.

     *

     * @return generated list of test cases

     */

    protected List<TestCase> generateTestCases() {

        setProperties();

        List<TestCase> list = new ArrayList<>();

        List<List<Modifier>> outerMods = getAllCombinations(outerAccessModifiers, outerOtherModifiers);

        List<List<Modifier>> innerMods = getAllCombinations(innerAccessModifiers, innerOtherModifiers);

        for (List<Modifier> outerMod : outerMods) {

            if (isForbiddenWithoutStaticInOuterMods && !outerMod.contains(Modifier.STATIC)) {

                continue;

            }

            StringBuilder sb = new StringBuilder();

            sb.append("public class InnerClassesSrc {")

                    .append(toString(outerMod)).append(' ')

                    .append(outerClassType).append(' ')

                    .append(prefix).append(' ').append('\n');

            int count = 0;

            Map<String, Set<String>> class2Flags = new HashMap<>();

            List<String> syntheticClasses = new ArrayList<>();

            for (List<Modifier> innerMod : innerMods) {

                ++count;

                String privateConstructor = "";

                if (hasSyntheticClass && !innerMod.contains(Modifier.ABSTRACT)) {

                    privateConstructor = "private A" + count + "() {}";

                    syntheticClasses.add("new A" + count + "();");

                }

                sb.append(toString(innerMod)).append(' ');

                sb.append(String.format("%s A%d {%s}\n", innerClassType, count, privateConstructor));

                Set<String> flags = getFlags(innerClassType, innerMod);

                class2Flags.put("A" + count, flags);

            }

            if (hasSyntheticClass) {

                // Source to generate synthetic classes

                sb.append(syntheticClasses.stream().collect(Collectors.joining(" ", "{", "}")));

                class2Flags.put("1", new HashSet<>(Arrays.asList("ACC_STATIC", "ACC_SYNTHETIC")));

            }

            sb.append(suffix).append("\n}");

            getAdditionalFlags(class2Flags, outerClassType, outerMod.toArray(new Modifier[outerMod.size()]));

            list.add(new TestCase(sb.toString(), class2Flags));

        }

        return list;

    }

    /**

     * Methods returns flags which must have type.

     *

     * @param type class, interface, enum or annotation

     * @param mods modifiers

     * @return set of access flags

     */

    protected Set<String> getFlags(ClassType type, List<Modifier> mods) {

        Set<String> flags = mods.stream()

                .map(Modifier::getString)

                .filter(str -> !str.isEmpty())

                .map(str -> "ACC_" + str.toUpperCase())

                .collect(Collectors.toSet());

        type.addSpecificFlags(flags);

        return flags;

    }

    private List<List<Modifier>> getAllCombinations(Modifier[] accessModifiers, Modifier[] otherModifiers) {

        List<List<Modifier>> list = new ArrayList<>();

        for (Modifier access : accessModifiers) {

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

                Modifier mod1 = otherModifiers[i];

                for (int j = i + 1; j < otherModifiers.length; ++j) {

                    Modifier mod2 = otherModifiers[j];

                    if (isForbidden(mod1, mod2)) {

                        continue;

                    }

                    list.add(Arrays.asList(access, mod1, mod2));

                }

                if (mod1 == Modifier.EMPTY) {

                    list.add(Arrays.asList(access));

                }

            }

        }

        return list;

    }

    private boolean isForbidden(Modifier mod1, Modifier mod2) {

        return mod1 == Modifier.FINAL && mod2 == Modifier.ABSTRACT

                || mod1 == Modifier.ABSTRACT && mod2 == Modifier.FINAL;

    }

    private String toString(List<Modifier> mods) {

        return mods.stream()

                .map(Modifier::getString)

                .filter(s -> !s.isEmpty())

                .collect(Collectors.joining(" "));

    }

    /**

     * Method is called in generateTestCases().

     * If you need to add additional access flags, you should override this method.

     *

     *

     * @param class2Flags map with flags

     * @param type class, interface, enum or @annotation

     * @param mods modifiers

     */

    public void getAdditionalFlags(Map<String, Set<String>> class2Flags, ClassType type, Modifier...mods) {

        class2Flags.values().forEach(type::addFlags);

    }

    public enum ClassType {

        CLASS("class") {

            @Override

            public void addSpecificFlags(Set<String> flags) {

            }

        },

        INTERFACE("interface") {

            @Override

            public void addFlags(Set<String> flags) {

                flags.add("ACC_STATIC");

                flags.add("ACC_PUBLIC");

            }

            @Override

            public void addSpecificFlags(Set<String> flags) {

                flags.add("ACC_INTERFACE");

                flags.add("ACC_ABSTRACT");

                flags.add("ACC_STATIC");

            }

        },

        ANNOTATION("@interface") {

            @Override

            public void addFlags(Set<String> flags) {

                flags.add("ACC_STATIC");

                flags.add("ACC_PUBLIC");

            }

            @Override

            public void addSpecificFlags(Set<String> flags) {

                flags.add("ACC_INTERFACE");

                flags.add("ACC_ABSTRACT");

                flags.add("ACC_STATIC");

                flags.add("ACC_ANNOTATION");

            }

        },

        ENUM("enum") {

            @Override

            public void addSpecificFlags(Set<String> flags) {

                flags.add("ACC_ENUM");

                flags.add("ACC_FINAL");

                flags.add("ACC_STATIC");

            }

        },

        OTHER("") {

            @Override

            public void addSpecificFlags(Set<String> flags) {

            }

        };

        private final String classType;

        private ClassType(String clazz) {

            this.classType = clazz;

        }

        public abstract void addSpecificFlags(Set<String> flags);

        public String toString() {

            return classType;

        }

        public void addFlags(Set<String> set) {

        }

    }

    public enum Modifier {

        PUBLIC("public"), PRIVATE("private"),

        PROTECTED("protected"), DEFAULT("default"),

        FINAL("final"), ABSTRACT("abstract"),

        STATIC("static"), EMPTY("");

        private final String str;

        private Modifier(String str) {

            this.str = str;

        }

        public String getString() {

            return str;

        }

    }

}