/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.surefire.common.junit48;

import java.lang.annotation.Inherited;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Set;

import org.apache.maven.surefire.group.match.AndGroupMatcher;
import org.apache.maven.surefire.group.match.GroupMatcher;
import org.apache.maven.surefire.group.match.InverseGroupMatcher;
import org.junit.experimental.categories.Category;
import org.junit.runner.Description;
import org.junit.runner.manipulation.Filter;

import static java.util.Collections.addAll;
import static org.junit.runner.Description.createSuiteDescription;

final class GroupMatcherCategoryFilter extends Filter {
    /**
     * Only traverse the tree if <code>@Category</code> annotation is inherited (since <code>junit 4.12</code>).
     */
    private static final boolean IS_CATEGORY_INHERITED = Category.class.isAnnotationPresent(Inherited.class);

    private final AndGroupMatcher matcher;

    GroupMatcherCategoryFilter(GroupMatcher included, GroupMatcher excluded) {
        GroupMatcher invertedExclude = excluded == null ? null : new InverseGroupMatcher(excluded);
        if (included != null || invertedExclude != null) {
            matcher = new AndGroupMatcher();
            if (included != null) {
                matcher.addMatcher(included);
            }

            if (invertedExclude != null) {
                matcher.addMatcher(invertedExclude);
            }
        } else {
            matcher = null;
        }
    }

    @Override
    public boolean shouldRun(Description description) {
        if (invalidTestClass(description)) {
            return shouldRun(description, null, null);
        }

        if (describesTestClass(description)) // is a test class
        {
            Class<?> testClass = description.getTestClass();
            return shouldRun(description, null, testClass);
        } else
        // is a test method
        {
            Class<?> testClass = description.getTestClass();
            return shouldRun(description, createSuiteDescription(testClass), testClass);
        }
    }

    private boolean describesTestClass(Description description) {
        String methodName = description.getMethodName();
        // Description parser in Junit 4.8 can return "null" String.
        return methodName == null || methodName.equals("null");
    }

    private boolean invalidTestClass(Description description) {
        return description.getTestClass() == null;
    }

    private static void findSuperclassCategories(Set<Class<?>> cats, Class<?> clazz) {
        if (IS_CATEGORY_INHERITED && hasSuperclass(clazz)) {
            Category cat = clazz.getSuperclass().getAnnotation(Category.class);
            if (cat != null) {
                // Found categories in current superclass
                addAll(cats, cat.value());
            }
            // Search the hierarchy
            findSuperclassCategories(cats, clazz.getSuperclass());
        }
    }

    private static boolean hasSuperclass(Class<?> clazz) {
        return clazz != null && clazz.getSuperclass() != null;
    }

    private boolean shouldRun(Description description, Description parent, Class<?> parentClass) {
        if (matcher == null) {
            return true;
        } else {
            Set<Class<?>> cats = new HashSet<>();
            Category cat = description.getAnnotation(Category.class);
            if (cat != null) {
                // Found categories in current description
                addAll(cats, cat.value());
            }

            if (parent != null) {
                cat = parent.getAnnotation(Category.class);
                if (cat != null) {
                    // Found categories in current parent
                    addAll(cats, cat.value());
                }
            }
            if (parentClass != null) {
                findSuperclassCategories(cats, parentClass);
            }

            Class<?> testClass = description.getTestClass();
            if (testClass != null) {
                cat = testClass.getAnnotation(Category.class);
                if (cat != null) {
                    // Found categories in current testClass
                    addAll(cats, cat.value());
                }
            }

            cats.remove(null);
            boolean result = matcher.enabled(cats.toArray(new Class<?>[cats.size()]));

            if (!result) {
                ArrayList<Description> children = description.getChildren();
                if (children != null) {
                    for (Description child : children) {
                        if (shouldRun(child, description, null)) {
                            result = true;
                            break;
                        }
                    }
                }
            }

            return result;
        }
    }

    @Override
    public String describe() {
        return matcher == null ? "ANY" : matcher.toString();
    }
}
