/*
 * 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.api.util;

import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 * @author Kristian Rosenvold
 */
public class DefaultScanResult implements ScanResult {
    private final List<String> classes;

    private static final String SCAN_RESULT_NUMBER = "tc.";

    public DefaultScanResult(List<String> classes) {
        this.classes = Collections.unmodifiableList(classes);
    }

    @Override
    public int size() {
        return classes.size();
    }

    @Override
    public String getClassName(int index) {
        return classes.get(index);
    }

    @Override
    public void writeTo(Map<String, String> properties) {
        for (int i = 0, size = classes.size(); i < size; i++) {
            properties.put(SCAN_RESULT_NUMBER + i, classes.get(i));
        }
    }

    public static DefaultScanResult from(Map<String, String> properties) {
        List<String> result = new ArrayList<>();
        int i = 0;
        while (true) {
            String item = properties.get(SCAN_RESULT_NUMBER + (i++));
            if (item == null) {
                return new DefaultScanResult(result);
            }
            result.add(item);
        }
    }

    public boolean isEmpty() {
        return classes.isEmpty();
    }

    public List<String> getClasses() {
        return classes;
    }

    @Override
    public TestsToRun applyFilter(ScannerFilter scannerFilter, ClassLoader testClassLoader) {
        Set<Class<?>> result = new LinkedHashSet<>();

        int size = size();
        for (int i = 0; i < size; i++) {
            String className = getClassName(i);

            Class<?> testClass = loadClass(testClassLoader, className);

            if (scannerFilter == null || scannerFilter.accept(testClass)) {
                result.add(testClass);
            }
        }

        return new TestsToRun(result);
    }

    @Override
    public List<Class<?>> getClassesSkippedByValidation(ScannerFilter scannerFilter, ClassLoader testClassLoader) {
        List<Class<?>> result = new ArrayList<>();

        int size = size();
        for (int i = 0; i < size; i++) {
            String className = getClassName(i);

            Class<?> testClass = loadClass(testClassLoader, className);

            if (scannerFilter != null && !scannerFilter.accept(testClass)) {
                result.add(testClass);
            }
        }

        return result;
    }

    private static Class<?> loadClass(ClassLoader classLoader, String className) {
        try {
            return classLoader.loadClass(className);
        } catch (ClassNotFoundException e) {
            throw new RuntimeException("Unable to create test class '" + className + "'", e);
        }
    }

    public DefaultScanResult append(DefaultScanResult other) {
        if (other != null) {
            List<String> src = new ArrayList<>(classes);
            src.addAll(other.classes);
            return new DefaultScanResult(src);
        } else {
            return this;
        }
    }
}
