/*
    *    Copyright 2015-2023 the original author or authors.
    *
    *    Licensed 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
    *
    *       https://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.mybatis.spring.boot.autoconfigure;
  
  import java.io.IOException;
  import java.io.UncheckedIOException;
  import java.net.URL;
  import java.net.URLDecoder;
  import java.nio.charset.Charset;
  import java.text.Normalizer;
  import java.util.List;
  import java.util.function.Supplier;
  import java.util.stream.Collectors;
  import java.util.stream.Stream;
  
  import org.apache.ibatis.io.VFS;
  import org.springframework.core.io.Resource;
  import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
  import org.springframework.core.io.support.ResourcePatternResolver;
  import org.springframework.util.ClassUtils;
  
  /**
   * @author Hans Westerbeek
   * @author Eddú Meléndez
   * @author Kazuki Shimizu
   */
  public class SpringBootVFS extends VFS {
  
    private static Charset urlDecodingCharset;
    private static Supplier<ClassLoader> classLoaderSupplier;
    private final ResourcePatternResolver resourceResolver;
  
    static {
      setUrlDecodingCharset(Charset.defaultCharset());
      setClassLoaderSupplier(ClassUtils::getDefaultClassLoader);
    }
  
    public SpringBootVFS() {
      this.resourceResolver = new PathMatchingResourcePatternResolver(classLoaderSupplier.get());
    }
  
    @Override
    public boolean isValid() {
      return true;
    }
  
    @Override
    protected List<String> list(URL url, String path) throws IOException {
      String urlString = URLDecoder.decode(url.toString(), urlDecodingCharset.name());
      String baseUrlString = urlString.endsWith("/") ? urlString : urlString.concat("/");
      Resource[] resources = resourceResolver.getResources(baseUrlString + "**/*.class");
      return Stream.of(resources).map(resource -> preserveSubpackageName(baseUrlString, resource, path))
          .collect(Collectors.toList());
    }
  
    /**
     * Set the charset for decoding an encoded URL string.
     * <p>
     * Default is system default charset.
     * </p>
     *
     * @param charset
     *          the charset for decoding an encoded URL string
     *
     * @since 2.3.0
     */
    public static void setUrlDecodingCharset(Charset charset) {
      urlDecodingCharset = charset;
    }
  
    /**
     * Set the supplier for providing {@link ClassLoader} to used.
     * <p>
     * Default is a returned instance from {@link ClassUtils#getDefaultClassLoader()}.
     * </p>
     *
     * @param supplier
     *          the supplier for providing {@link ClassLoader} to used
     *
     * @since 3.0.2
     */
    public static void setClassLoaderSupplier(Supplier<ClassLoader> supplier) {
      classLoaderSupplier = supplier;
    }
  
    private static String preserveSubpackageName(final String baseUrlString, final Resource resource,
       final String rootPath) {
     try {
       return rootPath + (rootPath.endsWith("/") ? "" : "/") + Normalizer
           .normalize(URLDecoder.decode(resource.getURL().toString(), urlDecodingCharset.name()), Normalizer.Form.NFC)
           .substring(baseUrlString.length());
     } catch (IOException e) {
       throw new UncheckedIOException(e);
     }
   }
 
 }