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/*
 * Copyright (C) 2011-2021 Objectos Software LTDA.
 *
 * 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
 *
 * 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 br.com.objectos.io;

import static br.com.objectos.lang.Lang.checkArgument;

import br.com.objectos.lang.Lang;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;

public class Resource extends AbstractInputStreamSource implements FileName {

  private final String resourceName;

  private final URL url;

  private Resource(URL url, String resourceName) {
    this.url = url;
    this.resourceName = resourceName;
  }

  public static Resource getResource(Class contextClass, String resourceName) {
    URL url = contextClass.getResource(resourceName);
    checkUrl(url, resourceName);
    Package pkg = contextClass.getPackage();
    pkg.getName().replace('.', '/');
    return new Resource(
        url,
        pkg.getName().replace('.', '/') + '/' + resourceName
    );
  }

  public static Resource getResource(String resourceName) {
    checkArgument(!resourceName.startsWith("/"), "resourceName MUST NOT start with a '/'");

    ClassLoader loader = Thread.currentThread().getContextClassLoader();
    URL url = loader.getResource(resourceName);
    checkUrl(url, resourceName);
    return new Resource(url, resourceName);
  }

  private static void checkUrl(URL url, String resourceName) {
    if (url == null) {
      throw new IllegalArgumentException("Resource " + resourceName + " not found.");
    }
  }

  @Override
  public final boolean equals(Object obj) {
    if (obj == this) {
      return true;
    }
    if (!(obj instanceof Resource)) {
      return false;
    }
    Resource that = (Resource) obj;
    return url.equals(that.url);
  }

  @Override
  public final String getExtension() {
    return Io.getExtension(resourceName);
  }

  @Override
  public final String getName() {
    return url.getFile();
  }

  @Override
  public final int hashCode() {
    return url.hashCode();
  }

  @Override
  public final InputStream openInputStream() throws IOException {
    return url.openStream();
  }

  public final String resourceName() {
    return resourceName;
  }

  @Override
  public final String toString() {
    return Lang.toString(
        this,
        "resourceName", resourceName
    );
  }

  public final URI toUri() throws URISyntaxException {
    return url.toURI();
  }

}