/*
    * #%L
    * wcm.io
    * %%
    * Copyright (C) 2017 wcm.io
    * %%
    * 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.
   * #L%
   */
  package io.wcm.tooling.commons.packmgr.download;
  
  import java.io.Closeable;
  import java.io.File;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.nio.file.Files;
  
  import org.apache.commons.io.IOUtils;
  import org.apache.http.HttpStatus;
  import org.apache.http.client.methods.CloseableHttpResponse;
  import org.apache.http.client.methods.HttpGet;
  import org.apache.http.client.methods.HttpPost;
  import org.apache.http.client.protocol.HttpClientContext;
  import org.apache.http.impl.client.CloseableHttpClient;
  import org.apache.http.util.EntityUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import io.wcm.tooling.commons.packmgr.PackageManagerException;
  import io.wcm.tooling.commons.packmgr.PackageManagerHelper;
  import io.wcm.tooling.commons.packmgr.PackageManagerProperties;
  import io.wcm.tooling.commons.packmgr.install.VendorInstallerFactory;
  
  /**
   * Downloads a single AEM content package.
   */
  public final class PackageDownloader implements Closeable {
  
    private final PackageManagerProperties props;
    private final PackageManagerHelper pkgmgr;
    private final CloseableHttpClient httpClient;
  
    private static final Logger log = LoggerFactory.getLogger(PackageDownloader.class);
  
    /**
     * @param props Package manager configuration properties.
     */
    public PackageDownloader(PackageManagerProperties props) {
      this.props = props;
      this.pkgmgr = new PackageManagerHelper(props);
      this.httpClient = pkgmgr.getHttpClient();
    }
  
    /**
     * Upload the given local package definition (without actually installing it).
     * @param file Package definition file
     * @return Package path
     */
    public String uploadPackageDefinition(File file) {
  
      if (!file.exists()) {
        throw new PackageManagerException("File not found: " + file.getAbsolutePath());
      }
      String packageManagerUrl = props.getPackageManagerUrl();
  
      // try upload to get path of package - or otherwise make sure package def exists (no install!)
      log.info("Upload package definition for {} to {} ...", file.getName(), packageManagerUrl);
      VendorPackageDownloader downloader = VendorInstallerFactory.getPackageDownloader(packageManagerUrl);
      return downloader.uploadPackageDefinition(packageManagerUrl, file, pkgmgr);
    }
  
    /**
     * Download content package from CRX package manager.
     * @param packagePath Content Package path in AEM instance.
     * @param ouputFilePath Path to download package from AEM instance to.
     * @param rebuildPackage Whether to rebuild the package within the CRX package manager before downloading it to
     *          include the latest content from repository.
     * @return Downloaded content package file
     */
    public File downloadContentPackage(String packagePath, String ouputFilePath, boolean rebuildPackage) {
      try {
        HttpClientContext httpClientContext = pkgmgr.getPackageManagerHttpClientContext();
        String packageManagerUrl = props.getPackageManagerUrl();
        VendorPackageDownloader downloader = VendorInstallerFactory.getPackageDownloader(packageManagerUrl);
  
        // (Re-)build package
        if (rebuildPackage) {
          log.info("Rebuilding package {} ...", packagePath);
         HttpPost buildMethod = downloader.createRebuildMethod(packagePath, packageManagerUrl);
         pkgmgr.executePackageManagerMethodHtmlOutputResponse(httpClient, httpClientContext, buildMethod);
       }
 
       // Download package
       String baseUrl = downloader.createDownloadZipBaseUrl(packageManagerUrl);
       log.info("Downloading package {} from {} ...", packagePath, baseUrl);
 
       HttpGet downloadMethod = new HttpGet(baseUrl + packagePath);
 
       // execute download
       CloseableHttpResponse response = httpClient.execute(downloadMethod, httpClientContext);
       try (response) {
         if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
 
           // get response stream
           InputStream responseStream = response.getEntity().getContent();
 
           // delete existing file
           File outputFileObject = new File(ouputFilePath);
           Files.deleteIfExists(outputFileObject.toPath());
 
           // write response file
           try (OutputStream fos = Files.newOutputStream(outputFileObject.toPath())) {
             IOUtils.copy(responseStream, fos);
             fos.flush();
             responseStream.close();
           }
 
           log.info("Package downloaded to {}", outputFileObject.getAbsolutePath());
 
           return outputFileObject;
         }
         else {
           throw new PackageManagerException("Package download failed:\n"
               + EntityUtils.toString(response.getEntity()));
         }
       }
       finally {
         EntityUtils.consumeQuietly(response.getEntity());
       }
     }
     catch (IOException ex) {
       throw new PackageManagerException("Download operation failed.", ex);
     }
   }
 
   @Override
   public void close() throws IOException {
     httpClient.close();
   }
 
 }