package com.atlassian.plugin.spring.scanner.runtime.impl.util;
   
   import com.atlassian.plugin.spring.scanner.ProductFilter;
   import com.atlassian.plugin.spring.scanner.util.CommonConstants;
   import com.google.common.base.Charsets;
   import org.osgi.framework.Bundle;
   import org.osgi.framework.BundleContext;
   import org.slf4j.Logger;
   import org.slf4j.LoggerFactory;
  
  import java.io.BufferedReader;
  import java.io.FileNotFoundException;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.net.URL;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Properties;
  
  /**
   * A utility class to read index files from a classloader or bundle.
   * Can handle reading a single index file, or concating multiple index files based on the
   * currently running product.
   */
  public class AnnotationIndexReader {
      private static final Logger log = LoggerFactory.getLogger(AnnotationIndexReader.class);
  
      /**
       * Read a file from a bundle and return the list of lines of the file.
       *
       * @param resourceFile the path to the file in the bundle
       * @param bundle       the bundle to read from
       * @return the lines in the file
       */
      public static List<String> readIndexFile(final String resourceFile, final Bundle bundle) {
          final URL url = bundle.getEntry(resourceFile);
          return readIndexFile(url);
      }
  
      /**
       * Read both the cross-product file and the product-specific file for the currently running product from the bundle and returns
       * their lines as a single list.
       *
       * @param resourceFile the path to the cross-product file in the bundle
       * @param bundle       the bundle to read from
       * @param bundleContext the bundle context used to determine the running product
       * @return the lines in the file
       */
      public static List<String> readAllIndexFilesForProduct(final String resourceFile, final Bundle bundle,
                                                             final BundleContext bundleContext) {
  
          final URL url = bundle.getEntry(resourceFile);
  
          final List<String> entries = new ArrayList<String>(readIndexFile(url));
  
          final ProductFilter filter = ProductFilterUtil.getFilterForCurrentProduct(bundleContext);
          if (null != filter) {
              entries.addAll(readIndexFile(filter.getPerProductFile(resourceFile), bundle));
          }
  
          return entries;
      }
  
      public static List<String> readIndexFile(final URL url) {
          final List<String> resources = new ArrayList<String>();
  
          try {
              if (null == url) {
                  log.debug("Could not find annotation index file (null url).");
                  return resources;
              }
  
              final BufferedReader reader;
              try {
                  reader = new BufferedReader(new InputStreamReader(url.openStream(), Charsets.UTF_8));
              } catch (final FileNotFoundException e) {
                  log.debug("Could not find annotation index file " + url);
                  return resources;
              }
  
              String line = reader.readLine();
              while (line != null) {
                  resources.add(line);
  
                  line = reader.readLine();
              }
  
              if (log.isDebugEnabled()) {
                  log.debug("Read annotation index file: " + url);
                  log.debug("Printing out found annotated beans: ");
                  log.debug(resources.toString());
              }
  
              reader.close();
          } catch (final IOException e) {
              throw new RuntimeException("Cannot read index file [" + url.toString() + "]", e);
          }
  
          return resources;
     }
 
     public static Properties readPropertiesFile(final URL url) {
         final Properties resources = new Properties();
         try {
             if (null == url) {
                 return resources;
             }
 
             final BufferedReader reader;
             try {
                 reader = new BufferedReader(new InputStreamReader(url.openStream(), Charsets.UTF_8));
             } catch (final FileNotFoundException e) {
                 return resources;
             }
 
             resources.load(reader);
         } catch (final IOException e) {
             throw new RuntimeException("Cannot read properties file [" + url.toString() + "]", e);
         }
         return resources;
     }
 
     public static String[] splitProfiles(final String profiles) {
         return (profiles != null && !profiles.trim().isEmpty()) ? profiles.split(",") : new String[0];
     }
 
     public static Iterable<String> getIndexFilesForProfiles(final String[] profileNames, final String indexFileName) {
         final List<String> filesToRead = new ArrayList<String>();
         if (profileNames.length > 0) {
             for (String profileName : profileNames) {
                 profileName = ((profileName == null) ? "" : profileName).trim();
                 if (!profileName.isEmpty()) {
                     final String fileToRead = CommonConstants.INDEX_FILES_DIR + "/"
                             + CommonConstants.PROFILE_PREFIX + profileName + "/"
                             + indexFileName;
 
                     filesToRead.add(fileToRead);
                 }
             }
         } else {
             final String fileToRead = CommonConstants.INDEX_FILES_DIR + "/" + indexFileName;
             filesToRead.add(fileToRead);
         }
         return filesToRead;
     }
 }