content: package act.app;
  
  /*-
   * #%L
   * ACT Framework
   * %%
   * Copyright (C) 2014 - 2017 ActFramework
   * %%
   * 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%
   */
  
  import act.Act;
  import act.internal.util.AppDescriptor;
  import org.osgl.$;
  import org.osgl.logging.L;
  import org.osgl.logging.Logger;
  import org.osgl.util.E;
  import org.osgl.util.IO;
  import org.osgl.util.Iterators;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.*;
  
  /**
   * Scan file system and construct {@link App} instances
   */
  public class AppScanner {
  
      private static Logger logger = L.get(AppScanner.class);
  
      public static AppScanner DEF_SCANNER = new AppScanner();
      public static AppScanner SINGLE_APP_SCANNER = new SingleAppScanner();
  
      private final Map<String, ProjectLayoutProbe> buildFileProbeMap = new HashMap<>();
      private final List<ProjectLayoutProbe> projectLayoutProbes = new ArrayList<>();
  
      protected AppScanner() {
      }
  
      public AppScanner register(ProjectLayoutProbe probe) {
          if (probe instanceof BuildFileProbe) {
              buildFileProbeMap.put(((BuildFileProbe) probe).buildFileName(), probe);
          } else {
              projectLayoutProbes.add(probe);
          }
          return this;
      }
  
      public int test_probeCnt() {
          return buildFileProbeMap.size() + projectLayoutProbes.size();
      }
  
      void scan(AppDescriptor descriptor, $.Func1<App, ?> callback) {
          File[] appBases = appBases();
          int size = appBases.length;
          for (int i = 0; i < size; ++i) {
              File appBase = appBases[i];
              scan(descriptor, appBase, callback);
          }
      }
  
      protected File[] appBases() {
          File appBase = Act.conf().appBase();
          return appBase.listFiles();
      }
  
      private void scan(AppDescriptor descriptor, File appBase, $.Func1<App, ?> callback) {
          App app;
          ProjectLayout layout = probe(appBase);
          if (null == layout && !Act.isDev()) {
              layout = ProjectLayout.PredefinedLayout.PKG;
          }
          if (null != layout) {
              app = App.create(appBase, descriptor.getVersion(), layout);
              if (null != descriptor.getAppName()) {
                  app.name(descriptor.getAppName());
              }
              callback.apply(app);
          } else {
              logger.warn("%s is not a valid app base", appBase.getPath());
          }
      }
  
      private ProjectLayout probe(File appBase) {
          ProjectLayout layout = probeLayoutPropertiesFile(appBase);
          if (null != layout) {
              return layout;
          }
          layout = probeLayoutPlugin(appBase);
          if (null != layout) {
              return layout;
          }
          return probeDefaultLayouts(appBase);
      }
  
      private ProjectLayout probeLayoutPlugin(File appBase) {
          Iterator<ProjectLayoutProbe> probes = pluginProbes();
          while (probes.hasNext()) {
              ProjectLayoutProbe probe = probes.next();
              ProjectLayout layout = probe.probe(appBase);
              if (null != layout) {
                  return layout;
              }
          }
          return null;
      }
  
      private ProjectLayout probeDefaultLayouts(File appBase) {
          ProjectLayout[] predefined = ProjectLayout.PredefinedLayout.values();
          for (int i = predefined.length - 1; i >= 0; --i) {
              ProjectLayout layout = predefined[i];
              if (ProjectLayout.util.probeAppBase(appBase, layout)) {
                  return layout;
              }
          }
          return null;
      }
  
      private ProjectLayout probeLayoutPropertiesFile(File appBase) {
          File f = new File(appBase, ProjectLayout.PROJ_LAYOUT_FILE);
          if (f.exists() && f.canRead()) {
              Properties p = new Properties();
              InputStream is = IO.is(f);
              try {
                  p.load(is);
              } catch (IOException e) {
                  throw E.ioException(e);
              } finally {
                  IO.close(is);
              }
              return ProjectLayout.util.build(p);
          } else {
              return null;
          }
      }
  
      private Iterator<ProjectLayoutProbe> pluginProbes() {
          return Iterators.composite(buildFileProbeMap.values().iterator(), projectLayoutProbes.iterator());
      }
  }
  