content: package act.app.conf;
  
  /*-
   * #%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.app.App;
  import act.app.AppByteCodeScanner;
  import act.app.data.StringValueResolverManager;
  import act.app.event.SysEventId;
  import act.conf.AppConfig;
  import act.event.SysEventListenerBase;
  import act.util.AnnotatedTypeFinder;
  import org.osgl.$;
  import org.osgl.exception.NotAppliedException;
  import org.osgl.inject.BeanSpec;
  import org.osgl.inject.Injector;
  import org.osgl.logging.LogManager;
  import org.osgl.logging.Logger;
  import org.osgl.util.Const;
  import org.osgl.util.E;
  import org.osgl.util.StringValueResolver;
  
  import java.lang.reflect.Field;
  import java.lang.reflect.Modifier;
  import java.util.Collection;
  import java.util.EventObject;
  import java.util.Map;
  import java.util.Set;
  
  public class AutoConfigPlugin extends AnnotatedTypeFinder {
  
      private static final Logger logger = LogManager.get(AutoConfigPlugin.class);
  
      public AutoConfigPlugin() {
          super(true, false, AutoConfig.class, new $.F2<App, String, Map<Class<? extends AppByteCodeScanner>, Set<String>>>() {
              @Override
              public Map<Class<? extends AppByteCodeScanner>, Set<String>> apply(final App app, final String className) throws NotAppliedException, $.Break {
                  app.eventBus().bind(SysEventId.PRE_START, new SysEventListenerBase() {
                      @Override
                      public void on(EventObject event) throws Exception {
                          Class<?> autoConfigClass = app.classForName(className);
                          new AutoConfigLoader(app, autoConfigClass).load();
                      }
                  });
                  return null;
              }
          });
      }
  
      /**
       * Used by plugin that to load their {@link AutoConfig auto configure class}
       *
       * @param autoConfigClass the class with {@link AutoConfig} annotation
       * @param app             the application instance
       */
      public static void loadPluginAutoConfig(Class<?> autoConfigClass, App app) {
          new AutoConfigLoader(app, autoConfigClass).load();
      }
  
      private static class AutoConfigLoader {
          //private App app;
          private AppConfig conf;
          private Class<?> autoConfigClass;
          private String ns;
          private StringValueResolverManager resolverManager;
          private Injector injector;
  
          AutoConfigLoader(App app, Class<?> autoConfigClass) {
              this.conf = app.config();
              this.autoConfigClass = autoConfigClass;
              this.ns = (autoConfigClass.getAnnotation(AutoConfig.class)).value();
              this.resolverManager = app.resolverManager();
              this.injector = app.injector();
          }
  
          void load() {
              loadClass(autoConfigClass, ns);
          }
  
          void loadClass(Class<?> c, String ns) {
              Class[] ca = c.getClasses();
              for (Class c0 : ca) {
                  if (c0 == c) {
                      continue;
                  }
                  int mod = c0.getModifiers();
                  if (Modifier.isStatic(mod)) {
                      loadClass(c0, ns + "." + c0.getSimpleName());
                  }
              }
              Field[] fa = c.getDeclaredFields();
              for (Field f : fa) {
                  if (Modifier.isStatic(f.getModifiers())) {
                      loadAutoConfig_(f, ns);
                  }
              }
          }
  
          private void loadAutoConfig_(Field f, String ns) {
              String key = ns + "." + f.getName();
              Object val = conf.getIgnoreCase(key);
              if (null == val) {
                  // try to change the "prefix.key_x_an_y" form to "prefix.key.x.an.y" form
                  key = key.replace('_', '.');
                  val = conf.getIgnoreCase(key);
                  if (null == val) {
                      return;
                  }
              }
              BeanSpec spec = BeanSpec.of(f, injector);
              try {
                  setField(f, null, key, val, spec);
              } catch (Exception e) {
                  throw E.invalidConfiguration(e, "Error get configuration " + key + ": " + e.getMessage());
              }
          }
  
          private void setField(Field f, Object host, String key, Object val, BeanSpec spec) throws Exception {
              f.setAccessible(true);
              if (spec.isInstanceOf($.Val.class)) {
                  $.Val value = $.cast(f.get(host));
                  Field fVal = $.Var.class.getDeclaredField("v");
                  fVal.setAccessible(true);
                  BeanSpec spec0 = BeanSpec.of(spec.typeParams().get(0), null, injector);
                  setField(fVal, value, key, val, spec0);
                  fVal.setAccessible(false);
              } else if (spec.isInstanceOf(Const.class)) {
                  Const value = $.cast(f.get(host));
                  Field fConst = Const.class.getDeclaredField("v");
                  fConst.setAccessible(true);
                  BeanSpec spec0 = BeanSpec.of(spec.typeParams().get(0), null, injector);
                  setField(fConst, value, key, val, spec0);
                  fConst.setAccessible(false);
              } else if (spec.isInstanceOf(Collection.class)) {
                  BeanSpec spec0 = BeanSpec.of(spec.typeParams().get(0), null, injector);
                  StringValueResolver resolver = resolverManager.resolver(spec0.rawType(), spec);
                  if (null == resolver) {
                      logger.warn("Config[%s] field type[%s] not recognized", key, spec);
                  } else {
                      Collection col = (Collection) injector.get(spec.rawType());
                      String[] sa = val.toString().split(",");
                      for (String s : sa) {
                          col.add(resolver.resolve(s));
                      }
                      f.set(host, col);
                  }
              } else {
                  StringValueResolver resolver = resolverManager.resolver(spec.rawType());
                  if (null == resolver) {
                      logger.warn("Config[%s] field type[%s] not recognized", key, spec.rawType());
                  } else {
                      f.set(host, resolver.resolve(val.toString()));
                  }
              }
          }
      }
  
  }
  