/*
    * SPDX-FileCopyrightText: none
    * SPDX-License-Identifier: CC0-1.0
    */
   
   package gov.nist.secauto.metaschema.databind;
   
   import gov.nist.secauto.metaschema.core.model.IBoundObject;
   import gov.nist.secauto.metaschema.core.model.IModule;
  import gov.nist.secauto.metaschema.core.model.IModuleLoader;
  import gov.nist.secauto.metaschema.core.model.MetaschemaException;
  import gov.nist.secauto.metaschema.core.util.CollectionUtil;
  import gov.nist.secauto.metaschema.databind.IBindingContext.IBindingMatcher;
  import gov.nist.secauto.metaschema.databind.model.IBoundDefinitionModelComplex;
  import gov.nist.secauto.metaschema.databind.model.IBoundModule;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Set;
  import java.util.concurrent.locks.Lock;
  import java.util.concurrent.locks.ReentrantLock;
  
  import edu.umd.cs.findbugs.annotations.NonNull;
  
  public class PostProcessingModuleLoaderStrategy
      implements IBindingContext.IModuleLoaderStrategy {
    @NonNull
    private final List<IModuleLoader.IModulePostProcessor> modulePostProcessors;
    // private final Set<IModule> resolvedModules = new HashSet<>();
    // private final Lock resolvedModulesLock = new ReentrantLock();
    private final IBindingContext.IModuleLoaderStrategy delegate;
    private final Set<IModule> postProcessedModules = new HashSet<>();
    private final Lock postProcessedModulesLock = new ReentrantLock();
  
    public PostProcessingModuleLoaderStrategy(
        @NonNull List<IModuleLoader.IModulePostProcessor> modulePostProcessors) {
      this(modulePostProcessors, new SimpleModuleLoaderStrategy());
    }
  
    public PostProcessingModuleLoaderStrategy(
        @NonNull List<IModuleLoader.IModulePostProcessor> modulePostProcessors,
        @NonNull IBindingContext.IModuleLoaderStrategy delegate) {
      this.modulePostProcessors = CollectionUtil.unmodifiableList(new ArrayList<>(modulePostProcessors));
      this.delegate = delegate;
    }
  
    @NonNull
    protected List<IModuleLoader.IModulePostProcessor> getModulePostProcessors() {
      return modulePostProcessors;
    }
  
    @Override
    public IBoundModule loadModule(Class<? extends IBoundModule> clazz, IBindingContext bindingContext) {
      return delegate.loadModule(clazz, bindingContext);
    }
  
    @Override
    public void postProcessModule(IModule module, IBindingContext bindingContext) {
      processModule(module);
      delegate.postProcessModule(module, bindingContext);
    }
  
    @Override
    public IBoundModule registerModule(IModule module, IBindingContext bindingContext) throws MetaschemaException {
      IBoundModule boundModule;
      postProcessedModulesLock.lock();
      try {
        // process before registering
        processModule(module);
  
        boundModule = delegate.registerModule(module, bindingContext);
  
        // ensure the resulting bound module is not processed again
        postProcessedModules.add(boundModule);
      } finally {
        postProcessedModulesLock.unlock();
      }
      return boundModule;
    }
  
    /**
     * Perform post-processing on the provided module.
     *
     * @param module
     *          the module to post process
     */
    protected void processModule(@NonNull IModule module) {
      postProcessedModulesLock.lock();
      try {
        if (!postProcessedModules.contains(module)) {
          for (IModuleLoader.IModulePostProcessor postProcessor : getModulePostProcessors()) {
            postProcessor.processModule(module);
          }
          postProcessedModules.add(module);
        }
      } finally {
        postProcessedModulesLock.unlock();
     }
   }
 
   @Override
   public Collection<IBindingMatcher> getBindingMatchers() {
     return delegate.getBindingMatchers();
   }
 
   @Override
   public IBoundDefinitionModelComplex getBoundDefinitionForClass(
       Class<? extends IBoundObject> clazz,
       IBindingContext bindingContext) {
 
     //
     // resolvedModulesLock.lock();
     // try {
     // if (!resolvedModules.contains(module)) {
     // // add first, to avoid loops
     // resolvedModules.add(module);
     // for (IModuleLoader.IModulePostProcessor postProcessor :
     // getModulePostProcessors()) {
     // postProcessor.processModule(module);
     // }
     // }
     // } finally {
     // resolvedModulesLock.unlock();
     // }
     return delegate.getBoundDefinitionForClass(clazz, bindingContext);
   }
 }