package com.atlassian.plugin.validation;
   
   
   import com.atlassian.fugue.Either;
   import com.atlassian.plugin.Application;
   import com.atlassian.plugin.InstallationMode;
   import com.atlassian.plugin.parsers.ModuleReader;
   import com.atlassian.plugin.parsers.PluginDescriptorReader;
   import com.google.common.annotations.VisibleForTesting;
  import com.google.common.collect.Iterables;
  import com.google.common.collect.Sets;
  import com.google.common.io.InputSupplier;
  
  import java.io.InputStream;
  import java.io.Reader;
  import java.util.Collections;
  import java.util.Map;
  import java.util.Set;
  import java.util.stream.Collectors;
  
  import static com.atlassian.plugin.validation.Dom4jUtils.readDocument;
  import static com.google.common.base.Preconditions.checkNotNull;
  import static com.google.common.collect.ImmutableSet.copyOf;
  import static com.google.common.collect.Iterables.transform;
  
  /**
   * A simple validator that given a descriptor and a schema will check that the permissions set in the plugin are valid
   * and all required have been asked.
   *
   * @since 3.0.0
   */
  public final class DescriptorValidator {
      private static final String REMOTE_PLUGIN_CONTAINER_MODULE_NAME = "remote-plugin-container";
  
      private final PluginDescriptorReader descriptorReader;
      private final SchemaReader schemaReader;
  
      public DescriptorValidator(InputStream descriptor, InputStream schema, Set<Application> applications) {
          descriptorReader = new PluginDescriptorReader(readDocument(descriptor), copyOf(checkNotNull(applications)));
          schemaReader = new SchemaReader(readDocument(schema));
      }
  
      public Either<ValidationError, ValidationSuccess> validate(InstallationMode installationMode) {
          final Set<String> allowedPermissions = schemaReader.getAllowedPermissions();
          final Set<String> askedPermissions = descriptorReader.getPluginInformationReader().getPermissions(installationMode);
  
          final Sets.SetView<String> invalidPermissions = Sets.difference(askedPermissions, allowedPermissions);
  
          final Set<String> requiredPermissions = getRequiredPermissions(installationMode);
          final Sets.SetView<String> notAskedPermissions = Sets.difference(requiredPermissions, askedPermissions);
  
          if (!invalidPermissions.isEmpty() || (!descriptorReader.getPluginInformationReader().hasAllPermissions() && !notAskedPermissions.isEmpty())) {
              return Either.left(new ValidationError(invalidPermissions, notAskedPermissions));
          } else {
              return Either.right(new ValidationSuccess(isRemotable(installationMode)));
          }
      }
  
      private boolean isRemotable(InstallationMode installationMode) {
          final ModuleReader remotePluginContainerModuleReader = Iterables.find(descriptorReader.getModuleReaders(installationMode),
                  moduleReader -> moduleReader.getType().equals(REMOTE_PLUGIN_CONTAINER_MODULE_NAME), null);
  
          return remotePluginContainerModuleReader != null;
      }
  
      @VisibleForTesting
      Set<String> getRequiredPermissions(InstallationMode installationMode) {
          final Set<String> moduleKeys = getModuleKeys(installationMode);
          final Map<String, Set<String>> modulesRequiredPermissions = schemaReader.getModulesRequiredPermissions();
  
          return Collections.unmodifiableSet(modulesRequiredPermissions.entrySet().stream()
                  .filter(entry -> moduleKeys.contains(entry.getKey()))
                  .flatMap(entry -> entry.getValue().stream())
                  .collect(Collectors.toSet()));
      }
  
      private Set<String> getModuleKeys(InstallationMode installationMode) {
          return copyOf(transform(descriptorReader.getModuleReaders(installationMode), ModuleReader::getType));
      }
  
      public static final class ValidationError {
          private final Set<String> nonValidPermissions;
          private final Set<String> notAskedPermissions;
  
          private ValidationError(Sets.SetView<String> nonValidPermissions, Sets.SetView<String> notAskedPermissions) {
              this.nonValidPermissions = nonValidPermissions.immutableCopy();
              this.notAskedPermissions = notAskedPermissions.immutableCopy();
          }
  
          public Set<String> getNonValidPermissions() {
              return nonValidPermissions;
          }
  
          public Set<String> getNotAskedPermissions() {
              return notAskedPermissions;
          }
      }
  
      public static final class ValidationSuccess {
         private final boolean remotable;
 
         private ValidationSuccess(boolean remotable) {
             this.remotable = remotable;
         }
 
         public boolean isRemotable() {
             return remotable;
         }
     }
 }