package com.atlassian.activeobjects.backup;
   
   import com.atlassian.activeobjects.admin.PluginInfo;
   import com.atlassian.activeobjects.admin.PluginToTablesMapping;
   import com.atlassian.activeobjects.plugin.ActiveObjectModuleDescriptor;
   import com.atlassian.activeobjects.spi.PluginInformation;
   import com.atlassian.plugin.ModuleDescriptor;
   import com.atlassian.plugin.Plugin;
   import com.atlassian.plugin.PluginAccessor;
  import com.atlassian.plugin.predicate.ModuleDescriptorPredicate;
  
  import java.util.Collection;
  
  import static com.google.common.base.Preconditions.checkNotNull;
  
  public final class PluginInformationFactory {
      private final PluginToTablesMapping pluginToTablesMapping;
      private final PluginAccessor pluginAccessor;
  
      public PluginInformationFactory(PluginToTablesMapping pluginToTablesMapping, PluginAccessor pluginAccessor) {
          this.pluginToTablesMapping = checkNotNull(pluginToTablesMapping);
          this.pluginAccessor = checkNotNull(pluginAccessor);
      }
  
      /**
       * Gets plugin information from the Active Objects table hash
       *
       * @param tableName the table name
       * @return some plugin information
       */
      public PluginInformation getPluginInformation(final String tableName) {
          if (tableName == null) {
              return new NotAvailablePluginInformation();
          }
  
          final PluginInfo pluginInfo = pluginToTablesMapping.get(tableName);
          if (pluginInfo != null) {
              return new AvailablePluginInformation(pluginInfo);
          }
  
          final ActiveObjectModuleDescriptor aomd = getModuleDescriptor(tableName);
          if (aomd != null) {
              return new AvailablePluginInformation(aomd.getPlugin());
          }
  
          return new NotAvailablePluginInformation();
      }
  
      private ActiveObjectModuleDescriptor getModuleDescriptor(String tableName) {
          final Collection<ModuleDescriptor<Object>> moduleDescriptors = findModuleDescriptors(tableName);
          return moduleDescriptors.isEmpty() ? null : (ActiveObjectModuleDescriptor) moduleDescriptors.iterator().next();
      }
  
      private Collection<ModuleDescriptor<Object>> findModuleDescriptors(final String tableName) {
          return pluginAccessor.getModuleDescriptors(new ModuleDescriptorPredicate<Object>() {
              @Override
              public boolean matches(ModuleDescriptor<? extends Object> moduleDescriptor) {
                  return moduleDescriptor instanceof ActiveObjectModuleDescriptor
                          && ((ActiveObjectModuleDescriptor) moduleDescriptor).getConfiguration().getTableNamePrefix().isStarting(tableName, false);
              }
          });
      }
  
      private static final class NotAvailablePluginInformation implements PluginInformation {
          @Override
          public boolean isAvailable() {
              return false;
          }
  
          @Override
          public String getPluginName() {
              return null;
          }
  
          @Override
          public String getPluginKey() {
              return null;
          }
  
          @Override
          public String getPluginVersion() {
              return null;
          }
  
          @Override
          public String getVendorName() {
              return null;
          }
  
          @Override
          public String getVendorUrl() {
              return null;
          }
  
          @Override
          public boolean equals(Object o) {
              return o != null && o instanceof NotAvailablePluginInformation;
          }
  
         @Override
         public int hashCode() {
             return 0;
         }
 
         @Override
         public String toString() {
             return "<unknown plugin>";
         }
     }
 
     private static final class AvailablePluginInformation implements PluginInformation {
         private final String name;
         private final String key;
         private final String version;
         private final String vendorName;
         private final String vendorUrl;
 
         public AvailablePluginInformation(Plugin plugin) {
             this(
                     checkNotNull(plugin).getName(),
                     plugin.getKey(),
                     plugin.getPluginInformation().getVersion(),
                     plugin.getPluginInformation().getVendorName(),
                     plugin.getPluginInformation().getVendorUrl()
             );
         }
 
         public AvailablePluginInformation(PluginInfo pluginInfo) {
             this(checkNotNull(pluginInfo).name, pluginInfo.key, pluginInfo.version, pluginInfo.vendorName, pluginInfo.vendorUrl);
         }
 
         private AvailablePluginInformation(String name, String key, String version, String vendorName, String vendorUrl) {
             this.name = name;
             this.key = key;
             this.version = version;
             this.vendorName = vendorName;
             this.vendorUrl = vendorUrl;
         }
 
         @Override
         public boolean isAvailable() {
             return true;
         }
 
         @Override
         public String getPluginName() {
             return name;
         }
 
         @Override
         public String getPluginKey() {
             return key;
         }
 
         @Override
         public String getPluginVersion() {
             return version;
         }
 
         @Override
         public String getVendorName() {
             return vendorName;
         }
 
         @Override
         public String getVendorUrl() {
             return vendorUrl;
         }
 
         @Override
         public boolean equals(Object o) {
             if (this == o) {
                 return true;
             }
             if (o == null || getClass() != o.getClass()) {
                 return false;
             }
 
             final AvailablePluginInformation that = (AvailablePluginInformation) o;
 
             if (key != null ? !key.equals(that.key) : that.key != null) {
                 return false;
             }
             if (name != null ? !name.equals(that.name) : that.name != null) {
                 return false;
             }
             if (vendorName != null ? !vendorName.equals(that.vendorName) : that.vendorName != null) {
                 return false;
             }
             if (vendorUrl != null ? !vendorUrl.equals(that.vendorUrl) : that.vendorUrl != null) {
                 return false;
             }
             if (version != null ? !version.equals(that.version) : that.version != null) {
                 return false;
             }
 
             return true;
         }
 
         @Override
         public int hashCode() {
             int result = name != null ? name.hashCode() : 1;
             result = 31 * result + (key != null ? key.hashCode() : 1);
             result = 31 * result + (version != null ? version.hashCode() : 1);
             result = 31 * result + (vendorName != null ? vendorName.hashCode() : 1);
             result = 31 * result + (vendorUrl != null ? vendorUrl.hashCode() : 1);
             return result;
         }
 
         @Override
         public String toString() {
             return "plugin " + getPluginName() + "(" + getPluginKey() + ") #" + getPluginVersion();
         }
     }
 }