package com.atlassian.plugin.refimpl.tenant;
   
   import com.atlassian.tenancy.api.Tenant;
   import com.atlassian.tenancy.api.TenantAccessor;
   import com.atlassian.tenancy.api.TenantContext;
   import com.atlassian.tenancy.api.TenantUnavailableException;
   import com.google.common.base.Preconditions;
   
   import javax.annotation.Nullable;
  import java.lang.reflect.InvocationTargetException;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.concurrent.Callable;
  
  /**
   * Dummy single tenant accessor - always there
   */
  public class RefappTenantRegistry implements TenantAccessor, TenantContext {
      private RefappTenant tenant;
  
      @Override
      public Iterable<Tenant> getAvailableTenants() {
          if (tenant != null) {
              List<Tenant> list = new ArrayList<Tenant>();
              list.add(tenant);
              return list;
          } else {
              return new ArrayList<Tenant>();
          }
      }
  
      public List<RefappTenant> getRefappTenants() {
          List<RefappTenant> list = new ArrayList<RefappTenant>();
          if (tenant != null) {
              list.add(tenant);
          }
          return list;
      }
  
  
      public void setTenant(RefappTenant tenant) {
          this.tenant = tenant;
      }
  
  
      public boolean hasTenant() {
          return (tenant != null);
      }
  
  
      @Nullable
      @Override
      public Tenant getCurrentTenant() {
          return tenant;
      }
  
  
      @Override
      public <T> T asTenant(final Tenant tenant, final Callable<T> callback)
              throws TenantUnavailableException, InvocationTargetException {
          Preconditions.checkNotNull(tenant);
          Preconditions.checkNotNull(callback);
  
          if (tenant != this.tenant) {
              throw new TenantUnavailableException();
          }
  
          try {
              return callback.call();
          } catch (Exception e) {
              throw new InvocationTargetException(e);
          }
      }
  }