/*
    * Copyright 2003 - 2013 The eFaps Team
    *
    * 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.
   *
   * Revision:        $Rev$
   * Last Changed:    $Date$
   * Last Changed By: $Author$
   */
  
  package org.efaps.admin.datamodel.ui;
  
  import java.io.Serializable;
  import java.util.List;
  
  import org.efaps.admin.datamodel.Attribute;
  import org.efaps.admin.event.EventDefinition;
  import org.efaps.admin.event.EventType;
  import org.efaps.admin.event.Parameter;
  import org.efaps.admin.event.Parameter.ParameterValues;
  import org.efaps.admin.event.Return;
  import org.efaps.admin.event.Return.ReturnValues;
  import org.efaps.admin.ui.AbstractUserInterfaceObject.TargetMode;
  import org.efaps.admin.ui.field.Field;
  import org.efaps.admin.ui.field.Field.Display;
  import org.efaps.db.Context;
  import org.efaps.db.Instance;
  import org.efaps.util.EFapsException;
  import org.efaps.util.cache.CacheReloadException;
  
  /**
   * Wrapper Class to get a value for a UserInterface.
   *
   * @author The eFaps Team
   * @version $Id$
   */
  public final class UIValue
      implements Serializable, IUIValue
  {
  
      /**
       *Needed foer serialization.
       */
      private static final long serialVersionUID = 1L;
  
      /**
       * Value form the database.
       */
      private Serializable dbValue;
  
      /**
       * Id of the field this Value belongs to.
       */
      private final long fieldId;
  
      /**
       * Id of the Attribute this value belongs to.
       */
      private final long attributeId;
  
      /**
       * Stores he display mode for this field.
       */
      private Display display;
  
      /**
       * The TargetMode the value is wanted for.
       */
      private TargetMode targetMode;
  
      /**
       * The variable stores the field instance for this value.
       *
       * @see #getInstance
       */
      private Instance instance;
  
      /**
       * Object that will be passed to the event as CLASS.
       */
      private Object classObject;
  
      /**
       * Object that will be passed to the event as CLASS.
       */
      private Instance callInstance;
  
      /**
       * Object that will be passed to the event as CLASS.
      */
     private Object requestInstances;
 
     /**
      *  Value in case of readonly.
      */
     private Object readOnlyValue;
 
     /**
      *  Value in case of edit.
      */
     private Object editValue;
 
     /**
      * Value in case of hidden.
      */
     private Object hiddenValue;
 
     /**
      * @param _field        Field
      * @param _attribute    attribute
      * @param _value        value
      */
     private UIValue(final Field _field,
                     final Attribute _attribute,
                     final Serializable _value)
     {
         this.fieldId = _field == null ? 0 : _field.getId();
         this.attributeId = _attribute == null ? 0 : _attribute.getId();
         this.dbValue = _value;
     }
 
     /**
      * @param _field        Field
      * @param _attribute    attribute
      * @param _value        value
      * @return  UIValue
      */
     public static UIValue get(final Field _field,
                               final Attribute _attribute,
                               final Object _value)
     {
         UIValue ret;
         if (_value instanceof Serializable) {
             ret = new UIValue(_field, _attribute, (Serializable) _value);
         } else if (_value == null) {
             ret = new UIValue(_field, _attribute, null);
         } else {
             // throw warning!
             ret = new UIValue(_field, _attribute, null);
         }
         return ret;
     }
 
     /**
      * @return the field belonging to this UIValue
      */
     @Override
     public Field getField()
     {
         return Field.get(this.fieldId);
     }
 
     @Override
     public String toString()
     {
         return String.valueOf(this.dbValue);
     }
 
     /**
      * Method to get a plain string for this FieldValue .
      *
      * @see #executeEvents
      * @param _mode target mode
      * @throws EFapsException on error
      * @return plain string
      * @throws EFapsException
      */
     public Object getEditValue(final TargetMode _mode)
         throws EFapsException
     {
         this.display = Display.EDITABLE;
         this.targetMode = _mode;
         if (this.editValue == null) {
             Object obj = executeEvents(EventType.UI_FIELD_VALUE, _mode);
             if (obj == null) {
                 obj = executeEvents(EventType.UI_FIELD_FORMAT, _mode);
                 if (obj == null && getUIProvider() != null) {
                     obj = getUIProvider().getValue(this);
                 }
             } else if (getUIProvider() != null) {
                 obj = getUIProvider().transformObject(this, obj);
             }
             this.editValue = obj;
         }
         return this.editValue;
     }
 
     /**
      * Method to get a plain string for this FieldValue .
      *
      * @see #executeEvents
      * @param _mode target mode
      * @throws EFapsException on error
      * @return plain string
      * @throws EFapsException
      */
     public Object getHiddenValue(final TargetMode _mode)
         throws EFapsException
     {
         this.display = Display.HIDDEN;
         this.targetMode = _mode;
         if (this.hiddenValue == null) {
             Object obj = executeEvents(EventType.UI_FIELD_VALUE, _mode);
             if (obj == null) {
                 obj = executeEvents(EventType.UI_FIELD_FORMAT, _mode);
                 if (obj == null && getUIProvider() != null) {
                     obj = getUIProvider().getValue(this);
                 }
             } else if (getUIProvider() != null) {
                 obj = getUIProvider().transformObject(this, obj);
             }
             this.hiddenValue = obj;
         }
         return this.hiddenValue;
     }
 
     /**
      * Method to get a plain string for this FieldValue .
      *
      * @see #executeEvents
      * @param _mode target mode
      * @throws EFapsException on error
      * @return plain string
      * @throws EFapsException
      */
     public Object getReadOnlyValue(final TargetMode _mode)
         throws EFapsException
     {
         this.display = Display.READONLY;
         this.targetMode = _mode;
         if (this.readOnlyValue == null) {
             Object obj = executeEvents(EventType.UI_FIELD_VALUE, _mode);
             if (obj == null) {
                 obj = executeEvents(EventType.UI_FIELD_FORMAT, _mode);
                 if (obj == null && getUIProvider() != null) {
                     obj = getUIProvider().getValue(this);
                 }
             } else if (getUIProvider() != null) {
                 obj = getUIProvider().transformObject(this, obj);
             }
             this.readOnlyValue = obj;
         }
         return this.readOnlyValue;
     }
 
     /**
      * @return the UIProvider for this value
      * @throws CacheReloadException on eror
      */
     public IUIProvider getUIProvider()
         throws CacheReloadException
     {
         IUIProvider ret;
         if (this.attributeId > 0) {
             ret =  getAttribute().getAttributeType().getUIProvider();
         } else {
             ret = getField().getUIProvider();
         }
         return ret;
     }
 
     /**
      * Getter method for the instance variable {@link #display}.
      *
      * @return value of instance variable {@link #display}
      */
     @Override
     public Display getDisplay()
     {
         return this.display;
     }
 
     /**
      * Getter method for the instance variable {@link #dbValue}.
      *
      * @return value of instance variable {@link #dbValue}
      */
     public Serializable getDbValue()
     {
         return this.dbValue;
     }
 
     /**
      * @return Attribute
      * @throws CacheReloadException on error
      */
     public Attribute getAttribute()
         throws CacheReloadException
     {
         return Attribute.get(this.attributeId);
     }
 
     /**
      * Getter method for the instance variable {@link #targetMode}.
      *
      * @return value of instance variable {@link #targetMode}
      */
     public TargetMode getTargetMode()
     {
         return this.targetMode;
     }
 
     /**
      * Executes the field value events for a field.
      *
      * @param _eventType    type of event to be executed
      * @param _targetMode   targetmode
      * @throws EFapsException on error
      * @return string from called field value events or <code>null</code> if no
      *         field value event is defined
      *
      */
     protected Object executeEvents(final EventType _eventType,
                                    final TargetMode _targetMode)
         throws EFapsException
     {
         Object ret = null;
         if (this.fieldId > 0 && getField().hasEvents(_eventType)) {
 
             final List<EventDefinition> events = getField().getEvents(_eventType);
 
             final StringBuilder html = new StringBuilder();
             if (events != null) {
                 final Parameter parameter = new Parameter();
                 parameter.put(ParameterValues.ACCESSMODE, _targetMode);
                 parameter.put(ParameterValues.INSTANCE, this.instance);
                 parameter.put(ParameterValues.CLASS, this.classObject);
                 parameter.put(ParameterValues.UIOBJECT, this);
                 parameter.put(ParameterValues.CALL_INSTANCE, getCallInstance());
                 parameter.put(ParameterValues.REQUEST_INSTANCES, getRequestInstances());
                 if (parameter.get(ParameterValues.PARAMETERS) == null) {
                     parameter.put(ParameterValues.PARAMETERS, Context.getThreadContext().getParameters());
                 }
                 for (final EventDefinition evenDef : events) {
                     final Return retu = evenDef.execute(parameter);
                     if (retu.get(ReturnValues.SNIPLETT) != null) {
                         html.append(retu.get(ReturnValues.SNIPLETT));
                     } else if (retu.get(ReturnValues.VALUES) != null) {
                         ret = retu.get(ReturnValues.VALUES);
                         if (retu.get(ReturnValues.INSTANCE) != null) {
                            final Instance inst = (Instance) retu.get(ReturnValues.INSTANCE);
                            if (inst != null && inst.isValid()) {
                                setInstance(inst);
                            } else {
                                setInstance(null);
                            }
                         }
                     }
                 }
             }
             if (html.length() > 0) {
                 ret = html.toString();
             }
         }
         return ret;
     }
 
     /**
      * Setter method for instance variable {@link #dbValue}.
      *
      * @param _dbValue value for instance variable {@link #dbValue}
      */
     protected void setDbValue(final Serializable _dbValue)
     {
         this.dbValue = _dbValue;
     }
 
     /**
      * Getter method for the instance variable {@link #instance}.
      *
      * @return value of instance variable {@link #instance}
      */
     @Override
     public Instance getInstance()
     {
         return this.instance;
     }
 
     /**
      * Setter method for instance variable {@link #instance}.
      *
      * @param _instance value for instance variable {@link #instance}
      * @return this, for chaining
      */
     public UIValue setInstance(final Instance _instance)
     {
         this.instance = _instance;
         return this;
     }
 
     /**
      * Setter method for instance variable {@link #instance}.
      *
      * @param _instance value for instance variable {@link #instance}
      * @return this, for chaining
      */
     public UIValue setCallInstance(final Instance _instance)
     {
         this.callInstance = _instance;
         return this;
     }
 
     /**
      * Getter method for the instance variable {@link #callInstance}.
      *
      * @return value of instance variable {@link #callInstance}
      */
     public Instance getCallInstance()
     {
         return this.callInstance;
     }
 
     /**
      * Getter method for the instance variable {@link #classObject}.
      *
      * @return value of instance variable {@link #classObject}
      */
     public Object getClassObject()
     {
         return this.classObject;
     }
 
     /**
      * Setter method for instance variable {@link #classObject}.
      *
      * @param _classObject value for instance variable {@link #classObject}
      * @return this, for chaining
      */
     public UIValue setClassObject(final Object _classObject)
     {
         this.classObject = _classObject;
         return this;
     }
 
     /**
      * Getter method for the instance variable {@link #requestInstances}.
      *
      * @return value of instance variable {@link #requestInstances}
      */
     public Object getRequestInstances()
     {
         return this.requestInstances;
     }
 
     /**
      * Setter method for instance variable {@link #requestInstances}.
      *
      * @param _requestInstances value for instance variable {@link #requestInstances}
      * @return this, for chaining
      */
     public UIValue setRequestInstances(final Object _requestInstances)
     {
         this.requestInstances = _requestInstances;
         return this;
     }
 
     /**
      * Reset the UIValue, meaning that the values will be evaluated again.
      *
      * @return this, for chaining
      */
     public UIValue reset()
     {
         this.editValue = null;
         this.hiddenValue = null;
         this.readOnlyValue = null;
         return this;
     }
 }