/*
    * Copyright 2013 smartics, Kronseder & Reiner GmbH
    *
    * 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.
   */
  package de.smartics.properties.admin.resources.controller;
  
  import java.net.URI;
  
  import javax.annotation.security.RolesAllowed;
  import javax.ws.rs.FormParam;
  import javax.ws.rs.GET;
  import javax.ws.rs.POST;
  import javax.ws.rs.Path;
  import javax.ws.rs.PathParam;
  import javax.ws.rs.Produces;
  import javax.ws.rs.core.Context;
  import javax.ws.rs.core.MediaType;
  import javax.ws.rs.core.Response;
  import javax.ws.rs.core.Response.Status;
  import javax.ws.rs.core.UriInfo;
  
  import org.apache.commons.lang3.StringUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import de.smartics.properties.admin.domain.model.ConfigurationProperty;
  import de.smartics.properties.admin.domain.model.ManagedApplication;
  import de.smartics.properties.admin.domain.model.Paths;
  import de.smartics.properties.admin.domain.model.Roles;
  import de.smartics.properties.api.config.domain.ConfigControl;
  import de.smartics.properties.api.config.domain.ConfigurationPropertiesManagement;
  import de.smartics.properties.api.config.domain.DescribedProperty;
  import de.smartics.properties.api.config.domain.ValidatedProperty;
  import de.smartics.properties.api.core.domain.PropertyDescriptor;
  import de.smartics.properties.api.core.domain.PropertyDescriptorRegistry;
  import de.smartics.properties.api.core.domain.PropertyValidationException;
  import de.smartics.properties.api.core.domain.PropertyValueConversionException;
  import de.smartics.properties.api.core.domain.ReadOnlyPropertyException;
  import de.smartics.properties.api.core.security.PropertyValueSecurity;
  
  /**
   * Provides access to properties used by the application.
   */
  @Path("")
  @RolesAllowed(Roles.VIEW)
  public class PropertyResource
  {
    // ********************************* Fields *********************************
  
    // --- constants ------------------------------------------------------------
  
    /**
     * Reference to the logger for this class.
     */
    private static final Logger LOG = LoggerFactory
        .getLogger(PropertyResource.class);
  
    // --- members --------------------------------------------------------------
  
    /**
     * Helper to construct paths.
     */
    @Context
    private UriInfo uriInfo;
  
    // ****************************** Initializer *******************************
  
    // ****************************** Constructors ******************************
  
    // ****************************** Inner Classes *****************************
  
    // ********************************* Methods ********************************
  
    // --- init -----------------------------------------------------------------
  
    // --- get&set --------------------------------------------------------------
  
    // --- business -------------------------------------------------------------
  
    /**
     * Returns the property value for a given property key.
     *
     * @param configurationKey the configuration key.
     * @param propertyKey the key to the requested property.
     * @return the string representation.
     */
    @GET
    @Path(Paths.PATH_PROPERTY_VALUE)
   @Produces(MediaType.TEXT_PLAIN)
   public Response getAsText(
       @PathParam(Paths.PARAM_CONFIGURATION_KEY) final String configurationKey,
       @PathParam(Paths.PARAM_PROPERTY_KEY) final String propertyKey)
   {
     final PropertyDescriptor descriptor = fetchPropertyDescriptor(propertyKey);
     if (descriptor == null && propertyKey.endsWith(".xml"))
     {
       return getAsDotXml(configurationKey,
           propertyKey.substring(0, propertyKey.length() - 4));
     }
     else if (descriptor == null)
     {
       final Response response = Response.status(Status.NOT_FOUND).build();
       return response;
     }
 
     final ConfigurationProperty resource =
         fetchValidatedProperty(configurationKey, propertyKey);
     final String value = String.valueOf(resource.getPropertyValue());
 
     final Response response = Response.ok().entity(value).build();
     return response;
   }
 
   private PropertyDescriptor fetchPropertyDescriptor(final String propertyKey)
   {
     final ManagedApplication app = ManagedApplication.getApplication();
     final PropertyDescriptorRegistry registry = app.getDescriptorRegistry();
     final PropertyDescriptor descriptor = registry.get(propertyKey);
     return descriptor;
   }
 
   /**
    * Returns the property value for a given property key.
    *
    * @param configurationKey the configuration.
    * @param propertyKey the key to the requested property.
    * @return the HTML representation.
    */
   @GET
   @Path(Paths.PATH_PROPERTY_VALUE)
   @Produces(MediaType.TEXT_HTML)
   public Response getAsHtml(
       @PathParam(Paths.PARAM_CONFIGURATION_KEY) final String configurationKey,
       @PathParam(Paths.PARAM_PROPERTY_KEY) final String propertyKey)
   {
     final PropertyDescriptor descriptor = fetchPropertyDescriptor(propertyKey);
     if (descriptor == null && propertyKey.endsWith(".xml"))
     {
       return getAsDotXml(configurationKey,
           propertyKey.substring(0, propertyKey.length() - 4));
     }
     else if (descriptor == null)
     {
       final Response response = Response.status(Status.NOT_FOUND).build();
       return response;
     }
 
     final ConfigurationProperty resource =
         fetchValidatedProperty(configurationKey, propertyKey);
 
     final Response response = Response.ok().entity(resource).build();
     return response;
   }
 
   private ConfigurationProperty fetchValidatedProperty(
       final String configurationKey, final String propertyKey)
   {
     if (LOG.isDebugEnabled())
     {
       LOG.debug("Fetching value from configuration {} with key {}.",
           configurationKey, propertyKey);
     }
 
     final ManagedApplication app = ManagedApplication.getApplication();
     final ConfigurationPropertiesManagement configuration =
         app.getConfiguration(configurationKey);
     final PropertyDescriptor descriptor =
         configuration.getDescriptor(propertyKey);
     try
     {
       final ValidatedProperty property =
           configuration.getValidatedProperty(propertyKey, null);
       final ConfigurationProperty resource =
           new ConfigurationProperty(configurationKey, propertyKey, descriptor,
               property);
       return resource;
     }
     catch (final PropertyValueConversionException e)
     {
       final ConfigurationProperty resource =
           createSimpleProperty(configurationKey, propertyKey, configuration,
               descriptor);
       return resource;
     }
     catch (final PropertyValidationException e)
     {
       final ConfigurationProperty resource =
           createSimpleProperty(configurationKey, propertyKey, configuration,
               descriptor);
       return resource;
     }
   }
 
   private ConfigurationProperty createSimpleProperty(
       final String configurationKey, final String propertyKey,
       final ConfigurationPropertiesManagement configuration,
       final PropertyDescriptor descriptor)
   {
     final DescribedProperty property =
         configuration.getProperty(propertyKey, null);
     final ConfigurationProperty resource =
         new ConfigurationProperty(configurationKey, propertyKey, descriptor,
             property);
     return resource;
   }
 
   /**
    * Changes the property value and returns the representation of the changed
    * property.
    *
    * @param configurationKey the configuration .
    * @param propertyKey the key to the requested property.
    * @param propertyValue the new value to set.
    * @return the HTML representation.
    * @throws PropertyValidationException if the {@code propertyValue} is not
    *           successfully validated.
    * @throws ReadOnlyPropertyException if the property referenced by
    *           {@code propertyKey} is read-only and therefore cannot be changed.
    */
   @POST
   @Path(Paths.PATH_PROPERTY_VALUE)
   @Produces(MediaType.TEXT_HTML)
   @RolesAllowed(Roles.EDIT_PROPERTY)
   public Response postAsHtml(
       @PathParam(Paths.PARAM_CONFIGURATION_KEY) final String configurationKey,
       @PathParam(Paths.PARAM_PROPERTY_KEY) final String propertyKey,
       @FormParam(Paths.PARAM_VALUE) final String propertyValue)
     throws PropertyValidationException, ReadOnlyPropertyException
   {
     try
     {
       ConfigControl.get().setAdminMode(true);
 
       final ConfigurationProperty configProperty =
           create(configurationKey, propertyKey, propertyValue);
 
       final URI self = uriInfo.getRequestUriBuilder().build();
       final Response response =
           Response.seeOther(self).entity(configProperty).build();
 
       return response;
     }
     finally
     {
       ConfigControl.get().setAdminMode(false);
     }
   }
 
   private ConfigurationProperty create(final String configurationKey,
       final String propertyKey, final String propertyValue)
   {
     final ManagedApplication app = ManagedApplication.getApplication();
     final ConfigurationPropertiesManagement configuration =
         app.getConfiguration(configurationKey);
     final PropertyDescriptor descriptor =
         configuration.getDescriptor(propertyKey);
 
     if (StringUtils.isEmpty(propertyValue))
     {
       configuration.setProperty(descriptor.getKey(), null);
     }
     else
     {
       if (descriptor.isSecured())
       {
         final PropertyValueSecurity security = app.getSecurity();
         final String securedValue = security.encrypt(descriptor, propertyValue);
         configuration.validate(descriptor, securedValue);
       }
       else
       {
         configuration.validate(descriptor, propertyValue);
       }
       configuration.setProperty(descriptor.getKey(), propertyValue);
     }
 
     final ValidatedProperty property =
         configuration.getValidatedProperty(propertyKey, null);
     final ConfigurationProperty configProperty =
         new ConfigurationProperty(configurationKey, propertyKey, descriptor,
             property);
     return configProperty;
   }
 
   /**
    * Returns the property value for a given property key in its SDoc XML
    * representation.
    *
    * @param configurationKey the configuration .
    * @param propertyKey the key to the requested property.
    * @return the HTML representation.
    */
   @GET
   @Path(Paths.PATH_PROPERTY_VALUE + ".xml")
   @Produces(MediaType.WILDCARD)
   public Response getAsDotXml(
       @PathParam(Paths.PARAM_CONFIGURATION_KEY) final String configurationKey,
       @PathParam(Paths.PARAM_PROPERTY_KEY) final String propertyKey)
   {
     final Response response = getAsXml(configurationKey, propertyKey);
     return response;
   }
 
   /**
    * Returns the property value for a given property key in its SDoc XML
    * representation.
    *
    * @param configurationKey the configuration .
    * @param propertyKey the key to the requested property.
    * @return the HTML representation.
    */
   @GET
   @Path(Paths.PATH_PROPERTY_VALUE)
   @Produces({ MediaType.APPLICATION_XML, MediaType.TEXT_XML })
   public Response getAsXml(
       @PathParam(Paths.PARAM_CONFIGURATION_KEY) final String configurationKey,
       @PathParam(Paths.PARAM_PROPERTY_KEY) final String propertyKey)
   {
     final PropertyDescriptor descriptor = fetchPropertyDescriptor(propertyKey);
 
     if (descriptor == null)
     {
       final Response response = Response.status(Status.NOT_FOUND).build();
       return response;
     }
 
     final ConfigurationProperty resource =
         fetchValidatedProperty(configurationKey, propertyKey);
 
     final Response response =
         Response.ok().type(MediaType.TEXT_XML_TYPE).entity(resource).build();
     return response;
   }
 
   // --- object basics --------------------------------------------------------
 
 }