/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 freemarker.ext.jython;

import org.python.core.PyException;
import org.python.core.PyObject;

import freemarker.ext.util.ModelFactory;
import freemarker.template.ObjectWrapper;
import freemarker.template.TemplateCollectionModel;
import freemarker.template.TemplateHashModelEx;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateModelException;

Model for Jython dictionaries (PyDictionary and PyStringMap). Note that the basic JythonModel already provides access to the __finditem__.__finditem__(String) method. This class only adds TemplateHashModelEx functionality in a somewhat skewed way. One could say it even violates TemplateHashModelEx semantics, as both the returned keys and values are only those from the item mapping, while the get() method works for attributes as well. However, in practice
when you ask for dict?keys inside a template, you'll really
want to retrieve only items, not attributes so this is considered OK.
/**
 * Model for Jython dictionaries ({@link org.python.core.PyDictionary}
 * and {@link org.python.core.PyStringMap}).
 * Note that the basic {@link JythonModel} already provides access to the
 * {@link PyObject#__finditem__(String)} method. This class only adds 
 * {@link TemplateHashModelEx} functionality in a somewhat skewed way. One
 * could say it even violates TemplateHashModelEx semantics, as both the
 * returned keys and values are only those from the item mapping, while the
 * <code>get()</code> method works for attributes as well. However, in practice
 * when you ask for <code>dict?keys</code> inside a template, you'll really
 * want to retrieve only items, not attributes so this is considered OK.
 */
public class JythonHashModel
extends 
    JythonModel 
implements 
    TemplateHashModelEx {
    private static final String KEYS = "keys";
    private static final String KEYSET = "keySet";
    private static final String VALUES = "values";
    
    static final ModelFactory FACTORY =
        new ModelFactory()
        {
            public TemplateModel create(Object object, ObjectWrapper wrapper) {
                return new JythonHashModel((PyObject) object, (JythonWrapper) wrapper);
            }
        };
        
    public JythonHashModel(PyObject object, JythonWrapper wrapper) {
        super(object, wrapper);
    }
    
    
Returns __len__.__len__(). /**
     * Returns {@link PyObject#__len__()}.
     */
    public int size() throws TemplateModelException {
        try {
            return object.__len__();
        } catch (PyException e) {
            throw new TemplateModelException(e);
        }
    }

    
Returns either object.__findattr__("keys").__call__()
or object.__findattr__("keySet").__call__().
/**
     * Returns either <code>object.__findattr__("keys").__call__()</code>
     * or <code>object.__findattr__("keySet").__call__()</code>.
     */
    public TemplateCollectionModel keys() throws TemplateModelException {
        try {
            PyObject method = object.__findattr__(KEYS);
            if (method == null) {
                method = object.__findattr__(KEYSET);
            }
            if (method != null) {
                return (TemplateCollectionModel) wrapper.wrap(method.__call__());
            }
        } catch (PyException e) {
            throw new TemplateModelException(e);
        }
        throw new TemplateModelException(
                "'?keys' is not supported as there is no 'keys' nor 'keySet' attribute on an instance of "
                + JythonVersionAdapterHolder.INSTANCE.getPythonClassName(object));
    }

    
Returns object.__findattr__("values").__call__().
/**
     * Returns <code>object.__findattr__("values").__call__()</code>.
     */
    public TemplateCollectionModel values() throws TemplateModelException {
        try {
            PyObject method = object.__findattr__(VALUES);
            if (method != null) {
                return (TemplateCollectionModel) wrapper.wrap(method.__call__());
            }
        } catch (PyException e) {
            throw new TemplateModelException(e);
        }
        throw new TemplateModelException(
                "'?values' is not supported as there is no 'values' attribute on an instance of "
                + JythonVersionAdapterHolder.INSTANCE.getPythonClassName(object));
    }
}