/*
 * Copyright 2015 Oleg Nenashev.
 *
 * 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 com.github.dockerjava.test.serdes;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.github.dockerjava.api.command.CommandJSONSamples;
import java.io.IOException;
import java.io.InputStream;
import org.apache.commons.io.IOUtils;
import static org.testng.Assert.assertEquals;
import static org.testng.Assert.assertNotNull;

/**
 * Provides helper methods for serialization-deserialization tests
 * @author Oleg Nenashev
 * @since TODO
 */
public class JSONTestHelper {
    
    /**
     * Reads JSON String from the specified resource
     * @param resource JSON File
     * @return JSON String 
     * @throws IOException JSON Conversion error 
     */
    public static String readString(JSONResourceRef resource) throws IOException {
        InputStream istream = CommandJSONSamples.class.getResourceAsStream(resource.getFileName());
        if (istream == null) {
            throw new IOException("Cannot retrieve resource " + resource.getFileName());
        }
        return IOUtils.toString(istream, "UTF-8");
    }
    
    /**
     * Reads item from the resource.
     * @param <TClass> Data class to be read
     * @param resource Resource reference
     * @param tclass Class entry
     * @return Item
     * @throws IOException JSON conversion error
     */
    public static <TClass> TClass readObject(JSONResourceRef resource, Class<TClass> tclass) throws IOException {
        ObjectMapper mapper = new ObjectMapper();
        String str = readString(resource);
        return mapper.readValue(str, tclass);
    }
    
    /**
     * Basic serialization-deserialization consistency test for the resource.
     * @param <TClass> Data class
     * @param resource Resource reference
     * @param tclass Class entry
     * @throws IOException JSON conversion error
     * @throws AssertionError Validation error
     * @return Deserialized object after the roundtrip
     */
    public static <TClass> TClass testRoundTrip(JSONResourceRef resource, Class<TClass> tclass) 
            throws IOException, AssertionError {
        TClass item = readObject(resource, tclass);
        assertNotNull(item);
        return testRoundTrip(item, tclass);
    }
    
    /**
     * Performs roundtrip test for the specified class.
     * @param <TClass> Item class
     * @param item Item to be checked
     * @return Deserialized object after the roundtrip
     * @throws IOException JSON Conversion error
     * @throws AssertionError Validation error
     */
    @SuppressWarnings("unchecked")
    public static <TClass> TClass testRoundTrip(TClass item) 
            throws IOException, AssertionError {
        return testRoundTrip(item, (Class<TClass>)item.getClass());
    }
    
    /**
     * Performs roundtrip test for the specified class.
     * @param <TClass> Item class
     * @param item Item to be checked
     * @param asclass Class to be used during conversions
     * @return Deserialized object after the roundtrip
     * @throws IOException JSON Conversion error
     * @throws AssertionError Validation error
     */
    public static <TClass> TClass testRoundTrip(TClass item, Class<TClass> asclass) 
            throws IOException, AssertionError {
        ObjectMapper mapper = new ObjectMapper();
       
        String inputItemString = mapper.writeValueAsString(item);
        TClass convertedItem = mapper.readValue(inputItemString, asclass);
        String convertedItemString = mapper.writeValueAsString(convertedItem);
        assertEquals(convertedItemString, inputItemString, "JSONs must be equal after the second roundtrip");
        return convertedItem;
    }
}

@@ -636,16 +636,64 @@
 erdes;%0A%0A
+import com.fasterxml.jackson.databind.JsonNode;%0A
 import c
@@ -736,16 +736,16 @@
 Mapper;%0A
-
 import c
@@ -797,16 +797,17 @@
 amples;%0A
+%0A
 import j
@@ -854,16 +854,17 @@
 Stream;%0A
+%0A
 import o
@@ -889,24 +889,25 @@
 io.IOUtils;%0A
+%0A
 import stati
@@ -3915,31 +3915,27 @@
  String 
-inputItemString
+serialized1
  = mappe
@@ -3974,28 +3974,83 @@
     
-TClass convertedItem
+JsonNode json1 = mapper.readTree(serialized1);%0A        TClass deserialized1
  = m
@@ -4065,31 +4065,27 @@
 adValue(
-inputItemString
+serialized1
 , asclas
@@ -4103,35 +4103,27 @@
  String 
-convertedItemString
+serialized2
  = mappe
@@ -4147,81 +4147,192 @@
 ing(
-convertedItem);%0A        assertEquals(convertedItemString, inputItemString
+deserialized1);%0A        JsonNode json2 = mapper.readTree(serialized2);%0A        TClass deserialized2 = mapper.readValue(serialized2, asclass);%0A        %0A        assertEquals(json2, json1
 , %22J
@@ -4399,21 +4399,21 @@
 urn 
-convertedItem
+deserialized2
 ;%0A  

Fix roundtrip test