public static TypeSafePolicyDocument fromJson()

in src/main/java/com/awslabs/iot/data/TypeSafePolicyDocument.java [29:82]
33 lines of code
4 McCabe index (conditional complexity)

    public static TypeSafePolicyDocument fromJson(String json) {
        HashMap<String, JsonElement> rawHashMap = GsonHelper.fromJson(HashMap.class, json.getBytes(StandardCharsets.UTF_8));

        String version = rawHashMap.get(VERSION)
                .map(JsonElement::getAsString)
                .getOrElse("2012-10-17");

        JsonElement rawStatement = rawHashMap.get(STATEMENT)
                .getOrElse(JsonObject::new);

        if (!rawStatement.isJsonArray()) {
            JsonArray temp = new JsonArray();
            temp.add(rawStatement);
            rawStatement = temp;
        }

        // Turn this into a list that is easier to work with
        List<JsonObject> jsonObjectList = List.ofAll((JsonArray) rawStatement)
                .map(JsonElement::getAsJsonObject);

        List<Statement> statementList = jsonObjectList
                // Does this have an Effect key?
                .filter(jsonObject -> jsonObject.has(EFFECT))
                // Get the Effect key in a tuple with the original object
                .map(jsonObject -> Tuple.of(jsonObject.get(EFFECT), jsonObject))
                // Is the Effect key a JSON primitive?
                .filter(tuple -> tuple._1.isJsonPrimitive())
                // Get the Effect key as a JSON primitive with the original object
                .map(tuple -> Tuple.of((JsonPrimitive) tuple._1, tuple._2))
                // Is the Effect key a string?
                .filter(tuple -> tuple._1.isString())
                // Get the Effect key as a string with the original object
                .map(tuple -> Tuple.of(tuple._1.getAsString(), tuple._2))
                // Does this have an Action key?
                .filter(tuple -> tuple._2.has(ACTION))
                // Get the Action key in a tuple with the original object
                .map(tuple -> Tuple.of(tuple._1, tuple._2.get(ACTION), tuple._2))
                // Is the Action key a JSON primitive or an array?
                .filter(tuple -> tuple._2.isJsonArray() || tuple._2.isJsonPrimitive())
                // Turn the Action value into a list of strings
                .map(tuple -> Tuple.of(tuple._1, toListOfStrings(tuple._2), tuple._3))
                // Does this have a Resource key?
                .filter(tuple -> tuple._3.has(RESOURCE))
                // Get the Resource key and finally ditch the original object
                .map(tuple -> Tuple.of(tuple._1, tuple._2, tuple._3.get(RESOURCE)))
                // Is the Resource key a JSON primitive or an array?
                .filter(tuple -> tuple._3.isJsonArray() || tuple._3.isJsonPrimitive())
                // Turn the Resource value into a list of strings
                .map(tuple -> Tuple.of(tuple._1, tuple._2, toListOfStrings(tuple._3)))
                .map(TypeSafePolicyDocument::toStatement)
                .toList();

        return new TypeSafePolicyDocument(version, statementList);
    }