/*******************************************************************************
 * Copyright (c) 2017 Politecnico di Torino and others.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Apache License, Version 2.0
 * which accompanies this distribution, and is available at
 * http://www.apache.org/licenses/LICENSE-2.0
 *******************************************************************************/
package it.polito.verigraph.service;

import java.io.File;
import java.io.IOException;
import java.net.URL;

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.node.ObjectNode;
import com.github.fge.jackson.JsonLoader;
import com.github.fge.jsonschema.core.exceptions.ProcessingException;
import com.github.fge.jsonschema.core.report.ProcessingMessage;
import com.github.fge.jsonschema.core.report.ProcessingReport;
import com.github.fge.jsonschema.main.JsonSchema;
import com.github.fge.jsonschema.main.JsonSchemaFactory;

public class ValidationUtils {

    public static final String JSON_V4_SCHEMA_IDENTIFIER= "http://json-schema.org/draft-04/schema#";
    public static final String JSON_SCHEMA_IDENTIFIER_ELEMENT= "$schema";

    public static JsonNode getJsonNode(String jsonText) throws IOException {
        return JsonLoader.fromString(jsonText);
    } // getJsonNode(text) ends

    public static JsonNode getJsonNode(File jsonFile) throws IOException {
        return JsonLoader.fromFile(jsonFile);
    } // getJsonNode(File) ends

    public static JsonNode getJsonNode(URL url) throws IOException {
        return JsonLoader.fromURL(url);
    } // getJsonNode(URL) ends

    public static JsonNode getJsonNodeFromResource(String resource) throws IOException {
        return JsonLoader.fromResource(resource);
    } // getJsonNode(Resource) ends

    public static JsonSchema getSchemaNode(String schemaText) throws IOException, ProcessingException {
        final JsonNode schemaNode = getJsonNode(schemaText);
        return _getSchemaNode(schemaNode);
    } // getSchemaNode(text) ends

    public static JsonSchema getSchemaNode(File schemaFile) throws IOException, ProcessingException {
        final JsonNode schemaNode = getJsonNode(schemaFile);
        return _getSchemaNode(schemaNode);
    } // getSchemaNode(File) ends

    public static JsonSchema getSchemaNode(URL schemaFile) throws IOException, ProcessingException {
        final JsonNode schemaNode = getJsonNode(schemaFile);
        return _getSchemaNode(schemaNode);
    } // getSchemaNode(URL) ends

    public static JsonSchema getSchemaNodeFromResource(String resource) throws IOException, ProcessingException {
        final JsonNode schemaNode = getJsonNodeFromResource(resource);
        return _getSchemaNode(schemaNode);
    } // getSchemaNode() ends

    public static void validateJson(JsonSchema jsonSchemaNode, JsonNode jsonNode) throws ProcessingException {
        ProcessingReport report = jsonSchemaNode.validate(jsonNode);
        if (!report.isSuccess()) {
            for (ProcessingMessage processingMessage : report) {
                throw new ProcessingException(processingMessage);
            }
        }
    } // validateJson(Node) ends

    public static boolean isJsonValid(JsonSchema jsonSchemaNode, JsonNode jsonNode) throws ProcessingException {
        ProcessingReport report = jsonSchemaNode.validate(jsonNode);
        return report.isSuccess();
    } // validateJson(Node) ends

    public static boolean isJsonValid(String schemaText, String jsonText) throws ProcessingException, IOException {
        final JsonSchema schemaNode = getSchemaNode(schemaText);
        final JsonNode jsonNode = getJsonNode(jsonText);
        return isJsonValid(schemaNode, jsonNode);
    } // validateJson(Node) ends

    public static boolean isJsonValid(File schemaFile, File jsonFile) throws ProcessingException, IOException {
        final JsonSchema schemaNode = getSchemaNode(schemaFile);
        final JsonNode jsonNode = getJsonNode(jsonFile);
        return isJsonValid(schemaNode, jsonNode);
    } // validateJson(Node) ends

    public static boolean isJsonValid(URL schemaURL, URL jsonURL) throws ProcessingException, IOException {
        final JsonSchema schemaNode = getSchemaNode(schemaURL);
        final JsonNode jsonNode = getJsonNode(jsonURL);
        return isJsonValid(schemaNode, jsonNode);
    } // validateJson(Node) ends

    public static void validateJson(String schemaText, String jsonText) throws IOException, ProcessingException {
        final JsonSchema schemaNode = getSchemaNode(schemaText);
        final JsonNode jsonNode = getJsonNode(jsonText);
        validateJson(schemaNode, jsonNode);
    } // validateJson(text) ends

    public static void validateJson(File schemaFile, File jsonFile) throws IOException, ProcessingException {
        final JsonSchema schemaNode = getSchemaNode(schemaFile);
        final JsonNode jsonNode = getJsonNode(jsonFile);
        validateJson(schemaNode, jsonNode);
    } // validateJson(File) ends

    public static void validateJson(URL schemaDocument, URL jsonDocument) throws IOException, ProcessingException {
        final JsonSchema schemaNode = getSchemaNode(schemaDocument);
        final JsonNode jsonNode = getJsonNode(jsonDocument);
        validateJson(schemaNode, jsonNode);
    } // validateJson(URL) ends

    public static void validateJsonResource(String schemaResource, String jsonResource)throws IOException,
    ProcessingException {
        final JsonSchema schemaNode = getSchemaNode(schemaResource);
        final JsonNode jsonNode = getJsonNodeFromResource(jsonResource);
        validateJson(schemaNode, jsonNode);
    } // validateJsonResource() ends

    private static JsonSchema _getSchemaNode(JsonNode jsonNode) throws ProcessingException {
        final JsonNode schemaIdentifier = jsonNode.get(JSON_SCHEMA_IDENTIFIER_ELEMENT);
        if (null == schemaIdentifier) {
            ((ObjectNode) jsonNode).put(JSON_SCHEMA_IDENTIFIER_ELEMENT, JSON_V4_SCHEMA_IDENTIFIER);
        }

        final JsonSchemaFactory factory = JsonSchemaFactory.byDefault();
        return factory.getJsonSchema(jsonNode);
    } // _getSchemaNode() ends
}