/*
 * Modern C++ JSON schema validator
 *
 * Licensed under the MIT License <http://opensource.org/licenses/MIT>.
 *
 * Copyright (c) 2016 Patrick Boettcher <patrick.boettcher@posteo.de>.
 *
 * Permission is hereby  granted, free of charge, to any  person obtaining a
 * copy of this software and associated  documentation files (the "Software"),
 * to deal in the Software  without restriction, including without  limitation
 * the rights to  use, copy,  modify, merge,  publish, distribute,  sublicense,
 * and/or  sell copies  of  the Software,  and  to  permit persons  to  whom
 * the Software  is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE  IS PROVIDED "AS  IS", WITHOUT WARRANTY  OF ANY KIND,  EXPRESS
 * OR IMPLIED,  INCLUDING BUT  NOT  LIMITED TO  THE  WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR  A PARTICULAR PURPOSE AND  NONINFRINGEMENT. IN
 * NO EVENT  SHALL THE AUTHORS  OR COPYRIGHT  HOLDERS  BE  LIABLE FOR  ANY
 * CLAIM,  DAMAGES OR  OTHER LIABILITY, WHETHER IN AN ACTION OF  CONTRACT, TORT
 * OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE  OR
 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
#include <json-schema.hpp>

#include <fstream>
#include <set>

using nlohmann::json;
using nlohmann::json_uri;
using nlohmann::json_schema_draft4::json_validator;

static void usage(const char *name)
{
	std::cerr << "Usage: " << name << " <schema> < <document>\n";
	exit(EXIT_FAILURE);
}


#if 0
	resolver r(nlohmann::json_schema_draft4::root_schema,
			   nlohmann::json_schema_draft4::root_schema["id"]);
	schema_refs_.insert(r.schema_refs.begin(), r.schema_refs.end());
	assert(r.undefined_refs.size() == 0);
#endif

int main(int argc, char *argv[])
{
	if (argc != 2)
		usage(argv[0]);

	json_validator validator;

	std::fstream f(argv[1]);
	if (!f.good()) {
		std::cerr << "could not open " << argv[1] << " for reading\n";
		usage(argv[0]);
	}

	// 1) Read the schema for the document you want to validate
	json schema;
	try {
		f >> schema;
	} catch (std::exception &e) {
		std::cerr << e.what() << " at " << f.tellp() << "\n";
		return EXIT_FAILURE;
	}

	// 2) insert this schema to the validator
	//    this resolves remote-schemas, sub-schemas and references
	bool error = false;
	do {
		// inserting with json_uri("#") means this is the document's root-schema
		auto missing_schemas = validator.insert_schema(schema, json_uri("#"));

		// schema was inserted and all references have been fulfilled
		if (missing_schemas.size() == 0)
			break;

		// schema was not inserted because it references unknown schemas
		// 3) load missing schemas and insert them
		for (auto ref : missing_schemas) {
			std::cerr << "missing schema URL " << ref << " - trying to load it\n";

			std::fstream lf(ref.path());
			if (!lf.good()) {
				std::cerr << "could not open " << ref.url() << "\n";
				error = true;
				break;
			}
			json extra;
			try {
				lf >> extra;
			} catch (std::exception &e) {
				std::cerr << e.what() << " at " << lf.tellp() << "\n";
				return EXIT_FAILURE;
			}

			validator.insert_schema(extra, json_uri(ref.url()));
			std::cerr << "OK";
		}
	} while (!error);

	// 4) do the actual validation of the document
	json document;

	try {
		document << std::cin;
		validator.validate(document);
	} catch (std::exception &e) {
		std::cerr << "schema validation failed\n";
		std::cerr << e.what() << "\n";
		return EXIT_FAILURE;
	}

	std::cerr << "document is valid\n";

	return EXIT_SUCCESS;
}