#! /usr/bin/env python
import argparse
import fnmatch
import json
import logging
import os
import random
import sys
import unittest

try:
    import jsonschema
except ImportError:
    jsonschema = None


logging.basicConfig(level=logging.INFO)

SUITE_ROOT_DIR = os.path.join(os.path.dirname(__file__), os.pardir, "tests")
TESTSUITE_SCHEMA = {
    "$schema": "http://json-schema.org/draft-03/schema#",
    "type": "array",
    "items": {
        "type": "object",
        "properties": {
            "description": {"type": "string", "required": True},
            "schema": {"required": True},
            "tests": {
                "type": "array",
                "items": {
                    "type": "object",
                    "properties": {
                        "description": {"type": "string", "required": True},
                        "data": {"required": True},
                        "valid": {"type": "boolean", "required": True}
                    },
                    "additionalProperties": False
                },
                "minItems": 1
            }
        },
        "additionalProperties": False,
        "minItems": 1
    }
}


def files(paths):
    for path in paths:
        with open(path) as test_file:
            yield json.load(test_file)


def groups(paths):
    for test_file in files(paths):
        for group in test_file:
            yield group


def cases(paths):
    for test_group in groups(paths):
        for test in test_group["tests"]:
            test["schema"] = test_group["schema"]
            yield test


def collect(root_dir):
    for root, dirs, files in os.walk(root_dir):
        for filename in fnmatch.filter(files, "*.json"):
            yield os.path.join(root, filename)


class SanityTests(unittest.TestCase):
    @classmethod
    def setUpClass(cls):
        logging.info("Looking for tests in %s", SUITE_ROOT_DIR)
        cls.test_files = list(collect(SUITE_ROOT_DIR))
        logging.info("Found %s test files", len(cls.test_files))
        assert cls.test_files, "Didn't find the test files!"

    def test_all_files_are_valid_json(self):
        for path in self.test_files:
            with open(path) as test_file:
                try:
                    json.load(test_file)
                except ValueError as error:
                    self.fail("%s contains invalid JSON (%s)" % (path, error))

    def test_all_descriptions_have_reasonable_length(self):
        for case in cases(self.test_files):
            descript = case["description"]
            self.assertLess(
                len(descript),
                60,
                "%r is too long! (keep it to less than 60 chars)" % (descript,)
            )

    def test_all_descriptions_are_unique(self):
        for group in groups(self.test_files):
            descriptions = {test["description"] for test in group["tests"]}
            self.assertEqual(
                len(descriptions),
                len(group["tests"]),
                "%r contains a duplicate description" % (group,)
            )

    @unittest.skipIf(jsonschema is None, "Validation library not present!")
    def test_all_schemas_are_valid(self):
        for schema in os.listdir(SUITE_ROOT_DIR):
            schema_validator = jsonschema.validators.get(schema)
            if schema_validator:
                test_files = collect(os.path.join(SUITE_ROOT_DIR, schema))
                for case in cases(test_files):
                    try:
                        schema_validator.check_schema(case["schema"])
                    except jsonschema.SchemaError as error:
                        self.fail("%s contains an invalid schema (%s)" %
                                  (case, error))
            else:
                logging.warning("No schema validator for %s" % schema)

    @unittest.skipIf(jsonschema is None, "Validation library not present!")
    def test_suites_are_valid(self):
        validator = jsonschema.Draft3Validator(TESTSUITE_SCHEMA)
        for tests in files(self.test_files):
            try:
                validator.validate(tests)
            except jsonschema.ValidationError as error:
                self.fail(str(error))


def main(arguments):
    if arguments.command == "check":
        suite = unittest.TestLoader().loadTestsFromTestCase(SanityTests)
        result = unittest.TextTestRunner(verbosity=2).run(suite)
        sys.exit(not result.wasSuccessful())
    elif arguments.command == "flatten":
        selected_cases = [case for case in cases(collect(arguments.version))]

        if arguments.randomize:
            random.shuffle(selected_cases)

        json.dump(selected_cases, arguments.out, indent=4)


parser = argparse.ArgumentParser(
    description="JSON Schema Test Suite utilities",
)
subparsers = parser.add_subparsers(help="utility commands", dest="command")

check = subparsers.add_parser("check", help="Sanity check the test suite.")

flatten = subparsers.add_parser(
    "flatten",
    help="Output a flattened file containing the test cases and any "
            "additionally specified optional test cases."
)
flatten.add_argument(
    "--randomize",
    action="store_true",
    help="randomize the order of the outputted cases",
)
flatten.add_argument(
    "version", help="the directory containing the version to output",
)
flatten.add_argument(
    "out", help="the output file to write to", type=argparse.FileType("w"),
)


if __name__ == "__main__":
    main(parser.parse_args())
