#! /usr/bin/env python3
import argparse
import errno
import fnmatch
import json
import os
import random
import shutil
import sys
import textwrap
import unittest
import warnings

try:
    import jsonschema.validators
except ImportError:
    jsonschema = None
    VALIDATORS = {}
else:
    VALIDATORS = {
        "draft3": jsonschema.validators.Draft3Validator,
        "draft4": jsonschema.validators.Draft4Validator,
        "draft6": jsonschema.validators.Draft6Validator,
        "draft7": jsonschema.validators.Draft7Validator,
        "draft2019-09": jsonschema.validators.Draft201909Validator,
        "draft2020-12": jsonschema.validators.Draft202012Validator,
        "latest": jsonschema.validators.Draft202012Validator,
    }


ROOT_DIR = os.path.abspath(
    os.path.join(os.path.dirname(__file__), os.pardir).rstrip("__pycache__"),
)
SUITE_ROOT_DIR = os.path.join(ROOT_DIR, "tests")
REMOTES_DIR = os.path.join(ROOT_DIR, "remotes")


with open(os.path.join(ROOT_DIR, "test-schema.json")) as schema:
    TESTSUITE_SCHEMA = json.load(schema)


def files(paths):
    """
    Each test file in the provided paths.
    """
    for path in paths:
        with open(path) as test_file:
            yield json.load(test_file)


def groups(paths):
    """
    Each test group within each file in the provided paths.
    """
    for test_file in files(paths):
        for group in test_file:
            yield group


def cases(paths):
    """
    Each individual test case within all groups within the provided paths.
    """
    for test_group in groups(paths):
        for test in test_group["tests"]:
            test["schema"] = test_group["schema"]
            yield test


def collect(root_dir):
    """
    All of the test file paths within the given root directory, recursively.
    """
    for root, _, 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):
        print("Looking for tests in %s" % SUITE_ROOT_DIR)
        print("Looking for remotes in %s" % REMOTES_DIR)
        cls.test_files = list(collect(SUITE_ROOT_DIR))
        cls.remote_files = list(collect(REMOTES_DIR))
        print("Found %s test files" % len(cls.test_files))
        print("Found %s remote files" % len(cls.remote_files))
        assert cls.test_files, "Didn't find the test files!"
        assert cls.remote_files, "Didn't find the remote files!"

    def test_all_test_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_remote_files_are_valid_json(self):
        for path in self.remote_files:
            with open(path) as remote_file:
                try:
                    json.load(remote_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):
            description = case["description"]
            self.assertLess(
                len(description),
                70,
                "%r is too long! (keep it to less than 70 chars)" % (
                    description,
                ),
            )

    def test_all_descriptions_are_unique(self):
        for group in groups(self.test_files):
            descriptions = set(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 version in os.listdir(SUITE_ROOT_DIR):
            Validator = VALIDATORS.get(version)
            if Validator is not None:
                test_files = collect(os.path.join(SUITE_ROOT_DIR, version))
                for case in cases(test_files):
                    try:
                        Validator.check_schema(case["schema"])
                    except jsonschema.SchemaError as error:
                        self.fail("%s contains an invalid schema (%s)" %
                                  (case, error))
            else:
                warnings.warn("No schema validator for %s" % schema)

    @unittest.skipIf(jsonschema is None, "Validation library not present!")
    def test_suites_are_valid(self):
        Validator = jsonschema.validators.validator_for(TESTSUITE_SCHEMA)
        validator = Validator(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, sys.stdout, indent=4, sort_keys=True)
    elif arguments.command == "remotes":
        remotes = {}
        for path in collect(REMOTES_DIR):
            relative_path = os.path.relpath(path, REMOTES_DIR)
            with open(path) as schema_file:
                remotes[relative_path] = json.load(schema_file)
        json.dump(remotes, sys.stdout, indent=4, sort_keys=True)
    elif arguments.command == "dump_remotes":
        if arguments.update:
            shutil.rmtree(arguments.out_dir, ignore_errors=True)

        try:
            shutil.copytree(REMOTES_DIR, arguments.out_dir)
        except OSError as e:
            if e.errno == errno.EEXIST:
                print("%s already exists. Aborting." % arguments.out_dir)
                sys.exit(1)
            raise
    elif arguments.command == "serve":
        try:
            import flask
        except ImportError:
            print(textwrap.dedent("""
                The Flask library is required to serve the remote schemas.

                You can install it by running `pip install Flask`.

                Alternatively, see the `jsonschema_suite remotes` or
                `jsonschema_suite dump_remotes` commands to create static files
                that can be served with your own web server.
            """.strip("\n")))
            sys.exit(1)

        app = flask.Flask(__name__)

        @app.route("/<path:path>")
        def serve_path(path):
            return flask.send_from_directory(REMOTES_DIR, path)

        app.run(port=1234)


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

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

flatten = subparsers.add_parser(
    "flatten",
    help="Output a flattened file containing a selected version's 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",
)

remotes = subparsers.add_parser(
    "remotes",
    help="Output the expected URLs and their associated schemas for remote "
         "ref tests as a JSON object."
)

dump_remotes = subparsers.add_parser(
    "dump_remotes", help="Dump the remote ref schemas into a file tree",
)
dump_remotes.add_argument(
    "--update",
    action="store_true",
    help="Update the remotes in an existing directory.",
)
dump_remotes.add_argument(
    "--out-dir",
    default=REMOTES_DIR,
    type=os.path.abspath,
    help="The output directory to create as the root of the file tree",
)

serve = subparsers.add_parser(
    "serve",
    help="Start a webserver to serve schemas used by remote ref tests."
)

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