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

if getattr(unittest, "skipIf", None) is None:
    unittest.skipIf = lambda cond, msg : lambda fn : fn

try:
    import jsonschema
except ImportError:
    jsonschema = None
else:
    validators = getattr(
        jsonschema.validators, "validators", jsonschema.validators
    )


ROOT_DIR = os.getenv("ROOT_DIR", "/usr/share/json-schema-test-suite")
SUITE_ROOT_DIR = os.path.join(ROOT_DIR, "tests")

REMOTES = {
    "integer.json": {u"type": u"integer"},
    "name.json": {
        u"type": "string",
        u"definitions": {
            u"orNull": {u"anyOf": [{u"type": u"null"}, {u"$ref": u"#"}]},
        },
    },
    "subSchemas.json": {
        u"integer": {u"type": u"integer"},
        u"refToInteger": {u"$ref": u"#/integer"},
    },
    "folder/folderInteger.json": {u"type": u"integer"}
}
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):
    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):
        print("Looking for tests in %s" % SUITE_ROOT_DIR)
        cls.test_files = list(collect(SUITE_ROOT_DIR))
        print("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 = 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 schema in os.listdir(SUITE_ROOT_DIR):
            schema_validator = validators.get(schema)
            if schema_validator is not None:
                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:
                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.Draft3Validator(TESTSUITE_SCHEMA)
        for tests in files(self.test_files):
            try:
                validator.validate(tests)
            except jsonschema.ValidationError as error:
                self.fail(str(error))

    def test_remote_schemas_are_updated(self):
        files = {}
        for parent, _, paths in os.walk(REMOTES_DIR):
            for path in paths:
                absolute_path = os.path.join(parent, path)
                with open(absolute_path) as schema_file:
                    files[absolute_path] = json.load(schema_file)

        self.assertEqual(
            files, {
                os.path.join(REMOTES_DIR, path): contents
                for path, contents in REMOTES.items()
            },
        )


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":
        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:
            os.makedirs(arguments.out_dir)
        except OSError as e:
            if e.errno == errno.EEXIST:
                print("%s already exists. Aborting." % arguments.out_dir)
                sys.exit(1)
            raise

        for url, schema in REMOTES.items():
            filepath = os.path.join(arguments.out_dir, url)

            try:
                os.makedirs(os.path.dirname(filepath))
            except OSError as e:
                if e.errno != errno.EEXIST:
                    raise

            with open(filepath, "wb") as out_file:
                json.dump(schema, out_file, indent=4, sort_keys=True)
    elif arguments.command == "serve":
        try:
            from flask import Flask, jsonify
        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(__name__)

        @app.route("/<path:path>")
        def serve_path(path):
            if path in REMOTES:
                return jsonify(REMOTES[path])
            return "Document does not exist.", 404

        app.run(port=1234)


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 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())