# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import gzip
import io
import os
import random
import re
import socket
import string
import sys
import tempfile
import time
import unittest

import requests

try:
    import docker
except ImportError:
    docker = None

from libcloud.common.types import LibcloudError
from libcloud.storage import providers, types


MB = 1024 * 1024


class Integration:
    class TestBase(unittest.TestCase):
        provider = None
        account = None
        secret = None

        container_name_prefix = 'lcsit'
        container_name_max_length = 63

        def setUp(self):
            for required in 'provider', 'account', 'secret':
                value = getattr(self, required, None)
                if value is None:
                    raise unittest.SkipTest('config {} not set'.format(required))

            kwargs = {'key': self.account, 'secret': self.secret}

            for optional in 'host', 'port', 'secure':
                value = getattr(self, optional, None)
                if value is not None:
                    kwargs[optional] = value

            driver_class = providers.get_driver(self.provider)
            self.driver = driver_class(**kwargs)

        def tearDown(self):
            for container in self.driver.list_containers():
                if not container.name.startswith(self.container_name_prefix):
                    continue

                for obj in container.list_objects():
                    try:
                        obj.delete()
                    except LibcloudError as ex:
                        print(
                            'Unable to delete object {} in container {}: {}.'
                            'Delete it manually.'
                            .format(obj.name, container.name, ex),
                            file=sys.stderr
                        )

                try:
                    container.delete()
                except LibcloudError as ex:
                    print(
                        'Unable to delete container {}: {}.'
                        'Delete it manually.'
                        .format(container.name, ex),
                        file=sys.stderr
                    )

        def test_containers(self):
            # make a new container
            container_name = self._random_container_name()
            container = self.driver.create_container(container_name)
            self.assertEqual(container.name, container_name)
            container = self.driver.get_container(container_name)
            self.assertEqual(container.name, container_name)

            self.assert_existing_container_cannot_be_recreated(container)

            # check that the new container can be listed
            containers = self.driver.list_containers()
            self.assertIn(container_name, [c.name for c in containers])

            # delete the container
            self.driver.delete_container(container)

            # check that a deleted container can't be looked up
            with self.assertRaises(types.ContainerDoesNotExistError):
                self.driver.get_container(container_name)

            # check that the container is deleted
            containers = self.driver.list_containers()
            self.assertNotIn(container_name, [c.name for c in containers])

        def _test_objects(self, do_upload, do_download, size=1 * MB):
            content = os.urandom(size)
            blob_name = 'testblob'
            container = self.driver.create_container(self._random_container_name())

            # upload a file
            obj = do_upload(container, blob_name, content)
            self.assertEqual(obj.name, blob_name)
            obj = self.driver.get_object(container.name, blob_name)

            # check that the file can be listed
            blobs = self.driver.list_container_objects(container)
            self.assertEqual([blob.name for blob in blobs], [blob_name])

            # upload another file and check it's excluded in prefix listing
            do_upload(container, blob_name[::-1], content[::-1])
            blobs = self.driver.list_container_objects(
                container, prefix=blob_name[0:3]
            )
            self.assertEqual([blob.name for blob in blobs], [blob_name])

            # check that the file can be read back
            self.assertEqual(do_download(obj), content)

            # delete the file
            self.driver.delete_object(obj)

            # check that a missing file can't be deleted or looked up
            self.assert_file_is_missing(container, obj)

            # check that the file is deleted
            blobs = self.driver.list_container_objects(container)
            self.assertEqual([blob.name for blob in blobs], [blob_name[::-1]])

        def assert_existing_container_cannot_be_recreated(self, container):
            with self.assertRaises(types.ContainerAlreadyExistsError):
                self.driver.create_container(container.name)

        def assert_file_is_missing(self, container, obj):
            with self.assertRaises(types.ObjectDoesNotExistError):
                self.driver.delete_object(obj)
            with self.assertRaises(types.ObjectDoesNotExistError):
                self.driver.get_object(container.name, obj.name)

        def test_objects(self, size=1 * MB):
            def do_upload(container, blob_name, content):
                infile = self._create_tempfile(content=content)
                return self.driver.upload_object(infile, container, blob_name)

            def do_download(obj):
                outfile = self._create_tempfile()
                self.driver.download_object(obj, outfile, overwrite_existing=True)
                with open(outfile, 'rb') as fobj:
                    return fobj.read()

            self._test_objects(do_upload, do_download, size)

        def test_objects_range_downloads(self):
            blob_name = 'testblob-range'
            content = b'0123456789'
            container = self.driver.create_container(self._random_container_name())

            obj = self.driver.upload_object(
                self._create_tempfile(content=content),
                container,
                blob_name
            )
            self.assertEqual(obj.name, blob_name)
            self.assertEqual(obj.size, len(content))

            obj = self.driver.get_object(container.name, blob_name)
            self.assertEqual(obj.name, blob_name)
            self.assertEqual(obj.size, len(content))

            values = [
                {'start_bytes': 0, 'end_bytes': 1, 'expected_content': b'0'},
                {'start_bytes': 1, 'end_bytes': 5, 'expected_content': b'1234'},
                {'start_bytes': 5, 'end_bytes': None, 'expected_content': b'56789'},
                {'start_bytes': 5, 'end_bytes': len(content), 'expected_content': b'56789'},
                {'start_bytes': 0, 'end_bytes': None, 'expected_content': b'0123456789'},
                {'start_bytes': 0, 'end_bytes': len(content), 'expected_content': b'0123456789'},
            ]

            for value in values:
                # 1. download_object_range
                start_bytes = value['start_bytes']
                end_bytes = value['end_bytes']
                outfile = self._create_tempfile()

                result = self.driver.download_object_range(
                    obj,
                    outfile,
                    start_bytes=start_bytes,
                    end_bytes=end_bytes,
                    overwrite_existing=True,
                )
                self.assertTrue(result)

                with open(outfile, 'rb') as fobj:
                    downloaded_content = fobj.read()

                if end_bytes is not None:
                    expected_content = content[start_bytes:end_bytes]
                else:
                    expected_content = content[start_bytes:]

                msg = 'Expected "%s", got "%s" for values: %s' % (
                    expected_content, downloaded_content, str(value)
                )
                self.assertEqual(downloaded_content, expected_content, msg)
                self.assertEqual(downloaded_content, value['expected_content'], msg)

                # 2. download_object_range_as_stream
                downloaded_content = read_stream(
                    self.driver.download_object_range_as_stream(
                        obj, start_bytes=start_bytes, end_bytes=end_bytes
                    )
                )
                self.assertEqual(downloaded_content, expected_content)

        @unittest.skipUnless(os.getenv('LARGE_FILE_SIZE_MB'), 'config not set')
        def test_objects_large(self):
            size = int(float(os.environ['LARGE_FILE_SIZE_MB']) * MB)
            self.test_objects(size)

        def test_objects_stream_io(self):
            def do_upload(container, blob_name, content):
                content = io.BytesIO(content)
                return self.driver.upload_object_via_stream(content, container, blob_name)

            def do_download(obj):
                return read_stream(self.driver.download_object_as_stream(obj))

            self._test_objects(do_upload, do_download)

        def test_objects_stream_iterable(self):
            def do_upload(container, blob_name, content):
                content = iter([content[i:i + 1] for i in range(len(content))])
                return self.driver.upload_object_via_stream(content, container, blob_name)

            def do_download(obj):
                return read_stream(self.driver.download_object_as_stream(obj))

            self._test_objects(do_upload, do_download)

        def test_upload_via_stream_with_content_encoding(self):
            object_name = 'content_encoding.gz'
            content = gzip.compress(os.urandom(MB // 100))
            container = self.driver.create_container(self._random_container_name())
            self.driver.upload_object_via_stream(
                iter(content),
                container,
                object_name,
                headers={'Content-Encoding': 'gzip'},
            )

            obj = self.driver.get_object(container.name, object_name)

            self.assertEqual(obj.extra.get('content_encoding'), 'gzip')

        def test_cdn_url(self):
            content = os.urandom(MB // 100)
            container = self.driver.create_container(self._random_container_name())
            obj = self.driver.upload_object_via_stream(iter(content), container, 'cdn')

            response = requests.get(self.driver.get_object_cdn_url(obj))
            response.raise_for_status()

            self.assertEqual(response.content, content)

        def _create_tempfile(self, prefix='', content=b''):
            fobj, path = tempfile.mkstemp(prefix=prefix, text=False)
            os.write(fobj, content)
            os.close(fobj)
            self.addCleanup(os.remove, path)
            return path

        @classmethod
        def _random_container_name(cls):
            suffix = random_string(cls.container_name_max_length)
            name = cls.container_name_prefix + suffix
            name = re.sub('[^a-z0-9-]', '-', name)
            name = re.sub('-+', '-', name)
            name = name[:cls.container_name_max_length]
            name = name.lower()
            return name

    class ContainerTestBase(TestBase):
        image = None
        version = 'latest'
        environment = {}
        command = None
        ready_message = None

        host = 'localhost'
        port = None
        secure = False

        client = None
        container = None
        verbose = False

        @classmethod
        def setUpClass(cls):
            if docker is None:
                raise unittest.SkipTest('missing docker library')

            try:
                cls.client = docker.from_env()
            except docker.errors.DockerException:
                raise unittest.SkipTest('unable to create docker client')

            for required in 'image', 'port':
                value = getattr(cls, required, None)
                if value is None:
                    raise unittest.SkipTest('config {} not set'.format(required))

            cls.container = cls.client.containers.run(
                '{}:{}'.format(cls.image, cls.version),
                command=cls.command,
                detach=True,
                auto_remove=True,
                ports={cls.port: cls.port},
                environment=cls.environment,
            )

            wait_for(cls.port, cls.host)

            container_ready = cls.ready_message is None

            while not container_ready:
                time.sleep(1)

                container_ready = any(
                    cls.ready_message in line
                    for line in cls.container.logs().splitlines()
                )

        @classmethod
        def tearDownClass(cls):
            if cls.verbose:
                for line in cls.container.logs().splitlines():
                    print(line)

            try:
                cls.container.kill()
            except docker.errors.DockerException as ex:
                print(
                    'Unable to terminate docker container {}: {}.'
                    'Stop it manually.'
                    .format(cls.container.short_id, ex),
                    file=sys.stderr
                )


def wait_for(port, host='localhost', timeout=10):
    start_time = time.perf_counter()

    while True:
        try:
            with socket.create_connection((host, port), timeout=timeout):
                break
        except OSError as ex:
            if time.perf_counter() - start_time >= timeout:
                raise TimeoutError(
                    'Waited too long for the port {} on host {} to start accepting '
                    'connections.'.format(port, host)
                ) from ex

            time.sleep(1)


def random_string(length, alphabet=string.ascii_lowercase + string.digits):
    return ''.join(random.choice(alphabet) for _ in range(length))


def read_stream(stream):
    buffer = io.BytesIO()
    buffer.writelines(stream)
    buffer.seek(0)
    return buffer.read()