# -*- coding: utf-8 -*-
# Copyright 2018 New Vector Ltd
#
# Licensed 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 os
import shutil
import tempfile
from binascii import unhexlify
from io import BytesIO
from typing import Optional
from urllib import parse

from mock import Mock

import attr
from parameterized import parameterized_class
from PIL import Image as Image

from twisted.internet import defer
from twisted.internet.defer import Deferred

from synapse.logging.context import make_deferred_yieldable
from synapse.rest.media.v1._base import FileInfo
from synapse.rest.media.v1.filepath import MediaFilePaths
from synapse.rest.media.v1.media_storage import MediaStorage
from synapse.rest.media.v1.storage_provider import FileStorageProviderBackend

from tests import unittest


class MediaStorageTests(unittest.HomeserverTestCase):

    needs_threadpool = True

    def prepare(self, reactor, clock, hs):
        self.test_dir = tempfile.mkdtemp(prefix="synapse-tests-")
        self.addCleanup(shutil.rmtree, self.test_dir)

        self.primary_base_path = os.path.join(self.test_dir, "primary")
        self.secondary_base_path = os.path.join(self.test_dir, "secondary")

        hs.config.media_store_path = self.primary_base_path

        storage_providers = [FileStorageProviderBackend(hs, self.secondary_base_path)]

        self.filepaths = MediaFilePaths(self.primary_base_path)
        self.media_storage = MediaStorage(
            hs, self.primary_base_path, self.filepaths, storage_providers
        )

    def test_ensure_media_is_in_local_cache(self):
        media_id = "some_media_id"
        test_body = "Test\n"

        # First we create a file that is in a storage provider but not in the
        # local primary media store
        rel_path = self.filepaths.local_media_filepath_rel(media_id)
        secondary_path = os.path.join(self.secondary_base_path, rel_path)

        os.makedirs(os.path.dirname(secondary_path))

        with open(secondary_path, "w") as f:
            f.write(test_body)

        # Now we run ensure_media_is_in_local_cache, which should copy the file
        # to the local cache.
        file_info = FileInfo(None, media_id)

        # This uses a real blocking threadpool so we have to wait for it to be
        # actually done :/
        x = defer.ensureDeferred(
            self.media_storage.ensure_media_is_in_local_cache(file_info)
        )

        # Hotloop until the threadpool does its job...
        self.wait_on_thread(x)

        local_path = self.get_success(x)

        self.assertTrue(os.path.exists(local_path))

        # Asserts the file is under the expected local cache directory
        self.assertEquals(
            os.path.commonprefix([self.primary_base_path, local_path]),
            self.primary_base_path,
        )

        with open(local_path) as f:
            body = f.read()

        self.assertEqual(test_body, body)


@attr.s
class _TestImage:
    """An image for testing thumbnailing with the expected results

    Attributes:
        data: The raw image to thumbnail
        content_type: The type of the image as a content type, e.g. "image/png"
        extension: The extension associated with the format, e.g. ".png"
        expected_cropped: The expected bytes from cropped thumbnailing, or None if
            test should just check for success.
        expected_scaled: The expected bytes from scaled thumbnailing, or None if
            test should just check for a valid image returned.
    """

    data = attr.ib(type=bytes)
    content_type = attr.ib(type=bytes)
    extension = attr.ib(type=bytes)
    expected_cropped = attr.ib(type=Optional[bytes])
    expected_scaled = attr.ib(type=Optional[bytes])
    expected_found = attr.ib(default=True, type=bool)


@parameterized_class(
    ("test_image",),
    [
        # smoll png
        (
            _TestImage(
                unhexlify(
                    b"89504e470d0a1a0a0000000d4948445200000001000000010806"
                    b"0000001f15c4890000000a49444154789c63000100000500010d"
                    b"0a2db40000000049454e44ae426082"
                ),
                b"image/png",
                b".png",
                unhexlify(
                    b"89504e470d0a1a0a0000000d4948445200000020000000200806"
                    b"000000737a7af40000001a49444154789cedc101010000008220"
                    b"ffaf6e484001000000ef0610200001194334ee0000000049454e"
                    b"44ae426082"
                ),
                unhexlify(
                    b"89504e470d0a1a0a0000000d4948445200000001000000010806"
                    b"0000001f15c4890000000d49444154789c636060606000000005"
                    b"0001a5f645400000000049454e44ae426082"
                ),
            ),
        ),
        # small lossless webp
        (
            _TestImage(
                unhexlify(
                    b"524946461a000000574542505650384c0d0000002f0000001007"
                    b"1011118888fe0700"
                ),
                b"image/webp",
                b".webp",
                None,
                None,
            ),
        ),
        # an empty file
        (_TestImage(b"", b"image/gif", b".gif", None, None, False,),),
    ],
)
class MediaRepoTests(unittest.HomeserverTestCase):

    hijack_auth = True
    user_id = "@test:user"

    def make_homeserver(self, reactor, clock):

        self.fetches = []

        def get_file(destination, path, output_stream, args=None, max_size=None):
            """
            Returns tuple[int,dict,str,int] of file length, response headers,
            absolute URI, and response code.
            """

            def write_to(r):
                data, response = r
                output_stream.write(data)
                return response

            d = Deferred()
            d.addCallback(write_to)
            self.fetches.append((d, destination, path, args))
            return make_deferred_yieldable(d)

        client = Mock()
        client.get_file = get_file

        self.storage_path = self.mktemp()
        self.media_store_path = self.mktemp()
        os.mkdir(self.storage_path)
        os.mkdir(self.media_store_path)

        config = self.default_config()
        config["media_store_path"] = self.media_store_path
        config["thumbnail_requirements"] = {}
        config["max_image_pixels"] = 2000000

        provider_config = {
            "module": "synapse.rest.media.v1.storage_provider.FileStorageProviderBackend",
            "store_local": True,
            "store_synchronous": False,
            "store_remote": True,
            "config": {"directory": self.storage_path},
        }
        config["media_storage_providers"] = [provider_config]

        hs = self.setup_test_homeserver(config=config, http_client=client)

        return hs

    def prepare(self, reactor, clock, hs):

        self.media_repo = hs.get_media_repository_resource()
        self.download_resource = self.media_repo.children[b"download"]
        self.thumbnail_resource = self.media_repo.children[b"thumbnail"]

        self.media_id = "example.com/12345"

    def _req(self, content_disposition):

        request, channel = self.make_request("GET", self.media_id, shorthand=False)
        request.render(self.download_resource)
        self.pump()

        # We've made one fetch, to example.com, using the media URL, and asking
        # the other server not to do a remote fetch
        self.assertEqual(len(self.fetches), 1)
        self.assertEqual(self.fetches[0][1], "example.com")
        self.assertEqual(
            self.fetches[0][2], "/_matrix/media/r0/download/" + self.media_id
        )
        self.assertEqual(self.fetches[0][3], {"allow_remote": "false"})

        headers = {
            b"Content-Length": [b"%d" % (len(self.test_image.data))],
            b"Content-Type": [self.test_image.content_type],
        }
        if content_disposition:
            headers[b"Content-Disposition"] = [content_disposition]

        self.fetches[0][0].callback(
            (self.test_image.data, (len(self.test_image.data), headers))
        )

        self.pump()
        self.assertEqual(channel.code, 200)

        return channel

    def test_disposition_filename_ascii(self):
        """
        If the filename is filename=<ascii> then Synapse will decode it as an
        ASCII string, and use filename= in the response.
        """
        channel = self._req(b"inline; filename=out" + self.test_image.extension)

        headers = channel.headers
        self.assertEqual(
            headers.getRawHeaders(b"Content-Type"), [self.test_image.content_type]
        )
        self.assertEqual(
            headers.getRawHeaders(b"Content-Disposition"),
            [b"inline; filename=out" + self.test_image.extension],
        )

    def test_disposition_filenamestar_utf8escaped(self):
        """
        If the filename is filename=*utf8''<utf8 escaped> then Synapse will
        correctly decode it as the UTF-8 string, and use filename* in the
        response.
        """
        filename = parse.quote("\u2603".encode("utf8")).encode("ascii")
        channel = self._req(
            b"inline; filename*=utf-8''" + filename + self.test_image.extension
        )

        headers = channel.headers
        self.assertEqual(
            headers.getRawHeaders(b"Content-Type"), [self.test_image.content_type]
        )
        self.assertEqual(
            headers.getRawHeaders(b"Content-Disposition"),
            [b"inline; filename*=utf-8''" + filename + self.test_image.extension],
        )

    def test_disposition_none(self):
        """
        If there is no filename, one isn't passed on in the Content-Disposition
        of the request.
        """
        channel = self._req(None)

        headers = channel.headers
        self.assertEqual(
            headers.getRawHeaders(b"Content-Type"), [self.test_image.content_type]
        )
        self.assertEqual(headers.getRawHeaders(b"Content-Disposition"), None)

    def test_thumbnail_crop(self):
        self._test_thumbnail(
            "crop", self.test_image.expected_cropped, self.test_image.expected_found
        )

    def test_thumbnail_scale(self):
        self._test_thumbnail(
            "scale", self.test_image.expected_scaled, self.test_image.expected_found
        )

    def _test_thumbnail(self, method, expected_body, expected_found):
        params = "?width=32&height=32&method=" + method
        request, channel = self.make_request(
            "GET", self.media_id + params, shorthand=False
        )
        request.render(self.thumbnail_resource)
        self.pump()

        headers = {
            b"Content-Length": [b"%d" % (len(self.test_image.data))],
            b"Content-Type": [self.test_image.content_type],
        }
        self.fetches[0][0].callback(
            (self.test_image.data, (len(self.test_image.data), headers))
        )
        self.pump()

        if expected_found:
            self.assertEqual(channel.code, 200)
            if expected_body is not None:
                self.assertEqual(
                    channel.result["body"], expected_body, channel.result["body"]
                )
            else:
                # ensure that the result is at least some valid image
                Image.open(BytesIO(channel.result["body"]))
        else:
            # A 404 with a JSON body.
            self.assertEqual(channel.code, 404)
            self.assertEqual(
                channel.json_body,
                {
                    "errcode": "M_NOT_FOUND",
                    "error": "Not found [b'example.com', b'12345?width=32&height=32&method=%s']"
                    % method,
                },
            )
