#
# This file is licensed under the Affero General Public License (AGPL) version 3.
#
# Copyright 2020-2021 The Matrix.org Foundation C.I.C.
# Copyright (C) 2023 New Vector, Ltd
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# See the GNU Affero General Public License for more details:
# <https://www.gnu.org/licenses/agpl-3.0.html>.
#
# Originally licensed under the Apache License, Version 2.0:
# <http://www.apache.org/licenses/LICENSE-2.0>.
#
# [This file includes modifications made by New Vector Limited]
#
#
import logging
import os
from typing import Any

from twisted.internet.protocol import Factory
from twisted.internet.testing import MemoryReactor
from twisted.web.http import HTTPChannel
from twisted.web.server import Request

from synapse.rest import admin
from synapse.rest.client import login, media
from synapse.server import HomeServer
from synapse.util.clock import Clock

from tests.http import (
    TestServerTLSConnectionFactory,
    get_test_ca_cert_file,
    wrap_server_factory_for_tls,
)
from tests.replication._base import BaseMultiWorkerStreamTestCase
from tests.server import FakeChannel, FakeTransport, make_request
from tests.test_utils import SMALL_PNG
from tests.unittest import override_config

logger = logging.getLogger(__name__)

test_server_connection_factory: TestServerTLSConnectionFactory | None = None


class MediaRepoShardTestCase(BaseMultiWorkerStreamTestCase):
    """Checks running multiple media repos work correctly."""

    servlets = [
        admin.register_servlets_for_client_rest_resource,
        login.register_servlets,
    ]

    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
        self.user_id = self.register_user("user", "pass")
        self.access_token = self.login("user", "pass")

        self.reactor.lookups["example.com"] = "1.2.3.4"

    def default_config(self) -> dict:
        conf = super().default_config()
        conf["federation_custom_ca_list"] = [get_test_ca_cert_file()]
        return conf

    def make_worker_hs(
        self, worker_app: str, extra_config: dict | None = None, **kwargs: Any
    ) -> HomeServer:
        worker_hs = super().make_worker_hs(worker_app, extra_config, **kwargs)
        # Force the media paths onto the replication resource.
        worker_hs.get_media_repository_resource().register_servlets(
            self._hs_to_site[worker_hs].resource, worker_hs
        )
        return worker_hs

    def _get_media_req(
        self, hs: HomeServer, target: str, media_id: str
    ) -> tuple[FakeChannel, Request]:
        """Request some remote media from the given HS by calling the download
        API.

        This then triggers an outbound request from the HS to the target.

        Returns:
            The channel for the *client* request and the *outbound* request for
            the media which the caller should respond to.
        """
        channel = make_request(
            self.reactor,
            self._hs_to_site[hs],
            "GET",
            f"/_matrix/media/r0/download/{target}/{media_id}",
            shorthand=False,
            access_token=self.access_token,
            await_result=False,
        )
        self.pump()

        clients = self.reactor.tcpClients
        self.assertGreaterEqual(len(clients), 1)
        (host, port, client_factory, _timeout, _bindAddress) = clients.pop()

        # build the test server
        server_factory = Factory.forProtocol(HTTPChannel)
        # Request.finish expects the factory to have a 'log' method.
        server_factory.log = _log_request

        server_tls_protocol = wrap_server_factory_for_tls(
            server_factory, self.reactor, sanlist=[b"DNS:example.com"]
        ).buildProtocol(None)

        # now, tell the client protocol factory to build the client protocol (it will be a
        # _WrappingProtocol, around a TLSMemoryBIOProtocol, around an
        # HTTP11ClientProtocol) and wire the output of said protocol up to the server via
        # a FakeTransport.
        #
        # Normally this would be done by the TCP socket code in Twisted, but we are
        # stubbing that out here.
        client_protocol = client_factory.buildProtocol(None)
        client_protocol.makeConnection(
            FakeTransport(server_tls_protocol, self.reactor, client_protocol)
        )

        # tell the server tls protocol to send its stuff back to the client, too
        server_tls_protocol.makeConnection(
            FakeTransport(client_protocol, self.reactor, server_tls_protocol)
        )

        # fish the test server back out of the server-side TLS protocol.
        http_server: HTTPChannel = server_tls_protocol.wrappedProtocol

        # give the reactor a pump to get the TLS juices flowing.
        self.reactor.pump((0.1,))

        self.assertEqual(len(http_server.requests), 1)
        request = http_server.requests[0]

        self.assertEqual(request.method, b"GET")
        self.assertEqual(
            request.path,
            f"/_matrix/media/v3/download/{target}/{media_id}".encode(),
        )
        self.assertEqual(
            request.requestHeaders.getRawHeaders(b"host"), [target.encode("utf-8")]
        )

        return channel, request

    @override_config({"enable_authenticated_media": False})
    def test_basic(self) -> None:
        """Test basic fetching of remote media from a single worker."""
        hs1 = self.make_worker_hs("synapse.app.generic_worker")

        channel, request = self._get_media_req(hs1, "example.com:443", "ABC123")

        request.setResponseCode(200)
        request.responseHeaders.setRawHeaders(b"Content-Type", [b"text/plain"])
        request.write(b"Hello!")
        request.finish()

        self.pump(0.1)

        self.assertEqual(channel.code, 200)
        self.assertEqual(channel.result["body"], b"Hello!")

    @override_config({"enable_authenticated_media": False})
    def test_download_simple_file_race(self) -> None:
        """Test that fetching remote media from two different processes at the
        same time works.
        """
        hs1 = self.make_worker_hs("synapse.app.generic_worker")
        hs2 = self.make_worker_hs("synapse.app.generic_worker")

        start_count = self._count_remote_media()

        # Make two requests without responding to the outbound media requests.
        channel1, request1 = self._get_media_req(hs1, "example.com:443", "ABC123")
        channel2, request2 = self._get_media_req(hs2, "example.com:443", "ABC123")

        # Respond to the first outbound media request and check that the client
        # request is successful
        request1.setResponseCode(200)
        request1.responseHeaders.setRawHeaders(b"Content-Type", [b"text/plain"])
        request1.write(b"Hello!")
        request1.finish()

        self.pump(0.1)

        self.assertEqual(channel1.code, 200, channel1.result["body"])
        self.assertEqual(channel1.result["body"], b"Hello!")

        # Now respond to the second with the same content.
        request2.setResponseCode(200)
        request2.responseHeaders.setRawHeaders(b"Content-Type", [b"text/plain"])
        request2.write(b"Hello!")
        request2.finish()

        self.pump(0.1)

        self.assertEqual(channel2.code, 200, channel2.result["body"])
        self.assertEqual(channel2.result["body"], b"Hello!")

        # We expect only one new file to have been persisted.
        self.assertEqual(start_count + 1, self._count_remote_media())

    @override_config(
        {"enable_authenticated_media": False, "enable_local_media_storage": False}
    )
    def test_download_simple_file_race_no_local_storage(self) -> None:
        """Test that fetching remote media works when local storage is disabled.

        This test verifies that the system handles the case where local storage
        is disabled. Without storage providers configured, the media cannot be
        retrieved, but the important thing is that the race condition is still
        handled correctly.
        """
        hs1 = self.make_worker_hs("synapse.app.generic_worker")
        hs2 = self.make_worker_hs("synapse.app.generic_worker")

        start_count = self._count_remote_media()

        # Make two requests without responding to the outbound media requests.
        channel1, request1 = self._get_media_req(hs1, "example.com:443", "ABC123")
        channel2, request2 = self._get_media_req(hs2, "example.com:443", "ABC123")

        # Respond to the first outbound media request and check that the client
        # request is successful
        request1.setResponseCode(200)
        request1.responseHeaders.setRawHeaders(b"Content-Type", [b"text/plain"])
        request1.write(b"Hello!")
        request1.finish()

        self.pump(0.1)

        # With local storage disabled and no storage providers,
        # we expect a 404 error
        self.assertEqual(channel1.code, 404, channel1.result["body"])

        # Now respond to the second with the same content.
        request2.setResponseCode(200)
        request2.responseHeaders.setRawHeaders(b"Content-Type", [b"text/plain"])
        request2.write(b"Hello!")
        request2.finish()

        self.pump(0.1)

        # Same for the second request
        self.assertEqual(channel2.code, 404, channel2.result["body"])

        # No files should be stored locally
        self.assertEqual(start_count, self._count_remote_media())

    @override_config({"enable_authenticated_media": False})
    def test_download_image_race(self) -> None:
        """Test that fetching remote *images* from two different processes at
        the same time works.

        This checks that races generating thumbnails are handled correctly.
        """
        hs1 = self.make_worker_hs("synapse.app.generic_worker")
        hs2 = self.make_worker_hs("synapse.app.generic_worker")

        start_count = self._count_remote_thumbnails()

        channel1, request1 = self._get_media_req(hs1, "example.com:443", "PIC1")
        channel2, request2 = self._get_media_req(hs2, "example.com:443", "PIC1")

        request1.setResponseCode(200)
        request1.responseHeaders.setRawHeaders(b"Content-Type", [b"image/png"])
        request1.write(SMALL_PNG)
        request1.finish()

        self.pump(0.1)

        self.assertEqual(channel1.code, 200, channel1.result["body"])
        self.assertEqual(channel1.result["body"], SMALL_PNG)

        request2.setResponseCode(200)
        request2.responseHeaders.setRawHeaders(b"Content-Type", [b"image/png"])
        request2.write(SMALL_PNG)
        request2.finish()

        self.pump(0.1)

        self.assertEqual(channel2.code, 200, channel2.result["body"])
        self.assertEqual(channel2.result["body"], SMALL_PNG)

        # We expect only three new thumbnails to have been persisted.
        self.assertEqual(start_count + 3, self._count_remote_thumbnails())

    def _count_remote_media(self) -> int:
        """Count the number of files in our remote media directory."""
        path = os.path.join(
            self.hs.get_media_repository().primary_base_path, "remote_content"
        )
        return sum(len(files) for _, _, files in os.walk(path))

    def _count_remote_thumbnails(self) -> int:
        """Count the number of files in our remote thumbnails directory."""
        path = os.path.join(
            self.hs.get_media_repository().primary_base_path, "remote_thumbnail"
        )
        return sum(len(files) for _, _, files in os.walk(path))


class AuthenticatedMediaRepoShardTestCase(BaseMultiWorkerStreamTestCase):
    """Checks running multiple media repos work correctly using autheticated media paths"""

    servlets = [
        admin.register_servlets_for_client_rest_resource,
        login.register_servlets,
        media.register_servlets,
    ]

    file_data = b"\r\n\r\n--6067d4698f8d40a0a794ea7d7379d53a\r\nContent-Type: application/json\r\n\r\n{}\r\n--6067d4698f8d40a0a794ea7d7379d53a\r\nContent-Type: text/plain\r\nContent-Disposition: inline; filename=test_upload\r\n\r\nfile_to_stream\r\n--6067d4698f8d40a0a794ea7d7379d53a--\r\n\r\n"

    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
        self.user_id = self.register_user("user", "pass")
        self.access_token = self.login("user", "pass")

        self.reactor.lookups["example.com"] = "1.2.3.4"

    def default_config(self) -> dict:
        conf = super().default_config()
        conf["federation_custom_ca_list"] = [get_test_ca_cert_file()]
        return conf

    def make_worker_hs(
        self, worker_app: str, extra_config: dict | None = None, **kwargs: Any
    ) -> HomeServer:
        worker_hs = super().make_worker_hs(worker_app, extra_config, **kwargs)
        # Force the media paths onto the replication resource.
        worker_hs.get_media_repository_resource().register_servlets(
            self._hs_to_site[worker_hs].resource, worker_hs
        )
        return worker_hs

    def _get_media_req(
        self, hs: HomeServer, target: str, media_id: str
    ) -> tuple[FakeChannel, Request]:
        """Request some remote media from the given HS by calling the download
        API.

        This then triggers an outbound request from the HS to the target.

        Returns:
            The channel for the *client* request and the *outbound* request for
            the media which the caller should respond to.
        """
        channel = make_request(
            self.reactor,
            self._hs_to_site[hs],
            "GET",
            f"/_matrix/client/v1/media/download/{target}/{media_id}",
            shorthand=False,
            access_token=self.access_token,
            await_result=False,
        )
        self.pump()

        clients = self.reactor.tcpClients
        self.assertGreaterEqual(len(clients), 1)
        (host, port, client_factory, _timeout, _bindAddress) = clients.pop()

        # build the test server
        server_factory = Factory.forProtocol(HTTPChannel)
        # Request.finish expects the factory to have a 'log' method.
        server_factory.log = _log_request

        server_tls_protocol = wrap_server_factory_for_tls(
            server_factory, self.reactor, sanlist=[b"DNS:example.com"]
        ).buildProtocol(None)

        # now, tell the client protocol factory to build the client protocol (it will be a
        # _WrappingProtocol, around a TLSMemoryBIOProtocol, around an
        # HTTP11ClientProtocol) and wire the output of said protocol up to the server via
        # a FakeTransport.
        #
        # Normally this would be done by the TCP socket code in Twisted, but we are
        # stubbing that out here.
        client_protocol = client_factory.buildProtocol(None)
        client_protocol.makeConnection(
            FakeTransport(server_tls_protocol, self.reactor, client_protocol)
        )

        # tell the server tls protocol to send its stuff back to the client, too
        server_tls_protocol.makeConnection(
            FakeTransport(client_protocol, self.reactor, server_tls_protocol)
        )

        # fish the test server back out of the server-side TLS protocol.
        http_server: HTTPChannel = server_tls_protocol.wrappedProtocol

        # give the reactor a pump to get the TLS juices flowing.
        self.reactor.pump((0.1,))

        self.assertEqual(len(http_server.requests), 1)
        request = http_server.requests[0]

        self.assertEqual(request.method, b"GET")
        self.assertEqual(
            request.path,
            f"/_matrix/federation/v1/media/download/{media_id}".encode(),
        )
        self.assertEqual(
            request.requestHeaders.getRawHeaders(b"host"), [target.encode("utf-8")]
        )

        return channel, request

    def test_basic(self) -> None:
        """Test basic fetching of remote media from a single worker."""
        hs1 = self.make_worker_hs("synapse.app.generic_worker")

        channel, request = self._get_media_req(hs1, "example.com:443", "ABC123")

        request.setResponseCode(200)
        request.responseHeaders.setRawHeaders(
            b"Content-Type",
            ["multipart/mixed; boundary=6067d4698f8d40a0a794ea7d7379d53a"],
        )
        request.write(self.file_data)
        request.finish()

        self.pump(0.1)

        self.assertEqual(channel.code, 200)
        self.assertEqual(channel.result["body"], b"file_to_stream")

    def test_download_simple_file_race(self) -> None:
        """Test that fetching remote media from two different processes at the
        same time works.
        """
        hs1 = self.make_worker_hs("synapse.app.generic_worker")
        hs2 = self.make_worker_hs("synapse.app.generic_worker")

        start_count = self._count_remote_media()

        # Make two requests without responding to the outbound media requests.
        channel1, request1 = self._get_media_req(hs1, "example.com:443", "ABC123")
        channel2, request2 = self._get_media_req(hs2, "example.com:443", "ABC123")

        # Respond to the first outbound media request and check that the client
        # request is successful
        request1.setResponseCode(200)
        request1.responseHeaders.setRawHeaders(
            b"Content-Type",
            ["multipart/mixed; boundary=6067d4698f8d40a0a794ea7d7379d53a"],
        )
        request1.write(self.file_data)
        request1.finish()

        self.pump(0.1)

        self.assertEqual(channel1.code, 200, channel1.result["body"])
        self.assertEqual(channel1.result["body"], b"file_to_stream")

        # Now respond to the second with the same content.
        request2.setResponseCode(200)
        request2.responseHeaders.setRawHeaders(
            b"Content-Type",
            ["multipart/mixed; boundary=6067d4698f8d40a0a794ea7d7379d53a"],
        )
        request2.write(self.file_data)
        request2.finish()

        self.pump(0.1)

        self.assertEqual(channel2.code, 200, channel2.result["body"])
        self.assertEqual(channel2.result["body"], b"file_to_stream")

        # We expect only one new file to have been persisted.
        self.assertEqual(start_count + 1, self._count_remote_media())

    @override_config({"enable_local_media_storage": False})
    def test_download_simple_file_race_no_local_storage(self) -> None:
        """Test that fetching remote media works when local storage is disabled.

        When enable_local_media_storage is False, files should only be stored in
        the storage providers and not in the local filesystem.
        """
        hs1 = self.make_worker_hs("synapse.app.generic_worker")
        hs2 = self.make_worker_hs("synapse.app.generic_worker")

        start_count = self._count_remote_media()

        # Make two requests without responding to the outbound media requests.
        channel1, request1 = self._get_media_req(hs1, "example.com:443", "ABC123")
        channel2, request2 = self._get_media_req(hs2, "example.com:443", "ABC123")

        # Respond to the first outbound media request and check that the client
        # request is successful
        request1.setResponseCode(200)
        request1.responseHeaders.setRawHeaders(
            b"Content-Type",
            ["multipart/mixed; boundary=6067d4698f8d40a0a794ea7d7379d53a"],
        )
        request1.write(self.file_data)
        request1.finish()

        self.pump(0.1)
        # With local storage disabled and no storage providers,
        # we expect a 404 error
        self.assertEqual(channel1.code, 404, channel1.result["body"])

        # Now respond to the second with the same content.
        request2.setResponseCode(200)
        request2.responseHeaders.setRawHeaders(
            b"Content-Type",
            ["multipart/mixed; boundary=6067d4698f8d40a0a794ea7d7379d53a"],
        )
        request2.write(self.file_data)
        request2.finish()

        self.pump(0.1)

        self.assertEqual(channel2.code, 404, channel2.result["body"])

        # With local storage disabled, no files should be stored locally
        self.assertEqual(start_count, self._count_remote_media())

    def test_download_image_race(self) -> None:
        """Test that fetching remote *images* from two different processes at
        the same time works.

        This checks that races generating thumbnails are handled correctly.
        """
        hs1 = self.make_worker_hs("synapse.app.generic_worker")
        hs2 = self.make_worker_hs("synapse.app.generic_worker")

        start_count = self._count_remote_thumbnails()

        channel1, request1 = self._get_media_req(hs1, "example.com:443", "PIC1")
        channel2, request2 = self._get_media_req(hs2, "example.com:443", "PIC1")

        request1.setResponseCode(200)
        request1.responseHeaders.setRawHeaders(
            b"Content-Type",
            ["multipart/mixed; boundary=6067d4698f8d40a0a794ea7d7379d53a"],
        )
        img_data = b"\r\n\r\n--6067d4698f8d40a0a794ea7d7379d53a\r\nContent-Type: application/json\r\n\r\n{}\r\n--6067d4698f8d40a0a794ea7d7379d53a\r\nContent-Type: image/png\r\nContent-Disposition: inline; filename=test_img\r\n\r\n"
        request1.write(img_data)
        request1.write(SMALL_PNG)
        request1.write(b"\r\n--6067d4698f8d40a0a794ea7d7379d53a--\r\n\r\n")
        request1.finish()

        self.pump(0.1)

        self.assertEqual(channel1.code, 200, channel1.result["body"])
        self.assertEqual(channel1.result["body"], SMALL_PNG)

        request2.setResponseCode(200)
        request2.responseHeaders.setRawHeaders(
            b"Content-Type",
            ["multipart/mixed; boundary=6067d4698f8d40a0a794ea7d7379d53a"],
        )
        request2.write(img_data)
        request2.write(SMALL_PNG)
        request2.write(b"\r\n--6067d4698f8d40a0a794ea7d7379d53a--\r\n\r\n")
        request2.finish()

        self.pump(0.1)

        self.assertEqual(channel2.code, 200, channel2.result["body"])
        self.assertEqual(channel2.result["body"], SMALL_PNG)

        # We expect only three new thumbnails to have been persisted.
        self.assertEqual(start_count + 3, self._count_remote_thumbnails())

    def _count_remote_media(self) -> int:
        """Count the number of files in our remote media directory."""
        path = os.path.join(
            self.hs.get_media_repository().primary_base_path, "remote_content"
        )
        return sum(len(files) for _, _, files in os.walk(path))

    def _count_remote_thumbnails(self) -> int:
        """Count the number of files in our remote thumbnails directory."""
        path = os.path.join(
            self.hs.get_media_repository().primary_base_path, "remote_thumbnail"
        )
        return sum(len(files) for _, _, files in os.walk(path))


def _log_request(request: Request) -> None:
    """Implements Factory.log, which is expected by Request.finish"""
    logger.info("Completed request %s", request)
