# SPDX-License-Identifier: MIT
#
# Copyright (c) 2017 PySSB contributors (see AUTHORS for more details)
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

from asyncio import Event, ensure_future, gather
import json

from nacl.signing import SigningKey
import pytest
from secret_handshake.network import SHSDuplexStream

from ssb.packet_stream import PacketStream, PSMessageType


async def _collect_messages(generator):
    results = []
    async for msg in generator:
        results.append(msg)
    return results


MSG_BODY_1 = (
    b'{"previous":"%KTGP6W8vF80McRAZHYDWuKOD0KlNyKSq6Gb42iuV7Iw=.sha256","author":"@1+Iwm79DKvVBqYKFkhT6fWRbA'
    b'VvNNVH4F2BSxwhYmx8=.ed25519","sequence":116,"timestamp":1496696699331,"hash":"sha256","content":{"type"'
    b':"post","channel":"crypto","text":"Does anybody know any good resources (e.g. books) to learn cryptogra'
    b"phy? I'm not speaking of basic concepts (e.g. what's a private key) but the actual mathematics behind"
    b' the whole thing.\\nI have a copy of the \\"Handbook of Applied Cryptography\\" on my bookshelf but I f'
    b'ound it too long/hard to follow. Are there any better alternatives?","mentions":[]},"signature":"hqKePb'
    b'bTXWxEi1njDnOWFsL0M0AoNoWyBFgNE6KXj//DThepaZSy9vRbygDHX5uNmCdyOrsQrwZsZhmUYKwtDQ==.sig.ed25519"}'
)

MSG_BODY_2 = (
    b'{"previous":"%iQRhPyqmNLpGaO1Tpm1I22jqnUEwRwkCTDbwAGtM+lY=.sha256","author":"@1+Iwm79DKvVBqYKFkhT6fWRbA'
    b'VvNNVH4F2BSxwhYmx8=.ed25519","sequence":103,"timestamp":1496674211806,"hash":"sha256","content":{"type"'
    b':"post","channel":"git-ssb","text":"Is it only me or `git.scuttlebot.io` is timing out?\\n\\nE.g. try a'
    b'ccessing %vZCTqraoqKBKNZeATErXEtnoEr+wnT3p8tT+vL+29I4=.sha256","mentions":[{"link":"%vZCTqraoqKBKNZeATE'
    b'rXEtnoEr+wnT3p8tT+vL+29I4=.sha256"}]},"signature":"+i4U0HUGDDEyNoNr2NIROPnT3WQj3RuTaIhY5koWW8f0vwr4tZsY'
    b'mAkqqMwFWfP+eBIbc7DZ835er6r6h9CwAg==.sig.ed25519"}'
)


class MockSHSSocket(SHSDuplexStream):
    def __init__(self, *args, **kwargs):
        super(MockSHSSocket, self).__init__()
        self.input = []
        self.output = []
        self.is_connected = False
        self._on_connect = []

    def on_connect(self, cb):
        self._on_connect.append(cb)

    async def read(self):
        if not self.input:
            raise StopAsyncIteration
        return self.input.pop(0)

    def write(self, data):
        self.output.append(data)

    def feed(self, input):
        self.input += input

    def get_output(self):
        while True:
            if not self.output:
                break
            yield self.output.pop(0)

    def disconnect(self):
        self.is_connected = False


class MockSHSClient(MockSHSSocket):
    async def connect(self):
        self.is_connected = True
        for cb in self._on_connect:
            await cb()


class MockSHSServer(MockSHSSocket):
    def listen(self):
        self.is_connected = True
        for cb in self._on_connect:
            ensure_future(cb())


@pytest.fixture
def ps_client(event_loop):
    return MockSHSClient()


@pytest.fixture
def ps_server(event_loop):
    return MockSHSServer()


@pytest.mark.asyncio
async def test_on_connect(ps_server):
    called = Event()

    async def _on_connect():
        called.set()

    ps_server.on_connect(_on_connect)
    ps_server.listen()
    await called.wait()
    assert ps_server.is_connected


@pytest.mark.asyncio
async def test_message_decoding(ps_client):
    await ps_client.connect()

    ps = PacketStream(ps_client)

    assert ps.is_connected

    ps_client.feed(
        [
            b"\n\x00\x00\x00\x9a\x00\x00\x04\xfb",
            b'{"name":["createHistoryStream"],"args":[{"id":"@omgyp7Pnrw+Qm0I6T6Fh5VvnKmodMXwnxTIesW2DgMg=.ed25519",'
            b'"seq":10,"live":true,"keys":false}],"type":"source"}',
        ]
    )

    messages = await _collect_messages(ps)
    assert len(messages) == 1
    assert messages[0].type == PSMessageType.JSON
    assert messages[0].body == {
        "name": ["createHistoryStream"],
        "args": [
            {
                "id": "@omgyp7Pnrw+Qm0I6T6Fh5VvnKmodMXwnxTIesW2DgMg=.ed25519",
                "seq": 10,
                "live": True,
                "keys": False,
            }
        ],
        "type": "source",
    }


@pytest.mark.asyncio
async def test_message_encoding(ps_client):
    await ps_client.connect()

    ps = PacketStream(ps_client)

    assert ps.is_connected

    ps.send(
        {
            "name": ["createHistoryStream"],
            "args": [
                {
                    "id": "@1+Iwm79DKvVBqYKFkhT6fWRbAVvNNVH4F2BSxwhYmx8=.ed25519",
                    "seq": 1,
                    "live": False,
                    "keys": False,
                }
            ],
            "type": "source",
        },
        stream=True,
    )

    header, body = list(ps_client.get_output())

    assert header == b"\x0a\x00\x00\x00\xa6\x00\x00\x00\x01"
    assert json.loads(body.decode("utf-8")) == {
        "name": ["createHistoryStream"],
        "args": [
            {
                "id": "@1+Iwm79DKvVBqYKFkhT6fWRbAVvNNVH4F2BSxwhYmx8=.ed25519",
                "seq": 1,
                "live": False,
                "keys": False,
            }
        ],
        "type": "source",
    }


@pytest.mark.asyncio
async def test_message_stream(ps_client, mocker):
    await ps_client.connect()

    ps = PacketStream(ps_client)
    mocker.patch.object(ps, "register_handler", wraps=ps.register_handler)

    assert ps.is_connected

    ps.send(
        {
            "name": ["createHistoryStream"],
            "args": [
                {
                    "id": "@1+Iwm79DKvVBqYKFkhT6fWRbAVvNNVH4F2BSxwhYmx8=.ed25519",
                    "seq": 1,
                    "live": False,
                    "keys": False,
                }
            ],
            "type": "source",
        },
        stream=True,
    )

    assert ps.req_counter == 2
    assert ps.register_handler.call_count == 1
    handler = list(ps._event_map.values())[0][1]
    mock_process = mocker.AsyncMock()

    mocker.patch.object(handler, "process", mock_process)

    ps_client.feed([b"\n\x00\x00\x02\xc5\xff\xff\xff\xff", MSG_BODY_1])
    msg = await ps.read()
    assert mock_process.await_count == 1

    # responses have negative req
    assert msg.req == -1
    assert msg.body["previous"] == "%KTGP6W8vF80McRAZHYDWuKOD0KlNyKSq6Gb42iuV7Iw=.sha256"

    assert ps.req_counter == 2

    stream_handler = ps.send(
        {
            "name": ["createHistoryStream"],
            "args": [
                {
                    "id": "@1+Iwm79DKvVBqYKFkhT6fWRbAVvNNVH4F2BSxwhYmx8=.ed25519",
                    "seq": 1,
                    "live": False,
                    "keys": False,
                }
            ],
            "type": "source",
        },
        stream=True,
    )

    assert ps.req_counter == 3
    assert ps.register_handler.call_count == 2
    handler = list(ps._event_map.values())[1][1]

    mock_process = mocker.patch.object(handler, "process", wraps=handler.process)
    ps_client.feed(
        [
            b"\n\x00\x00\x02\xc5\xff\xff\xff\xfe",
            MSG_BODY_1,
            b"\x0e\x00\x00\x023\xff\xff\xff\xfe",
            MSG_BODY_2,
        ]
    )

    # execute both message polling and response handling loops
    collected, handled = await gather(_collect_messages(ps), _collect_messages(stream_handler))

    # No messages collected, since they're all responses
    assert collected == []

    assert mock_process.call_count == 2

    for msg in handled:
        # responses have negative req
        assert msg.req == -2


@pytest.mark.asyncio
async def test_message_request(ps_server, mocker):
    ps_server.listen()

    ps = PacketStream(ps_server)

    mocker.patch.object(ps, "register_handler", wraps=ps.register_handler)

    ps.send({"name": ["whoami"], "args": []})

    header, body = list(ps_server.get_output())
    assert header == b"\x02\x00\x00\x00 \x00\x00\x00\x01"
    assert json.loads(body.decode("utf-8")) == {"name": ["whoami"], "args": []}

    assert ps.req_counter == 2
    assert ps.register_handler.call_count == 1
    handler = list(ps._event_map.values())[0][1]
    mock_process = mocker.AsyncMock()

    mocker.patch.object(handler, "process", mock_process)
    ps_server.feed(
        [
            b"\x02\x00\x00\x00>\xff\xff\xff\xff",
            b'{"id":"@1+Iwm79DKvVBqYKFkhT6fWRbAVvNNVH4F2BSxwhYmx8=.ed25519"}',
        ]
    )
    msg = await ps.read()
    assert mock_process.await_count == 1

    # responses have negative req
    assert msg.req == -1
    assert msg.body["id"] == "@1+Iwm79DKvVBqYKFkhT6fWRbAVvNNVH4F2BSxwhYmx8=.ed25519"
    assert ps.req_counter == 2