# Copyright BigchainDB GmbH and BigchainDB contributors
# SPDX-License-Identifier: (Apache-2.0 AND CC-BY-4.0)
# Code is Apache-2.0 and docs are CC-BY-4.0

import asyncio
import json
import queue
import threading
from unittest.mock import patch

import pytest


class MockWebSocket:
    def __init__(self):
        self.received = []

    def send_str(self, s):
        self.received.append(s)


def test_eventify_block_works_with_any_transaction():
    from bigchaindb.web.websocket_server import eventify_block

    block = {
        'height': 1,
        'transactions': [{
            'id': 1
        }, {
            'id': 2,
            'asset': {'id': 1}
            }]
        }

    expected_events = [{
            'height': 1,
            'asset_id': 1,
            'transaction_id': 1
        }, {
            'height': 1,
            'asset_id': 1,
            'transaction_id': 2
        }]

    for event, expected in zip(eventify_block(block), expected_events):
        assert event == expected


@asyncio.coroutine
def test_bridge_sync_async_queue(loop):
    from bigchaindb.web.websocket_server import _multiprocessing_to_asyncio

    sync_queue = queue.Queue()
    async_queue = asyncio.Queue(loop=loop)

    bridge = threading.Thread(target=_multiprocessing_to_asyncio,
                              args=(sync_queue, async_queue, loop),
                              daemon=True)
    bridge.start()

    sync_queue.put('fahren')
    sync_queue.put('auf')
    sync_queue.put('der')
    sync_queue.put('Autobahn')

    result = yield from async_queue.get()
    assert result == 'fahren'

    result = yield from async_queue.get()
    assert result == 'auf'

    result = yield from async_queue.get()
    assert result == 'der'

    result = yield from async_queue.get()
    assert result == 'Autobahn'

    assert async_queue.qsize() == 0


@patch('threading.Thread')
@patch('aiohttp.web.run_app')
@patch('bigchaindb.web.websocket_server.init_app')
@patch('asyncio.get_event_loop', return_value='event-loop')
@patch('asyncio.Queue', return_value='event-queue')
def test_start_creates_an_event_loop(queue_mock, get_event_loop_mock,
                                     init_app_mock, run_app_mock,
                                     thread_mock):
    from bigchaindb import config
    from bigchaindb.web.websocket_server import start, _multiprocessing_to_asyncio

    start(None)
    thread_mock.assert_called_once_with(
        target=_multiprocessing_to_asyncio,
        args=(None, queue_mock.return_value, get_event_loop_mock.return_value),
        daemon=True,
    )
    thread_mock.return_value.start.assert_called_once_with()
    init_app_mock.assert_called_with('event-queue', loop='event-loop')
    run_app_mock.assert_called_once_with(
        init_app_mock.return_value,
        host=config['wsserver']['host'],
        port=config['wsserver']['port'],
    )


@asyncio.coroutine
def test_websocket_string_event(test_client, loop):
    from bigchaindb.web.websocket_server import init_app, POISON_PILL, EVENTS_ENDPOINT

    event_source = asyncio.Queue(loop=loop)
    app = init_app(event_source, loop=loop)
    client = yield from test_client(app)
    ws = yield from client.ws_connect(EVENTS_ENDPOINT)

    yield from event_source.put('hack')
    yield from event_source.put('the')
    yield from event_source.put('planet!')

    result = yield from ws.receive()
    assert result.data == 'hack'

    result = yield from ws.receive()
    assert result.data == 'the'

    result = yield from ws.receive()
    assert result.data == 'planet!'

    yield from event_source.put(POISON_PILL)


@asyncio.coroutine
def test_websocket_block_event(b, test_client, loop):
    from bigchaindb import events
    from bigchaindb.web.websocket_server import init_app, POISON_PILL, EVENTS_ENDPOINT
    from bigchaindb.models import Transaction
    from bigchaindb.common import crypto

    user_priv, user_pub = crypto.generate_key_pair()
    tx = Transaction.create([user_pub], [([user_pub], 1)])
    tx = tx.sign([user_priv])

    event_source = asyncio.Queue(loop=loop)
    app = init_app(event_source, loop=loop)
    client = yield from test_client(app)
    ws = yield from client.ws_connect(EVENTS_ENDPOINT)
    block = {'height': 1, 'transactions': [tx.to_dict()]}
    block_event = events.Event(events.EventTypes.BLOCK_VALID, block)

    yield from event_source.put(block_event)

    for tx in block['transactions']:
        result = yield from ws.receive()
        json_result = json.loads(result.data)
        assert json_result['transaction_id'] == tx['id']
        # Since the transactions are all CREATEs, asset id == transaction id
        assert json_result['asset_id'] == tx['id']
        assert json_result['height'] == block['height']

    yield from event_source.put(POISON_PILL)


@pytest.mark.skip('Processes are not stopping properly, and the whole test suite would hang')
def test_integration_from_webapi_to_websocket(monkeypatch, client, loop):
    # XXX: I think that the `pytest-aiohttp` plugin is sparkling too much
    # magic in the `asyncio` module: running this test without monkey-patching
    # `asycio.get_event_loop` (and without the `loop` fixture) raises a:
    #     RuntimeError: There is no current event loop in thread 'MainThread'.
    #
    # That's pretty weird because this test doesn't use the pytest-aiohttp
    # plugin explicitely.
    monkeypatch.setattr('asyncio.get_event_loop', lambda: loop)

    import json
    import random
    import aiohttp

    from bigchaindb.common import crypto
    # TODO processes does not exist anymore, when reactivating this test it
    # will fail because of this
    from bigchaindb import processes
    from bigchaindb.models import Transaction

    # Start BigchainDB
    processes.start()

    loop = asyncio.get_event_loop()

    import time
    time.sleep(1)

    ws_url = client.get('http://localhost:9984/api/v1/').json['_links']['streams_v1']

    # Connect to the WebSocket endpoint
    session = aiohttp.ClientSession()
    ws = loop.run_until_complete(session.ws_connect(ws_url))

    # Create a keypair and generate a new asset
    user_priv, user_pub = crypto.generate_key_pair()
    asset = {'random': random.random()}
    tx = Transaction.create([user_pub], [([user_pub], 1)], asset=asset)
    tx = tx.sign([user_priv])
    # Post the transaction to the BigchainDB Web API
    client.post('/api/v1/transactions/', data=json.dumps(tx.to_dict()))

    result = loop.run_until_complete(ws.receive())
    json_result = json.loads(result.data)
    assert json_result['transaction_id'] == tx.id