import json
import io
import logging
import random
import uuid

from tornado import concurrent, gen, locks, testing, web
import fastavro
from pika import spec

from sprockets.mixins import amqp, avro_publisher

LOGGER = logging.getLogger(__name__)

MESSAGE_TYPE = "example.avro.Test"

AVRO_SCHEMA = {
    "namespace": "example.avro",
    "type": "record",
    "name": "User",
    "fields": [
        {"name": "name", "type": "string"},
        {"name": "favorite_number", "type": ["int", "null"]},
        {"name": "favorite_color", "type": ["string", "null"]}]}


def deserialize(value):
    return fastavro.schemaless_reader(io.BytesIO(value), AVRO_SCHEMA)


class Test1RequestHandler(avro_publisher.PublishingMixin, web.RequestHandler):

    def initialize(self):
        self.correlation_id = self.request.headers.get('Correlation-Id')
        self.publish = self.amqp_publish

    @gen.coroutine
    def get(self, *args, **kwargs):
        LOGGER.debug('Handling Request %r', self.correlation_id)
        parameters = self.parameters()
        try:
            yield self.publish(**parameters)
        except amqp.AMQPException as error:
            self.write({'error': str(error),
                        'type': error.__class__.__name__,
                        'parameters': parameters})
        else:
            self.write(parameters)  # Correlation-ID is added pass by reference
            self.finish()

    def parameters(self):
        return {
            'exchange': self.get_argument('exchange', str(uuid.uuid4())),
            'routing_key': self.get_argument('routing_key', str(uuid.uuid4())),
            'body': {
                'name': str(uuid.uuid4()),
                'favorite_number': random.randint(1, 1000),
                'favorite_color': str(uuid.uuid4())
            },
            'properties': {
                'content_type': avro_publisher.DATUM_MIME_TYPE,
                'message_id': str(uuid.uuid4()),
                'type': MESSAGE_TYPE}}

class Test2RequestHandler(Test1RequestHandler):

    def initialize(self):
        self.correlation_id = self.request.headers.get('Correlation-Id')
        self.publish = self.avro_amqp_publish

    def parameters(self):
        return {
            'exchange': self.get_argument('exchange', str(uuid.uuid4())),
            'routing_key': self.get_argument('routing_key', str(uuid.uuid4())),
            'message_type': MESSAGE_TYPE,
            'data': {
                'name': str(uuid.uuid4()),
                'favorite_number': random.randint(1, 1000),
                'favorite_color': str(uuid.uuid4())
            },
            'properties': {'message_id': str(uuid.uuid4())}}


class SchemaRequestHandler(web.RequestHandler):
    def get(self, *args, **kwargs):
        LOGGER.debug('Returning Schema for %r %r', args, kwargs)
        self.finish(AVRO_SCHEMA)


def setUpModule():
    logging.getLogger('pika').setLevel(logging.INFO)


class AsyncHTTPTestCase(testing.AsyncHTTPTestCase):
    CONFIRMATIONS = True

    def setUp(self):
        super(AsyncHTTPTestCase, self).setUp()
        self.correlation_id = str(uuid.uuid4())
        self.exchange = str(uuid.uuid4())
        self.get_delivered_message = concurrent.Future()
        self.get_returned_message = concurrent.Future()
        self.queue = str(uuid.uuid4())
        self.routing_key = str(uuid.uuid4())
        self.ready = locks.Event()
        avro_publisher.install(self._app, self.io_loop, **{
            'on_ready_callback': self.on_amqp_ready,
            'enable_confirmations': self.CONFIRMATIONS,
            'on_return_callback': self.on_message_returned,
            'url': 'amqp://guest:guest@127.0.0.1:5672/%2f'})
        self.io_loop.start()

    def get_app(self):
        return web.Application(
            [(r'/test1', Test1RequestHandler),
             (r'/test2', Test2RequestHandler),
             (r'/schema/(.*).avsc', SchemaRequestHandler)],
            **{'avro_schema_uri_format': self.get_url('/schema/%(name)s.avsc'),
               'service': 'test',
               'version': avro_publisher.__version__})

    def on_amqp_ready(self, _client):
        LOGGER.debug('AMQP ready')
        self._app.amqp.channel.exchange_declare(
            self.on_exchange_declared, self.exchange,
            durable=False, auto_delete=True)

    def on_exchange_declared(self, method):
        LOGGER.debug('Exchange declared: %r', method)
        self._app.amqp.channel.queue_declare(
            self.on_queue_declared, self.queue,
            arguments={'x-expires': 30000},
            auto_delete=True, durable=False)

    def on_queue_declared(self, method):
        LOGGER.debug('Queue declared: %r', method)
        self._app.amqp.channel.queue_bind(
            self.on_queue_bound, self.queue, self.exchange, self.routing_key)

    def on_queue_bound(self, method):
        LOGGER.debug('Queue bound: %r', method)
        self._app.amqp.channel.basic_consume(
            self.on_message_delivered, self.queue)
        self.io_loop.stop()

    def on_message_delivered(self, _channel, method, properties, body):
        self.get_delivered_message.set_result((method, properties, body))

    def on_message_returned(self, method, properties, body):
        self.get_returned_message.set_result((method, properties, body))


class PublisherConfirmationTestCase(AsyncHTTPTestCase):

    @testing.gen_test
    def test_amqp_publish(self):
        response = yield self.http_client.fetch(
            self.get_url('/test1?exchange={}&routing_key={}'.format(
                self.exchange, self.routing_key)),
            headers={'Correlation-Id': self.correlation_id})
        published = json.loads(response.body.decode('utf-8'))
        delivered = yield self.get_delivered_message
        self.assertIsInstance(delivered[0], spec.Basic.Deliver)
        self.assertEqual(delivered[1].correlation_id, self.correlation_id)
        self.assertEqual(
            delivered[1].content_type, avro_publisher.DATUM_MIME_TYPE)
        self.assertEqual(delivered[1].type, MESSAGE_TYPE)
        self.assertEqual(deserialize(delivered[2]), published['body'])

    @testing.gen_test
    def test_avro_amqp_publish(self):
        response = yield self.http_client.fetch(
            self.get_url('/test2?exchange={}&routing_key={}'.format(
                self.exchange, self.routing_key)),
            headers={'Correlation-Id': self.correlation_id})
        published = json.loads(response.body.decode('utf-8'))
        delivered = yield self.get_delivered_message
        self.assertIsInstance(delivered[0], spec.Basic.Deliver)
        self.assertEqual(delivered[1].correlation_id, self.correlation_id)
        self.assertEqual(
            delivered[1].content_type, avro_publisher.DATUM_MIME_TYPE)
        self.assertEqual(delivered[1].type, MESSAGE_TYPE)
        self.assertEqual(deserialize(delivered[2]), published['data'])