import base64
import pytest
import random
import sys
import uuid

from io import BytesIO

from twisted.internet.defer import gatherResults
from twisted.internet.defer import returnValue
from twisted.internet.defer import DeferredSemaphore

from leap.soledad.common.blobs import Flags
from leap.soledad.client._db.blobs import BlobDoc


def payload(size):
    random.seed(1337)  # same seed to avoid different bench results
    payload_bytes = bytearray(random.getrandbits(8) for _ in xrange(size))
    # encode as base64 to avoid ascii encode/decode errors
    return base64.b64encode(payload_bytes)[:size]  # remove b64 overhead


# used to limit the amount of concurrent accesses to the blob manager
semaphore = DeferredSemaphore(2)


def reclaim_free_space(client):
    return client.blobmanager.local.dbpool.runQuery("VACUUM")


#
# Download tests
#

@pytest.inlineCallbacks
def load_up_downloads(client, amount, data):
    # delete blobs from server
    ids = yield client.blobmanager.remote_list(namespace='payload')
    deferreds = []
    for blob_id in ids:
        d = semaphore.run(
            client.blobmanager.delete, blob_id, namespace='payload')
        deferreds.append(d)
    yield gatherResults(deferreds)

    # deliver some incoming blobs
    deferreds = []
    for i in xrange(amount):
        fd = BytesIO(data)
        doc = BlobDoc(fd, blob_id=uuid.uuid4().hex)
        size = sys.getsizeof(fd)
        d = semaphore.run(
            client.blobmanager.put, doc, size, namespace='payload')
        deferreds.append(d)
    yield gatherResults(deferreds)


@pytest.inlineCallbacks
def download_blobs(client, pending):
    deferreds = []
    for item in pending:
        d = semaphore.run(
            client.blobmanager.get, item, namespace='payload')
        deferreds.append(d)
    yield gatherResults(deferreds)


def create_blobs_download(amount, size):
    group = 'test_blobs_download_%d_%dk' % (amount, (size / 1000))

    @pytest.inlineCallbacks
    @pytest.mark.benchmark(group=group)
    def test(soledad_client, txbenchmark_with_setup):
        client = soledad_client()
        blob_payload = payload(size)

        yield load_up_downloads(client, amount, blob_payload)

        @pytest.inlineCallbacks
        def setup():
            yield client.blobmanager.local.dbpool.runQuery(
                "DELETE FROM blobs WHERE 1;")
            yield reclaim_free_space(client)
            returnValue(soledad_client(force_fresh_db=True))

        @pytest.inlineCallbacks
        def download(client):
            pending = yield client.blobmanager.remote_list(
                namespace='payload', filter_flag=Flags.PENDING)
            yield download_blobs(client, pending)
            yield client.sync()

        yield txbenchmark_with_setup(setup, download)
    return test


# ATTENTION: update the documentation in ../docs/benchmarks.rst if you change
# the number of docs or the doc sizes for the tests below.
test_blobs_download_10_1000k = create_blobs_download(10, 1000 * 1000)
test_blobs_download_100_100k = create_blobs_download(100, 100 * 1000)
test_blobs_download_1000_10k = create_blobs_download(1000, 10 * 1000)


#
# Upload tests
#

@pytest.inlineCallbacks
def load_up_uploads(client, amount, data):
    # delete blobs from server
    ids = yield client.blobmanager.remote_list(namespace='payload')
    deferreds = []
    for blob_id in ids:
        d = semaphore.run(
            client.blobmanager.delete, blob_id, namespace='payload')
        deferreds.append(d)
    yield gatherResults(deferreds)


@pytest.inlineCallbacks
def upload_blobs(client, amount, data):
    deferreds = []
    for i in xrange(amount):
        fd = BytesIO(data)
        doc = BlobDoc(fd, blob_id=uuid.uuid4().hex)
        size = sys.getsizeof(fd)
        d = semaphore.run(
            client.blobmanager.put, doc, size, namespace='payload')
        deferreds.append(d)
    yield gatherResults(deferreds)


def create_blobs_upload(amount, size):
    group = 'test_blobs_upload_%d_%dk' % (amount, (size / 1000))

    @pytest.inlineCallbacks
    @pytest.mark.benchmark(group=group)
    def test(soledad_client, txbenchmark_with_setup):
        client = soledad_client()
        blob_payload = payload(size)

        @pytest.inlineCallbacks
        def setup():
            yield load_up_uploads(client, amount, blob_payload)
            returnValue(soledad_client(force_fresh_db=True))

        @pytest.inlineCallbacks
        def upload(client):
            yield upload_blobs(client, amount, blob_payload)
            yield client.sync()

        yield txbenchmark_with_setup(setup, upload)
    return test


# ATTENTION: update the documentation in ../docs/benchmarks.rst if you change
# the number of docs or the doc sizes for the tests below.
test_blobs_upload_10_1000k = create_blobs_upload(10, 1000 * 1000)
test_blobs_upload_100_100k = create_blobs_upload(100, 100 * 1000)
test_blobs_upload_1000_10k = create_blobs_upload(1000, 10 * 1000)