import json
import os
import pytest
import requests
import random
import base64
import signal
import time

from hashlib import sha512
from uuid import uuid4
from subprocess import call
from urlparse import urljoin
from twisted.internet import threads, reactor

from leap.soledad.client import Soledad
from leap.soledad.common.couch import CouchDatabase


# we have to manually setup the events server in order to be able to signal
# events. This is usually done by the enclosing application using soledad
# client (i.e. bitmask client).
from leap.common.events import server
server.ensure_server()


def pytest_addoption(parser):
    parser.addoption(
        "--couch-url", type="string", default="http://127.0.0.1:5984",
        help="the url for the couch server to be used during tests")
    parser.addoption(
        "--num-docs", type="int", default=100,
        help="the number of documents to use in performance tests")


#
# default options for all tests
#

DEFAULT_PASSPHRASE = '123'

DEFAULT_URL = 'http://127.0.0.1:2424'
DEFAULT_PRIVKEY = 'soledad_privkey.pem'
DEFAULT_CERTKEY = 'soledad_certkey.pem'
DEFAULT_TOKEN = 'an-auth-token'


@pytest.fixture()
def payload():
    def generate(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
    return generate


#
# soledad_dbs fixture: provides all databases needed by soledad server in a per
# module scope (same databases for all tests in this module).
#

def _token_dbname():
    dbname = 'tokens_' + \
        str(int(time.time() / (30 * 24 * 3600)))
    return dbname


class SoledadDatabases(object):

    def __init__(self, url):
        self._token_db_url = urljoin(url, _token_dbname())
        self._shared_db_url = urljoin(url, 'shared')

    def setup(self, uuid):
        self._create_dbs()
        self._add_token(uuid)

    def _create_dbs(self):
        requests.put(self._token_db_url)
        requests.put(self._shared_db_url)

    def _add_token(self, uuid):
        token = sha512(DEFAULT_TOKEN).hexdigest()
        content = {'type': 'Token', 'user_id': uuid}
        requests.put(
            self._token_db_url + '/' + token, data=json.dumps(content))

    def teardown(self):
        requests.delete(self._token_db_url)
        requests.delete(self._shared_db_url)


@pytest.fixture()
def soledad_dbs(request):
    couch_url = request.config.option.couch_url

    def create(uuid):
        db = SoledadDatabases(couch_url)
        request.addfinalizer(db.teardown)
        return db.setup(uuid)
    return create


#
# remote_db fixture: provides an empty database for a given user in a per
# function scope.
#

class UserDatabase(object):

    def __init__(self, url, uuid):
        self._remote_db_url = urljoin(url, 'user-%s' % uuid)

    def setup(self):
        return CouchDatabase.open_database(
            url=self._remote_db_url, create=True, replica_uid=None)

    def teardown(self):
        requests.delete(self._remote_db_url)


@pytest.fixture()
def remote_db(request):
    couch_url = request.config.option.couch_url

    def create(uuid):
        db = UserDatabase(couch_url, uuid)
        request.addfinalizer(db.teardown)
        return db.setup()
    return create


def get_pid(pidfile):
    if not os.path.isfile(pidfile):
        return 0
    try:
        with open(pidfile) as f:
            return int(f.read())
    except IOError:
        return 0


#
# soledad_server fixture: provides a running soledad server in a per module
# context (same soledad server for all tests in this module).
#

class SoledadServer(object):

    def __init__(self, tmpdir_factory, couch_url):
        tmpdir = tmpdir_factory.mktemp('soledad-server')
        self._pidfile = os.path.join(tmpdir.strpath, 'soledad-server.pid')
        self._logfile = os.path.join(tmpdir.strpath, 'soledad-server.log')
        self._couch_url = couch_url

    def start(self):
        self._create_conf_file()
        # start the server
        call([
            'twistd',
            '--logfile=%s' % self._logfile,
            '--pidfile=%s' % self._pidfile,
            'web',
            '--wsgi=leap.soledad.server.application',
            '--port=2424'
        ])

    def _create_conf_file(self):
        if not os.access('/etc', os.W_OK):
            return
        if not os.path.isdir('/etc/soledad'):
            os.mkdir('/etc/soledad')
        with open('/etc/soledad/soledad-server.conf', 'w') as f:
            content = '[soledad-server]\ncouch_url = %s' % self._couch_url
            f.write(content)

    def stop(self):
        pid = get_pid(self._pidfile)
        os.kill(pid, signal.SIGKILL)


@pytest.fixture(scope='module')
def soledad_server(tmpdir_factory, request):
    couch_url = request.config.option.couch_url
    server = SoledadServer(tmpdir_factory, couch_url)
    server.start()
    request.addfinalizer(server.stop)
    return server


@pytest.fixture()
def txbenchmark(benchmark):
    def blockOnThread(*args, **kwargs):
        return threads.deferToThread(
            benchmark, threads.blockingCallFromThread,
            reactor, *args, **kwargs)
    return blockOnThread


@pytest.fixture()
def txbenchmark_with_setup(benchmark):
    def blockOnThreadWithSetup(setup, f):
        def blocking_runner(*args, **kwargs):
            return threads.blockingCallFromThread(reactor, f, *args, **kwargs)

        def blocking_setup():
            args = threads.blockingCallFromThread(reactor, setup)
            try:
                return tuple(arg for arg in args), {}
            except TypeError:
                    return ((args,), {}) if args else None

        def bench():
            return benchmark.pedantic(blocking_runner, setup=blocking_setup,
                                      rounds=4, warmup_rounds=1)
        return threads.deferToThread(bench)
    return blockOnThreadWithSetup


#
# soledad_client fixture: provides a clean soledad client for a test function.
#

@pytest.fixture()
def soledad_client(tmpdir, soledad_server, remote_db, soledad_dbs, request):
    passphrase = DEFAULT_PASSPHRASE
    server_url = DEFAULT_URL
    token = DEFAULT_TOKEN
    default_uuid = uuid4().hex
    remote_db(default_uuid)
    soledad_dbs(default_uuid)

    # get a soledad instance
    def create():
        secrets_path = os.path.join(tmpdir.strpath, '%s.secret' % uuid4().hex)
        local_db_path = os.path.join(tmpdir.strpath, '%s.db' % uuid4().hex)
        soledad_client = Soledad(
            default_uuid,
            unicode(passphrase),
            secrets_path=secrets_path,
            local_db_path=local_db_path,
            server_url=server_url,
            cert_file=None,
            auth_token=token)
        request.addfinalizer(soledad_client.close)
        return soledad_client
    return create